Variety Of Culture Conditions Research Articles

Embryonic Stem Cell Differentiation to Definitive Endoderm As a Model of Heterogeneity Onset During Germ Layer Specification.

Embryonic stem cells (ESCs) hold great promise for regenerative medicine thanks to their ability to self-renew and differentiate into somatic cells and the germline. ESCs correspond to pluripotent epiblast - the tissue from which the following three germ layers originate during embryonic gastrulation: the ectoderm, mesoderm, and endoderm. Importantly, ESCs can be induced to differentiate toward various cell types by varying culture conditions, which can be exploited for in vitro modeling of developmental processes such as gastrulation. The classical model of gastrulation postulates that mesoderm and endoderm specification is made possible through the FGF-, BMP-, Wnt-, and Nodal-signaling gradients. Hence, it can be expected that one of these signals should direct ESC differentiation towards specific germ layers. However, ESC specification appears to be more complicated, and the same signal can be interpreted differently depending on the readout. In this research, using chemically defined culture conditions, homogeneous naïve ESCs as a starting cell population, and the Foxa2 gene-driven EGFP reporter tool, we established a robust model of definitive endoderm (DE) specification. This in vitro model features formative pluripotency as an intermediate state acquired by the epiblast in vivo shortly after implantation. Despite the initially homogeneous state of the cells in the model and high Activin concentration during endodermal specification, there remains a cell subpopulation that does not reach the endodermal state. This simple model developed by us can be used to study the origins of cellular heterogeneity during germ layer specification.

Chemical Diversity of Aspergillus alliaceus Phenotypes: Discovery of Brominated Bianthrones with Activity against Triple-Negative Breast Cancer Cell Lines.

Marine-derived fungi have emerged as a source for novel metabolites with a broad range of bioactivities. However, accessing the full potential of fungi under standard laboratory conditions remains challenging. LC-MS-based metabolomics in combination with varied culture conditions is a fast and powerful tool to detect new metabolites. Here, three developmental forms of the marine-derived fungus Aspergillus alliaceus were analyzed and 14 fungal metabolites, including new brominated polyketides (11-14) were isolated. Structure elucidation relied mainly on 1D and 2D NMR techniques and was supported by low- and high-resolution mass spectrometry and DFT-based computations. We sequenced the A. alliaceus genome, identified the bianthrone-producing biosynthetic gene cluster, and conducted expression analysis on genes involved in sexual development and biosynthesis. The NCI-60 cell line panel revealed selective in vitro activity against triple-negative breast cancer (TNBC) for the halogenated allianthrones and their full antiproliferative and cytotoxic effects were evaluated in five TNBC cell lines.

Bioactivity of Amphidinol-Containing Extracts of Amphidinium carterae Grown Under Varying Cultivation Conditions.

Microalgae are of great interest due to their ability to produce valuable compounds, such as pigments, omega-3 fatty acids, antioxidants, and antimicrobials. The dinoflagellate genus Amphidinium is particularly notable for its amphidinol-like compounds, which exhibit antibacterial and antifungal properties. This study utilized a two-stage cultivation method to grow Amphidinium carterae CCAP 1102/8 under varying conditions, such as blue LED light, increased salinity, and the addition of sodium carbonate or hydrogen peroxide. After cultivation, the biomass was extracted and fractionated using solid-phase extraction, yielding six fractions per treatment. These fractions were analyzed using Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS/MS) to identify their chemical components. Key amphidinol compounds (AM-B, AM-C, AM-22, and AM-A) were identified, with AM-B being the most abundant in Fraction 4, followed by AM-C. Fraction 5 also contained a significant amount of AM-C along with an unknown compound. Fraction 4 returned the highest antimicrobial activity against the pathogens Staphylococcus aureus, Enterococcus faecalis, and Candida albicans, with Minimal Biocidal Concentrations (MBCs) ranging from 1 to 512µg/mL. Results indicate that the modulation of both amphidinol profile and fraction bioactivity can be induced by adjusting the cultivation parameters used to grow two-stage batch cultures of A. carterae.

Development of Tissue-Engineered Model of Fibrotic Scarring after Spinal Cord Injury to Study Astrocyte Activation and Neurite Outgrowth In Vitro.

Traumatic spinal cord injuries (SCI) are debilitating injuries affecting twenty-seven million people worldwide and cause functional impairments. Despite decades of research and medical advancements, current treatment options for SCI remain limited, in part due to the complex pathophysiology of spinal cord lesions including cellular transformation and extracellular matrix (ECM) remodeling. Recent studies have increased focus on fibrotic scarring after SCI, and yet much remains unclear about the impact of fibrotic scarring on SCI lesion progression. Here, using collagen and decellularized spinal cord-based composite hydrogels, a three-dimensional (3D) cell culture model mimicking the fibrous core of spinal cord lesions was implemented to investigate its influence on the surrounding astrocytes. To mimic the fibrotic milieu, collagen fibril thickness was tuned using previously established temperature-controlled casting methods. In our platforms, astrocytes in fibro-mimetic hydrogels exhibited increased levels of activation markers such as glial fibrillary acidic protein and N-cadherin. Furthermore, astrocytes in fibro-mimetic hydrogels deposited more fibronectin and laminin, further hinting that astrocytes may also contribute to fibrotic scarring. These markers were decreased when Rho-ROCK and integrin β1 were inhibited via pharmacological inhibitors. Mechanistic analysis of Yes-associated protein reveals that blocking integrin β1 prevents mechanosensing of astrocytes, contributing to altered phenotypes in variable culture conditions. In the presence of these inhibitors, astrocytes increased the secretion of brain-derived neurotrophic factor, and a greater degree of dorsal root ganglia neurite infiltration into the underlying hydrogels was observed. Altogether, this study presents a novel tissue-engineered platform to study fibrotic scarring after SCI and may be a useful platform to advance our understanding of SCI lesion aggravation.

Gilthead seabream mucus glycosylation is complex, differs between epithelial sites and carries unusual poly N-acetylhexosamine motifs

Gilthead seabream (Sparus aurata) is a marine finfish of economic importance in aquaculture. Despite its adaptability to varying culture conditions, gilthead seabream culture can be affected by viral, bacterial or parasitic diseases. The main route of entry of pathogens is through mucosal surfaces. Teleost external and internal surfaces are covered by mucus, mainly comprised of highly glycosylated proteins called mucins. The mucin glycans regulate pathogen growth, adhesion, virulence and inter and intra species communication. Here, we characterized the gilthead seabream mucus glycosylation, compared it to previously described species and investigated associations with microbiota. 214 glycans were identified. The majority of the glycans were found at more than one epithelial surface, but 27, 22 and 89 O-glycan structures were unique to skin, gill and intestinal sample groups, respectively. Six O-glycan core types were observed. The majority of the seabream skin and gill O-glycans were neutral with unusual poly HexNAc motifs. In contrast, seabream intestinal O-glycans were highly acidic and not of the ‘poly HexNAc’ type observed in skin and gill. Furthermore, gilthead seabream gill mucosa had less oligomannose and more complex N-glycans compared to skin and intestine. The concentration and diversity of bacteria was similar in skin, gill and intestine, but the bacterial species differed between epithelia and co-varied with glycan epitopes. The presence of a complex mucus glycosylation with plenty of glycan epitopes for bacterial foraging, suggest that the skin mucosal defense in seabream includes an abundant resident microbiota. This large library of structures provides a platform for further studies, for example aiming to identifying glycans to use for diagnostic purposes, to study host-microbe interactions or disease intervention therapies.

Green Synthesis of Bioplastics from Microalgae: A State-of-the-Art Review.

The synthesis of conventional plastics has increased tremendously in the last decades due to rapid industrialization, population growth, and advancement in the use of modern technologies. However, overuse of these fossil fuel-based plastics has resulted in serious environmental and health hazards by causing pollution, global warming, etc. Therefore, the use of microalgae as a feedstock is a promising, green, and sustainable approach for the production of biobased plastics. Various biopolymers, such as polyhydroxybutyrate, polyurethane, polylactic acid, cellulose-based polymers, starch-based polymers, and protein-based polymers, can be produced from different strains of microalgae under varying culture conditions. Different techniques, including genetic engineering, metabolic engineering, the use of photobioreactors, response surface methodology, and artificial intelligence, are used to alter and improve microalgae stocks for the commercial synthesis of bioplastics at lower costs. In comparison to conventional plastics, these biobased plastics are biodegradable, biocompatible, recyclable, non-toxic, eco-friendly, and sustainable, with robust mechanical and thermoplastic properties. In addition, the bioplastics are suitable for a plethora of applications in the agriculture, construction, healthcare, electrical and electronics, and packaging industries. Thus, this review focuses on techniques for the production of biopolymers and bioplastics from microalgae. In addition, it discusses innovative and efficient strategies for large-scale bioplastic production while also providing insights into the life cycle assessment, end-of-life, and applications of bioplastics. Furthermore, some challenges affecting industrial scale bioplastics production and recommendations for future research are provided.

Exploring alkaline serine protease production and characterization in proteolytic bacteria Stenotrophomonas maltophilia: Insights from real-time PCR and fermentation techniques

This study focuses on identifying a potent microbe for efficient alkaline protease production, characterizing its properties, and investigating protease gene expression across diverse culture conditions. Stenotrophomonas maltophilia strain GEBN5 is methodically chosen and refined for peak alkaline protease production at 36 h (75.37 U/mL) in basal media employing precise adjustments in temperature, pH, incubation time, and carbon/nitrogen sources, achieving a noteworthy maximum protease activity of 97.03 U/mL in shake flask culture. Alkaline protease gene (StmPr1) up-regulation was explored via Real-time PCR under varied culture conditions (pH, temperature, carbon, and nitrogen sources) in a 2L fermenter at 150 rpm, resulting in peak protease production of 113 ± 0.53 U/mL in batch culture at pH 9.0, 35 °C, with sucrose and casein, respectively. The characterization data demonstrates exceptional stability of the current protease across a broad pH (9.0–11.0) and optimum temperature of 35 °C, highlighting its promising applications in diverse industrial and biotechnological settings. A higher instability complex of protein 28.59 was revealed by in silico analysis, indicating prolonged stability during hydrolysis and a wide range of potential uses. The purified protease demonstrates superior compatibility (45%–88% residual activity) with diverse detergent brands treated for 45 min at 40 °C, indicating its potential as a valuable additive for enhanced washing efficacy. Current research offers a novel strategy to boost protease production, presenting a promising alternative to chemical dehairing in leather industries and solid organic waste treatment. This approach holds the potential for mitigating environmental pollution through bioremediation.

Evaluation of annual production and economic benefits of tropical rice-crayfish coculture system in China

CONTEXTIn recent years, the rice-crayfish coculture has shown significant progress as an agricultural technology with significant economic value in the middle and lower reaches of the Yangtze River in China. Nonetheless, as the promotion of the technology expands, the unvarying co-culture method poses challenges in adapting to the diverse environmental conditions across different regions. This has resulted in regional disparities dominated by environmental factors, which have emerged as the primary obstacle to the advancement of rice-crayfish coculture. OBJECTIVEIt is uncertain whether the rice-crayfish coculture model can be implemented in tropical regions due to the higher temperature and stronger solar radiation. Therefore, this study analyzes the feasibility of establishing the rice-crayfish coculture model through estimating the rice and crayfish annual production and the economic and ecological benefits in the tropical region. METHODSThe growth, annual production, and nitrogen partial factor productivity (NPFP) of rice, nitrogen dynamics in the field water, as well as the economic inputs and benefits associated with the rice-crayfish coculture system over two years were evaluated in Hainan province. RESULTS AND CONCLUSIONSIt was found that: 1) Even with a reduction of 33.3% in nitrogen fertilizer application, the annual production of the rice-crayfish coculture system remains equivalent to that of the rice monoculture system. Furthermore, the rice-crayfish coculture can increase the effective panicle number of rice. 2) The rice-crayfish coculture system can provide nutrients to support rice growth without polluting the water environment. The nitrogen fertilizer partial productivity in the rice-crayfish coculture system is significantly higher than that in the rice monoculture system. Crayfish culture introduced additional nitrogen in rice field at early stage, but it did not gain any form of nitrogen content in the field water at the end of the season. 3) In comparison to the rice monoculture system, the tropical rice-crayfish coculture system increased net profit by 152.82% -745.26%. 4) Comprehensive analyses of the growth, yield, and economic benefits showed that SXHN is better than YXYLS, which indicated that suitable varieties were needed for developing rice-crayfish coculture in the tropics. SIGNIFICANCERice-crayfish coculture is an economic and ecological agricultural system. However, rice-crayfish coculture encounters extensive technical challenges across various regions, because of the varied culture conditions. These challenges impede the expansion of the rice-crayfish coculture model. Therefore, this study aimed to evaluate the practicality of the rice-crayfish coculture system in the tropics to facilitate the development of the rice-crayfish coculture model.

Modular tissue-in-a-CUBE platform to model blood-brain barrier (BBB) and brain interaction

With the advent of increasingly sophisticated organoids, there is growing demand for technology to replicate the interactions between multiple tissues or organs. This is challenging to achieve, however, due to the varying culture conditions of the different cell types that make up each tissue. Current methods often require complicated microfluidic setups, but fragile tissue samples tend not to fare well with rough handling. Furthermore, the more complicated the human system to be replicated, the more difficult the model becomes to operate. Here, we present the development of a multi-tissue chip platform that takes advantage of the modularity and convenient handling ability of a CUBE device. We first developed a blood-brain barrier-in-a-CUBE by layering astrocytes, pericytes, and brain microvascular endothelial cells in the CUBE, and confirmed the expression and function of important tight junction and transporter proteins in the blood-brain barrier model. Then, we demonstrated the application of integrating Tissue-in-a-CUBE with a chip in simulating the in vitro testing of the permeability of a drug through the blood-brain barrier to the brain and its effect on treating the glioblastoma brain cancer model. We anticipate that this platform can be adapted for use with organoids to build complex human systems in vitro by the combination of multiple simple CUBE units.

The Transcription Factor StuA Regulates the Glyoxylate Cycle in the Dermatophyte Trichophyton rubrum under Carbon Starvation.

Trichophyton rubrum is the primary causative agent of dermatophytosis worldwide. This fungus colonizes keratinized tissues and uses keratin as a nutritional source during infection. In T. rubrum-host interactions, sensing a hostile environment triggers the adaptation of its metabolic machinery to ensure its survival. The glyoxylate cycle has emerged as an alternative metabolic pathway when glucose availability is limited; this enables the conversion of simple carbon compounds into glucose via gluconeogenesis. In this study, we investigated the impact of stuA deletion on the response of glyoxylate cycle enzymes during fungal growth under varying culture conditions in conjunction with post-transcriptional regulation through alternative splicing of the genes encoding these enzymes. We revealed that the ΔstuA mutant downregulated the malate synthase and isocitrate lyase genes in a keratin-containing medium or when co-cultured with human keratinocytes. Alternative splicing of an isocitrate lyase gene yielded a new isoform. Enzymatic activity assays showed specific instances where isocitrate lyase and malate synthase activities were affected in the mutant strain compared to the wild type strain. Taken together, our results indicate a relevant balance in transcriptional regulation that has distinct effects on the enzymatic activities of malate synthase and isocitrate lyase.

Analysis of Aureobasidium pullulans LB83 secretome reveals distinct carbohydrate active enzymes for biomass saccharification

Aureobasidium pullulans LB83 is a versatile biocatalyst that produces a plethora of bioactive products thriving on a variety of feedstocks under the varying culture conditions. In our last study using this microorganism, we found cellulase activity (FPase, 2.27 U/ml; CMCase, 7.42 U/ml) and other plant cell wall degrading enzyme activities grown on sugarcane bagasse and soybean meal as carbon source and nitrogen, respectively. In the present study, we provide insights on the secretome analysis of this enzymatic cocktail. The secretome analysis of A. pullulans LB83 by Liquid Chromatography coupled to Mass Spectroscopy (LC-MS/MS) revealed 38 classes of Carbohydrate Active enZymes (CAZymes) of a total of 464 identified proteins. These CAZymes consisted of 21 glycoside hydrolases (55.26%), 12 glycoside hydrolases harboring carbohydrate-binding module (31.58%), 4 carbohydrate esterases (10.53%) and one glycosyl transferase (2.63%). To the best of our knowledge, this is the first report on the secretome analysis of A. pullulans LB83.

Reproducibility and Robustness of a Liver Microphysiological System PhysioMimix LC12 under Varying Culture Conditions and Cell Type Combinations.

The liver is one of the key organs for exogenous and endogenous metabolism and is often a target for drug- and chemical-driven toxicity. A wide range of experimental approaches has been established to model and characterize the mechanisms of drug- and chemical-induced hepatotoxicity. A number of microfluidics-enabled in vitro models of the liver have been developed, but the unclear translatability of these platforms has hindered their adoption by the pharmaceutical industry; to achieve wide use for drug and chemical safety evaluation, demonstration of reproducibility and robustness under various contexts of use is required. One of these commercially available platforms is the PhysioMimix LC12, a microfluidic device where cells are seeded into a 3D scaffold that is continuously perfused with recirculating cell culture media to mimic liver sinusoids. Previous studies demonstrated this model's functionality and potential applicability to preclinical drug development. However, to gain confidence in PhysioMimix LC12's robustness and reproducibility, supplementary characterization steps are needed, including the assessment of various human hepatocyte sources, contribution of non-parenchymal cells (NPCs), and comparison to other models. In this study, we performed replicate studies averaging 14 days with either primary human hepatocytes (PHHs) or induced pluripotent stem cell (iPSC)-derived hepatocytes, with and without NPCs. Albumin and urea secretion, lactate dehydrogenase, CYP3A4 activity, and metabolism were evaluated to assess basal function and metabolic capacity. Model performance was characterized by different cell combinations under intra- and inter-experimental replication and compared to multi-well plates and other liver platforms. PhysioMimix LC12 demonstrated the highest metabolic function with PHHs, with or without THP-1 or Kupffer cells, for up to 10-14 days. iPSC-derived hepatocytes and PHHs co-cultured with additional NPCs demonstrated sub-optimal performance. Power analyses based on replicate experiments and different contexts of use will inform future study designs due to the limited throughput and high cell demand. Overall, this study describes a workflow for independent testing of a complex microphysiological system for specific contexts of use, which may increase end-user adoption in drug development.

Dextrans of Weissella cibaria DSM14295: Microbial production, structure and functionality

Lactic acid bacteria of the genus Weissella contribute to spontaneous fermentation in, e.g., sourdough or sauerkraut, but are not registered as starter cultures because of their pending safety assessment. Some strains are able to produce high amounts of exopolysaccharides. This study aims to demonstrate the techno-functionality of five dextrans from W. cibaria DSM14295, produced under varying cultivation conditions, with respect to structural and macromolecular properties. A maximum of 23.1 g/L dextran was achieved by applying the “cold shift” temperature regime. The dextrans differed in molecular mass (9–22∙108 Da, determined by HPSEC-RI/MALLS), intrinsic viscosity (52–73 mL/g), degree of branching (3.8–5.7 % at position O3, determined by methylation analysis) and their side chain length and architecture, determined by HPAEC-PAD after enzymatic hydrolysis. Stiffness of acid gels from milk spiked with these dextrans increased linearly with dextran concentration. Principal component analysis showed that dextrans produced in a semi-defined medium are primarily described by moisture sorption and branching properties, whereas dextrans produced in whey permeate were similar because of their functional and macromolecular properties. Overall, dextrans from W. cibaria DSM14295 have a high potential because of the high production yield and their functionality which can be tailored by the conditions during fermentation.

Bacterial degradation kinetics of poly(Ɛ-caprolactone) (PCL) film by Aquabacterium sp. CY2-9 isolated from plastic-contaminated landfill

Despite the identification of numerous bioplastic-degrading bacteria, the inconsistent rate of bioplastic degradation under differing cultivation conditions limits the intercomparison of results on biodegradation kinetics. In this study, we isolated a poly (Ɛ-caprolactone) (PCL)-degrading bacterium from a plastic-contaminated landfill and determined the principle-based biodegradation kinetics in a confined model system of varying cultivation conditions. Bacterial degradation of PCL films synthesized by different polymer number average molecular weights (Mn) and concentrations (% w/v) was investigated using both solid and liquid media at various temperatures. As a result, the most active gram-negative bacterial strain at ambient temperature (28 °C), designated CY2-9, was identified as Aquabacterium sp. Based on 16 S rRNA gene analysis. A clear zone around the bacterial colony was apparently exhibited during solid cultivation, and the diameter sizes increased with incubation time. During biodegradation processes in the PCL film, the thermal stability declined (determined by TGA; weight changes at critical temperature), whereas the crystalline proportion increased (determined by DSC; phase transition with temperature increment), implying preferential degradation of the amorphous region in the polymer structure. The surface morphologies (determined by SEM; electron optical system) were gradually hydrolyzed, creating destruction patterns as well as alterations in functional groups on film surfaces (determined by FT-IR; infrared spectrum of absorption or emission). In the kinetic study based on the weight loss of the PCL film (4.5 × 104 Da, 1% w/v), ∼1.5 (>±0.1) × 10−1 day−1 was obtained from linear regression for both solid and liquid media cultivation at 28 °C. The biodegradation efficiencies increased proportionally by a factor of 2.6–7.9, depending on the lower polymer number average molecular weight and lower concentration. Overall, our results are useful for measuring and/or predicting the degradation rates of PCL films by microorganisms in natural environments.

Effects of varied culture conditions on crude bacitracin produced by Bacillus subtilis isolated from the soil

Aim: To determine the effects subjecting Bacillus subtilis to different cultural conditions will have on the crude Bacitracin produced in inhibiting the growth of known susceptible organisms. Method: Bacillus subtilis known to be a bacitracin producer was isolated from the soil and identified. The isolate was used to produce bacitracin under various culture conditions with peptone water serving as a basal fermentation medium. The resultant crude bacitracin produced was checked for its antimicrobial activity against Staphylococcus aureus by using the agar well diffusion method. Culture conditions varied were the addition of glycerol, arabinose, fructose, mannose, sucrose, urea, MgSO4, CaCO3, KCl, sodium citrate, and the adjustment of initial pH at pH 5, 6, 8 and 9. Bacitracin production was done at 37 oC for 4 days in an orbital shaker incubator rotating at 150rpm. Result: The antimicrobial activity against the test organism (Staphylococcus aureus) was determined by the mm of the zone of inhibition, with the best result obtained from the addition of glycerol (14 mm) and the least zone of inhibition was observed from the addition of MgSO4 (3 mm). Also, pH 8 produced the best result (20 mm), while at pH 5, the antimicrobial activity of the crude bacitracin was reduced (14 mm). Conclusion: Bacitracin produced from Bacillus subtilis under various culture conditions has antimicrobial effect against Staphylococcus aureus. The highest antimicrobial activities can be gotten by the addition of glycerol and by raising the initial pH of the basal broth to pH 8 while that produced by addition of MgSO4 will have the lowest antimicrobial effect.

The Effect of Varied Culture Conditions and Nutritional Requirements in the Production of Antimicrobial Metabolite by Streptomyces

the Effect of Varied Culture Conditions and Nutritional Requirements in the Production of Antimicrobial Metabolite by Streptomyces

Phaeodactylum tricornutum as a potential feedstock for an integrated biorefinery process under varying cultivation conditions

In this study, the effects of temperature, light intensity, and aeration rate on the biomass, total lipid, and the residual water-soluble fractions of Phaeodactylum tricornutum were ascertained. The maximum total lipid yield of 22.39% was attained at a n-hexane/biomass ratio of 200/1, Soxhlet extraction time of 6 h and a heating rate level of 6 at 69 °C. The optimum fatty acid composition with a mass fraction of 99.70% was detected at a temperature of 10 °C, a light intensity of 431 μmol m−2 s−1, and an aeration rate of 3.0 L min−1. The total fatty acid consisted of a major percentage of MUFAs (46.1–56.6%), followed by SFAs (39.5–53.2%), and PUFAs (0–12.5%) providing a CN index of 59.3, IV of 70 g I2/100 g FAMEs, DU of 71%, CFPP of −4.5 °C, and SV and HHV of 205 mg KOH g−1 and 39.5 MJ kg−1, respectively, meeting the requirements of EN 14214 and ASTM D6751. Additionally, the maximum total phenol content value of 3.53 mg Gallic acid equivalent g−1 dry weight was obtained via a Folin-Ciocalteu assay at 22 °C, 98 μmol m−2s−1, and 3.0 L min−1, while, the maximum total antioxidant capacity of 16.27 μmol Trolox equivalent antioxidant capacity g−1 dry weight was observed with the help of the ABTS method over a broader cultivation condition range. Hence, P. tricornutum can be considered as a potential feedstock for biofuel and value-added bioproduct production offering a novel integrated lab-scale biorafination process.

Analysis and correlations of the protein content and selected 'antinutrients' of faba beans (Vicia faba) in a German sample set of the cultivation years 2016, 2017, and 2018.

Faba beans (Vicia faba) experienced a significant revival in cultivation in Western Europe in the last decade. In this study, potential correlations between protein content (PC), trypsin inhibitory activity (TIA), and tannin content were investigated in a large German sample set with bean samples obtained from 50 different farms present in 11 German federal states. Three consecutive cultivation years (2016, 2017, and 2018) were included. The faba bean samples were grown under real cultivation conditions without any specific experimental design and finally marketed by the farmers. This enabled researchers to identify the relationship and extent of the three quality parameters towards the varying cultivation conditions and practices. Moreover, the correlations observed between the parameters were brought into the context of well-known theoretical plant hypotheses such as the carbon-nutrient balance hypothesis (CNBH), the growth-differentiation balance hypothesis (GDBH), as well as the protein competition model (PCM) for evaluating the potential for use in predictions. The study showed a significant negative correlation between PC and tannin content in faba beans over each cultivation year, whereas a positive correlation between TIA and tannin content was found. No clear correlation was observed between PC and TIA. The three plant hypotheses (CNBH, GDBH, and PCM) seem to be not fully valid. Nonetheless, these findings might be a useful guideline for predicting the composition of selected compounds, and sustainable recommendations about cultivation and exploitation for the feed and food sector can be derived. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of acetate concentration, temperature, pH and nutrient concentration on polyhydroxyalkanoates (PHA) production by glycogen accumulating organisms

Low PHA accumulation is one of the main limitations of the industrial production of polyhydroxyalkanoates (PHA) from mixed cultures. Different PHA yields and physical properties were obtained by varying culture conditions (acetate concentration, nitrogen and phosphate availability, temperature and pH). Glycogen accumulating organisms (GAOs), microorganisms able to create and store PHA, which use acetate as their sole carbon source, were obtained after selection from mixed culture from activated sludge. All PHA presented good adhesion properties and were soluble in halogenated and polar solvents. The maximum PHA storage rate (20 % of cell dry weight) was achieved with a concentration of 4 g/L acetate. The optimum temperature for PHA production was 23 °C (24 % of cell dry weight). Low nitrogen concentration increased the yield (22 %) while phosphate concentration and pH did not influence PHA production. PHA accumulation of almost 30 % was obtained with previously found optimum parameters.

Single cell protein production by Candida robusta isolated from sugar cane (Saccharum sp.) for animal feed

The protein obtained from the microorganisms is not only cheap but can be used as additive to provide a balanced nutrition for many animals feeding. The aim of this work was the single cell protein (SCP) production by Candida robusta URM5293 using sugarcane bagasse as substrate. The yeast C. robusta URM5293 was isolated from root sugarcane and was identified based on morphological and biochemical characteristics. Biomass production was done into Erlenmayers flasks (250 mL) containing culture medium supplemented of sugarcane bagasse hydrolyzate. Fermentations were carried varying culture conditions through the study of four different variables: temperature (25, 30, and 35°C), agitation intensity (110, 140 or 170 rpm), pH (6.0, 7.0, and 8.0) and production time (72, 96, and 120h), according to a 24-1 fractional factorial design. Results demonstrated that this yeast was able to ensure the highest level of biomass (141 g/L) when cultivated at 25°C, pH 6.0, 170 rpm of agitation intensity after 72h of cultivation using sugarcane bagasse. The present results demonstrate the potential of sugarcane bagasse hemicellulosic hydrolyzate as a substrate for the production of microbial protein by C. robusta URM5293.