Yeast Extract Research Articles

Improvement of nucleotide content of Cordyceps tenuipes by Schisandra chinensis: fermentation process optimization and application prospects.

Nucleotides are important components and the main indicators for judging Cordyceps quality. In this paper, the mixed fermentation process of Schisandra chinensis and Cordyceps tenuipes was systematically studied, and it was proposed that the fermentation products aqueous extract (S-ZAE) had antioxidant activity and anti-AChE ability. Herein, the results of a single factor showed that S. chinensis, yeast extract, inoculum amount, and pH had significant effects on nucleotide synthesis. The fermentation process optimization results were 3% glucose, 0.25% KH2PO4, 2.1% yeast extract, and S. chinensis 0.49% (m/v), the optimal fermentation conditions were 25℃, inoculum 5.8% (v/v), pH 3.8, 6 d. The yield of total nucleotides in the scale-up culture was 0.64 ± 0.027mg/mL, which was 10.6 times higher than before optimization. S-ZAE has good antioxidant and anti-AChE activities (IC50 0.50 ± 0.050mg/mL). This fermentation method has the advantage of industrialization, and its fermentation products have the potential to become good functional foods or natural therapeutic agents.

Optimization studies on laccase activity of Proteus mirabilis isolated from treatment sludge of textile industry factories : Optimization of laccase activity of Proteus mirabilis.

Laccase is an exothermic enzyme with copper in its structure and has an important role in biodegradation by providing oxidation of phenolic compounds and aromatic amines and decomposing lignin. The aim of this study is to reach maximum laccase enzyme activity with minimum cost and energy through optimization studies of Proteusmirabilis isolated from treatment sludge of a textile factory. In order to increase the laccase enzyme activities of the isolates, medium and culture conditions were optimized with the study of carbon (Glucose, Fructose, Sodium Acetate, Carboxymethylcellulose, Xylose) and nitrogen sources (Potassium nitrate, Yeast Extract, Peptone From Soybean, Bacteriological Peptone), incubation time, pH, temperature and Copper(II) sulfate concentration then according to the results obtained. Response Surface Method (RSM) was performed on six different variables with three level. According to the data obtained from the RSM, the maximum laccase enzyme activity is reached at pH 7.77, temperature 30.03oC, 0.5g/L CuSO4, 0.5g/L fructose and 0.082g/L yeast extract conditions. After all, the laccase activity increased 2.7 times. As a result, laccase activity of P. mirabilis can be increased by optimization studies. The information obtained as a result of the literature studies is that the laccase enzymes produced in laboratory and industrial scale are costly and their amounts are low. This study is important in terms of obtaining more laccase activity from P.mirabilis with less cost and energy.

Association between organic nitrogen substrates and the optical purity of d-lactic acid during the fermentation by Sporolactobacillus terrae SBT-1

The development of biotechnological lactic acid production has attracted attention to the potential production of an optically pure isomer of lactic acid, although the relationship between fermentation and the biosynthesis of highly optically pure d-lactic acid remains poorly understood. Sporolactobacillus terrae SBT-1 is an excellent d-lactic acid producer that depends on cultivation conditions. Herein, three enzymes responsible for synthesizing optically pure d-lactic acid, including d-lactate dehydrogenase (D-LDH; encoded by ldhDs), l-lactate dehydrogenase (L-LDH; encoded by ldhLs), and lactate racemase (Lar; encoded by larA), were quantified under different organic nitrogen sources and concentration to study the relationship between fermentation conditions and synthesis pathway of optically pure lactic acid. Different organic nitrogen sources and concentrations significantly affected the quantity and quality of d-lactic acid produced by strain SBT-1 as well as the synthetic optically pure lactic acid pathway. Yeast extract is a preferred organic nitrogen source for achieving high catalytic efficiency of d-lactate dehydrogenase and increasing the transcription level of ldhA2, indicating that this enzyme plays a major role in d-lactic acid formation in S. terrae SBT-1. Furthermore, lactate racemization activity could be regulated by the presence of d-lactic acid. The results of this study suggest that specific nutrient requirements are necessary to achieve a stable and highly productive fermentation process for the d-lactic acid of an individual strain.

Optimization of fermentation conditions for the production of γ-aminobutyric acid by Lactobacillus hilgardii GZ2 from traditional Chinese fermented beverage system.

γ-Aminobutyric acid (GABA) is a crucial neurotransmitter with wide application prospects. In this study, we focused on a GABA-producing strain from a traditional Chinese fermented beverage system. Among the six isolates, Lactobacillus hilgardii GZ2 exhibited the greatest ability to produce GABA in the traditional Chinese fermented beverage system. To increase GABA production, we optimized carbon sources, nitrogen sources, temperature, pH, and monosodium glutamate and glucose concentrations and conducted fed-batch fermentation. The best carbon and nitrogen sources for GABA production and cell growth were glucose, yeast extract and tryptone. Gradual increases in GABA were observed as the glucose and monosodium glutamate concentrations increased from 10g/L to 50g/L. During fed-batch fermentation, lactic acid was used to maintain the pH at 5.56, and after feeding with 0.03g/mL glucose and 0.4g/mL sodium glutamate for 72h, the GABA yield reached 239g/L. This novel high-GABA-producing strain holds great potential for the industrial production of GABA, as well as the development of health-promoting functional foods and medical fields.

Optimization of Fermentation Culture Medium for Sanghuangporus alpinus Using Response-Surface Methodology

The newly identified Sanghuangporus alpinus species of the Sanghuang mushroom genus has been found to possess significant medical benefits. However, the current artificial cultivation technology has not reached the requisite maturity. The response-surface methodology (RSM) was used to optimize the Sanghuangporus alpinus culture medium formulation and evaluate the functional activity of S. alpinus exopolysaccharides. First, a single-factor experiment was conducted to screen for optimal carbon and nitrogen sources for S. alpinus. Then, using Box–Behnken’s central composite design, a response-surface experiment was conducted to determine optimal culture parameters. Finally, the rationality of those parameters was assessed in a shaking flask experiment. The optimal culture parameters, determined through regression analysis, were 20.20 ± 0.17 g/L fructose (carbon source), 7.29 ± 0.10 g/L yeast extract (nitrogen source), and 0.99 ± 0.01 g/L dandelion. With optimization, the S. alpinus yield increased to 12.79 ± 1.41 g/L, twice that obtained from the initial culture medium. The S. alpinus exopolysaccharide exhibited an excellent antioxidant capacity, with the strongest scavenging effect noted on ABTS free radicals (lowest half-inhibitory concentration: 0.039 mg/mL). Additionally, this exopolysaccharide effectively inhibited various cancer cells, exhibiting the strongest activity against human glioma cells U251 (half-inhibitory concentration: 0.91 mg/mL). The RSM used to optimize the fermentation culture parameters of S. alpinus significantly increased the mycelial biomass. The improvement of Sanghuangporus alpinus yield through liquid fermentation and optimizing the fermentation medium could fill the existing gap in the cultivation of Sanghuangporus alpinus, as well as provide valuable data for the large-scale production of S. alpinus.

194 Effects of combining plant and yeast extracts with essential oils or protected betaine on performance and health of weaned piglets

Abstract To raise piglets without antibiotics and high trace elements levels, favoring immune development and maturation is a potentially successful strategy, as long as over-stimulation of immune system does not harm animal performance. A trial was undertaken to evaluate response of piglet to varied blend of plant and yeast extracts selected for renowned effects on immune system. Weanling piglets (n = 400; 21 d of age), females and castrated males, were allocated to 4 dietary treatments across 80 pens: negative control (NC), blend of plant and yeast extracts for immune stimulation added to NC (B1), essential oils with anti-inflammatory properties added to B1 (B2), protected betaine added to B2 (B3). Pre-starter diets were fed from weaning to d 42, followed by starter diets offered until the end of the trial at d 69. On d 49, coughing and sneezing (CS) were counted per pen in both rooms, and individual fecal samples were taken from 20 piglets per diet, selected at weaning, to assay total peroxidase activity (TPO), a marker of gut inflammation. Statistical analyses were performed on pen data to analyze effects of treatment on piglet growth rate (average daily gain; ADG), feed intake (average daily feed intake; ADFI) and feed conversion ratio (FCR). The model included the effect of weaning weight, treatment, and interactions. Linear contrasts were used to compare B1 to NC, B2 to B1, and B3 to B2. A similar model was applied to individual fecal TPO measurements. Sneezing count frequency was analyzed with Chi² statistics and odd ratio (OR) were computed per treatment. Dietary treatment did not affect CS counts. Compared with NC, B1 reduced initial ADG and ADFI (from d 21 to 42) and increased initial FCR (P < 0.05). In the following period, ADG, ADFI and FCR improved with B1 (P < 0.05), resuming body weight (BW; final BW: 26.8, 26.8, 27.3 and 27.5, P > 0.20, for NC, B1, B2 and B3, respectively). Overall FCR slightly decreased (1.66 vs. 1.64, P < 0.05, for NC and B1 respectively). Compared with B1, B2 increased initial ADG and ADFI (ADG21-42: 0.244 vs. 0.258 kg, P < 0.05, for B1 and B2, respectively), and decreased FCR initial and overall (overall: 1,64 vs. 1.60, P < 0.05, for B1 and B2 respectively). B2 also minimized fecal TPO compared with other treatments (Uּּ•mL-1: 13.7 vs. 21.3 vs. 7.0 vs. 10.1, P < 0.001, for NC, B1, B2 and B3, respectively). B3 did not provide statistical benefit over B2. In this trial, immune stimulation decreased initial growth and reduced feed efficiency. Anti-inflammatory essential oils tempered consequences of gut inflammation and restored performance, while protected betaine did not provide additional benefit.

277 Effect of yeast probiotics in lactation and nursery diets on progeny lifetime growth performance, immune response, and carcass characteristics

Abstract Mixed parity sows (n = 28; Line 241; DNA) and their offspring were used in a farrow-to-finish study to evaluate the effect of live yeast supplementation during lactation with or without yeast extract supplementation during the nursery period on sow and litter performance and lifetime growth performance, antibody titers, and carcass characteristics. Sows were blocked by parity and body weight (BW) on d 110 of gestation and allotted to 1 of 2 dietary treatments with 14 replications per treatment which consisted of a standard corn-soybean meal lactation diet with or without a yeast-based probiotic (0.10% Actisaf Sc 47 HR+; Phileo by Lesaffre, Milwaukee, WI). Following weaning, pigs (n = 350; 241×600, DNA; initial BW = 6.1 ± 0.02 kg) were randomly assigned in a 2 × 2 factorial design within sow treatment to 1 of 2 nursery diets which consisted of a control diet or a diet with pre-probiotic combination (0.10% MS309; Phileo by Lesaffre, Milwaukee, WI) fed for 42 d after weaning followed by common diets until marketing. Two nursery pens were combined in the finisher, such that there were 5 and 10 pigs/pen with 18 and 9 replications/treatment during the nursery and finishing periods, respectively. There were no significant effects of live yeast supplementation on lactation performance (P > 0.079). There was a sow × nursery diet interaction (P = 0.024) during the nursery period where pigs from sows fed Actisaf had increased average daily gain (ADG) when fed control nursery diets compared with pigs from control sows fed control nursery diets (Table). Pigs fed MS309 in the nursery from either sow treatment were intermediate. Pigs from sows fed Actisaf tended to be heavier at marketing (P = 0.067) with heavier hot carcass weight (HCW; P = 0.101), but there were no differences in overall finishing growth performance with the inclusion of yeast in lactation diets or nursery diets (P > 0.10). A subset of pigs were sampled at 7 time points to determine serum porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae antibody sample-to-positive (S/P) ratios and at 5 time points to ascertain percent inhibition of Lawsonia intracellularis. For all 3 immunological criteria, there were no sow diet × nursery diet × day interactions. There was a sow diet × day interaction for PCV2 S/P ratio (P = 0.097) where offspring from Actisaf sows tended to have greater PCV2 S/P ratios at 101 d of age compared with offspring from control sows (P = 0.046). There was a PCV2 S/P ratio nursery diet × day interaction (P = 0.036) where pigs fed MS309 had reduced PCV2 S/P ratios at 66, 78, and 162 d of age (P ≤ 0.022). In conclusion, feeding a pre/probiotic combination in the nursery did not affect performance or immune criteria. Conversely, feeding a live yeast probiotic during lactation resulted in tendencies for increased nursery ADG, final BW, and HCW.

Production of cellulase enzymes by <i>Bacillus</i> sp and <i>Pseudomonas</i> sp isolated from anthill soil

Cellulase turns the most widespread biopolymer and biologically sustainable resource, 'cellulose,' into reducing sugar. The study aimed at producing cellulase enzymes by bacteria isolated from anthill soil. Cellulase-producing bacteria were isolated from anthill soil using Carboxymethyl cellulose (CMC) medium. The isolates were screened for cellulase production by cultural, morphological, biochemical and sugar fermentation tests. Optimization of the fermentation medium for maximum cellulase production was carried out by one factor at a time (OFAT). Data obtained were analysed with the analysis of variance (ANOVA) using SPSS 2007, version 16.0. The identified Pseudomonas sp, Staphylococcus sp, E. coli and Bacillus sp were isolated with highest potential of cellulase production. The culture conditions like pH, temperature, carbon sources and nitrogen sources were optimized. The optimum conditions found for cellulase production were 40oC at pH 8.5 with maltose as carbon source and yeast extract as nitrogen source. The highest activity and stability of cellulase enzymes between neutral to alkaline pH and high temperature.

MobiLipid: A Tool for Enhancing CCS Quality Control of Ion Mobility-Mass Spectrometry Lipidomics by Internal Standardization.

Ion mobility-mass spectrometry (IM-MS) offers benefits for lipidomics by obtaining IM-derived collision cross sections (CCS), a conditional property of an ion that can enhance lipid identification. While drift tube (DT) IM-MS retains a direct link to the primary experimental method to derive CCS values, other IM technologies rely solely on external CCS calibration, posing challenges due to dissimilar chemical properties between lipids and calibrants. To address this, we introduce MobiLipid, a novel tool facilitating the CCS quality control of IM-MS lipidomics workflows by internal standardization. MobiLipid utilizes a newly established DTCCSN2 library for uniformly (U)13C-labeled lipids, derived from a U13C-labeled yeast extract, containing 377 DTCCSN2 values. This automated open-source R Markdown tool enables internal monitoring and straightforward compensation for CCSN2 biases. It supports lipid class- and adduct-specific CCS corrections, requiring only three U13C-labeled lipids per lipid class-adduct combination across 10 lipid classes without requiring additional external measurements. The applicability of MobiLipid is demonstrated for trapped IM (TIM)-MS measurements of an unlabeled yeast extract spiked with U13C-labeled lipids. Monitoring the CCSN2 biases of TIMCCSN2 values compared to DTCCSN2 library entries utilizing MobiLipid resulted in mean absolute biases of 0.78% and 0.33% in positive and negative ionization mode, respectively. By applying the CCS correction integrated into the tool for the exemplary data set, the mean absolute CCSN2 biases of 10 lipid classes could be reduced to approximately 0%.

Investigating cultivation strategies for enhancing protein content in Auxenochlorella pyrenoidosa FACHB-5

This study investigated the influence of yeast extract addition, carbon source, and photoperiod on the growth dynamics of Auxenochlorella pyrenoidosa FACHB-5. Employing response surface methodology, the culture strategy was optimized, resulting in the following optimal conditions: yeast extract addition at 0.75 g L-1, glucose concentration of 0.83 g L-1, and a photoperiod set at Light: Dark = 18 h: 6 h. Under these conditions, the biomass reached 1.76 g L-1 with a protein content of 750.00 g L-1, containing 40 % of essential amino acids, representing a 1.52-fold increase. Proteomic analysis revealed that the targeted cultivation strategy up-regulated genes involved in microalgal protein synthesis. The combined effect of yeast extract and glucose enhanced both the glutamine synthetase-glutamate synthetase mechanism and the free amino acid content.

Atrimonas thermophila gen. nov., sp. nov., a novel anaerobic thermophilic bacterium of the phylum Atribacterota isolated from deep subsurface gas field and proposal of Atrimonadaceae fam. nov. within the class Atribacteria in the phylum Atribacterota

A novel anaerobic, thermophilic bacterium of the class Atribacteria, strain M15T, was isolated from a high-temperature gas reservoir, Japan. Cells of strain M15T were gram-negative, short oval-shaped, and lacked flagella. Growth occurred at 45–75 °C (optimum 70–75 °C) and pH 6.5–8.5 (optimum pH 7.5–8.0) and was fast under optimal conditions (doubling time 11.4 h). Yeast extract was required for growth. Fermentative growth with glucose, arabinose, xylose, and cellobiose was observed. The major fermentative end products of glucose were acetate and hydrogen. The major cellular fatty acids were C16:0, iso-C15:0, and C18:0. The genomic G + C content was 46.0 mol%. Fluorescence and electron microscopy observations revealed the intracellular localization of genomic DNA surrounded by a membrane in the cells of strain M15T as reported in a sole validly described species of the class Atribacteria in the phylum Atribacterota, Atribacter laminatus strain RT761T, suggesting that the unique morphological traits are widely shared in this class. Phylogenetic analyses indicated that strain M15T belongs to a distinct family-level lineage in the class Atribacteria and shows low similarities to Atribacter laminatus strain RT761T (16S rRNA gene sequence identity of 90.1 %, average nucleotide identity [ANI] of 66.1 %, average amino acid identity [AAI] of 55.8 %). Phenotypic traits of strain M15T (thermophilic, fast-growing, relatively high G + C content, etc.) were clearly distinct from A. laminatus. Based on these phenotypic and genomic properties, we propose a novel genus and species, Atrimonas thermophila gen. nov., sp. nov. for strain M15T (=JCM39389T, =KCTC25731T) representing a novel family Atrimonadaceae fam., nov. in the class Atribacteria.

Investigating the concomitant production of carotenoids and lipids by the yeast Rhodosporidium babjevae using sugarcane bagasse hydrolysate or corn steep liquor

The yeast Rhodosporidium babjevae was used to produce carotenoids, lipids, and fatty acids using sugarcane bagasse hydrolysates or glucose. Investigating the impact of glucose concentrations (10-150 g/L), the yeast showed the capability to yield 16.9 g/L biomass and 10.5 g/L lipids at 60 g glucose/L, while the highest pigments concentration (312 μg/g) was observed at 10 g glucose/L. Pre-treatment methods, including organosolv (ethanol 60 %(w/w)), alkali (NaOH 2 %(w/v)) and alkaline-organosolv (ethanol 60 %(w/w) and NaOH 2 %(w/v)) were used on the sugarcane bagasse following enzymatic hydrolysis. Among these, alkaline organosolv pre-treatment exhibited the most effective lignin removal of 81.9 %, releasing 46.7 g/L sugars by hydrolysis. Yeast cultivation on the enzymatic hydrolysates of alkaline organosolv pre-treatment resulted in the highest biomass (9.6 g/L) and lipids (5.0 g/L) yields. However, the highest content of pigments (280 μg/g) was achieved when the yeast was cultivated on the enzymatic hydrolysates of organosolv pre-treatment. Production of 11.3 g/L biomass, 204 μg/g pigments, and 6.7 g/L lipids established that corn steep liquor holds potential as a cheap and viable alternative to yeast extract as nitrogen source. The analysis of fatty acid composition revealed the prevalence of oleic acid and linoleic acid as dominant components.

A novel indirect ELISA for serodiagnosis of mucormycosis using antigens from Rhizopus arrhizus.

Due to a delay in diagnosis by conventional techniques and high mortality, the development of a standardised and rapid non-culture-based technique is an unmet need in pulmonary, gastrointestinal, and disseminated forms of mucormycosis. Though limited studies have been conducted for molecular diagnosis, there are no established serologic tests for this highly fatal infection. To develop and evaluate an indirect in-house enzyme-linked immunosorbent assay (ELISA) utilising antigens of Rhizopus arrhizus for detecting anti-Rhizopus antibodies (IgG and IgM) in sera of patients with mucormycosis. We extracted both secretory and mycelial Rhizopus antigens using standardised protocols. Bradford assay was used for protein quantification. We then standardised an indirect ELISA using R. arrhizus mycelial and secretory antigens (10.0 μg/mL in bicarbonate buffer pH 9.2) for detecting anti-Rhizopus IgG and IgM antibodies in patient sera. We included patients with mucormycosis, other fungal infections, and healthy controls. Antibody index value (E-value) was calculated for each patient sample. Asparagine broth culture filtrate utilising 85% ammonium sulphate salt fractionation and mycelial homogenate grown in yeast extract peptone dextrose (YPD) broth precipitated with trichloroacetic acid (TCA) yielded a large amount of good-quality protein for the assay. We included 55 patients with mucormycosis (rhino-orbito-cerebral mucormycosis [ROCM, n = 39], pulmonary [n = 15], gastrointestinal [n = 1]), 24 with other fungal infections (probable aspergillosis [n = 14], candidiasis [n = 10]), and healthy controls (n = 16). The sensitivity of the antibody test for diagnosing mucormycosis ranged from 83.6-92.7% for IgG and 72.7-87.3% for IgM, with a specificity of 91.7-92.5% for IgG and 80-82.5% for IgM. The sera from patients with other fungal infections and healthy individuals did not show significant cross-reactivity. The detection of anti-Rhizopus IgG antibody performed significantly better in comparison to IgM-based ELISA for diagnosing both ROCM (sensitivity of 84.6% vs. 69.2%) and pulmonary cases (86.6% vs. 80.0%). More extensive studies are required to confirm our findings.

Improvement of morphophysiological and anatomical attributes of plants under abiotic stress conditions using plant growth-promoting bacteria and safety treatments.

Drought and salinity are the major abiotic stress factors negatively affecting the morphophysiological, biochemical, and anatomical characteristics of numerous plant species worldwide. The detrimental effects of these environmental factors can be seen in leaf and stem anatomical structures including the decrease in thickness of cell walls, palisade and spongy tissue, phloem and xylem tissue. Also, the disintegration of grana staking, and an increase in the size of mitochondria were observed under salinity and drought conditions. Drought and salt stresses can significantly decrease plant height, number of leaves and branches, leaf area, fresh and dry weight, or plant relative water content (RWC%) and concentration of photosynthetic pigments. On the other hand, stress-induced lipid peroxidation and malondialdehyde (MDA) production, electrolyte leakage (EL%), and production of reactive oxygen species (ROS) can increase under salinity and drought conditions. Antioxidant defense systems such as catalase, peroxidase, glutathione reductase, ascorbic acid, and gamma-aminobutyric acid are essential components under drought and salt stresses to protect the plant organelles from oxidative damage caused by ROS. The application of safe and eco-friendly treatments is a very important strategy to overcome the adverse effects of drought and salinity on the growth characteristics and yield of plants. It is shown that treatments with plant growth-promoting bacteria (PGPB) can improve morphoanatomical characteristics under salinity and drought stress. It is also shown that yeast extract, mannitol, proline, melatonin, silicon, chitosan, α-Tocopherols (vitamin E), and biochar alleviate the negative effects of drought and salinity stresses through the ROS scavenging resulting in the improvement of plant attributes and yield of the stressed plants. This review discusses the role of safety and eco-friendly treatments in alleviating the harmful effects of salinity and drought associated with the improvement of the anatomical, morphophysiological, and biochemical features in plants.

Study on isolating, breeding, and cultivation of Xylaria nigripes (Klotzsch) Cooke

The Xylaria nigripes fungus is one of the medicinal materials that was used in traditional medicine. Extracts from the mycelium and fruiting bodies of the X. nigripes showed protecting cells, preventing DNA damage, and reducing the programmed death cell rate. In this study, the fruiting bodies of the X. nigripes were collected to isolate, propagate in the liquid medium, and then cultured to induce the fruiting body formation in the rice medium. The results showed that the X. nigripes was successfully isolated on PDAY (Potato Dextrose Agar Yeast Extract) medium, and the mycelium and spore of the X. nigripes had unique characteristics of the species. The biomass of X. nigripes grew well in a liquid nutrient medium containing 20g glucose, 1g MgSO4.7H2O, 2g KH2PO4, and 5g peptone, reaching the best mass after 21 to 28 days. Using an initial cultured liquid of X. nigripes to culture on rice medium, fruiting bodies were formed and developed after 14 days of culture. This result could potentially be applied to the production of X. nigripes biomass via mycelium and fruit bodies for application in medicine.

Fodinisporobacter ferrooxydans gen. nov., sp. nov.—A Spore-Forming Ferrous-Oxidizing Bacterium Isolated from a Polymetallic Mine

A novel acidophilic, aerobic bacterium strain, MYW30-H2T, was isolated from a heap of polymetallic mine. Cells of strain MYW30-H2T were Gram-stain-positive, endospore-forming, motile, and rod-shaped. Strain MYW30-H2T grew at a temperature range of 30–45 °C (optimum 40 °C) and a pH range of 3.5–6.0 (optimum 4.0) in the presence of 0–0.5% (w/v) NaCl. Strain MYW30-H2T could grow heterotrophically on yeast extract and glucose, and grow mixotrophically using ferrous iron as an electron donor with yeast extract. Menaquinone-7 (MK-7) was the sole respiratory quinone of the strain. Iso-C15:0 and anteiso-C15:0 were the major cellular fatty acids. The 16S rRNA gene sequence analysis showed that MYW30-H2T was phylogenetically affiliated with the family Alicyclobacillaceae, and the sequence similarity with other Alicyclobacillaceae genera species was below 91.51%. The average amino acid identity value of the strain with its phylogenetically related species was 52.3–62.1%, which fell into the genus boundary range. The DNA G+C content of the strain was 44.2%. Based on physiological and phylogenetic analyses, strain MYW30-H2T represents a novel species of a new genus of the family Alicyclobacillaceae, for which the name Fodinisporobacter ferrooxydans gen. nov., sp. nov. is proposed. The type strain is MYW30-H2T (=CGMCC 1.17422T = KCTC 43278T).

Production of kojic acid by Aspergillus flavus OL314748 using box-Behnken statistical design and its antibacterial and anticancer applications using molecular docking technique

Kojic acid is a wonderful fungal secondary metabolite that has several applications in the food, medical, and agriculture sectors. Many human diseases become resistant to normal antibiotics and normal treatments. We need to search for alternative treatment sources and understand their mode of action. Aspergillus flavus ASU45 (OL314748) was isolated from the caraway rhizosphere as a non-aflatoxin producer and identified genetically using 18S rRNA gene sequencing. After applying the Box-Behnken statistical design to maximize KA production, the production raised from 39.96 to 81.59 g/l utilizing (g/l) glucose 150, yeast extract 5, KH2PO4 1, MgSO4.7H2O 2, and medium pH 3 with a coefficient (R2) of 98.45%. Extracted KA was characterized using FTIR, XRD, and a scanning electron microscope. Crystalized KA was an effective antibacterial agent against six human pathogenic bacteria (Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Serratia marcescens, and Serratia plymuthica). KA achieves high inhibition activity against Bacillus cereus, K. pneumonia, and S. plymuthica at 100 μg/ml concentration by 2.75, 2.85, and 2.85 compared with chloramphenicol which gives inhibition zones 1, 1.1, and 1.6, respectively. Crystalized KA had anticancer activity versus three types of cancer cell lines (Mcf-7, HepG2, and Huh7) and demonstrated high cytotoxic capabilities on HepG-2 cells that propose strong antitumor potent of KA versus hepatocellular carcinoma. The antibacterial and anticancer modes of action were illustrated using the molecular docking technique. Crystalized kojic acid from a biological source represented a promising microbial metabolite that could be utilized as an alternative antibacterial and anticancer agent effectively.

Cellulases production optimization and inductors evaluation in pretreated plantain rachis by Penicillium oxalicum

AbstractPretreated lignocellulosic residues are suitable substrates for cellulases production by filamentous fungi. In the current work, plantain rachis was pretreated with sequential acid and alkali and then used as the main carbon source for cellulases production. First, a full 23 factorial design and response surface methodology (RSM), based on central composite rotatable design (CCRD), were carried out to cellulases production media optimization from plantain rachis by Penicillium oxalicum. The cellulases production was evaluated in flasks and bioreactor scale; in parallel, the addition of possible cellulases inductors was evaluated in flasks: molasses, beer bran, oat bran, and wheat bran. Results from statistical analyses with a level of confidence of 95% demonstrated that the concentration of ammonium sulfate must be kept at 1.625 g/L. The optimum urea and yeast extract concentrations were 0.560 g/L and 0.250 g/L, respectively. Cellulases volumetric productivities were higher in instrumented bioreactor than in flasks: 78.03% for exoglucanase, 10.87% for endoglucanase, 1.58% for β‐glucosidase, and 44.36% for FPU. Therefore, P. oxalicum was able to produce cellulases from plantain rachis in flasks and bioreactor, and molasses was the additional inductor that presented an increment in cellulases activities: endoglucanase 15%, exoglucanase 81%, and β‐glucosidase 55%.

Two-pot optimization of nutrient sources to enhance antioxidants in Citrus reticulata peel powder through solid-state fermentation with Aspergillus niger CGMCC 3.6189

This study aimed to optimize nutrient sources for enhancing the accumulation of antioxidants in Citrus reticulata peel powder (CRPP) through solid-state fermentation (SSF) using Aspergillus niger CGMCC 3.6189. A Plackett-Burman design revealed that four medium compositions, including yeast extract, NH4Cl, CaCl2, and MgCl2, significantly affected antioxidant accumulation in fermented CRPP. The optimal concentrations of these four compositions were predicted as 13.86, 0.40, 0.06, and 0.04 mg/g of CRPP, respectively, using a Box-Behnken design (BBD) when simultaneous optimization of total phenolic content (TPC), total flavonoid content (TFC), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacities using Derringer's desirability function. Under the optimal medium compositions, TPC, TFC, ABTS, and DPPH scavenging capacities of fermented CRPP (FO-CRPP) increased by 25.2%, 26.9%, 45.8%, and 57.3%, respectively, in comparison with the unfermented CRPP (UF-CRPP). The HPLC analysis exhibited notable decreases in the levels of hesperidin, narirutin, nobiletin, and tangeretin, while enhancements in the contents of p-coumaric acid, ferulic acid, narirutin, and hesperetin in FO-CRPP compared to UF-CRPP were observed. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses demonstrated changes in the surface microstructure and functional groups in FO-CRPP. Our findings suggested that yeast extract and NH4Cl significantly improve the accumulation of antioxidants in CRPP during SSF by A. niger CGMCC 3.6189.

Valorization of black carrot pomace and pea powder for co-production of polygalacturonase and pectin lyase

AbstractPectic enzyme groups, particularly polygalacturonase and pectin lyase, are vital components of a high-value microbial enzyme category widely employed in applications within the fruit juice and wine industries. The exploration of alternative carbon and nitrogen sources remains crucial for enhancing enzyme production while reducing costs. This study evaluates the impact of carbon (black carrot pomace) and nitrogen (pea protein) loading on fermentable sugar content, protein content, and enzyme activities during both batch and fed-batch cultivation. Additionally, three distinct valorization techniques—thermal (steam), thermochemical (steam assisted with dilute acid), and microwave-assisted with dilute acid pretreatments—were assessed for their effectiveness in hydrolyzing black carrot pomace as a carbon source. The findings indicate that microwave-assisted dilute acid, coupled with enzymatic saccharification, resulted in the highest fermentable sugar production (0.493 g/g), achieving an 87.3% conversion yield. Pea protein demonstrated more favorable outcomes with the highest polygalacturonase activity (20.50 ± 0.52 U/L) and pectin lyase activity (46.44 ± 3.45 U/L) compared to whey protein and yeast extract used as nitrogen sources. Meanwhile, the highest polygalacturonase and pectin lyase activity, along with the highest total protein content (52.25 ± 0.06 mg/L), was recorded under the same culture conditions, reaching 164.34 ± 2.26 and 188.22 ± 1.72 U/L, respectively, after 72 h, representing approximately 1.18- and 1.34-fold increases from the batch system. Consequently, these results prove that fed-batch cultivation, utilizing black carrot pomace hydrolyzate as a feeding substrate and pea protein as a nitrogen source, significantly increases polygalacturonase and pectin lyase activity compared to batch cultivation.