Yeast Extract Peptone Dextrose Research Articles

Improvement of Bacillus subtilis PI agarase production, hydrolysate scavenging capability assessment, and saccharification of algal biomass for green ethanol generation

The goal of the current work was to optimize the growth parameters needed to manufacture agarase enzyme from a non-marine PI strain of Bacillus subtilis on an agar-based medium. Using Plackett–Burman design (PBD), nine process parameters were evaluated, and agar, peptone, and yeast-extract were identified as the most significant independent factors influencing agarase production with confidence levels more than 90%. To evaluate the optimal concentrations of the indicated process parameters on agarase production, the Box–Behnken design (BBD) was applied. After optimization, B. subtilis strain PI produced 119.8 U/ml of agarase, representing a 1.36-fold increase. In addition the agar hydrolysate fermented products contain the liberated oligosaccharide acts as strong antioxidant which has 62.4% scavenging activity. Also, the agarase yields increased (1141.12, 1350.253, 1684.854 and 1921.863 U/ml) after substitution the agar with algal biomass of Carolina officinalis at different concentrations (2, 5, 10 and 15%), respectively. After completing the saccharification process, the resulted hydrolysate was used to produce ethanol through fermentation with Pichia pastoris yeast strain as an economical method giving yields (6.68317, 7.09748, 7.75648 and 8.22332 mg/ml), that are higher than using yeast extract peptone dextrose (YPD) medium (4.461 mg/ml).

Probiotic Growth Pattern and Physicochemical Evaluation of Water Kefir Fermentation

Probiotics are live-friendly microorganisms that can confer a health benefit on the host if it is consumed in sufficient amounts. Water kefir is a probiotic-rich fermented beverage that contains multi-species of live cultures. Brown sugar and palm sugar were used for water kefir fermentation due to their high sucrose and mineral contents. The objective of this study was to determine the probiotic growth pattern of water kefir and to evaluate the physicochemical parameters, including the pH changes, lactic acid content, reducing sugar content, and total soluble solids. The fermented water kefir was collected at every 6-hour interval, until the end of 72 hours of fermentation. The growth curve was determined by enumerated probiotics on De Man, Rogosa, and Sharpe (MRS) agar, Yeast Extract-Peptone-Dextrose (YPD) agar, and Gluconobacter (GM) agar plates, respectively. MRS, YPD, and GM agar plates were used to enumerate lactic acid bacteria, yeast, and acetic acid bacteria, respectively. The result showed increased probiotic growth as fermentation time increased with different phases observed from the growth curve. The stationary phase of probiotics was recorded at 30-42 h and was recommended as the optimal harvesting point. Besides, longer fermentation time produced lower pH values and lower total soluble solids while higher lactic acid and higher reducing sugars. At the end of fermentation, the concentration of lactic acid and reducing sugars were 2.16 ± 0.09 g/L and 13.66 ± 0.14 mg/mL, respectively. In conclusion, probiotics from water kefir fermentation are suggested to be best harvested between 30-42 hours and can be used for self-consume or downstream processing.

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.

Indole-3-Acetic Acid Producing Yeasts in the Phyllosphere of Legumes: Benefits for Chili Growth

Plant growth-promoting yeast (PGPY), which is associated with plants, has demonstrated the ability to enhance plant growth and crop yield and provide an effective alternative strategy for reducing the extensive use of chemical fertilizers. However, plant development and yield effects of the phyllosphere yeast have received comparatively little research. Therefore, 95 phylloplane yeast were isolated from the leaves of plants in Leguminosae, and their capability to produce indole-3-acetic acid (IAA) in yeast extract peptone dextrose (YPD) broth supplemented with L-tryptophan was evaluated in this research. Forty-two isolates were selected, due to their ability to produce IAA. Among these isolates, 7 showed high IAA production of more than 40 mg/g DW in YPD with tryptophan as the precursor. These strains were identified as Candida tropicalis, Pichia kudriavzevii and Tortispora caseinolytica based on morphological and D1/D2 domain of LSU rDNA sequence analysis. Other plant growth promotion traits, including the solubilization of phosphate, production of ammonia and siderophores and ACC deaminase activity, were also investigated. The results revealed that Candida tropicalis KPS2219 exhibited maximum IAA production of 54.10 mg/g DW, high ammonia production at 1.16 mg/mL and siderophore production. In a greenhouse experiment, the ability of C. tropicalis KPS2219 to enhance the growth of chili seedlings was investigated. The results revealed that seed priming followed by foliar spraying with C. tropicalis KPS2219 significantly increased the root length, shoot length, root dry weight and stem dry weight of the seedlings by 17.72, 29.15, 60 and 46.15 %, respectively, in comparison to those of the uninoculated control. These findings indicate the possibility of C. tropicalis KPS2219 as a bioinoculant to promote plant development and the effectiveness of foliar application. The efficacy of employing yeast consortiums to enhance growth will be investigated for further study. HIGHLIGHTS Phylloplane yeasts with remarkably high IAA production and multiple traits that promote the growth of plants were isolated from the new habitat, legumes. Spraying the yeast cells on the leaves of chili plants accelerated the growth of the plant. GRAPHICAL ABSTRACT

A New Species of Ganoderma (Ganodermataceae, Polyporales) from Southern China and Optimum Condition for Mycelia Production

The present study sought to propose Ganoderma guixiense sp. nov. as a new species based on phenotypic and genotypic evidence. Phylogenetic analyses were carried out based on the internal transcribed spacer (ITS), the large subunit of nuclear ribosomal RNA gene (nLSU), and the second subunit of RNA polymerase II (RPB2) sequence data. G. guixiense has been characterized by pileate basidiomata, long stipe, in addition to reddish-black zonate pileal surface. Basidiospores are broadly ellipsoid with one end tapering at maturity, and measuring 9–12.8 × 6.5–9.3 μm. Basidia are oval to subglobose. This study marks the first exploration of the biological characteristics of G. guixiense. The result indicated that the optimal medium of mycelial growth was observed on malt extract agar (MEA) and yeast extract peptone dextrose agar (YPD) while the optimal temperature was found to be 25–30 °C with pH range of 6–7.

Investigations in mutation breeding and culturing media by Xanthophyllomyces dendrorhous

Astaxanthin is a red-orange carotenoid compound that has been used as antioxidant, pigment, and immunopotentiator. Xanthophyllomyces dendrorhous is a promising source for natural astaxanthin. In order to improve the astaxanthin production capacity of X. dendrorhous AS2.1557 (designated WT), nitrosoguanidine (NTG), ultraviolet (UV), and atmospheric and room temperature plasma (ARTP) mutagenesis techniques were applied for mutation breeding. The astaxanthin yield was elevated stepwisely after three-staged mutagenesis: Firstly, WT strain was treated with NTG and thus resulted in a positive mutagenic strain As1-3 with higher astaxanthin production; subsequent, strain As1-3 was exposed to UV irradiation, thereby generating a positive mutagenic strain As2-3; finally, a positive mutant As3-8 was developed by ARTP-induced mutagenesis of strain As2-3. After 72 h of cultivation in yeast extract-peptone-dextrose (YPD) medium, the astaxanthin titer and content produced by strain As3-8 were determined to be 4.45 mg·L−1 and 0.96 mg·g−11, which were 8.24 and 11.95 times that of WT strain, respectively. Afterward, the culture medium composition was optimized using the Plackett-Burman design (PBD), Box-Behnken design (BBD) and response surface methodology (RSM), the astaxanthin titer and content of As3-8 were determined to be 13.05 mg·L−1 and 2.04 mg·g−1 dry biomass after 96 h of cultivation in the optimized medium TM2, 24.17-/25.36-fold of the amounts of WT strain. This study provides a good reference for the enhancement of microbial metabolite production by using mutation breeding and medium optimization, the obtained mutant As3-8 would be an interesting candidate for comparative genomics and transcriptomics analysis-guided metabolic engineering in the future.

Bio-Ethanol Production from Wheat Straw Using Yeast Isolates

In the first hand, the cost of fossil fuel is increasing alarmingly. On the second hand, combustion of fossil fuels contributes for global warming. Therefore, it need to strength the production of renewable energies. The aim of this study was to produce bioethanol from wheat straw using yeast isolates. The isolates were isolated from decomposed soil, termite soil and rotten wood samples using yeast extract peptone dextrose media (YPD) and characterized chemically and morphologically. The wheat straws were powdered and hydrolyzed with dilute sulfuric acids. After neutralization, it was used to produce ethanol. Response surface methodology was employed to optimize the ethanol production process from wheat straws. The isolates were grown optimally at a temperature of 30oC, pH nearly 5, and sugar concentration 70 to 120 g/L. Among hydrolysis conditions, lower acid concentration (less than 1.5%) and temperature of 60oC resulted higher reducing sugars. The optimization study showed that the highest bio-ethanol concentration of 6.8g/l was observed by SWX under the optimum conditions of with 1% H2S04, 60oC temperature and 52.5-minute time hydrolysis at 30°C for 48 hour incubation time. Wheat straws could be good candidate for ethanol production.

Cost-effective production of ergothioneine using Rhodotorula mucilaginosa DL-X01 from molasses and fish bone meal enzymatic hydrolysate

Ergothioneine (EGT) is a high-value natural antioxidant that cannot be synthesized by the human body. This study showed that Rhodotorula mucilaginosa DL-X01 can use untreated molasses and fish bone meal enzymatic hydrolysate as the substrates to synthesize EGT. By optimizing the growth conditions, the EGT yield reached 29.39 mg/L when molasses and fish bone meal (FBM) were added at 60 g/L and 400 g/L respectively. Finally, the EGT yield was increased to 216.25 mg/L by fed-batch fermentation in a 5 L bioreactor. Compared with the fermentation by yeast extract peptone dextrose medium, the feedstock cost of EGT production was reduced by 330.91 % by using molasses and FBM as substrates. These results showed that R. mucilaginosa DL-X01 can produce high-value EGT using two cheap processing by-products, molasses and FBM, which is of great significance for environmental protection and sustainable development.

Optimization of xylanase production by Pichia kudriavzevii and Candida tropicalis isolated from the wood product workshop.

Enzymatic compounds can be found abundantly and provide numerous advantages in microbial organisms. Xylanases are used in various pharmaceutical, food, livestock, poultry, and paper industries. This study aimed to investigate xylanase-producing yeasts, xylose concentration curve and their enzymatic activity under various factors including carbon and nitrogen sources, temperature, and pH. Enzyme activity was evaluated under different conditions before, during, and after purification. The yeast strains were obtained from the wood product workshop and were subsequently cultivated on YPD (yeast extract peptone dextrose) medium. Additionally, the growth curve of the yeast and its molecular identification were conducted. The optimization and design process of xylan isolated from corn wood involved the use of Taguchi software to test different parameters like carbon and nitrogen sources, temperature, and pH, with the goal of determining the most optimal conditions for enzyme production. In addition, the Taguchi method was utilized to conduct a multifactorial optimization of xylanase enzyme activity. The isolated species were partially purified using ammonium sulfate precipitation and dialysis bag techniques. The results indicated that 3 species (8S, 18S, and 16W) after molecular identification based on 18S rRNA gene sequencing were identified as Candida tropicalis SBN-IAUF-1, Candida tropicalis SBN-IAUF-3, and Pichia kudriavzevii SBN-IAUF-2, respectively. The optimal parameters for wheat carbon source and peptone nitrogen source were found at 50°C and pH 9.0 through single-factor optimization. By using the Taguchi approach, the best combination for highest activity was rice-derived carbon source and peptone nitrogen source at 50°C and pH 6.0. The best conditions for xylanase enzyme production in single-factor optimization of wheat bran were 2135.6 U/mL, peptone 4475.25 U/mL, temperature 50°C 1868 U/mL, and pH 9.0 2002.4 U/mL. Among the tested yeast, Candida tropicalis strain SBN-IAUF-1 to the access number MZ816946.1 in NCBI was found to be the best xylanase product. The highest ratio of enzyme production at the end of the delayed phase and the beginning of the logarithmic phase was concluded by comparing the growth ratio of 8S, 16W, and 18S yeasts with the level of enzymatic activity. This is the first report on the production of xylan polymer with a relative purity of 80% in Iran. The extracellular xylanases purified from the yeast species of C. tropicalis were introduced as a desirable biocatalyst due to their high enzymatic activity for the degradation of xylan polymers.

Ustilago maydis Yeast Mutant Produces Cytosolic Melanin by Tyrosine-Tyrosinase Activity with Stain Biosorption Capability

Ustilago maydis is a biotrophic basidiomycete fungus that infects corn plants and works as an excellent phytopathogen model, facilitating numerous genetic transformations for studying the mechanisms of plant infection. A random mutation event in the mutant strains designed to investigate the physiological significance of two plasma membrane proton-ATPases in this model resulted in a pigmented phenotype strain. For this study, the FB2 strain and the ΔPMA1 mutant were chosen to assess the pigment, which was confirmed as melanin through thin-layer chromatography, UV, and IR spectrophotometry. The melanin was observed to accumulate in the cytosol, as evident from scanning and transmission electron microscopy, and did not interfere with normal cell growth in yeast extract peptone dextrose media or minimal media. Notably, the mutant exhibited a 25% higher melanin yield compared to wild-type cells. To analyze the melanin synthesis, the tyrosinase activity was measured in a phosphate buffer at pH 6.5. The enzyme demonstrated greater activity with tyrosine as a substrate than with L-3,4 dihydroxyphenylalanine, maintaining the same trend in ion preference. Both FB2 and ΔPMA1 mutant cells were subjected to biosorption experiments, revealing that the mutants with an excess of cytosolic melanin were capable of removing at least 50 ppm of methylene blue. In conclusion, U. maydis can accumulate melanin in the cytosol without adverse physiological effects and this presents biotechnological potential for dye removal.

Isolation and identification of non-saccharomyces ethanol and thermo-tolerant yeasts strains from fermented carbohydrate wastes

Ethanol is an important chemical with its potential as a biofuel to displace the environmentally unfriendly fossil fuels. Isolation and identification of ethanol and thermo-tolerant yeast capable of producing ethanol were carried out in this study. Seventy (70) samples from different fermented foods and agricultural wastes from millets, sorghum, maize, rice and guinea corn were obtained from local sellers in Panteka, Farin-Gida, Barkallahu and Barnawa in Kaduna State (North West), Nigeria were used in this research. The samples were collected using a sterile plastic container and were transported immediately to the Biotechnology laboratory of the Nigerian Defence Academy in iced chamber. They were serially diluted in distilled water and inoculated on yeast extract peptone dextrose agar (YEPD) media plates supplemented with 0.2% chloramphenicol. The plates were incubated at 30°C for 72 hours and developed colonies were sub-cultured to obtain pure culture which was observed for their morphological and microscopic characteristics. After examination, ten (10) yeast isolates were obtained from the seventy (70) samples collected. Flocculation test, Hydrogen sulphide test, preliminary alcohol production and sugar fermentation test were carried out on the isolates and their tolerance to ethanol at varying concentration 5%-20% (v/v) and temperature at 37oC-45oC were studied. Using the internal transcribed spacer (ITS) 1 and 2 regions primer, the DNA were sequenced and the isolates identified. Four isolates FG 17, FG 27, P1 and BN50 showed ethanol tolerance potentials at 20% ethanol and were identified as strains of Diutina rugosa, Candida sp, Candida ethanolica and Candida tropicalis while one isolate FG 35 showed good thermo-tolerance ability at 45oC and was identified as Trichosporon sp.

Isolation and identification of carotenoid-producing Rhodotorula sp. from soils collected in the coastal environment of Kien Giang and Tra Vinh provinces

Rhodotorula is a genus of marine yeasts that is considered the most suitable for carotenoid production. In this study, collected soils at Kien Giang and Tra Vinh provinces were cultured on yeast extract peptone dextrose (YEPD) agar for 72 hours at room temperature. Twenty-three isolates exhibiting yellow, orange, and pink pigments were tested for physiological and biochemical characteristics such as carbohydrate fermentation and assimilation, nitrate assimilation, urease production, and growth temperature. Their oval dimensions were 4.24x3.64 μm for isolate 5S1-T and 3.88x3.17 μm for isolate 5S4-T. The two isolates could assimilate carbohydrate and nitrate sources and produce urease. The ITS rDNA sequence of isolates 5S1-T and 5S4-T both had 100% matches to Rhodotorula sphaerocarpaCBS:5940 and Rhodotorula sphaerocarpa CBS:5939, respectively. The maximum absorbance wavelengths of the solution extractions from the 5S1-T and 5S4-T were 496 and 487 nm, respectively. The total carotenoid content of strain 5S1-T was found to be the highest (1.81 mg/l) followed by strain 5S4-T (1.16 mg/ml). The antioxidant abilities of the 5S1-T and 5S4-T were demonstrated by scavenging the free radical DPPH and ferric reducing capacity. The free radical scavenging activity of the extract from isolate 5S1-T (96.15%) was higher than that of isolate 5S4-T (88.61%) at 0.14 mg/ml. The absorbance at 700 nm of the extracts of both 5S1-T and 5S4-T significantly increased from 0.05 to 0.3 mg/ml. The two strains 5S1-T and 5S4-T of Rhodotorulasphaerocarpa discovered in this study could contribute to carotenoid and antioxidant-producing yeasts for industries in the future.

Cultivation of Microalgae Chlorella vulgaris in Open Reactor for Bioethanol Production

Microalgae have a high growth rate, high CO2 absorption capacity, and high content of chlorophyll, proteins, vitamins, mineral salts, carbohydrates, antioxidant substances, and fatty acids. In recent years, Chlorella vulgaris has been widely used as a feedstock for producing third-generation biofuels, such as bioethanol. Thus, this work aims to develop a strategy to increase the production scale of the microalgae Chlorella vulgaris grown in distilled reused water, supplemented with a modified BG-11 medium, to use biomass in the production of bioethanol. The total cultivation of 72 L presented a concentration of 0.415 g·L−1·d−1, with 61.32 g of final biomass. To improve carbohydrate extraction, the biomass was pre-treated with sulfuric acid at different concentrations (1.5% and 3% v/v). The hydrolyzed solution was supplemented with YPD (yeast extract peptone dextrose) medium and inoculated with Saccharomyces cerevisae yeast, initiating fermentation. In each sample, the Brix degree, cell concentration, reducing sugar concentration, and alcohol content were analyzed. The sample pre-treated with sulfuric acid 1.5% v/v was the one that presented the best result, with alcohol content after distillation of 68 °GL (Gay-Lussac). It appears that the cultivation of the microalgae Chlorella vulgaris in scale-up, with reused water, has high potential in the production of third-generation biofuel.

Candida parapsilosis isolates carrying mutations outside FKS1 hotspot regions confer high echinocandin tolerance and facilitate the development of echinocandin resistance

Candida parapsilosis is a significant cause of candidemia worldwide. Echinocandin-resistant (ECR) and echinocandin-tolerant (ECT) C. parapsilosis isolates have been reported in various countries but are rare. Resistance and tolerance are predominantly caused by mutations related to the hotspot (HS) regions of the FKS1 gene. A relatively high proportion of clinical C. parapsilosis isolates carrying mutations outside the HS regions has been noted in some studies, but an association with echinocandin (EC) resistance or tolerance was not explored. Herein, CRISPR-Cas9 was used and the association between amino acid substitution in FKS1 outside HS 1/2 (V595I, S745L, M1328I, F1386S, and A1422G) with EC susceptibility profile was delineated. None of the mutations conferred EC resistance, but they resulted in a significantly higher level of EC tolerance than the parental isolate, ATCC 22019. When incubated on agar plates containing ECs, specifically caspofungin and micafungin, ECR colonies were exclusively observed among ECT isolates, particularly mutants carrying V595I, S745L, and F1386S. Additionally, mutants had significantly better growth rates in yeast extract peptone dextrose (YPD) and YPD containing agents inducing membrane and oxidative stresses. The mutants had a trivial fitness cost in the Galleria mellonella model relative to ATCC 22019. Collectively, this study supports epidemiological studies to catalog mutations occurring outside the HS regions of FKS1, even if they do not confer EC resistance. These mutations are important as they potentially confer a higher level of EC tolerance and a higher propensity to develop EC resistance, therefore unveiling a novel mechanism of EC tolerance in C. parapsilosis. The identification of EC tolerance in C. parapsilosis may have direct clinical benefit in patient management.

Efficient biosynthesis of resveratrol via combining phenylalanine and tyrosine pathways in Saccharomyces cerevisiae

BackgroundResveratrol is a commercially available stilbenoid widely used as dietary supplements, functional food ingredients, and cosmetic ingredients due to its diverse physiological activities. The production of resveratrol in microorganisms provides an ideal source that reduces the cost of resveratrol, but the titer in Saccharomyces cerevisiae was still much lower than that in other hosts.ResultsTo achieve enhanced production of resveratrol in S. cerevisiae, we constructed a biosynthetic pathway via combining phenylalanine and tyrosine pathways by introducing a bi-functional phenylalanine/tyrosine ammonia lyase from Rhodotorula toruloides. The combination of phenylalanine pathway with tyrosine pathway led to a 462% improvement of resveratrol production in yeast extract peptone dextrose (YPD) medium with 4% glucose, suggesting an alternative strategy for producing p-coumaric acid-derived compounds. Then the strains were further modified by integrating multi-copy biosynthetic pathway genes, improving metabolic flux to aromatic amino acids and malonyl-CoA, and deleting by-pathway genes, which resulted in 1155.0 mg/L resveratrol in shake flasks when cultured in YPD medium. Finally, a non-auxotrophic strain was tailored for resveratrol production in minimal medium without exogenous amino acid addition, and the highest resveratrol titer (4.1 g/L) ever reported was achieved in S. cerevisiae to our knowledge.ConclusionsThis study demonstrates the advantage of employing a bi-functional phenylalanine/tyrosine ammonia lyase in the biosynthetic pathway of resveratrol, suggesting an effective alternative in the production of p-coumaric acid-derived compounds. Moreover, the enhanced production of resveratrol in S. cerevisiae lays a foundation for constructing cell factories for various stilbenoids.Graphical

Bactericidal Effect of Underwater Plasma Treatment on Waste Brine from Kimchi Production Process and the Evaluation of Reusability of Plasma-Treated Waste Brine in Salting Kimchi Cabbage.

Recycling waste brine from the Kimchi production process is an important environmental and industry issue. We applied an underwater plasma to reduce food-borne pathogens in the waste brine. The capillary electrodes supplied by alternating current (AC) bi-polar pulsed power were applied to treat 100 L of waste brine. The inactivation efficacy was analyzed using four different agars (Tryptic Soy Agar (TSA), Marine agar (MA), de Man Rogosa Sharpe Agar (MRS), and Yeast Extract-Peptone-Dextrose (YPD), respectively. The microbial population was reduced linearly with treatment time, irrespective of culturing medium. The inactivation followed the log-linear model (R2: 0.96-0.99). The reusability of plasma-treated waste brine (PTWB) was determined by five parameters (salinity, pH, acidity, reducing sugar, and the population of microorganisms) of salted Kimchi cabbage, and they were compared with newly made brine (NMB) and waste brine (WB), respectively. The results showed that the quality of salted Kimchi cabbage prepared by PTWB was not significantly different from that of NMB, indicating that the underwater plasma treatment is feasible to reuse waste brine in the salting process of Kimchi production.

Examining How the Fermentation Medium Influences Thiol Expression and Its Perceived Aroma in Commercial Brewing Yeast Strains.

In Saccharomyces, the IRC7 gene encodes for a cysteine S-conjugate β-lyase enzyme which can release polyfunctional thiols from their cysteinylated precursor forms, thereby promoting thiol aroma in beer. This study examined the thiol production of 10 commercial yeast strains in two different media, a hopped yeast extract-peptone-dextrose (YPD) medium and a 100% barley malt wort to explore how differences in yeast strain and medium conditions influence the release of polyfunctional thiols. 3-Sulfanylhexan-1-ol was most affected by medium conditions, and its concentrations were highest in wort fermentations. The higher nitrogen content and pH of the YPD medium relative to the wort fermentations were notable differences, and significant correlations between these variables and the extent of free thiol production were observed. A strong association existed between polyfunctional thiol concentrations and the fermentation-derived, malt, and hop-derived compounds 2-phenylethanol, β-damascenone, and β-ionone. The sensory impressions of thiol character in beer were influenced by the presence of other aromatic compounds such as esters and terpene alcohols, and aroma attributes such as "tropical" were not the most suitable for describing beers brewed with yeasts that fully express homozygous IRC7F. Sensory attributes "sweaty", "vegetal", and "overripe fruit" were more strongly associated with these strains.

Holothurin And Caspofungin-Induced Alterations In Ttoll-Like Receptor 4expression In The Vagina Of Rattus Norvegicus Wistar With Candidiasis

Abstract Toll-like receptor 4 is a marker that indicates whether or not tissues have immunological or pro-inflammatory responses. Candida albicans has the potential to aggravate the tissue that makes up the epithelium. After candidiasis, the antifungal properties of holothurin and caspofungin have the ability to block toll-like receptor 4. A total of 48 white rats Rattus norvegius Wistar were divided into four positive control groups (P1) and given topical C. albicans after being grown in yeast extract peptone dextrose in the vagina of white rats Rattus norvegius Wistar. P2 and P3 groups were given 3500 g holothurin and 140 g caspofugin topically in the vagina of animal models at 12-, 24-, and 48-hour intervals. Immunofluorescence was used to analyse the study results both quantitatively and qualitatively by attaching the imaging. After that, the data was processed using the SPSS statistical software version 23. Toll-like receptor 4 expression decreased significantly in the treatment group compared to the positive control group (p0.05). This demonstrates that holothurin (P1) and caspofungin (P2) treatments reduced toll-like receptor 4 expression in C. albicans at 0.25 and 6.375 at 12 hours, 0.62 and 3. at 24 hours, and 1.68 and 4.18 at 48 hours. The mean difference in toll-like receptor 4 expression in the positive control group, on the other hand, did not differ statistically when compared to the negative (healthy) control group. This demonstrates that the treatment group’s holothurin and caspofungin have the potential to reduce toll-like receptor 4 expression. Holothurin has a potential effect compared to caspofungin on experimental animals with candidiasis experiencing significant changes in suppressing the number of toll-like receptor 4 in vaginal epithelial tissue of Rattus norvegicus Wistar

Begerowomyces aurantius sp. nov., a novel yeast isolated from koalas' habitat in a Japanese zoological park.

Koalas are iconic mammals indigenous to Australia. These rare animals and their habitats are occasionally associated with pathogenic fungi, including species of Cryptococcus, and consequently, monitoring the mycobiota of areas inhabited by koalas is of considerable importance. In this report, we describe a novel basidiomycetous yeast isolated from a site in Kanazawa Zoo, Japan, associated with captive koalas. Swab samples were collected from koala breeding environments, from which we isolated a novel unencapsulated yeast characterized by ovoid to ellipsoidal cells (3.2-4.9 × 3.5-5 μm). These cells were observed to undergo polar budding and grow as parent bud pairs, with an optimal growth temperature of 28°C. Colonies grown on yeast extract peptone dextrose agar at 28°C have a characteristic coral pink color. On the basis of physiological, morphological, and molecular characters, the new species was placed in the genus Begerowomyces, and the name Begerowomyces aurantius JCM33898T(LSEM1333T=CBS16241T) is proposed.

P345 The relationship between virulence of Candida albicans and environmental oxygen concentration

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PMObjectives Candida species are known to colonize human skins and mucous membranes, and cause candidemia under various immunosuppressive conditions. Among these Candida species, C. albicans is reported to be the most frequently isolated species, and could colonize on skins, vaginas, gastrointestinal tracts, and medical devices. Environmental factors including oxygen concentration is thought to affect the capability of colonization and virulence of Candida species; however, most previous research was performed under aerobic condition, and few research focused on hypoxic conditions imitating inside the human bodies. Given these backgrounds, we performed murine experiments by culturing C. albicans under various oxygen conditions to evaluate the effect of environmental oxygen concentration on virulence. Through our studies, we aimed to clarify the actual behavior of C. albicans in the human body.MethodsIn this study, female C57BL/6 mice, 7-8 weeks old, were used and injected via lateral tail vein to cause C. albicans dissemination. Mice were divided into 4 groups according to the pre-culture conditions: aerobic, microaerobic (5% oxygen concentration), microaerobic (1% oxygen concentration), and anaerobic. Under each oxygen condition, C. albicans was grown at 37°C for 2 days on yeast extract peptone dextrose (YPD) agar and then incubated in YPD broth for 16-24 h. After incubation, C. albicans was collected, washed, resuspended in sterile PBS, and injected into each mouse at ∼2.5 × 105 colony-forming units. In this study, one reference strain (SC5314) and one clinically isolated strain (from bloodstream infection) were used. These infected mice were euthanatized 2 or 4 days after injection, and organ (kidneys and brain) fungal burdens were evaluated.ResultsThe kidneys’ fungal burdens were significantly higher in the microaerobic groups than those in the aerobic or anaerobic groups 2 and 4 days after injection. There were no significant differences between 5% oxygen concentration pre-cultured group and 1% oxygen concentration pre-cultured group. On gross examination, disseminated lesion formations were visible in the kidneys of the microaerobic groups. Similarly, the fungal burdens of brain were significantly higher in the microaerobically pre-cultured groups than in the aerobically or anaerobically pre-cultured groups. This tendency was similar for both the reference and clinically isolated strain.ConclusionOur results indicated that C. albicans could become more virulent under hypoxia, especially under microaerobic conditions. We assumed that some virulence factors of C. albicans were elevated under microaerobic conditions. These results implicated that C. albicans could become more virulent under hypoxic conditions in human bodies. In the future, we will continue to evaluate factors related to this change in virulence and pathological analysis of infected organs.