Vince Ördög
6507324529
Publications - 30
Microalgal and cyanobacterial biostimulants used in wheat and maize production
Publication Name: Biostimulants for Improving Reproductive Growth and Crop Yield
Publication Date: 2025-01-01
Volume: Unknown
Issue: Unknown
Page Range: 169-218
Description:
Wheat and maize are staple cereals that are each cultivated on about 200 million hectares globally. Microalgae and cyanobacteria have potential to be developed as biostimulants for wheat and maize production. This review focuses on biostimulating effects of various microalgae and cyanobacteria on seed priming, soil and foliar treatments applied in pot experiments and field trials. Two case studies on wheat and maize field trials are included. Seed priming with selected microalgal extracts is a promising method to promote plant growth but still needs validation in field trials. Soil biofertilizers based on living N2-fixing cyanobacteria (algalization) applied alone or in combination with plant growth promoting rhizobacteria modulate soil microbial composition and enhance nutrient uptake. However, this requires application of tens or hundreds kg/ha biomass to substitute for N-fertilizers so is not yet an economically viable option. The case studies indicated that a single foliar treatment of wheat at tillering and maize at the V6 growth stage with Chlorella vulgaris or Tetracystis sp. suspensions (0.1–1g DW/L applied at 400L/ha) increased grain yield, grain protein content and improve stress tolerance. These results indicated that certain microalgae could be effective biostimulants. However, producing sufficient microalgae biomass on a commercial scale is still a challenge. Monoalgal mass production in closed photobioreactors is expensive. A promising approach is the cultivation of mixed algal cultures in nutrient rich wastewater using open raceway reactors.
Open Access: Yes
Approaches to studying wheat and maize drought stress responses
Publication Name: Plant and Soil
Publication Date: 2025-01-01
Volume: Unknown
Issue: Unknown
Page Range: Unknown
Description:
Introduction: Drought stress remains a critical challenge to sustainable agriculture worldwide, threatening crop productivity and food security. Understanding the physiological processes and defense mechanisms that crops employ under water-limited conditions is essential for developing strategies to enhance drought resilience. Plant responses to drought vary widely depending on species, genotype, developmental stage, and the severity and duration of stress. Beyond annual rainfall totals, yield is also shaped by seasonal precipitation patterns and related environmental factors, which influence the choice of cultivars and crop performance. Finding: This review examines the drought responses of maize and wheat, two globally important cereals, across morphological, physiological, biochemical, and molecular dimensions. Key responses include enhanced root development, reduced leaf area, stomatal regulation, decreased photosynthetic activity and water potential, and elevated proline and abscisic acid levels. Although varietal differences are noted, they are discussed only briefly. Water stress is commonly quantified via water potential and measured using tools such as the Scholander pressure chamber or the increasingly adopted ZIM probe, which allows non-destructive, continuous monitoring. While conventional breeding efforts have targeted drought tolerance, progress is constrained by these traits' polygenic and environmentally sensitive nature. Recently, biostimulants such as seaweed extracts and microalgae-based products have emerged as promising tools for enhancing stress tolerance. Conclusion: To meet the demands of a changing climate, future research should prioritize the integration of genetic, physiological, and biochemical strategies to develop crops with robust and durable drought resistance.
Open Access: Yes
Photosynthetic Activity Measured In Situ in Microalgae Cultures Grown in Pilot-Scale Raceway Ponds
Joaquín Pozo Dengra
Francisco Gabriel Acién Fernández
Bernardo Cicchi
Marta Barceló-Villalobos
Cintia Gómez-Serrano
João Artur Câmara Manoel
Victor A. Robles Carnero
Karolína Ranglová
Juan Luis Gómez Pinchetti
Vince Ördög
Ana Margarita Silva Benavides
Giuseppe Torzillo
Jiří Masojídek
Félix Lopez Figueroa
Publication Name: Plants
Publication Date: 2024-12-01
Volume: 13
Issue: 23
Page Range: Unknown
Description:
The microalga Scenedesmus sp. (Chlorophyceae) was cultured in a raceway pond (RWP) placed in a greenhouse. The objective of this case study was to monitor the photosynthesis performance and selected physicochemical variables (irradiance, temperature, dissolved oxygen concentration) of microalgae cultures in situ at various depths of RWP. The data of actual photochemical yield Y(II), the electron transport rate monitored by in vivo chlorophyll fluorescence and photosynthetic oxygen production both in situ and ex situ revealed that (i) even in diluted cultures (0.6 g DW L−1), the active photic layer in the culture was only about 1 cm, indicating that most of the culture was “photosynthetically” inactive; (ii) the mechanism of non-photochemical quenching may not be fast enough to respond once the cells move from the surface to the deeper layers; and (iii) even when cells were exposed to a high dissolved oxygen concentration of about 200% sat and higher, the cultures retained a relatively high Y(II) > 0.35 when monitored in situ. The presented work can be used as exemplary data to optimize the growth regime of microalgae cultures in large-scale RWPs by understanding the interplay between photosynthetic activity, culture depth and cell concentration.
Open Access: Yes
Cyanobacteria-Fungi Co-Cultures: Which Partner Contributes to Antifungal Activity?
Publication Name: Current Microbiology
Publication Date: 2024-11-01
Volume: 81
Issue: 11
Page Range: Unknown
Description:
Cyanobacteria synthesize secondary metabolites with antifungal activity, making them potential biopesticide agents for sustainable, eco-friendly agriculture. Programmes to identify Cyanobacterial strains with effective bioactivity generally screen strains maintained in culture collections. These strains are often monoclonal but non-axenic and this may potentially influence the bioactivity of the generated biomass. The present study investigated in vitro antifungal activity of Nostoc muscorum MACC-189 and N. linckia MACC-612 strains co-isolated with fungal co-partners and maintained in the Mosonmagyaróvár Algal Culture Collection (MACC). The fungal co-partners were isolated from the Cyanobacterial stock cultures and identified as Purpureocillium lilacinum and Sarocladium sp., respectively. The cultures were tested against seven phytopathogens. The phytopathogenic fungi were grown on potato dextrose agar plates and suspension cultures of the Cyanobacteria-fungi and isolated fungal co-partners were placed in the centre of the plate. Antifungal effects were assessed semi-quantitatively after 10 days of incubation. The Cyanobacteria-fungal co-cultures had antifungal activity against Monilinia fructigena and Aspergillus sp. with the N. muscorum/P. lilacinum culture being the most effective. The fungal isolates inhibited M. fructigena with P. lilacinum having a dose-dependent response but did not inhibit Aspergillus sp. This suggested that the antifungal effect of the Cyanobacterial cultures on M. fructigena was due to the fungal partner rather than the cyanobacterium while the antifungal effect on Aspergillus sp. was due to the cyanobacterium partner. As it was not possible to maintain living axenic N. muscorum and N. linckia cultures, this could not be conclusively confirmed. These results highlight the importance of either using axenic cultures or identifying the co-isolates when testing Cyanobacteria cultures for antifungal bioactivity.
Open Access: Yes
Comparison of plant biostimulating properties of Chlorella sorokiniana biomass produced in batch and semi-continuous systems supplemented with pig manure or acetate
Publication Name: Journal of Biotechnology
Publication Date: 2024-02-10
Volume: 381
Issue: Unknown
Page Range: 27-35
Description:
Microalgae-derived biostimulants provide an eco-friendly biotechnology for improving crop productivity. The strategy of circular economy includes reducing biomass production costs of new and robust microalgae strains grown in nutrient-rich wastewater and mixotrophic culture where media is enriched with organic carbon. In this study, Chlorella sorokiniana was grown in 100 l bioreactors under sub-optimal conditions in a greenhouse. A combination of batch and semi-continuous cultivation was used to investigate the growth, plant hormone and biostimulating effect of biomass grown in diluted pig manure and in nutrient medium supplemented with Na-acetate. C. sorokiniana tolerated the low light (sum of PAR 0.99 ± 0.18 mol/photons/(m2/day)) and temperature (3.7–23.7° C) conditions to maintain a positive growth rate and daily biomass productivity (up to 149 mg/l/day and 69 mg/l/day dry matter production in pig manure and Na-acetate supplemented cultures respectively). The protein and lipid content was significantly higher in the biomass generated in batch culture and dilute pig manure (1.4x higher protein and 2x higher lipid) compared to the Na-acetate enriched culture. Auxins indole-3-acetic acid (IAA) and 2-oxindole-3-acetic acid (oxIAA) and salicylic acid (SA) were present in the biomass with significantly higher auxin content in the biomass generated using pig manure (> 350 pmol/g DW IAA and > 84 pmol/g DW oxIAA) compared to cultures enriched with Na-acetate and batch cultures (< 200 pmol/g DW IAA and < 27 pmol/g DW oxIAA). No abscisic acid and jasmonates were detected. All samples had plant biostimulating activity measured in the mungbean rooting bioassay with the Na-acetate supplemented biomass eliciting higher rooting activity (equivalent to 1–2 mg/l IBA) compared to the pig manure (equivalent to 0.5–1 mg/l IBA) and batch culture (equivalent to water control) generated biomass. Thus C. sorokiniana MACC-728 is a robust new strain for biotechnology, tolerating low light and temperature conditions. The strain can adapt to alternative nutrient (pig manure) and carbon (acetate) sources with the generated biomass having a high auxin concentration and plant biostimulating activity detected with the mungbean rooting bioassay.
Open Access: Yes
Cataloguing microalgae and Cyanobacteria strains from the Mosonmagyaróvár Algal Culture Collection with in vitro antagonistic activity against phytopathogenic fungi and oomycetes
Publication Name: Phytoparasitica
Publication Date: 2023-09-01
Volume: 51
Issue: 4
Page Range: 747-762
Description:
Microalgae produce many secondary metabolites that are biologically active, including compounds that inhibit microbial growth. These could potentially function as biofungicides. The first selection criteria for potential strains suitable in the phytosanitary market is good in vitro inhibition of growth against specific phytopathogenic fungi and oomycetes and higher biomass productivity rates. In the present study, water extracts were prepared from 280 strains comprising of 33 Cyanophyceae strains (13 genera), 157 Chlorophyceae strains (29 genera), 80 Trebouxiophyceae strains (19 genera), 5 Klebsormidiophyceae strains (1 genus) and 1 Zygnematophyceae strain. These were tested in vitro against 6 phytopathogenic fungi and 3 phytopathogenic oomycetes. In total, 45% of the species had mycelial growth inhibitory activity against at least one pathogen. Cyanobacteria had the highest “hit-rate” (64%), followed by the Chlorophyceae (49%) and Trebouxiophyceae (30%). Water extracts of 19 strains had fungicidal and/or oomyceticidal activity – these were predominantly Cyanobacteria. The Cyanobacteria displayed a wider spectrum of inhibition with five strains being active against three or more phytopathogenic strains. Trichormis variabilis MACC-304 and Tolypothrix tenuis MACC-205 had inhibitory activity against 6 phytopathogens and Nostoc linckia MACC-612 inhibited 4 phytopathogenic strains. Each Chlorophyta strain was only active against 1-2 strains. However, the daily productivity rates of Cyanobacteria were significantly lower than Chlorophyta strains. Further investigation of 15 Nostocales species (Nostocaceae, Tolypothrichaceae and Calotrichaceae) showed the Nostoc species generally had significantly lower biomass generation compared to other Nostocacaeae strains. The most promising strain was Tolypothrix tenuis MACC-205 which had the most potent, broad spectrum fungal and oomyceticidal inhibitory activity as well as significantly higher daily biomass productivity rates. Thus, Cyanobacteria can potentially be developed as an effective agricultural tool for environmentally-friendly disease management.
Open Access: Yes
Salinity stress provokes diverse physiological responses of eukaryotic unicellular microalgae
Publication Name: Algal Research
Publication Date: 2023-06-01
Volume: 73
Issue: Unknown
Page Range: Unknown
Description:
Highly saline conditions represent a strong challenge for most microorganisms in freshwater ecosystems. Eukaryotic freshwater green algae from the Chlorophyta clade were investigated for their ability to survive in and adapt to increased salt concentration in the growth medium. Striking differences were detected between the responses of the various algae species to the elevated salt concentrations. The investigated Chlamydomonas reinhardtii cc124 and Coelastrella sp. MACC-549 algae showed a moderate resistance to increased salt concentration, while Chlorella sp. MACC-360 exhibited high salt tolerance, showed unaltered growth characteristics and photosynthetic efficiency compared to the saline-free control conditions even at 600 mM NaCl concentration. Diverse physiological responses to elevated salt concentrations were described for the tested algae including variations in their growth capacity, characteristic morphological changes, alterations in the structure and function of the photosynthetic machinery and differences in the production of reactive oxygen species. Special alterations were identified in the lipid and exopolysaccharide production patterns of the tested algal strains in response to high salinity. As a conclusion Chlorella sp. MACC-360 algae showed outstanding salt tolerance features. Together with the concomitant lipid-producing phenotype under highly saline conditions this unicellular green alga is a promising candidate for biotechnological applications.
Open Access: Yes
Bioactivity assessment, micropollutant and nutrient removal ability of Tetradesmus obliquus cultivated outdoors in centrate from urban wastewater
Publication Name: Journal of Applied Phycology
Publication Date: 2022-12-01
Volume: 34
Issue: 6
Page Range: 2955-2970
Description:
Nutrient and micropollutant removal, and bioactivity were studied in cultures of the green microalga Tetradesmus obliquus MACC-677 grown in centrate from municipal wastewater (WW). Two outdoor units, a thin-layer cascade (TLC) and a thin-layer raceway pond (TL-RWP), were tested for microalgal culturing in batch and semi-continuous regimes where their photosynthetic performance was monitored. The results revealed that the T. obliquus cultures grew well, showing a high specific growth rate µ of 0.31 day−1 and 0.25 day−1 when grown in WW in TLC and TL-RWP, respectively. The cultivation trials showed high nutrient removal efficiency for ammonium nitrogen (98.5%) as well as orthophosphate (89%), the most abundant forms of N and P occurring in municipal WW. The removal of selected pharmaceuticals and endocrine disruptors (e.g., ibuprofen, amitriptyline, bisphenol A, etc.) was also assessed. Ibuprofen was the most abundant micropollutant detected in the centrate, with concentrations up to 5000 ng L−1 and fast removal during the cultivation. The biomass produced in the centrate revealed antimicrobial activity against plant pathogens, including fungi, oomycota, and bacteria. These findings have shown that the culturing of T. obliquus can be considered a suitable way to contribute to a circular economy, to remove nutrients and micropollutants from municipal WW from which biomass extracts can be further used for plant protection in agriculture.
Open Access: Yes
Photosynthesis Monitoring in Microalgae Cultures Grown on Municipal Wastewater as a Nutrient Source in Large-Scale Outdoor Bioreactors
Zouhayr Arbib
Francisco Gabriel Acién Fernández
Bernardo Cicchi
Marta Barceló-Villalobos
João Artur Câmara Manoel
Cintia Gómez-Serrano
Victor A. Robles Carnero
Ángel Encinas Bogeat
Ana Sanches Zurano
Karolína Ranglová
Juan Luis Gómez Pinchetti
Vince Ördög
Ana Margarita Silva Benavides
Giuseppe Torzillo
Jiří Masojídek
L. Vörös
Frank Rogalla
Félix Lopez Figueroa
Publication Name: Biology
Publication Date: 2022-10-01
Volume: 11
Issue: 10
Page Range: Unknown
Description:
Microalgae cultures were used for a WW treatment to remediate nutrients while producing biomass and recycling water. In these trials, raceway ponds (RWPs; 1 and 0.5 ha) were located next to a municipal (WW) treatment plant in Mérida, Spain. The ponds were used for continuous, all-year-round microalgae production using WW as a source of nutrients. Neither CO2 nor air was supplied to cultures. The objective was to validate photosynthesis monitoring techniques in large-scale bioreactors. Various in-situ/ex-situ methods based on chlorophyll fluorescence and oxygen evolution measurements were used to follow culture performance. Photosynthesis variables gathered with these techniques were compared to the physiological behavior and growth of cultures. Good photosynthetic activity was indicated by the build-up of dissolved oxygen concentration up to 380% saturation, high photochemical yield (Fv/Fm = 0.62–0.71), and relative electron transport rate rETR between 200 and 450 μmol e− m−2 s−1 at midday, which resulted in biomass productivity of about 15–25 g DW m−2 day−1. The variables represent reliable markers reflecting the physiological status of microalgae cultures. Using waste nutrients, the biomass production cost can be significantly decreased for abundant biomass production in large-scale bioreactors, which can be exploited for agricultural purposes.
Open Access: Yes
Evaluation of the biostimulant effects of two Chlorophyta microalgae on tomato (Solanum lycopersicum)
Publication Name: Journal of Cleaner Production
Publication Date: 2022-09-01
Volume: 364
Issue: Unknown
Page Range: Unknown
Description:
Eukaryotic microalgae from the Chlorophyta division are used in various bio-industries due to their ability to produce high value compounds. Some of these compounds show plant biostimulant properties when applied to plants, soil or growth medium in hydroponic chambers. The first objective of this study was to evaluate if Chlamydomonas reinhardtii cc 124 and Chlorella sp. MACC-360 had biostimulant effect on Solanum lycopersicum L. The second objective was to investigate the importance of the application mode and time. The third goal was to reveal strain-specific actions of the two algae strains. Tomato plants were grown in pots layered with clay at the bottom and filled with the mixture of soil and vermiculate. In two sets of experiments the soil and plant leaves were treated with living algae and algal extract, respectively. In the first set, the culture suspension (CS) was centrifuged, the algae pellet was re-suspended in water (CCS), and this was applied weekly to soil, while algae extract (cell disrupted algae suspension – CDS) was sprayed on leaves bi-weekly. The flowering process, plant morphology, fruit features and pigment contents were analyzed. In the second set of experiments, the culture suspension per se (CS) was applied to the soil weekly and CDS was sprayed on leaves bi-weekly. Flowering kinetics, reproductive capacity and photosynthetic parameters were examined. Both algae strains increased pigment content, fruit weight and fruit diameter of tomato. Plants that received initial algae treatment at an advanced age performed better than those initially treated at a young age. Chlorella induced early flowering and fruit development while Chlamydomonas significantly delayed these milestone functions. Chlorella promoted conversion of light energy to chemical energy, while Chlamydomonas enhanced protection of photosynthetic parameters. Both strains increased leaf temperature differential as well as leaf thickness. Overall, both algae strains stimulated important agronomic-valuable functions in tomato.
Open Access: Yes
Biologia Futura: potential of different forms of microalgae for soil improvement
Publication Name: Biologia Futura
Publication Date: 2022-03-01
Volume: 73
Issue: 1
Page Range: Unknown
Description:
Products derived from microalgae have great potential in diverse field. As a part of the enhancing agriculture application, various forms of microalgae applications have been developed so far. They are known to influence soil properties. The various forms of application may enhance soil in more or less similar manner. They can help improve soil health, nitrogen, and phosphorus content, and even carbon sequestration. Thus, overall, it can enhance fertility of the soil.
Open Access: Yes
Effect of storage on plant biostimulant and bioactive properties of freeze-dried Chlorella vulgaris biomass
Publication Name: Journal of Applied Phycology
Publication Date: 2021-12-01
Volume: 33
Issue: 6
Page Range: 3797-3806
Description:
Microalgae are potential plant biostimulants and biocontrol agents. A major hurdle towards their commercialization is the production of large volumes of biomass at the correct time of year. Secondary metabolites are unstable and the “shelf-life” of bioactive microalgal biomass needs to be investigated. The aim of the study was to investigate the effects of storage conditions on freeze-dried microalgae to determine how long the biomass retained its growth promoting and bioactive properties under various temperature and light conditions. Chlorella vulgaris biomass was stored in the dark at − 70 °C, 10 °C, and 25 °C and in the light at 25 °C. Samples were tested every 3–4 months for 15 months. Storage time significantly influenced the rate of change in the bioactivity in the C. vulgaris biomass with storage temperature also having some effect. Rooting activity decreased in the mungbean rooting assay over time up to 12 months and then increased slightly. Antimicrobial activity increased against Staphylococcus aureus and Escherichia coli for up to 12 months and then declined. Antioxidant activity measured in the DPPH assay remained relatively stable for up to 12 months and then significantly decreased with longer storage. The change in bioactivity over time was attributed to the gradual breakdown of the rigid cell wall of C. vulgaris, thereby improving extraction efficiency but exposing the secondary metabolites to oxygen, thus quickening their degradation. Biomass produced for commercial purposes requires preliminary validation as the results of the present study showed that bioactive compounds are susceptible to degradation over time.
Open Access: Yes
Comparison of monocultures and a mixed culture of three Chlorellaceae strains to optimize biomass production and biochemical content in microalgae grown in a greenhouse
Publication Name: Journal of Applied Phycology
Publication Date: 2021-10-01
Volume: 33
Issue: 5
Page Range: 2755-2766
Description:
Light and temperature are important environmental conditions affecting microalgal growth in outdoor culture. It is essential to evaluate microalgae strains growing under outdoor conditions where they are subjected to variable environmental parameters. The present study investigated three Chlorellaceae strains (Micractinium sp. MACC-728, Chlorella sorokiniana MACC-438, and C. sorokiniana MACC-452) and a mixed culture combining these three strains. Cultures were grown in 2-L bioreactors in a greenhouse over 3 months to assess the effects of high temperature and light on their growth, macromolecule content, and antioxidant and plant-stimulating bioactivities. The most influential environmental parameters on growth were average air temperature and the sum of photosynthetically active radiation, followed by maximum air temperature. The most affected growth parameter was daily change in cell number. Chlorella sorokiniana MACC-438 produced the lowest biomass and was most affected by the high temperature and light conditions. Micractinium sp. produced the highest biomass and was least affected, suggesting it was the most suitable strain for outdoor cultivation. The mixed Chlorellaceae culture performed well in biomass production, exceeding C. sorokiniana monocultures but significantly underyielding in lipid content. Antioxidant activity and the root-stimulating activity varied with strain and culture age. Micractinium sp. had the highest but most variable antioxidant and plant-stimulating activity. Bioactivity in the mixed culture was more consistent, remaining high regardless of culture age and environmental conditions. Thus, mixed cultures of productive strains could be a useful strategy to ensure stable and high-quality biomass production in outdoor cultivation with fluctuating environmental conditions.
Open Access: Yes
Comparative and phylogenomic analysis of nuclear and organelle genes in cryptic Coelastrella vacuolata MACC-549 green algae
Publication Name: Algal Research
Publication Date: 2021-10-01
Volume: 58
Issue: Unknown
Page Range: Unknown
Description:
The nuclear, chloroplast and mitochondrial genomes of a unicellular green algal species of the Coelastrella genus was sequenced, assembled and annotated. The strain was previously classified as Chlamydomonas sp. MACC-549 based on morphology and partial 18S rDNA analysis. However, the proposed multi-loci phylogenomic approach described in this paper placed this strain within the Coelastrella genus, therefore it was re-named to Coelastrella vacuolata MACC-549. The strain was selected for de novo sequencing based on its potential value in biohydrogen production as revealed in earlier studies. This is the first thorough report and characterization for green algae from the Coelastrella genus. The whole genome annotation of Coelastrella vacuolata MACC-549 (including nuclear, chloroplast and mitochondrial genomes) shed light on interesting metabolic and sexual breeding features of this algae and served as a basis to taxonomically classify this strain.
Open Access: Yes
Plant biostimulating effects of the cyanobacterium Nostoc piscinale on maize (Zea mays L.) in field experiments
Publication Name: South African Journal of Botany
Publication Date: 2021-08-01
Volume: 140
Issue: Unknown
Page Range: 153-160
Description:
Biostimulants, when applied to plants in small amounts, increase crop yield and plant tolerance to abiotic and biotic stress. They play an important role in the development of new environmentally sustainable technologies. The aim of the current experiment was to investigate the potential of a cyanobacterium strain (Nostoc piscinale) to improve the growth, grain yield and stress tolerance of maize (Zea mays SY Zephir hybrid). Field trials were established at two sites. Freeze-dried biomass of N. piscinale resuspended in tap water (1g/L DW) was applied as a single foliar treatment (400 L/ha) at the V6-V7 phenological stage. Number of leaves, chlorophyll content, relative water content (RWC%) and free proline content were measured weekly. Grain yield, yield components and grain protein content were measured at harvest. N. piscinale treated maize had significantly earlier development in the vegetative growth stages with a higher number of leaves. Chlorophyll content (SPAD value) was significantly higher in the treated plants during the reproductive stages. There was little difference in the RWC and proline content compared to control plants. Faster vegetative growth and higher chlorophyll content in the cyanobacterium treated plants meant great photosynthetic light absorption over a longer period of time, resulting in significantly higher grain yield (6.5% and 11.5% at the two production sites) and increased grain protein content. Grain yield was significantly influenced by cob length and thousand grain weight. In conclusion, it was proved in field trials conducted in two different regions in Hungary that a single foliar application of a cyanobacterium-based biostimulant can contribute to crop production in a sustainable and environmentally friendly manner.
Open Access: Yes
Natural Resources for Human Health: A New Interdisciplinary Journal Dedicated to Natural Sciences
Ana Sanches Silva
Karel Šmejkal
Rasul Suleria
Michał Tomczyk
Chunpeng Wan
Dongdong Wang
Jianbo Xiao
Jialin Xu
Zhiling Yu
Gökhan Zengin
Jesus Simal-Gandara
Ren Wang
Manoj G. Kulkarni
Zhaojun Wei
Mohammad Amjad Kamal
Shafi Ullah Khan
Vince Ördög
Bharat B. Aggarwal
Onur Bender
Tarun Belwal
Ihosvany Camps
Carlos L.Cespedes Acuña
Alessandra Cincinelli
Ricardo DG De Albuquerque Diego
Jelena Popovićdjordjević
Jaruporn Rakmai
Claudio Ferrante
Andrei Mocan
Adriano Mollica
Ashwell R. Ndhlala
Visweswara Rao
Satyajit D. Sarker
Barbara Sawicka
Gautam Sethi
Hafiz Ansar
Si Mi
In Ho Kim
Haipeng Lv
Publication Name: Natural Resources for Human Health
Publication Date: 2021-08-01
Volume: 1
Issue: 1
Page Range: 1-2
Description:
No description provided
Open Access: Yes
Strain-specific biostimulant effects of chlorella and chlamydomonas green microalgae on medicago truncatula
Publication Name: Plants
Publication Date: 2021-06-01
Volume: 10
Issue: 6
Page Range: Unknown
Description:
Microalgae have been identified to produce a plethora of bioactive compounds exerting growth stimulating effects on plants. The objective of this study was to investigate the plant-growth-promoting effects of three selected strains of eukaryotic green microalgae. The biostimulatory effects of two Chlorella species (MACC-360 and MACC-38) and a Chlamydomonas reinhardtii strain (cc124) were investigated in a Medicago truncatula model plant grown under controlled greenhouse conditions. The physiological responses of the M. truncatula A17 ecotype to algal biomass addition were characterized thoroughly. The plants were cultivated in pots containing a mixture of vermiculite and soil (1:3) layered with clay at the bottom. The application of live algae cells using the soil drench method significantly increased the plants’ shoot length, leaf size, fresh weight, number of flowers and pigment content. For most of the parameters analyzed, the effects of treatment proved to be specific for the applied algae strains. Overall, Chlorella application led to more robust plants with increased fresh biomass, bigger leaves and more flowers/pods compared to the control and Chlamydomonas-treated samples receiving identical total nutrients.
Open Access: Yes
Growth and bioactivity of two chlorophyte (Chlorella and Scenedesmus) strains co-cultured outdoors in two different thin-layer units using municipal wastewater as a nutrient source
Publication Name: Algal Research
Publication Date: 2021-06-01
Volume: 56
Issue: Unknown
Page Range: Unknown
Description:
The application of microalgae in wastewater treatment has recently been at the forefront of interest due to the increasing concern about environmental protection and economic sustainability. This work aimed to study two chlorophyte species, Chlorella vulgaris and Scenedesmus acutus, co-cultured outdoors in centrate of municipal wastewater as a nutrient source. Two different thin-layer units were used in these trials — thin-layer cascade (TLC) and thin-layer raceway pond (TL-RWP), suitable for this purpose due to their high biomass productivity and better culture transparency when using muddy wastewater. The units were operated in batch, and subsequently in semi-continuous growth regime — and monitored in terms of photosynthetic performance, growth, nutrient removal rate, and bioactivity. The results showed that the co-cultures grew well in the centrate, achieving the maximum biomass densities of 1.3 and 2.1 g DW L−1 in TLC and TL-RWP, respectively, by the end of the batch regime and 1.9 and 2.0 g DW L−1 by the end of the semi-continuous regime. Although TL-RWP grown cultures showed faster growth, the TLC-one revealed better nutrient removal efficiencies batch wise than the culture grown in TL-RWP — removing up to 48% of total nitrogen and 43% of total phosphorus. Conversely, the latter was more efficient under the semi-continuous regime (54% and 42% consumption of total nitrogen and phosphorus, respectively). In the harvested biomass, an important antimicrobial activity (specifically antifungal) was detected. In this sense, the in-vitro growth of the oomycete Pythium ultimum was inhibited by up to 45% with regard to the control. However, no biostimulating activity was observed. The present findings confirm the possibility of using these two species for biomass production in municipal wastewater centrate using highly productive thin-layer systems. This technology can be a valuable contribution to circular economy since the produced biomass can be re-applied for agricultural purposes.
Open Access: Yes
Biomolecule composition and draft genome of a novel, high-lipid producing Scenedesmaceae microalga
Publication Name: Algal Research
Publication Date: 2021-04-01
Volume: 54
Issue: Unknown
Page Range: Unknown
Description:
Lipid biosynthesis in microalgae can be stimulated by cultivation in low nitrogen medium. MACC-401 was isolated from the soil surface in Tres Marias (MG-Brazil). The strain shows the morphological characteristics of the Scenedesmaceae green algae. The daily biomass and lipid production of MACC-401 is remarkable, 0.36 g L−1 and 110 mg L−1, respectively. Exploration of the genetic background of this promising strain not only allows the utilization of this species for industrial-scale lipid production, but also provides genetic targets to select lipid-producing strains from microalgae collections. We conducted physiological experiments by cultivating MACC-401 in complete and N-limited media and performed genome sequencing as well as transcriptome analysis. The estimated nuclear genome size of MACC-401 is 99.503 Mbp and the chloroplast genome is 0.15 Mbp. The phylogenetic analysis confirmed that the MACC-401 belongs to the Scenedesmaceae family, and represents a genetically distinct accession in this family. A basic comparative transcriptome analysis resulted in the identification of N-starvation responsive genes, which could serve as markers to monitor the onset of lipid accumulation in algal cultures.
Open Access: Yes
Growth, biostimulant and biopesticide activity of the MACC-1 Chlorella strain cultivated outdoors in inorganic medium and wastewater
Publication Name: Algal Research
Publication Date: 2021-03-01
Volume: 53
Issue: Unknown
Page Range: Unknown
Description:
The use of wastewater (WW) for cultivation contributes to the sustainability of microalgae production due to the reduced costs of cultivation. The main objective of this work was to study growth, physiological performance and bioactivity of the microalgae strain Chlorella vulgaris MACC-1 grown in two nutrient sources – inorganic BG-11 medium and centrate from municipal WW. For the comparison, two thin-layer cultivation units – thin-layer cascade and a novel, thin-layer raceway pond – were used. The cultures grew well in both units showing good photosynthetic activity. The germination index of watercress seeds, as well as the auxin-like activity in mung bean and cytokinin-like activity in wheat growth tests were used to evaluate the biostimulant potential. The slight increase on the germination index was determined in C. vulgaris cultures grown in BG-11, but the biomass revealed no biostimulant activity when cultivated in WW. On the other hand, the antibacterial and antifungal activities determined by antagonism bioassay using dual cultures were significantly higher when grown in WW. We expect that the antimicrobial activities may be induced by WW-microbes and the biostimulating effect could probably be suppressed by the presence of some inhibiting substances. The results revealed a clear interplay among ambient irradiance intensity, growth rate, maximum quantum yield of PSII, Fv /Fm and oxygen production/respiration.
Open Access: Yes
Categories of various plant biostimulants - Mode of application and shelf-life
Publication Name: Biostimulants for Crops from Seed Germination to Plant Development A Practical Approach
Publication Date: 2021-01-01
Volume: Unknown
Issue: Unknown
Page Range: 1-60
Description:
A plant biostimulant is any substance or microorganism which can be applied to plants to enhance seed germination and plant growth development along with its nutritional efficiency. Plant biostimulants collectively influence: plant growth development, pollen tube development, flower and fruit set, plant pigments, shoot and root development, nutritional efficiency, yield and shelf-life of crops, rhizospheric and soil microorganisms, general soil health and plant-environment interactions. Biostimulants are derived from natural origins and can help reduce the use of chemical products and also mitigate the negative impacts of harmful chemicals in the environment. This chapter focuses on their modes of application and effects on crops and horticultural plants. It also emphasizes impacts on the shelf-life and efficiencies of commercial biostimulants, as compared to synthetic chemical products and highlights the opportunities and challenges of their market expansion.
Open Access: Yes
Effect of cell disruption methods on the extraction of bioactive metabolites from microalgal biomass
Publication Name: Journal of Biotechnology
Publication Date: 2020-01-10
Volume: 307
Issue: Unknown
Page Range: 35-43
Description:
Microalgae synthesize a variety of potentially high-value compounds. Due to their robust cell wall, cell disruption is necessary to improve extraction of these compounds. While cell disruption methods have been optimized for lipid and protein extraction, there are limited studies for other bioactive compounds. The present study investigated the effect of freeze-drying combined with sonication or ball-milling on the extraction of antioxidant and plant biostimulating compounds from Chlorella sp., Chlorella vulgaris and Scenedesmus acutus. Both cell disruption methods resulted in higher extract yields from the biomass compared to freeze-dried biomass using 50% methanol as a solvent. Antioxidant activity of Chlorella extracts was generally higher than freeze-dried extracts based on the diphenylpicrylhydrazyl (DPPH) and β-carotene linoleic acid assays. However, the effectiveness of each treatment varied between microalgae strains. Sonication resulted in the highest antioxidant activity in Chlorella sp. extracts. Ball-milling gave the best results for C. vulgaris extracts in the DPPH assay. Both cell disruption methods decreased antioxidant activity in S. acutus extracts. Plant biostimulating activity was tested using the mung bean rooting assay. Damaging the membrane by freeze-drying was sufficient to release the active compounds using water extracts. In contrast, both cell disruption methods negatively affected the biological activity of the extracts. These results indicate that bioactive compounds in microalgae are sensitive to post-harvest processes and their biological activity can be negatively affected by cell disruption methods. Care must be taken to not only optimize yield but to also preserve the biological activity of the target compounds.
Open Access: Yes
Biostimulating effects of the cyanobacterium Nostoc piscinale on winter wheat in field experiments
Publication Name: South African Journal of Botany
Publication Date: 2019-11-01
Volume: 126
Issue: Unknown
Page Range: 99-106
Description:
Due to global warming, a permanent rainfall deficit and higher temperatures reduce the available water in the soil, which severely influences plant water status. Current research needs to address ways to overcome these problems in order to maintain crop yields. The beneficial effects of seaweed extracts against abiotic and biotic stress factors of plant growth is well known but the use of microalgae for the same purpose is not well described. The aim of the present work was to investigate the plant biostimulating effects of the cyanobacterium Nostoc piscinale on the winter wheat variety “Bőség.” Experiments were carried out over three years in Hungary at the Mosonmagyaróvár Faculty Farm. Freeze-dried cyanobacterium was re-suspended in water (0.3 or 1.0 g/L) and sprayed at 400 L/ha on wheat leaves at tillering or tillering and ear emergence. Root weight, relative water content (RWC), chlorophyll and proline content of leaves were measured during the vegetation period. Ear number, ear length, grain numbers in ear, thousand grain weight and yield were measured at harvest. The most economic and highest yield increase was obtained by 0.3 g/L treatment with N. piscinale at tillering and ear emergence. Beneficial effects included a stronger root system, elevated leaf RWC, higher proline content and increased leaf chlorophyll content, which remained high in plant leaves treated with N. piscinale for one or two weeks longer than in the control leaves. The high chlorophyll content extended the productive vegetation period of the treated plants. Cyanobacterium treatment increased the ear number, ear length, grain number per ear, thousand grain weight and yield of the wheat crop.
Open Access: Yes
Effect of gibberellins on growth and biochemical constituents in Chlorella minutissima (Trebouxiophyceae)
Publication Name: South African Journal of Botany
Publication Date: 2019-11-01
Volume: 126
Issue: Unknown
Page Range: 92-98
Description:
A hormonal network regulates growth processes and stress responses in vascular plants. There is evidence for a similar hormonal network in microalgae. This study investigated the effect of exogenous gibberellins (GAs) on Chlorella minutissima Fott et Nováková growth and biochemical composition. Two bioactive GAs i.e. GA3 and GA4 were applied at 10−8–10−5 M. Growth was monitored until cultures were harvested on day 7 when in an exponential growth phase. Primary metabolites (protein, chlorophyll and carotenoids) were quantified and endogenous GAs and phenolic acids were identified and quantified. GA3 had little beneficial effect on growth in C. minutissima while GA4 was inhibitory. GA application had little effect on the protein, chlorophyll and total carotenoid content. Analysis of the GA content suggested that GA3 was not readily taken up by the cells while GA4 was absorbed but not further metabolised. This high accumulation of GA4 could account for its inhibitory effect. Three phenolics acids were detected in C. minutissima i.e. p-hydroxybenzoic acid > salicylic acid > protocatechuic acid. Their concentrations were not affected by GA treatments or GA-type. The physiological role of GAs in microalgae is still unclear and further studies are required to gain clearer insight into uptake rates, metabolism and function.
Open Access: Yes
Phylogenetic re-evaluation of previously identified Chlamydomonas (Chlorophyta, Chlamydomonadaceae) strains from The Mosonmagyaróvár Algal Culture Collection, Hungary, using molecular data
Publication Name: South African Journal of Botany
Publication Date: 2019-09-01
Volume: 125
Issue: Unknown
Page Range: 16-23
Description:
Systematic studies on 70 MACC isolates previously identified as ‘Chlamydomonas’, a unicellular flagellate, were carried out based on partial 18S rRNA. The aim of this study was to determine the phylogenetic affiliations of Chlamydomonas strains in the MACC collection. The study found that most of the strains were not Chlamydomonas. Nine clusters of phylogenetically similar taxa were identified. The previous determinations were completed with their new phylogenetic affiliations (partly due to changes in green algae classification). Molecular data revealed that 3 of the 70 strains are from Arenicolinia, 14 are members of the phylogroup Stephanosphaerinia, 11 are Oogamochlamydinia, 1 is Chloromonadinia, 19 are Reinhardtinia, 2 are Polytominia, 9 are Scenedesmaceae, 5 are Moewusinia, and 6 are Chlorella. Clades were established by 18S rRNA similarity and p-distances. This study reveals the need to revise established culture collections whose isolates are solely identified with morphology.
Open Access: Yes
Molecular taxonomic evaluation of Anabaena and Nostoc strains from the Mosonmagyaróvár Algal Culture Collection
Publication Name: South African Journal of Botany
Publication Date: 2019-08-01
Volume: 124
Issue: Unknown
Page Range: 80-86
Description:
The taxonomy of genera Anabaena and Nostoc is very controversial. They are typically paraphyletic within phylogenetic trees and show similar morphological characters. The present study aimed to determine the taxonomic relationships among Anabaena and Nostoc strains of the Mosonmagyaróvár Algal Culture Collection (MACC)using 16S rRNA and rbcLX gene sequences. We concluded on the basis of the number of unsuccessful amplifications that more of the examined MACC Nostoc cultures are axenic than the Anabaena cultures. In agreement with previous studies we noticed that the applied phylogenetic algorithms gave congruent results in phylogenetic analyses. However, the genus Nostoc clearly was found not monophyletic in the present study and this finding differed from many of the previous studies. Molecular results contradicted the previous morphology-based classification of some MACC cyanobacteria strains, therefore polyphasic taxonomic approaches are required for the reliable identification of cyanobacterial species. Some strains seemed to be identical based on the alignment of 16S rRNA or rbcLX sequences.
Open Access: Yes
The reclassification of 37 strains from The Mosonmagyaróvár Algal Culture Collection, Hungary, which were previously identified as Anabaena (Cyanobacteria, Nostocaceae)
Publication Name: South African Journal of Botany
Publication Date: 2019-07-01
Volume: 123
Issue: Unknown
Page Range: 333-340
Description:
Study on 37 MACC isolates previously identified as “Anabaena,” a freshwater filamentous heterocytous taxon, were carried out using the 16S rRNA. The study found that most of the strains were misidentified at genus level. Three clusters of phylogenetically and morphologically similar taxa were identified. The previous determinations were amended with their new taxonomic classifications (partly due to changes in cyanobacterial classification). Some morphological structures could not be found in the cultures (e.g. akinetes). Molecular data revealed that 6 of the 37 strains are Desmonostoc, 8 are members of the genus Nostoc, 19 strains bear genetic resemblance to the genus Trichormus and 4 strains remain unresolved. Clades were established by 16S rRNA similarity and p-distances. The goal of this study was to amend the strain designations in this collection. This study reveals the necessity to revisit established culture collections that originally used only morphological classifications for species identification.
Open Access: Yes
Endogenous brassinosteroids in microalgae exposed to salt and low temperature stress
Publication Name: European Journal of Phycology
Publication Date: 2018-07-03
Volume: 53
Issue: 3
Page Range: 273-279
Description:
Brassinosteroids are part of the hormonal network that regulates growth processes and stress responses in plants. There is evidence for a similar hormonal network in microalgae. In the present study, six microalgae (Chlorococcum ellipsoideum, Gyoerffyana humicola, Nautococcus mamillatus, Acutodesmus acuminatus, Protococcus viridis and Chlorella vulgaris) were subjected to salt and low temperature stress with the addition of 36 g l–1 NaCl and transfer from 25°C to 15°C. There was a rapid response to salt stress with the brassinosteroid content (mainly castasterone with lower amounts of brassinolide, homocastasterone and typhasterol) increasing within 30 min of the salt treatment and remaining at these elevated levels after 7 h. The decrease in temperature had little effect on the brassinosteroid content. This was the first study to show that endogenous brassinosteroids increase in response to abiotic stress in a number of microalgae species.
Open Access: Yes
Biostimulant properties of cyanobacterial hydrolysate related to polyamines
Publication Name: Journal of Applied Phycology
Publication Date: 2018-02-01
Volume: 30
Issue: 1
Page Range: 453-460
Description:
Developing new and natural sources of plant growth promotors is essential to ensure the safe and sustainable production of vegetables for human consumption. In recent years, the potential of microalgae as plant biostimulants has been investigated. Arthrospira platensis (Spirulina platensis) biomass is a recognized protein source and its enzymatic hydrolysis contains molecules such as polyamines with potential to promote plant growth. Therefore, the aim of the present study was to investigate the biostimulant properties of hydrolyzed biomass of A. platensis. Bioassays were performed to determine auxin-like and cytokinin-like bioactivity of the hydrolysates. In addition, its effect on lettuce seedling growth was investigated and an organic system field trail performed where yield and free polyamine levels in leaves quantified. The hydrolysates had a cytokinin-like effect in the bioassay. Foliar applications promoted the growth of lettuce seedlings with the 4-h reaction hydrolysate (Sph4) being the most effective at promoting growth and increasing the spermine content by 64% in the lettuce leaves. The polyamine concentration was also compared in non-hydrolyzed A. platensis and Sph4. Hydrolysis resulted in a 34% increase in spermine content. It was concluded that Sph4 is a natural plant growth promoter that can be used as a raw material for biostimulants, and spermine could be an active compound and a metabolic indicator of Sph4 bioactivity.
Open Access: Yes
Factors influencing algal photobiohydrogen production in algal-bacterial co-cultures
Publication Name: Algal Research
Publication Date: 2017-12-01
Volume: 28
Issue: Unknown
Page Range: 161-171
Description:
Algal-bacterial co-cultures represent an alternative way for algal biohydrogen generation. Efficient algal hydrogen production requires anaerobiosis and electrons accessible for the algal FeFe‑hydrogenases. A number of factors strongly influence the development of this optimal environment. Various algal strains were tested for hydrogen evolution with a selected bacterial partner, a fully hydrogenase deficient Escherichia coli. During the hunt for the most efficient algae strains, gas-to-liquid phase ratio, algal optical density and algal cell size were identified as crucial factors influencing algal hydrogen evolution rate, accumulated algal hydrogen yield, carbon dioxide and oxygen levels as well as acetic acid consumption in illuminated algal-bacterial cultures. The highest accumulated hydrogen yields were observed for the different algal partners under similar experimental setup. The combination of a gas-to-liquid phase ratio of 1/1 with an algae cell density of 3.96 ∗ 108 algae cell ml− 1 (OD750 : 1) resulted in the highest accumulated algal hydrogen yields under continuous illumination of ~ 50 μmol m− 2 s− 1 light at 25 °C irrespective of the applied algae strain. Accumulated hydrogen yield was also strongly influenced by the algal cell size, smaller cell size correlated with higher hydrogen evolution rate. The highest accumulated algal hydrogen yield (88.98 ± 2.19 ml H2 l− 1 d− 1) was obtained with Chlorella sp. MACC 360 -E. coli ΔhypF co-culture.
Open Access: Yes
