Use of waste frying oil and coconut pulp for the production, isolation, and characterization of a new lipase from Moesziomyces aphidis.

Lipases comprise the third most commercialized group of enzymes worldwide and those of microbial origin are sought for their multiple advantages. Agro-industrial waste can be an alternative culture medium for producing lipases, reducing production costs and the improper disposal of waste frying oil (WFO). This study aimed to produce yeast lipases through submerged fermentation (SF) using domestic edible oil waste as inducer and alternative culture medium. The optimal culture conditions, most effective inducer, and purification method for a new lipase from Moesziomyces aphidis BRT57 were identified. Yeast was cultured in medium containing green coconut pulp and WFO waste for 72 h. The maximum production of lipases in SF occurred in a culture medium containing WFO and yeast extract at 48 and 72 h of incubation, with enzyme activities of 8.88 and 11.39 U mL-1, respectively. The lipase was isolated through ultrafiltration followed by size exclusion chromatography, achieving a 50.46 % recovery rate. To the best of our knowledge, this is the first study to report the production and purification of lipases from M. aphidis, demonstrating the value of frying oil as inducer and alternative medium for SF, contributing to the production of fatty acids for biodiesel from food waste.

Decreased Nuclear Immunoexpression of ING3 is a Frequent Event in Lip Carcinogenesis.

PURPOSE: Evaluate the immunohistochemical expression of the ING3 in actinic cheilitis and squamous cell carcinoma of the lower lip. METHODS: Forty-five specimens of actinic cheilitis and 48 specimens of squamous cell carcinoma of the lower lip were submitted to immunohistochemical detection of ING3. The protein expression in different cellular sublocations was compared between the two groups, and associations with the clinicopathological variables were analyzed. A significance level of 5% was adopted for all tests. RESULTS: Deaths were significantly more frequent in tumors with a high histopathological risk score (p < 0.05). In actinic cheilitis, significant differences were found in the nucleus-cytoplasmic expression of ING3 and expression restricted to the cytoplasm with binary histopathological grading (p < 0.05). In squamous cell carcinoma of the lower lip, there was no statistically significant difference when comparing ING3 expressions with clinical and morphological parameters (p > 0.05). Nucleo-cytoplasmic ING3 expression was significantly lower in squamous cell carcinoma of the lower lip when compared to actinic cheilitis (p < 0.05) and the expression restricted to the cytoplasm was significantly higher in squamous cell carcinoma of the lower lip (p < 0.05). CONCLUSION: The results of this study suggest that there is a marked decrease in the nuclear expression of ING3 as malignant progression occurs, indicating an impaired tumor suppressor function of this protein in actinic cheilitis and squamous cell carcinoma of the lower lip.

Transcriptome analysis reveals biosynthesis and regulation of flavonoid in common bean seeds during grain filling.

The Andean domesticated common beans (Phaseolus vulgaris) are significant sources of phenolic compounds associated with health benefits. However, the regulation of biosynthesis of these compounds during bean seed development remains unclear. To elucidate the gene expression patterns involved in the regulation of the flavonoid pathway, we conducted a transcriptome analysis of two contrasting Chilean varieties, Negro Argel (black bean) and Coscorron (white bean), at three developmental stages associated with seed color change, as well as different flavonoid compound accumulations. Our study reveals that phenolic compound synthesis initiates during seed filling, although it exhibits desynchronization between both varieties. We identified 10,153 Differentially Expressed Genes (DEGs) across all comparisons. The KEGG pathway 'Flavonoid biosynthesis' showed enrichment of induced DEGs in Negro Argel (PV172), consistent with the accumulation of delphinidin, petunidin, and malvidin hexosides in their seeds, while catechin glucoside, procyanidin and kaempferol derivatives were predominantly detected in Coscorrón (PV24). Furthermore, while the flavonoid pathway was active in both varieties, our results suggest that enzymes involved in the final steps, such as ANS and UGT, were crucial, inducing anthocyanin formation in Negro Argel. Additionally, during active anthocyanin biosynthesis, the accumulation of reserve proteins or those related to seed protection and germination was induced. These findings provide valuable insights and serve as a guide for plant breeding aimed at enhancing the health and nutritional properties of common beans.

Production and concentration of keratinases and application of fermentation residual in removing hexavalent chromium.

The production of keratinases was evaluated in submerged fermentation with Aspergillus niger and by pigs' swine hair in a batch bioreactor. Experimental planning was performed to assess the interaction between different variables. The enzyme extract produced was characterized at various pH and temperatures and subjected to enzyme concentration using a biphasic aqueous system and salt/solvent precipitation techniques. In addition, the substrate's potential in reducing hexavalent chromium from synthetic potassium dichromate effluent with an initial concentration of 20 mg L-1 of chromium was evaluated. The resulting enzyme extract showed 89 ± 2 U mL-1 of keratinase. The enzyme concentration resulted in a purification factor of 1.3, while sodium chloride/acetone and ammonium sulfate/acetone resulted in a purification factor of 1.9 and 1.4, respectively. Still using the residual substrate of swine hair from the fermentation, a 94% reduction of hexavalent chromium concentration occurred after 9 h of reaction. Thus, the study proved relevant for producing keratinases, with further environmental applicability and the possibility of concentrating the extract via low-cost processes.

Reduction in mitochondrial ATP synthesis mimics the effect of low glucose in depolarizing neurons from the subpostremal nucleus of the solitary tract of rats.

Neurons of the subpostremal nucleus of the solitary tract (NTS) respond to changes in extracellular glucose with alterations in membrane potential with both depolarization and hyperpolarization. From 5 mM glucose, a rapid shift to 0.5 mM glucose produces a membrane depolarization by an unknown mechanism in most neurons. However, the mechanism involved in this response needs to be known. Here, we investigated if the low glucose-induced depolarization could be mimicked by reducing ATP synthesis and possible mediators of this effect. We showed that applying the mitochondrial uncoupler CCCP (1 µM) reproduced the effects of low glucose depolarizing the membrane, generating an inward current, and decreasing membrane resistance. On the other hand, activation of AMPK did not alter these parameters. To test if low glucose and CCCP could depolarize the membrane by affecting the ionic gradient, we inhibited the electrogenic Na/K pump with 10 µM of ouabain. We observed a similar membrane depolarization but not a decrease in membrane resistance. We conclude that perfusion of neurons of the subpostremal NTS with a low glucose solution depolarizes the membrane by probably reducing intracellular ATP, but not by activating AMPK or decreasing the ionic gradient across the membrane.

Improving the medium composition for the production of the natural blue-violet pigment violacein by a new Janthinobacterium sp. isolate.

The interest in natural compounds has increased primarily due to their beneficial health and environmental aspects. However, natural sources of some compounds, such as bluish pigments, are limited, requiring the development of efficient processes to meet commercial demands. This study isolated a blue-violet bacterium from spoiled cooked rice and identified it as a potential new species of Janthinobacterium through 16S rDNA analysis. Ultra-high performance liquid chromatography-tandem mass spectrometry analyses confirmed that the blue-violet pigment violacein was responsible for the bluish color. In laboratory conditions, different carbon and nitrogen sources were evaluated in submerged culture media to enhance pigment production. Glycerol did not result in significant pigment production by this strain, as expected from previous reports. Instead, a culture medium composed of yeast extract and fructose yielded higher pigment production, reaching about 113.68 ± 16.68 mg l-1 after 120 h. This result provides crucial insights for future studies aiming for sustainable and commercially viable violacein production. Based on a bioeconomy concept, this approach has the potential to supply natural and economic bluish pigments for various industrial sectors, including pharmaceutical, cosmetic, and food.

Cunninghamella echinulata DSM1905 biofilm-based L-asparaginase production in pneumatically-driven bioreactors.

We evaluated by comparing the performance of three pneumatically-driven bioreactors in the production of L-asparaginase (L-ASNase), an enzyme used to treat leukaemia and lymphoma. A two-step screening process was conducted to detect Cunninghamella spp. strains producing L-ASNase. Cunninghamella echinulata DSM1905 produced the highest levels of L-ASNase during screening assays. Subsequently, fermentations were performed in bubble column (BCR), airlift (ALR), and hybrid fixed-bed airlift (FB-ALR) bioreactors to determine the best upstream bioprocess. Mycelial biomass production was higher in BCR than in ALR and FB-ALR (p ≤ 0.0322). The activity of L-ASNase produced in FB-ALR, in which the fungus grew as a consistent biofilm, was significantly higher (p ≤ 0.022) than that from ALR, which was higher than that of BCR (p = 0.036). The specific activity of ALR and FB-ALR presented no differences (p = 0.073), but it was higher than that of BCR (p ≤ 0.032). In conclusion, C. echinulata DSM1905, grown under the biofilm phenotype, produced the highest levels of L-ASNase, and FB-ALR was the best upstream system for enzyme production.

Social wasp-associated Tsukamurella sp. strains showed promising biosynthetic and bioactive potential for discovery of novel compounds.

In the face of escalating antibiotic resistance, the quest for novel antimicrobial compounds is critical. Actinobacteria is known for producing a substantial fraction of bioactive molecules from microorganisms, nonetheless there is the challenge of metabolic redundancy in bioprospecting. New sources of natural products are needed to overcome these current challenges. Our present work proposes an unexplored potential of Neotropical social wasp-associated microbes as reservoirs of novel bioactive compounds. Using social wasp-associated Tsukamurella sp. strains 8F and 8J, we aimed to determine their biosynthetic potential for producing novel antibiotics and evaluated phylogenetic and genomic traits related to environmental and ecological factors that might be associated with promising bioactivity and evolutionary specialization. These strains were isolated from the cuticle of social wasps and subjected to comprehensive genome sequencing. Our genome mining efforts, employing antiSMASH and ARTS, highlight the presence of BGCs with minimal similarity to known compounds, suggesting the novelty of the molecules they may produce. Previous, bioactivity assays of these strains against bacterial species which harbor known human pathogens, revealed inhibitory potential. Further, our study focuses into the phylogenetic and functional landscape of the Tsukamurella genus, employing a throughout phylogenetic analysis that situates strains 8F and 8J within a distinct evolutionary pathway, matching with the environmental and ecological context of the strains reported for this genus. Our findings emphasize the importance of bioprospecting in uncharted biological territories, such as insect-associated microbes as reservoirs of novel bioactive compounds. As such, we posit that Tsukamurella sp. strains 8F and 8J represent promising candidates for the development of new antimicrobials.

Kinetics of Riboflavin Production by Hyphopichia wangnamkhiaoensis under Varying Nutritional Conditions.

Riboflavin, an essential vitamin for humans, is extensively used in various industries, with its global demand being met through fermentative processes. Hyphopichia wangnamkhiaoensis is a novel dimorphic yeast species capable of producing riboflavin. However, the nutritional factors affecting riboflavin production in this yeast species remain unknown. Therefore, we conducted a kinetic study on the effects of various nutritional factors-carbon and energy sources, nitrogen sources, vitamins, and amino acids-on batch riboflavin production by H. wangnamkhiaoensis. Batch experiments were performed in a bubble column bioreactor to evaluate cell growth, substrate consumption, and riboflavin production. The highest riboflavin production was obtained when the yeast growth medium was supplemented with glucose, ammonium sulfate, biotin, and glycine. Using these chemical components, along with the mineral salts from Castañeda-Agullo's culture medium, we formulated a novel, low-cost, and effective culture medium (the RGE medium) for riboflavin production by H. wangnamkhiaoensis. This medium resulted in the highest levels of riboflavin production and volumetric productivity, reaching 16.68 mg/L and 0.713 mg/L·h, respectively, within 21 h of incubation. These findings suggest that H. wangnamkhiaoensis, with its shorter incubation time, could improve the efficiency and cost-effectiveness of industrial riboflavin production, paving the way for more sustainable production methods.

1H-1,2,3-triazol-1,4-naphthoquinone Derivatives: Novel Inhibitors Targeting Pyocyanin Biosynthesis for P. Aeruginosa Infection Treatment Advances.

BACKGROUND: This study investigates the potential of eleven 1H-1,2,3-triazol-1,4-naphthoquinone conjugates as virulence factor inhibitors (like Pyocyanin) and their affinity for PhzM, a crucial enzyme for Pyocyanin biosynthesis in Pseudomonas aeruginosa infections. METHODS: A straightforward synthetic pathway enabled the production of these compounds, which were characterized and structurally confirmed through spectroscopic analyses. Evaluation of their impact on PhzM thermal stability identified promising candidates for PhzM binders. RESULTS: Concentration-response behavior elucidated their binding affinity, revealing them as the first reported micromolar affinity ligands for PhzM. Structure-activity relationship analysis emphasized the role of specific molecular moieties in binding affinity modulation, paving the way for future advanced inhibitors' development. CONCLUSION: These findings highlight the potential of naphthoquinone-triazole derivatives as leads for novel therapeutics against P. aeruginosa infections.

Changes in Noradrenergic Synthesis and Dopamine Beta-Hydroxylase Activity in Response to Oxidative Stress after Iron-induced Brain Injury.

Noradrenaline (NA) levels are altered during the first hours and several days after cortical injury. NA modulates motor functional recovery. The present study investigated whether iron-induced cortical injury modulated noradrenergic synthesis and dopamine beta-hydroxylase (DBH) activity in response to oxidative stress in the brain cortex, pons and cerebellum of the rat. Seventy-eight rats were divided into two groups: (a) the sham group, which received an intracortical injection of a vehicle solution; and (b) the injured group, which received an intracortical injection of ferrous chloride. Motor deficits were evaluated for 20 days post-injury. On the 3rd and 20th days, the rats were euthanized to measure oxidative stress indicators (reactive oxygen species (ROS), reduced glutathione (GSH) and oxidized glutathione (GSSG)) and catecholamines (NA, dopamine (DA)), plus DBH mRNA and protein levels. Our results showed that iron-induced brain cortex injury increased noradrenergic synthesis and DBH activity in the brain cortex, pons and cerebellum at 3 days post-injury, predominantly on the ipsilateral side to the injury, in response to oxidative stress. A compensatory increase in contralateral noradrenergic activity was observed, but without changes in the DBH mRNA and protein levels in the cerebellum and pons. In conclusion, iron-induced cortical injury increased the noradrenergic response in the brain cortex, pons and cerebellum, particularly on the ipsilateral side, accompanied by a compensatory response on the contralateral side. The oxidative stress was countered by antioxidant activity, which favored functional recovery following motor deficits.

Structure and Biosynthesis of Perochalasins A-C, Open-Chain Merocytochalasans Produced by the Marine-Derived Fungus Peroneutypa sp. M16.

Novel open-chain merocytochalasans, perochalasins A-C (1-3), containing an unusual N-O six-membered heterocyclic moiety, were isolated from cultures of the marine-derived Peroneutypa sp. M16 fungus, along with cytochalasin Z27 (4), cytochalasin Z28 (5), [12]-cytochalasin (6), and phenochalasin B (7). The structures of compounds 1-3 were established by analysis of the spectroscopic data. Full genome sequencing of Peroneutypa sp. M16 enabled the identification of a cytochalasan biosynthetic gene cluster and a proposal for the biosynthetic assembly of perochalasins. The proposal is supported by the nonenzymatic conversion of phenochalasin B (7) into 1-3, based on isotope-labeled hydroxylamine (15NH2OH and ND2OD) feeding studies in vivo and in vitro. In contrast to other merocytochalasans, these are the first cytochalasans confirmed to arise via nucleophilic addition and at a distinct location from the reactive macrocycle olefin, potentially expanding further the range of merocytochalasans to be discovered or engineered. Cytochalasin Z27 (4) exhibited antiplasmodial activities in the low micromolar range against the chloroquine-sensitive Plasmodium falciparum 3D7 strain as well as against resistant strains of the parasite (Dd2, TM90C6B, and 3D7r_MMV848).

Structural and Functional Basis of GenB2 Isomerase Activity from Gentamicin Biosynthesis.

Aminoglycosides are essential antibiotics used to treat severe infections caused mainly by Gram-negative bacteria. Gentamicin is an aminoglycoside and, despite its toxicity, is clinically used to treat several pulmonary and urinary infections. The commercial form of gentamicin is a mixture of five compounds with minor differences in the methylation of one of their aminosugars. In the case of two compounds, gentamicin C2 and C2a, the only difference is the stereochemistry of the methyl group attached to C-6'. GenB2 is the enzyme responsible for this epimerization and is one of the four PLP-dependent enzymes encoded by the gentamicin biosynthetic gene cluster. Herein, we have determined the structure of GenB2 in its holo form in complex with PMP and also in the ternary complex with gentamicin X2 and G418, two substrate analogues. Based on the structural analysis, we were able to identify the structural basis for the catalytic mechanism of this enzyme, which was also studied by site-directed mutagenesis. Unprecedently, GenB2 is a PLP-dependent enzyme from fold I, which is able to catalyze an epimerization but with a mechanism distinct from that of fold III PLP-dependent epimerases using a cysteine residue near the N-terminus. The substitution of this cysteine residue for serine or alanine completely abolished the epimerase function of the enzyme, confirming its involvement. This study not only contributes to the understanding of the enzymology of gentamicin biosynthesis but also provides valuable details for exploring the enzymatic production of new aminoglycoside derivatives.

Biosynthesis of Polyhydroalkanoates Doped with Silver Nanoparticles Using Pseudomonas putida and Pseudomonas aeruginosa for Antibacterial Polymer Applications.

In this study, the biosynthesis of polyhydroxyalkanoates (PHAs) was carried out using Pseudomonas putida and Pseudomonas aeruginosa. These PHAs were produced using reagent-grade glycerol and crude glycerol as the carbon sources. The objective was to compare the production of PHAs and to functionalize these polymers with silver nanoparticles to provide antibacterial properties for potential biomedical applications. The findings from the physical and chemical analyses confirmed the successful synthesis and extraction of PHAs, achieving comparable yields using both crude glycerol and reagent-grade glycerol as carbon sources across both strains. Approximately 16% higher PHAs production was obtained using Pseudomonas putida compared to Pseudomonas aeruginosa, and no significant difference was observed in the production rate of PHAs between the two carbon sources used, which means that crude glycerol could be utilized even though it has more impurities. Notably, PHAs functionalized with silver nanoparticles showed improved antibacterial effectiveness, especially those derived from reagent-grade glycerol and the Pseudomonas aeruginosa strain.

Correlation between sporogenesis and lipopeptide production in Paenibacillus elgii.

Pelgipeptins, tridecaptins, and elgicins are among the antimicrobials produced by Paenibacillus elgii. Growth in complex media is commonly applied to obtain lipopeptides from culture's supernatant, but it requires further purification. This study aimed to improve the yield of pelgipeptins and tridecaptins using chemically defined media. The kinetics of antimicrobial lipopeptide yield in chemically defined media were evaluated in P. elgii AC13. Pelgipeptins were detected in the supernatant and the culture pellet, but tridecaptins were mainly associated with cell debris or endospores. We investigated whether removing Ca2+ would impair P. elgii sporogenesis, consequently improving the yield of tridecaptin. The kinetics of both lipopeptides in the presence and absence of Ca2+ were quantitatively and qualitatively evaluated and further correlated with the cell cycle. The impairment of P. elgii AC13 sporogenesis had no effect on tridecaptin production, which remained undetected in the supernatant of the culture. On the other hand, the yield of pelgipeptin in a Ca2+-free medium increased. We showed for the first time that the removal of Ca2+ interrupted the sporogenesis in P. elgii and improved the yield of pelgipeptins. However, Ca2+ absence had no effect on tridecaptin yield, which is possibly degraded or associated with other cell debris components.

Production of exopolysaccharide from Klebsiella oxytoca: Rheological, emulsifying, biotechnological properties, and bioremediation applications.

Bacteria can synthesize a broad spectrum of multifunctional polysaccharides including extracellular polysaccharides (EPS). Bacterial EPS can be utilized in the food, pharmaceutical, and biomedical areas owing to their physical and rheological properties in addition to generally presenting low toxicity. From an ecological viewpoint, EPS are biodegradable and environment compatible, offering several advantages over synthetic compounds. This study investigated the EPS produced by Klebsiella oxytoca (KO-EPS) by chemically characterizing and evaluating its properties. The monosaccharide components of the KO-EPS were determined by HPLC coupled with a refractive index detector and GC-MS. The KO-EPS was then analyzed by methylation analysis, FT-IR and NMR spectroscopy to give a potential primary structure. KO-EPS demonstrated the ability to stabilize hydrophilic emulsions with various hydrophobic compounds, including hydrocarbons and vegetable and mineral oils. In terms of iron chelation capacity, the KO-EPS could sequester 41.9 % and 34.1 % of the most common iron states, Fe2+ and Fe3+, respectively. Moreover, KO-EPS exhibited an improvement in the viscosity of aqueous dispersion, being proportional to the increase in its concentration and presenting a non-Newtonian pseudoplastic flow behavior. KO-EPS also did not present a cytotoxic effect indicating that the KO-EPS could have potential applications as a natural thickener, bioemulsifier, and bioremediation agent.

Inhibition of Aspergillus spp. growth and ochratoxin A production in Conilon and Arabica coffees based-medium by Saccharomyces cerevisiae.

Saccharomyces cerevisiae CCMA 0159 is reported as a promising biocontrol agent against ochratoxin A (OTA)-producing fungi in coffee. Coffea arabica and Coffea canephora (var. Conilon or Robusta) are the most widely consumed coffee species around the world, cultivated in tropical and subtropical regions, each exhibiting distinct physicochemical and sensory characteristics. The objective of this study was to compare the growth and OTA production by Aspergillus carbonarius, A. ochraceus, and A. westerdijkiae in C. arabica and C. canephora, along with assessing the efficiency of S. cerevisiae CCMA 0159 in biocontrolling ochratoxigenic fungi in both coffee varieties. A. carbonarius exhibited a higher growth rate and OTA production in both coffee varieties, with C. canephora showing particular susceptibility. Conversely, A. ochraceus and A. westerdijkiae demonstrated lower growth and OTA production. S. cerevisiae was effective in biocontrolling the fungal isolates, inhibiting over 80 % of A. carbonarius growth in both coffee varieties. Among the mechanisms of action of the biological control agent, the production of volatile organic compounds stands out. The results of this study confirm the significant potential of S. cerevisiae CCMA 0159 as a biocontrol agent against Aspergillus for application in coffee-producing areas.

Effect of proton pump inhibitors on susceptibility and melanogenesis of Sporothrix species.

Introduction. Sporotrichosis is a subcutaneous infection caused by dimorphic Sporothrix species embedded in the clinical clade. Fungi have virulence factors, such as biofilm and melanin production, which contribute to their survival and are related to the increase in the number of cases of therapeutic failure, making it necessary to search for new options.Gap statement. Proton pump inhibitors (PPIs) have already been shown to inhibit the growth and melanogenesis of other fungi.Aim. Therefore, this study aimed to evaluate the effect of the PPIs omeprazole (OMP), rabeprazole (RBP), esomeprazole, pantoprazole and lansoprazole on the susceptibility and melanogenesis of Sporothrix species, and their interactions with itraconazole, terbinafine and amphotericin B.Methodology. The antifungal activity of PPIs was evaluated using the microdilution method, and the combination of PPIs with itraconazole, terbinafine and amphotericin B was assessed using the checkerboard method. The assessment of melanogenesis inhibition was assessed using grey scale.Results. The OMP and RBP showed significant MIC results ranging from 32 to 256 µg ml-1 and 32 to 128 µg ml-1, respectively. Biofilms were sensitive, with a significant reduction (P<0.05) in metabolic activity of 52% for OMP and 50% for RBP at a concentration of 512 µg ml-1 and of biomass by 53% for OMP and 51% for RBP at concentrations of 512 µg ml-1. As for the inhibition of melanogenesis, only OMP showed inhibition, with a 54% reduction.Conclusion. It concludes that the PPIs OMP and RBP have antifungal activity in vitro against planktonic cells and biofilms of Sporothrix species and that, in addition, OMP can inhibit the melanization process in Sporothrix species.

Evaluation of individual and combined effect of lactic acid-consuming bacteria on mesophilic hydrogen production from lactic acid effluent from food waste treatment.

Lactic acid has been applied as a precursor for hydrogen (H2) production from substrates rich in lactic acid bacteria (LAB), focusing on microbial interactions between producing and consuming LAB tested with model substrates. Therefore, this study evaluated the effect of single and combined lactic acid-consuming bacteria on mesophilic H2 production in batch tests from lactic acid from fermented food waste (FW). Megasphaera elsdenii, Clostridium beijerinckii, and Clostridium butyricum were inoculated at different ratios (v/v). Additionally, thermal pretreated sludge (TPS) was added to the strain mixtures. The highest production was obtained with M. elsdenii, C. beijerinckii, and C. butyricum (17:66:17 ratio), obtaining 1629.0 mL/Lreactor. The optimal mixture (68:32:0 of M. elsdenii and C. beijerinckii) enriched with TPS reached 1739.3 ± 98.6 mL H2/Lreactor, consuming 98 % of lactic acid added. M. elsdenii and Clostridium strains enhance H2 production from lactic acid as they persist in a microbial community initially dominated by LAB.

Effects of light quality and intensity on phycobiliprotein productivity in two Leptolyngbya strains isolated from southern Bahia's Atlantic Forest.

Cyanobacterial phycocyanin and phycoerythrin are gaining commercial interest due to their nutrition and healthcare values. This research analyzed the biomass accumulation and pigment production of two strains of Leptolyngbya under different combinations of light colors and intensities. The results showed that while Leptolyngbya sp.4 B1 (B1) produced all phycobiliproteins, Leptolyngbya sp.5 F2 (F2) only had phycocyanin and allophycocyanin. Both the color of the light and its light intensity affect the biomass accumulation and phycoerythrin concentration in strain B1. Although white light at medium intensity (50 µmol m-2 s-1) causes greater biomass accumulation (1.66 ± 0.13 gDW L-1), low-intensity (25 µmol m-2 s-1) green light induces lower biomass accumulation with twice the pigment content (87.70 ± 2.46 mg gDW -1), culminating in 71% greater productivity. In contrast, for the F2 strain, light intensity positively influenced biomass and pigment accumulation, being observed 2.25 ± 0.10 gDW L-1 under white light at 100 µmol m-2 s-1 and higher phycocyanin concentration (138.38 ± 3.46 mg gDW -1) under red light at 100 µmol m-2 s-1. These findings provide insights into optimizing the growth conditions by altering the intensity and wavelength of light for future production of phycocyanin and phycoerythrin from local cyanobacteria.