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Background: Escherichia coli belongs to the Enterobacteriaceae family and is found in the digestive systems of humans and various animals as normal flora. Objective: This study aims to identify the optimal conditions necessary for the synthesis of hemolysin by E. coli isolated from a variety of clinical contexts. Methods: A total of 120 specimens were collected from different clinical sources in Baghdad Hospitals. Screening for hemolysin production was done by plate and Spectrophotometric methods. Furthermore, many conditions for producing hemolysin from clinical E. coli isolates were investigated including temperature, pH, incubation time, inoculum size, culture medium, and aeration. Results: Six isolates of E. coli exhibited hemolysin production. Optimal conditions for hemolysin production were determined: the temperature was 37 °C with an optical density of 0.931, the pH was 7 with an optical density of 0.976, the incubation period was 24 hours with an optical density of 0.885, 1% inoculum resulting in an optical density of 0.558, brain heart infusion as the best medium with an optical density of 1.697, and a shaker method showing superior results (optical density of 1.235) compared to static aeration (optical density of 0.988). Conclusions: This study identified the optimal conditions necessary for the synthesis of hemolysin by E. coli. By understanding these optimal conditions, researchers may be better equipped to develop strategies for managing and controlling the spread of these pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Algae require optimal conditions for efficient photosynthesis. The present study investigates the effect of different growth conditions on the production of biomass, lipid, protein, total chlorophyll, and carotenoid. The findings show that the increase of light intensity from 80 to 280 μ mol/(m2.s) leads to higher specific growth rates (21.03/h). Also, total chlorophyll, lipid, and carotenoid content at the end of cultivation are the highest in the light intensity of 280 μ mol/(m2.s) due to higher biomass production (1.92 g/L). Under salinity stress, the specific growth rates (11.81/h) and the content of biomass (1.4 g/L), lipid, total chlorophyll, and carotenoid are slightly reduced compared to the control culture at the end of cultivation. This study also investigates the kinetics of chlorophyll and carotenoid extraction from mixed microalgae at different operating conditions with methanol solvent for the first time. The extraction results reveal that the highest kinetic constant and extraction efficiency of chlorophyll and carotenoid (94.10 and 95.43%, respectively) were achieved at 40 ˚C, pH 7, agitation of 300 rpm, and algal concentration of 4 g/L‏. [ABSTRACT FROM AUTHOR]

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients represent a therapeutic challenge due to antibiotic resistance. Repurposing existing drugs is a promising approach for identifying new antimicrobials. A crucial factor in successful drug repurposing is using assay conditions that mirror the site of infection. Here, the impact of growth conditions on the anti-P. aeruginosa activity of a library of 3386 compounds was evaluated. To this, after 24 h exposure, the survival rate of CF P. aeruginosa RP73 planktonic cells was assessed spectrophotometrically under "CF-like" (artificial CF sputum, pH 6.8, 5% CO2) and enriched (Tryptone Soya Broth, pH 7.2, and aerobiosis) conditions. Among non-antibiotic compounds (n = 3127), 13.4% were active regardless of growth conditions, although only 3.2% had comparable activity; 4% and 6.2% were more active under CF-like or enriched conditions, respectively. Interestingly, 22.1% and 26.6% were active exclusively under CF-like and enriched conditions, respectively. Notably, 7 and 12 hits caused 100% killing under CF-like and enriched conditions, respectively. Among antibiotics (n = 234), 42.3% were active under both conditions, although only 18.4% showed comparable activity; 9.4% and 14.5% were more active under CF-like and enriched conditions, respectively. Interestingly, 23% and 16.6% were active exclusively under CF-like and enriched conditions, respectively. Sulphonamides showed higher activity under CF-like conditions, whereas tetracyclines, fluoroquinolones, and macrolides were more effective under enriched settings. Our findings indicated that growth conditions significantly affect the anti-P. aeruginosa activity of antibiotics and non-antibiotic drugs. Consequently, repurposing studies and susceptibility tests should be performed under physicochemical conditions that the pathogen tackles at the site of infection. [ABSTRACT FROM AUTHOR]

The contents of sesquiterpene glycosides (SGs) from Dendrobium nobile Lindl. were greatly influenced by different growth conditions. A quantitative method based on HPLC‐QqQ‐MS/MS in MRM mode was developed for simultaneous analysis of six SGs. The results were further analyzed by principal component analysis and hierarchical cluster analysis. The results showed the SG contents were relatively high in 3‐year‐old D. nobile grown at an altitude of approximately 500 m on Danxia rocks in Chishui, Guizhou. Introduction: The sesquiterpene glycosides (SGs) from Dendrobium nobile Lindl. have immunomodulatory effects. However, there are no studies on the growth conditions affecting its contents and quantitative analysis methods. Objective: In the present study, a quantitative analysis method for six SGs from D. nobile was established. We explored which growth conditions could affect the contents of SGs, providing a basis for the cultivation and clinical application of D. nobile. Methods: Firstly, based on the optimization of mass spectrometry parameters and extraction conditions for six SGs in D. nobile, a method for the determination of the contents of six SGs was established using high‐performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (HPLC‐QqQ‐MS/MS) in multiple reaction monitoring (MRM) mode. Then, the methodology of the established method was validated. Secondly, the established method was applied to determine the contents of six SGs from 78 samples of D. nobile grown under different growth conditions. Finally, chemometrics analysis was employed to analyze the results and select optimal growth conditions for D. nobile. Results: The results indicated significant variations in the contents of SGs from D. nobile grown under different growth conditions. The primary factors influencing SG contents included age, geographical origin, altitude, and epiphytic pattern. Conclusion: Therefore, the established method for determining SG contents from D. nobile is stable. In particular, the SG contents were relatively high in samples of 3‐year‐old D. nobile grown at an altitude of approximately 500 m on Danxia rocks in Chishui, Guizhou. [ABSTRACT FROM AUTHOR]

Background: Escherichia coli belongs to the Enterobacteriaceae family and is found in the digestive systems of humans and various animals as normal flora. Objective: This study aims to identify the optimal conditions necessary for the synthesis of hemolysin by E. coli isolated from a variety of clinical contexts. Methods: A total of 120 specimens were collected from different clinical sources in Baghdad Hospitals. Screening for hemolysin production was done by plate and Spectrophotometric methods. Furthermore, many conditions for producing hemolysin from clinical E. coli isolates were investigated including temperature, pH, incubation time, inoculum size, culture medium, and aeration. Results: Six isolates of E. coli exhibited hemolysin production. Optimal conditions for hemolysin production were determined: the temperature was 37 °C with an optical density of 0.931, the pH was 7 with an optical density of 0.976, the incubation period was 24 hours with an optical density of 0.885, 1% inoculum resulting in an optical density of 0.558, brain heart infusion as the best medium with an optical density of 1.697, and a shaker method showing superior results (optical density of 1.235) compared to static aeration (optical density of 0.988). Conclusions: This study identified the optimal conditions necessary for the synthesis of hemolysin by E. coli. By understanding these optimal conditions, researchers may be better equipped to develop strategies for managing and controlling the spread of these pathogenic bacteria.

Main conclusion: The Na+/Ca2+ ratio of 1/5 ameliorated the inhibitory action of NaCl and improved the germination and growth of Vicia faba. Addition of Rhizobium also enhanced nodulation and nitrogen fixation. Casting light upon the impact of salinity stress on growth and nitrogen fixation of Vicia faba supplemented with Rhizobium has been traced in this work. How Ca2+ antagonizes Na+ toxicity and osmotic stress of NaCl was also targeted in isosmotic combinations of NaCl and CaCl2 having various Na+:Ca2+ ratios. Growth of Viciafaba (cultivar Giza 3) was studied at two stages: germination and seedling. At both experiments, seeds or seedlings were exposed to successively increasing salinity levels (0, 50, 100, 150, and 200 mM NaCl) as well as isosmotic combinations of NaCl and CaCl2 (Na+:Ca2+ of 1:1, 1:5, 1:10, 1:15, 1:18, and 1: 20), equivalent to 150 mM NaCl. Inocula of the local nitrogen-fixing bacteria, Rhizobium leguminosarum (OP715892) were supplemented at both stages. NaCl salinity exerted a negative impact on growth and metabolism of Vicia faba; inhibition was proportional with increasing salinity level up to the highest level of 200 mM. Seed germination, shoot and root lengths, fresh and dry weights, chlorophyll content, and nodules (number, weight, leghemoglobin, respiration, and nitrogenase activity) were inhibited by salinity. Ca2+ substitution for Na+, particularly at a Na/Ca ratio of 1:5, was stimulatory to almost all parameters at both stages. Statistical correlations between salinity levels and Na/Ca combinations proved one of the four levels (strong- or weak positive, strong- or weak negative) with most of the investigated parameters, depending on the parameter. [ABSTRACT FROM AUTHOR]

Standardization of the growth conditions for Rhodotorula sp. MTCC 1446 for microbial biopigment production utilizing the horticultural wastes was conducted to replace the use of synthetic food colors by optimizing cheap media formulation. Screening of different horticultural wastes revealed potato waste based media 5% (w/v) showed maximum biomass growth and biopigment production. Cultural conditions viz. incubation temperature, pH, incubation time and DAHP supplementation were statistically optimized using Response Surface Methodology results revealed that incubation temperature of 30 °C, pH 7, incubation time 66 h and 362.5 mg/100 ml DAHP supplementation as optimized cultural conditions for the biopigment production. Temperature and pH were the most significant facorts to determine microbial biomass growth and biopigment production. Identification studies revealed the presence of carotenoids viz. β-carotene, torulene and torularhodin in the biopigment later confirmed by HPLC analysis also. Utilization of dried purified biopigment form in pear nectar and pear bar resulted in the increase in their phenolic content along with increase in the sensory score of both products in terms of appearance, flavor and overall acceptability. Hence, the biopigment produced on potato waste based media under optimized cultural conditions using Rhodotorula sp. can be serve as a nutritive alternative to synthetic food colors for food industries. [ABSTRACT FROM AUTHOR]

The need for cleaner energy as a sustainable alternative instead of fossil fuels has led to a plethora of research on biological H 2 production by microalgae and cyanobacteria. These species have a great potential to produce hydrogen in photobioreactors acting as a closed system that provides suitable conditions for algal cultivation. This review provides an overview of the requirements for green algae and cyanobacteria growth and focuses on the conditions required for hydrogen production. Also, the common types of bioreactors used for hydrogen production were critically assessed in terms of microbial growth and hydrogen production. Culturing these microorganisms within an electrochemical unit is a promising approach to increase biohydrogen production. The inclusion of nanoparticles is also an emerging technique to improve light scattering in photobioreactors. [Display omitted] • Review of biological production of hydrogen using microalgae and cyanobacteria. • Source of C, N, P, micronutrients, light, temperature, gas, flow rate are discussed. • Other strategies: S deprivation, anaerobic conditions, co-cultures, immobilization. • Most common photobioreactors and novel systems with hydrogen yield. [ABSTRACT FROM AUTHOR]

Traditionally, indigenous African leafy vegetables such as Amaranthus, blackjack, jute mallow, cleome monophyla, and spider plants have been conventionally and organically grown as weeds in open fields. However, the lack of land space due to the increase in population has resulted in unconventional, modern, and advanced agricultural farming. The introduction of a greenhouse has recently become the second most popular growing system alongside shade net and glasshouse to increase productivity and meet consumers' demand. Several studies on Amaranthus species have solely focused on physiological parameters and nutritional composition, leaving a huge gap on their metabolomic profile of the leaves which is crucial to comprehend when growing Amaranthus species in different cropping systems. Therefore, the study aimed to determine the influence of different cropping systems on the release of metabolites of two commonly consumed Amaranthus species in South Africa. H1 -Nuclear Magnetic Resonance (NMR) tool was used to profile the untargeted metabolites of green (Amaranthus graecizans L.) and red (Amaranthus cruentus L.) species. A total of 12 metabolites—trehalose, betaine, glutamine, choline, sucrose, caprate, adenosine, asparagine, carnitine, caffeine, aspartate, and alanine—were detected in green amaranth grown in open fields. Except for caffeine, aspartate, and caprate, which were found in the green amaranth grown in open fields, all the other metabolites were detected in the greenhouse grown once. Interestingly, allantoin, which serves as an allelochemical, was the sole distinct metabolite detected in greenhouse cultivated green amaranth. On the contrary, seven similar metabolites were quantified in red amaranth grown in both open fields and greenhouses, apart from caffeine, which was only detected in greenhouse-cultivated red amaranth. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients represent a therapeutic challenge due to antibiotic resistance. Repurposing existing drugs is a promising approach for identifying new antimicrobials. A crucial factor in successful drug repurposing is using assay conditions that mirror the site of infection. Here, the impact of growth conditions on the anti-P. aeruginosa activity of a library of 3386 compounds was evaluated. To this, after 24 h exposure, the survival rate of CF P. aeruginosa RP73 planktonic cells was assessed spectrophotometrically under “CF-like” (artificial CF sputum, pH 6.8, 5% CO2) and enriched (Tryptone Soya Broth, pH 7.2, and aerobiosis) conditions. Among non-antibiotic compounds (n = 3127), 13.4% were active regardless of growth conditions, although only 3.2% had comparable activity; 4% and 6.2% were more active under CF-like or enriched conditions, respectively. Interestingly, 22.1% and 26.6% were active exclusively under CF-like and enriched conditions, respectively. Notably, 7 and 12 hits caused 100% killing under CF-like and enriched conditions, respectively. Among antibiotics (n = 234), 42.3% were active under both conditions, although only 18.4% showed comparable activity; 9.4% and 14.5% were more active under CF-like and enriched conditions, respectively. Interestingly, 23% and 16.6% were active exclusively under CF-like and enriched conditions, respectively. Sulphonamides showed higher activity under CF-like conditions, whereas tetracyclines, fluoroquinolones, and macrolides were more effective under enriched settings. Our findings indicated that growth conditions significantly affect the anti-P. aeruginosa activity of antibiotics and non-antibiotic drugs. Consequently, repurposing studies and susceptibility tests should be performed under physicochemical conditions that the pathogen tackles at the site of infection.

Low-complexity prescribed performance control (PPC) is a control methodology whose strongest feature is its structural simplicity, namely, uncertainty can be handled without unknown parameter estimators or approximation structures, e.g., fuzzy logic or neural networks, considered in the design of the control scheme. This work shows that low-complexity PPC can tackle uncertain high-order odd-rational power nonlinear dynamics, i.e., an integrator chain where the power is the ratio of odd integers. State of the art has shown the feasibility of PPC for strict-feedback nonlinear dynamics (an integrator chain with a power equal to one) or high-order odd-integer-power nonlinear dynamics. In this paper, we show that the same structural simplicity of PPC can be retained for the more general class of high-order odd-rational-power nonlinear systems. Note that all the methods proposed in the literature for handling high-order nonlinearities cannot be used with rational powers (unless restricting the system's nonlinearity growth). Therefore, a new lemma is proposed to handle the odd-rational power scenario without restricting the nonlinearities' growth. Interestingly, the developed scheme generalizes the most advanced PPC and effectively handles the input quantization, and unknown power problems studied recently. [ABSTRACT FROM AUTHOR]

In this paper, by applying the Sadovskii’s fixed point theorem, we obtain the existence and uniqueness result of mild solution for a class of periodic boundary value problem of impulsive evolution equations in Banach space with noncompact semigroup in the case that the nonlinearity term f and impulsive functions I k satisfy growth conditions and the measure of noncompactness conditions. And we give a specific example to illustrate our main results. [ABSTRACT FROM AUTHOR]

Nanotechnology is especially useful in biotechnological and biomedical applications as nanomaterials have unique physicochemical properties. Current physical and chemical techniques used for the production of nanoparticles have various disadvantages that has led to the evaluation of biological strategies. This study focused on the use of a bacterial species known as Magnetospirillum magnetotacticum for the production of metallic nanoparticles. The cultivation of MTB is known to be tedious and time-consuming using the current standardized magnetic spirillum growth media (MSGM). This study explored the optimization of MSGM for improved growth and nanoparticle yield. It was found that glucose significantly improved and sustained the growth of M. magnetotacticum compared to other sole carbon sources having a sustainable OD of ~1.15. However, use of a higher concentration of sodium nitrate (40 mM) as a nitrogen source was able to significantly improve iron-containing nanoparticle yield by 1.6× with a final yield of 22 mg/50 mL when compared to the yield obtained from the MSGM original media. Growth media with a combination of glucose, sodium nitrate, ammonium sulphate and yeast extract showed the highest exponential growth of Magnetospirillum magnetotacticum compared to all other MSGM modifications with the highest OD being 1.7. Silver and gold nanoparticles were also successfully produced in addition to iron-containing nanoparticles. Overall, no direct correlation between growth and nanoparticle yield was found. [ABSTRACT FROM AUTHOR]

Nutrient stress as a tool for enhancement of yields and quality of biofuel products from thermal conversion processes has not received sufficient attention. Much research has been done on microalgal lipids conversion to biodiesel via the transesterification process route. However, the inefficient use of algae biomass due to the unutilized residual algal biomass and high production costs affect the economics and render the microalgal biodiesel technology less competitive to fossil-based fuels. Thermal conversion processes have gained increased attention since the processing can be applied to whole microalgae resulting in higher biofuel product yield and has the potential for producing other important products. The major challenges of thermal conversion processes of microalgae are the high level of nitrogen and oxygen content present in the product, which makes the bio-oil unstable for use as transportation fuels directly. Transportation fuels are expected to have low nitrogen content to meet environmental emission standards for combustion. Research efforts to address this challenge are ongoing, and the use of catalyst and co-thermal conversion of microalgae with other waste material has been proposed as possible options. Another promising yet to be explored approach with the thermal conversion process may involve the use of nitrogen nutrient alteration to manipulate the biomass composition to provide the requisite solution towards developing efficient and sustainable thermal conversion process for quality biofuel production from various species of microalgae. [ABSTRACT FROM AUTHOR]

The study considers variational aspects of physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood depending on conditions and growth areas in the boreal zone of the European Northeast. Anatomical traits of xylem and its strength properties were analyzed. Based on the data received, statistical processing of the material was carried out using correlation and multivariate analysis. The impact of hazardous air emissions on variation of linear dimensions in structural elements of the annual height increment in the trunk diameter was estimated. A varying nature of the influence of environmental factors on the formation of strength properties of P. sylvestris wood in growth areas was attested. The variation value of basic wood density decreases as soil and hydrological conditions of growth improve. A significant negative correlation between basic wood density and distance to sources of hazardous air emissions in the areas of concentration of industrial enterprises was established. The results of multivariate analysis make it possible to reveal the weight of the influence of environmental factors and biometric characteristics of wood on volumetric and strength properties of pine wood. Growth in the impact zone of air emissions from large industrial enterprises in the study area does not produce a significant effect on the dynamics of wood strength properties, taking into account various growth conditions. For Scots pine growing in the European Northeast, the study determined a significant impact of the size and structure of the annual height increment of the trunk in terms of diameter, as well as the position of the wood sample in terms of trunk volume, on strength properties of pine wood.

Genome streamlining, as a natural process in the evolution of microbes, has become a common approach for generating ideal chassis cells for synthetic biology studies and industrial applications. However, systematic genome reduction remains a bottleneck in the generation of such chassis cells with cyanobacteria, due to very time-consuming genetic manipulations. Synechococcus elongatus PCC 7942, a unicellular cyanobacterium, is a candidate for systematic genome reduction, as its essential and nonessential genes have been experimentally identified. Here, we report that at least 20 of the 23 over 10 kb nonessential gene regions could be deleted and that stepwise deletions of these regions could be achieved. A septuple-deletion mutant (genome reduced by 3.8%) was generated, and the effects of genome reduction on the growth and genome-wide transcription were investigated. In the ancestral triple to sextuple mutants (b, c, d, e1), an increasingly large number of genes (up to 998) were upregulated relative to the wild type, while slightly fewer genes (831) were upregulated in the septuple mutant (f). In a different sextuple mutant (e2) derived from the quintuple mutant d, much fewer genes (232) were upregulated. Under the standard conditions in this study, the mutant e2 showed a higher growth rate than the wild type, e1 and f. Our results indicate that it is feasible to extensively reduce the genomes of cyanobacteria for generation of chassis cells and for experimental evolutionary studies. [ABSTRACT FROM AUTHOR]

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract We investigated the literature to find the bioactive compounds’ profile of Brassicaceae microgreens and the influence of different production systems and the elicitors use in its overall quality. For this, a summary of the latest progress in bioactive compounds qualification and quantification are presented in the relevant databases. Determining the exact role of production systems is not a straightforward process, although it seems to have greater influence according to the intended plant. From the nutritional point of view, the microgreens production demonstrates a high content of bioactive compounds. The use of elicitors, as one of the dependent variables, appears to increase the concentrations of bioactive compounds, especially the use of the light. Besides that, the conditions of growth, harvest and processing remain crucial factors that should be considered in the successful development of the seed.

Traditionally, indigenous African leafy vegetables such as Amaranthus, blackjack, jute mallow, cleome monophyla, and spider plants have been conventionally and organically grown as weeds in open fields. However, the lack of land space due to the increase in population has resulted in unconventional, modern, and advanced agricultural farming. The introduction of a greenhouse has recently become the second most popular growing system alongside shade net and glasshouse to increase productivity and meet consumers’ demand. Several studies on Amaranthus species have solely focused on physiological parameters and nutritional composition, leaving a huge gap on their metabolomic profile of the leaves which is crucial to comprehend when growing Amaranthus species in different cropping systems. Therefore, the study aimed to determine the influence of different cropping systems on the release of metabolites of two commonly consumed Amaranthus species in South Africa. H1 -Nuclear Magnetic Resonance (NMR) tool was used to profile the untargeted metabolites of green (Amaranthus graecizans L.) and red (Amaranthus cruentus L.) species. A total of 12 metabolites—trehalose, betaine, glutamine, choline, sucrose, caprate, adenosine, asparagine, carnitine, caffeine, aspartate, and alanine—were detected in green amaranth grown in open fields. Except for caffeine, aspartate, and caprate, which were found in the green amaranth grown in open fields, all the other metabolites were detected in the greenhouse grown once. Interestingly, allantoin, which serves as an allelochemical, was the sole distinct metabolite detected in greenhouse cultivated green amaranth. On the contrary, seven similar metabolites were quantified in red amaranth grown in both open fields and greenhouses, apart from caffeine, which was only detected in greenhouse-cultivated red amaranth.

Dispersion is an essential step in the lifecycle of biofilms, since it enables the dissemination of microbial cells and, consequently, the potential colonization of new sites. Filamentous fungi belonging to the Scedosporium/Lomentospora genera are opportunistic human pathogens able to form multidrug-resistant biofilms on surfaces of different chemical compositions, environments and nutritional conditions. Despite the rising understanding of how biofilms are formed by Scedosporium/Lomentospora species, the cell dispersal step has not yet been explored. In the present study, the cell dispersion was investigated during biofilm formation by S. apiospermum, S. minutisporum, S. aurantiacum and L. prolificans cells. The results revealed that conidia were the major type of dispersed cells, which were detected throughout biofilm development (from 24 to 72 h). Dispersion was not influenced by increased glucose concentration (the main source for energetic metabolism) neither the presence of voriconazole (the most common antifungal used to treat scedosporiosis); however, the presence of mucin (a component of mucous, present in the lungs of cystic fibrosis patients, who are usually affected by these filamentous fungi) triggered cell dispersion. Contrarily, a poor nutritional environment (e.g., phosphate-buffered saline) inhibited this step. Overall, our study reveals new insights into the biofilm development of Scedosporium/Lomentospora species.

ABSTRACT Bacterial growth substrates influence a variety of biological functions, including the biosynthesis and regulation of lipid intermediates. The extent of this rewiring is not well understood nor has it been considered in the context of virally infected cells. Here, we used a one-host-two-temperate phage model system to probe the combined influence of growth substrate and phage infection on host carbon and lipid metabolism. Using untargeted metabolomics and lipidomics, we reported the detection of a suite of metabolites and lipid classes for two Sulfitobacter lysogens provided with three growth substrates of differing complexity and nutrient composition (yeast extract/tryptone [complex], glutamate and acetate). The growth medium led to dramatic differences in the detectable intracellular metabolites, with only 15% of 175 measured metabolites showing overlap across the three growth substrates. Between-strain differences were most evident in the cultures grown on acetate, followed by glutamate then complex medium. Lipid distribution profiles were also distinct between cultures grown on different substrates as well as between the two lysogens grown in the same medium. Five phospholipids, three aminolipid, and one class of unknown lipid-like features were identified. Most (≥94%) of these 75 lipids were quantifiable in all samples. Metabolite and lipid profiles were strongly determined by growth medium composition and modestly by strain type. Because fluctuations in availability and form of carbon substrates and nutrients, as well as virus pressure, are common features of natural systems, the influence of these intersecting factors will undoubtedly be imprinted in the metabolome and lipidome of resident bacteria. IMPORTANCE Community-level metabolomics approaches are increasingly used to characterize natural microbial populations. These approaches typically depend upon temporal snapshots from which the status and function of communities are often inferred. Such inferences are typically drawn from lab-based studies of select model organisms raised under limited growth conditions. To better interpret community-level data, the extent to which ecologically relevant bacteria demonstrate metabolic flexibility requires elucidation. Herein, we used an environmentally relevant model heterotrophic marine bacterium to assess the relationship between growth determinants and metabolome. We also aimed to assess the contribution of phage activity to the host metabolome. Striking differences in primary metabolite and lipid profiles appeared to be driven primarily by growth regime and, secondarily, by phage type. These findings demonstrated the malleable nature of metabolomes and lipidomes and lay the foundation for future studies that relate cellular composition with function in complex environmental microbial communities.

Nanotechnology is especially useful in biotechnological and biomedical applications as nanomaterials have unique physicochemical properties. Current physical and chemical techniques used for the production of nanoparticles have various disadvantages that has led to the evaluation of biological strategies. This study focused on the use of a bacterial species known as Magnetospirillum magnetotacticum for the production of metallic nanoparticles. The cultivation of MTB is known to be tedious and time-consuming using the current standardized magnetic spirillum growth media (MSGM). This study explored the optimization of MSGM for improved growth and nanoparticle yield. It was found that glucose significantly improved and sustained the growth of M. magnetotacticum compared to other sole carbon sources having a sustainable OD of ~1.15. However, use of a higher concentration of sodium nitrate (40 mM) as a nitrogen source was able to significantly improve iron-containing nanoparticle yield by 1.6× with a final yield of 22 mg/50 mL when compared to the yield obtained from the MSGM original media. Growth media with a combination of glucose, sodium nitrate, ammonium sulphate and yeast extract showed the highest exponential growth of Magnetospirillum magnetotacticum compared to all other MSGM modifications with the highest OD being 1.7. Silver and gold nanoparticles were also successfully produced in addition to iron-containing nanoparticles. Overall, no direct correlation between growth and nanoparticle yield was found.

Haslea ostrearia is a pennate diatom that produces marennine, a water-soluble blue pigment responsible for the greening phenomenon and the increase of organoleptic quality of oysters. Apart from the oyster industry, there is a growing interest in the mass cultivation of this diatom due to the biological activities of marennine. To gain knowledge about the feasibility to upscale production of this diatom, in particular, in the context of global warming, the effects of different temperatures (20, 25, and 30 °C), irradiances (100, 200, and 300 μmol photons m−2 s−1), and pH (7.0, 8.0, and 9.0) on growth and biochemical composition were studied in H. ostrearia cultured in an airlift plan-photobioreactor. The maximum growth rate of H. ostrearia (0.9 ± 0.0 day−1) was obtained at 20 °C, 200 μmol photons m−2 s−1, and pH 7.0, referred to as control conditions. The highest concentration in Chla (2.5 ± 0.1 µg 10−6 cells) and total fatty acids (71.6 ± 1.4 mg g−1 of dry weight, DW) was observed at 20 °C, 300 μmol photons m−2 s−1, and pH 7.0. The highest concentration of carotenoids (1.4 ± 0.1 µg 10−6 cells), Chlc (1.3 ± 0.1 µg 10−6 cells), and extracellular marennine (33.1 ± 0.2 µg 10−6 cells) was observed at 30 °C, 200 μmol photons m−2 s−1, and pH 7.0, and a higher protein content (309.7 ± 24.5 mg g−1 of DW) at 25 °C, 200 μmol photons m−2 s−1, and pH 7.0. The biomass of H. ostrearia was enriched with C14:0 fatty acid at 30 °C, 200 μmol photons m−2 s−1, and pH 7.0, and with C16:0 and C16:1n − 7 fatty acids at control conditions. However, DHA C22:6n − 3 (ω-3), C22:0, and C20:0 were only observed at 300 µmol photons m−2 s−1, 20 °C, and pH 7.0. A high abundance of essential polyunsaturated fatty acids C22:1n − 9 (ω-9) + C20:5n − 3 (EPA) was observed at 100 µmol photons m−2 s−1, 20 °C, and pH 7.0. It is thus possible to anticipate and tune the production of specific metabolites through the control of growth conditions of the benthic diatom H. ostrearia. Key points: • Validation of H. ostrearia culture in a new photobioreactor in batch mode • Biochemical composition variation of H. ostrearia in function of growth conditions • Growth inhibition and unbalanced metabolites induced by the treatment conditions [ABSTRACT FROM AUTHOR]

The uptake experiments with pesticides were performed to clarify differences among plant species, and the influence of growth stages and conditions on the uptake and translocation ability of pesticides. There were 2-10-fold differences among plant species in the root and shoot concentrations of each pesticide, and shoot concentrations of pesticides in Brassica rapa L. var. perviridis were relatively high. In addition, the changes in shoot concentrations with growth stage of B. rapa were affected by root system development. The influence of temperature on uptake and translocation ability differed for each pesticide, while uptake and translocation ability were high for short day lengths. This indicated that plant uptake and translocation of pesticides were affected by root system development and growth conditions such as temperature and day length, not only the relationships to the chemical's properties and behavior of organic chemicals in the soil. [ABSTRACT FROM AUTHOR]

Enriching a biomass with a high fraction of polyhydroxyalkanoate-storing organisms (PHA-storers) represents an essential step in the production of PHAs (bioplastics) from municipal wastewater using mixed microbial cultures. A major challenge is however to create selective growth conditions that are favourable to PHA-storers. Our study thus investigates to what extent the influent COD to phosphorus (COD:P) ratio can be used as a tool for the robust selection of PHA-storers in a single continuous-flow stirred-tank reactor (CSTR). Therefore, we operated five CSTRs in parallel, fed with synthetic wastewater (50% acetate - 50% propionate) with different COD:P ratios (200−1000 gCOD gP−1), and performed a detailed analysis of the microbial communities over long-term (30−70 solid retention times). Our study demonstrates that efficient and robust selection of PHA-storers can be achieved in a single CSTR at high influent COD:P ratios. The selective advantage for PHA-storers increases with the influent COD:P ratio, but only if growth conditions remain limited by both C-substrate and P. In contrast, selection performance deteriorates when COD:P ratios are too high and growth conditions are limited by P only. At an optimal COD:P ratio of 800 gCOD gP−1, a stable microbial community consisting of >90% PHA-storers and dominated by Pannonibacter sp. was selected in the long-term. Finally, our results suggest that high COD:P ratios provide a selective advantage to microorganisms with low cellular P requirements, explaining why different PHA-storers (i.e., Xanthobacter sp. vs. Pannonibacter sp.) were selected depending on the influent COD:P ratio (i.e., 200 vs. 800 gCOD gP−1). Overall, our results provide relevant insights for the development of a new approach for selecting PHA-storers, based on the use of a single CSTR and control of the influent COD:P ratio.

Microalgae are a group of microorganisms, mostly photoautotrophs with high CO 2 fixation capacity, that have gained increased attention in the last decades due to their ability to produce a wide range of valuable metabolites, such as carotenoids and polyunsaturated fatty acids, for application in food/feed, pharmaceutical, and cosmeceutical industries. Their increasing relevance has highlighted the importance of identifying and culturing new bioactive-rich microalgae species, as well as of a thorough understanding of the growth conditions to optimize the biomass production and master the biochemical composition according to the desired application. Thus, this review intends to describe the main cell processes behind the production of carotenoids and polyunsaturated fatty acids, in order to understand the possible main triggers responsible for the accumulation of those biocompounds. Their economic value and the biological relevance for human consumption are also summarized. In addition, an extensive review of the impact of culture conditions on microalgae growth performance and their biochemical composition is presented, focusing mainly on the studies involving Pavlovophyceae species. A complementary description of the biochemical composition of these microalgae is also presented, highlighting their potential applications as a promising bioresource of compounds for large-scale production and human and animal consumption. • Description of biosynthesis routes of fatty acids and carotenoids in Pavlovophyceae. • Biochemical profile of Pavlovophyceae and its potential applications. • Impact of culture conditions on Pavlovophyceae's growth and metabolites production. • Biological relevance of microalgal compounds for human consumption. [ABSTRACT FROM AUTHOR]

In strawberry micropropagation, several challenges must be overcome to obtain quality plants and achieve high survival rate to ex vitro acclimatization. In this study, therefore, a set of protocols were evaluated to optimize explant (meristem) disinfection, in vitro growth (multiplication and rooting), and ex vitro acclimatization of strawberry. The results showed that explants treated with 1.0% NaClO for 5 min had a lower percentage of contamination, and achieved a higher percentage of viability, height, and number of leaves. In vitro growth was favored by the use of 1 mg L−1 zeatin, since it allowed greater seedling growth (number of shoots, seedling height, number of leaves, number of roots and root length), and a higher pre-acclimation rate (100%). In the acclimatization phase, plants grown in a substrate composed of compost + peat combined with 4 g of humic acid achieved better response in morphological and physiological variables. In fact, the results of this study could be used to cultivate strawberry plants of the 'Aroma' variety with high commercial quality. [ABSTRACT FROM AUTHOR]

Morphometric methods of sex differentiation may be cheap, simple, quick, and reliable alternatives to molecular approaches. However, there are still important uncertainties regarding the use of morphometric methods in birds, particularly regarding their applicability to different populations and environmental conditions. Between 2004 and 2019, we sampled 245 Bonelli's Eagle Aquila fasciata nestlings, 197 from nests in Catalonia (northeastern Spain) and Andalusia (southeastern Spain) and 56 that were partially or totally raised in captivity. Our objective was to develop morphometry-based sexing methods for Bonelli's Eagle nestlings that can be applied in situ to different subpopulations and growth conditions. We recorded up to nine measures related to nestling body mass, bill, tarsus, and claw length. Tail and wing length were used to control for the age of nestlings, and all individuals were sexed genetically. We found important morphometric differences between the two natural subpopulations. According to our discriminant analyses, body mass and claw length were the most discriminant variables, both in wild and captivity conditions. Differences between sexes were more prominent during the flight feathers' growing period. Feeding ad libitum in captivity conditions led to larger nestlings and reduced between-sexes differences. We provide different models for sexing Bonelli's Eagle nestlings that can be applied according to the studied geographic location, growth conditions (wild versus captive), and balance between accuracy and simplicity. Overall, our findings highlight that extrapolating sex discriminant functions to different subpopulations and growth conditions may be risky. [ABSTRACT FROM AUTHOR]

Biometric characteristics of the hyphae and micromorphological features of Hohenbuehelia myxotricha mycelia, such as clamps, hyphal loops, crystals were observed by light and electron microscopy. The basic requirements for H. myxotricha growth and acquisition of antimycotic activity have been investigated. The highest mycelial growth (18.2 mm/day) of H. myxotricha was observed on beer wort agar medium. Suitable conditions for maximal H. myxotricha mycelia production were found after 14 days of liquid static cultivation at 25°C, pH 4.5, 30 g/L of glucose, and 2 g/L of yeast extract. The inhibitory effect of H. myxotricha was evaluated against Aspergillus niger, Issatchenkia orientalis, and Candida albicans strains. The optimal period for A. niger growth inhibition was 14 days while 21 days of H. myxotricha cultivation was more appropriated for tested Saccharomycetales growth inhibitions. The most suitable for promotion of antimycotic metabolites against all tested pathogenic fungi were glucose and yeast extract. [ABSTRACT FROM AUTHOR]

In the Czech Republic, the silver birch (Betula pendula Roth.) is considered as a pioneer and a soil preparing tree species. It occurs mainly on clearcutting areas after disturbances. The aim of this study was to fit breast height diameter increment model for birch with respect to tree age, share of birch trees and forest site type (ecological series - ES and forest vegetation zones - FVZ). We used data of both cycles of National Forest Inventory of the Czech Republic. We evaluated production potential of this species. We tested Korf and Michailoff increment models in variant of nonlinear least squares model (NLS) and nonlinear mixed effects model (NLME). Michailoff models performed better. We found seven statistically significant and practically applicable models. The greatest influence on increment of diameter at breast height have forest vegetation zone and ecological series whereas the influence of the share of birch in forest stand is smaller. The highest absolute values of diameter increment were on gleyed or enriched with water sites in the fourth forest vegetation zone.

Abstract Background The aim of this study was to construct a nationwide stand age model by using National Forest Inventory (NFI) data and nationwide airborne laser scanning (ALS) data. In plantation forestry, age is usually known. While this is not the case in boreal managed forests, age is still seldom predicted in forest management inventories. Measuring age accurately in situ is also very laborious. On the other hand, tree age is one of the accurately measured sample tree attributes in NFI field data. Many countries also have a nationwide coverage of airborne laser scanning (ALS) data. In this study, we merged these data sources and constructed a nationwide, area-based model for stand age. Results While constructing the model, we omitted old forests from the data, since the correlation between ALS height metrics and stand age diminished at stands with age > 100 years. Additionally, the effect of growth conditions was considerable, so we also utilized different geographical and NFI variables such as site fertility and soil type in the modeling. The resultant nationwide model for the stand age of managed forests yielded a root mean square error (RMSE) of about 14 years. The model could be improved further by additional forest structure variables, but such information may not be available in practice. Conclusions The results showed that the prediction of stand age by ALS, geographical and NFI information was challenging, but still possible with moderate success. This study is an example of the joint use of NFI and nationwide ALS data and re-use of NFI data in research.

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Plantacyclin B21AG is a promising natural preservative for food products. • Plantacyclin B21AG causes alterations and damage to target cell membranes. • Nitrogen source and Tween are essential for L. plantarum B21's bacteriocin activity. • Carbohydrate source is essential for growth but not bacteriocin production. • Plantacyclin B21AG may be useful as a natural biopreservative. Food waste is a global issue costing roughly US$ 680 billion annually in industrialized countries. Food spoilage is a major contribution to food waste but artificial food preservatives are often not well accepted by the public. The use of natural alternatives to control spoilage is therefore of interest to the food industry. Lactiplantibacillus plantarum B21, originally isolated from a Vietnamese fermented meat product, produces an antimicrobial bacteriocin peptide which is pH and temperature stable and capable of inhibiting spoilage and pathogenic bacterial strains, including Listeria. In this study the sources of nitrogen and Tween are demonstrated to be essential for growth and bacteriocin production in L. plantarum B21. Conversely, carbohydrate source was not critical for bacteriocin production but was essential for growth. The bacteriocin was found to interact with cell membranes of target microorganisms resulting in cell leakage and subsequent cell death. This study provides insight into the growth conditions needed for the potential development of L. plantarum B21 as a natural biopreservative for food products. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the growth potential in liquid cultures conditions of ten edible and medicinal mushrooms named: Flammulina velutipes, Lentinus edodes, Pleurotus eryngii 2600, Pleurotus ostreatus var. Florida, Trametes versicolor, Hericium coralloides, Ganoderma lucidum, Ganoderma applanatum, Agaricus campestris and Laetiporus sulphureus. The evaluation of the mushroom growth potential was carried out using six types of culture media with different chemical composition. After 21 days from the cultures initiation, it was found that Ganoderma species had the greatest potential for the production of biomass in liquid culture conditions on all six media; also, the pH values of culture media have undergone important changes from baseline. [ABSTRACT FROM AUTHOR]

MgSnN 2 thin films have been grown on yttria-stabilized zirconia substrates via plasma-assisted molecular beam epitaxy and analyzed using reflection high-energy electron diffraction, X-ray diffraction, optical transmission, and cathodoluminescence. By systematically varying the growth parameters, particularly the substrate temperature, Mg:Sn flux ratio, substrate, and nitrogen flow rate, we were able to achieve high quality films and control disorder in the cation sublattice. This control of disorder allows for the ability to adjust the band gap continuously over a wide range of values. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aflatoxin B1 (AFB1) is one of the toxic secondary metabolites of fungi belonging to the genus Aspergillus. AFB1 causes hepatotoxicity and carcinogenicity. Mostly, cereals, nuts, fruits, and stored commodities are prone to their attack. It has great health and economic importance. Under suitable conditions, fungus shows maximum pathogenicity which leads to the abundant production of AFB1. This study encompasses the selection of the most pathogenic strain producing abundant AFB1. For this purpose, 50 isolates were tested and YF18 was the most pathogenic. This isolate was then evaluated on 15 culture media which concluded that Yeast Extract Sucrose (YES) agar and Yeast Peptone Dextrose (YPD) agar media proved best for the optimal growth of A. flavus and abundant yield of AFB1. Moreover, the culture media showing optimal growth under different levels of growth conditions i.e., temperature, pH, and water activity, and their effect was verified with the aid of correlation and response surface methodology. The culture media were checked at five levels of temperature (15°C, 20°C, 25°C, 30°C, and 35°C), pH (3.5, 4.0, 4.5, 5.0 and 5.5), and water activity (0.80, 0.85, 0.90, 0.95, and 0.995) were tested, confirming that temperature of 30oC, pH of 5.5 and water activity level of 0.995 significantly enhanced the growth of A. flavus and production of AFB1 (P<0.05); while correlation, as well as response surface methodology, also concluded the level of conditions appropriate for mycelial growth and AFB1 yield. Afterward, the isolate YF18 was applied to the grapes and biochemical parameters were evaluated. The biochemical analysis concluded that fungal infected grapes showed less acidity, TSS, total sugars, TPC, and DPPH as compared to non-treated grapes while the berry size and berry weight was also reduced in infected grapes. The isolate was subjected to 16S rDNA analysis for identification which revealed that fungus is A. flavus and the aflR gene was responsible for activation and release of aflatoxin B1. The present study will help to devise management strategies to reduce the incidence of fungus and its respective toxin. [ABSTRACT FROM AUTHOR]

In strawberry micropropagation, several challenges must be overcome to obtain quality plants and achieve high survival rate to ex vitro acclimatization. In this study, therefore, a set of protocols were evaluated to optimize explant (meristem) disinfection, in vitro growth (multiplication and rooting), and ex vitro acclimatization of strawberry. The results showed that explants treated with 1.0% NaClO for 5 min had a lower percentage of contamination, and achieved a higher percentage of viability, height, and number of leaves. In vitro growth was favored by the use of 1 mg L−1 zeatin, since it allowed greater seedling growth (number of shoots, seedling height, number of leaves, number of roots and root length), and a higher pre-acclimation rate (100%). In the acclimatization phase, plants grown in a substrate composed of compost + peat combined with 4 g of humic acid achieved better response in morphological and physiological variables. In fact, the results of this study could be used to cultivate strawberry plants of the ‘Aroma’ variety with high commercial quality.

Assessment of Front Line Demonstration on Mustard Crop in Hathras District of Uttar Pradesh. The domestic requirement of oil seed had been manifold of a modern livening standard which has been fulfilled through the import that lead to imbalance the Indian economy. The aim of this study was to evaluate the influence of mustard varieties and year of production in relation of weather condition on seed yields, oil content and its quality with a focus on human nutrition value through a field study carried at three different locations in Hathras. The seed yield was significantly affected by the year of production the location and the variety. The environmental factors that negatively affected seed yield are temperature in summer, water shortage, wet and cold soil in spring. The highest seed yield reached at mid-heavy soil in the region with lower precipitation amount.R.H-749 would we recommendable for Hathras environmental condition. R.H.-749 variety gave the significantly highest oil yield. [ABSTRACT FROM AUTHOR]

Developing organisms typically mature earlier and at larger sizes in favorable growth conditions, while in rarer cases, maturity is delayed. The rarer reaction norm is easily accommodated by general life history models, whereas the common pattern is not. Theory suggests that a solution to this paradox lies in the existence of critical size thresholds at which maturation or metamorphosis can commence, and in the evolution of these threshold sizes in response to environmental variation. For example, ephemeral environments might favor the evolution of smaller thresholds, enabling earlier maturation. The threshold model makes two unique and untested predictions. First, reaction norms for age and size should steepen, and even change sign, with decreases in threshold size; second, food reductions at sizes below the threshold should delay maturation, while those occurring after the threshold should accelerate maturation. We test these predictions through food manipulations in five damselfly species that theory suggests should differ in threshold size. The results provide strong support for the threshold model's predictions. In all species, early food reductions delayed maturation, while late reductions accelerated maturation. Reaction norms were steeper, and the effect of food reductions changed from decelerating to accelerating at a much smaller size in species from ephemeral habitats. These results support the view that developmental thresholds can account for the widespread observation of negative correlations between age and size at maturity. Moreover, evolution of the threshold appears to be both predictable and central to the observed diversity of reaction norms for age and size at maturity. [ABSTRACT FROM AUTHOR]

Propionibacterium freudenreichii is a probiotic Gram-positive bacterium with promising immunomodulatory properties. It modulates regulatory cytokines and mitigates the inflammatory response in vitro and in vivo. These properties were initially attributed to specific bacterial surface proteins. Recently, we showed that extracellular vesicles (EVs) produced by P. freudenreichii CIRM-BIA129 mimic the immunomodulatory features of parent cells in vitro (i.e., modulating NF-κB transcription factor activity and interleukin-8 release), which underlies the role of EVs as mediators of the probiotic effects of the bacterium. The modulation of EV properties, and particularly of those with potential therapeutic applications, such as the EVs produced by the probiotic P. freudenreichii, is one of the challenges in the field to achieve efficient yields with the desired optimal functionality. Here, we evaluated whether the culture medium in which the bacteria are grown could be used as a lever to modulate the protein content and, hence, the properties of P. freudenreichii CIRM-BIA129 EVs. The physical, biochemical, and functional properties of EVs produced from cells cultivated on laboratory yeast extract lactate (YEL) medium and cow milk ultrafiltrate (UF) medium were compared. UF-derived EVs were more abundant and smaller in diameter, and they displayed more intense anti-inflammatory activity than YEL-derived EVs. Furthermore, the growth media modulated EV content in terms of both the identities and abundances of their protein cargos, suggesting different patterns of interaction with the host. Proteins involved in amino acid metabolism and central carbon metabolism were modulated, as were the key surface proteins mediating host-propionibacterium interactions. IMPORTANCE Extracellular vesicles (EVs) are cellular membrane-derived nanosized particles that are produced by most cells in all three kingdoms of life. They play a pivotal role in cell-cell communication through their ability to transport bioactive molecules from donor to recipient cells. Bacterial EVs are important factors in host-microbe interactions. Recently, we have shown that EVs produced by the probiotic P. freudenreichii exhibited immunomodulatory properties. We evaluate here the impact of environmental conditions, notably culture media, on P. freudenreichii EV production and function. We show that EVs display considerable differences in protein cargo and immunomodulation depending on the culture medium used. This work offers new perspectives for the development of probiotic EV-based molecular delivery systems and reinforces the optimization of growth conditions as a tool to modulate the potential therapeutic applications of EVs. [ABSTRACT FROM AUTHOR]

A vertical flat-type bioreactor consisting of transparent polyethylene (food safe) was constructed, which is characterized by a flexible design and allows the adjustment of a light path of 1 cm – 8.5 cm and a working volume of 1.5 l – 4 l. To characterize the performance of the bioreactor, cultivation experiments were performed with the cyanobacterium Arthrospira platensis (AP). The growth was assessed continuously by monitoring optical density and intermittently by measuring the dry weight of the AP biomass. An on-line measurement technique for estimating biomass production rate in a photosynthetic microalgae culture was developed. The oxygen produced by AP in the culture medium was flushed out sparging using a mixture of air and CO2 (1%). Factors which might influence the AP growth were monitored: pH, temperature, oxygen concentration and the filling level were corrected automatically to compensate evaporation losses. As an example, the huge influence of the light intensity on the AP growth was tested. The increase of the photon flux density of 15 to 1200μmol/(l · d) led to a 22-fold increase of the productivity and a 3.1-fold shorter doubling time. Using an online measurement technique - together with the control of the growth process via a wireless local area network (WLAN) router and virtual private network - allows monitoring the growth of Arthrospira platensis remotely. [ABSTRACT FROM AUTHOR]