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Indian Journal of Microbiology Dec 2020The search for promising yeasts that surpass the fermentative capacity of commercial strains, such as CAT-1, is of great importance for industrial ethanol processes in...
The search for promising yeasts that surpass the fermentative capacity of commercial strains, such as CAT-1, is of great importance for industrial ethanol processes in the world. Two yeasts, BB2 and BB9, were evaluated in comparison to the industrial yeast CAT-1. The objective was to evaluate the performance profile of the three studied strains in terms of growth, substrate consumption, and metabolite formation, aiming to determine their behaviour in different media and pH conditions. The results showed that under cultivation conditions simulating the medium used in the industrial process (must at 22° Brix at pH 3.0) the highest ethanol productivity was 0.41 g L h for CAT-1, compared to 0.11 g L h and 0.16 g L h for and BB2, respectively. CAT-1 produced three times more ethanol in must at pH 3.0 (28.30 g L) and in mineral medium at pH 3.0 (29.17 g L) and 5.0 (30.70 g L) when compared to the value obtained in sugarcane must pH 3.0 (9.89 g L). It was concluded that CAT-1 was not limited by the variation in pH in the mineral medium due to its nutritional composition, guaranteeing better performance of the yeast even in the presence of stressors. Only CAT-1 expressed he constitutive invertase enzyme, which is responsible for hydrolysing the sucrose contained in the must.
PubMed: 33087999
DOI: 10.1007/s12088-020-00891-6 -
Frontiers in Microbiology 2021Non- yeast with -glucosidase activity might positively contribute to the flavor and quality of wines. The contribution of four non- yeast strains SLY-4, F2-24, F2-16,...
Non- yeast with -glucosidase activity might positively contribute to the flavor and quality of wines. The contribution of four non- yeast strains SLY-4, F2-24, F2-16, and HX-13 with -glucosidase activity to the flavor and quality of wine making was studied. Compared with those of single fermentation, the four non- yeast strains could grow and consume sugar completely with longer fermentation periods, and with no significantly negative effect on chemical characteristics of wines. Moreover, they produced lower content of C compounds, benzene derivative, and fatty acid ethyl ester compounds and higher content of terpene, -ionone, higher alcohol, and acetate compounds. Different yeast strains produced different aroma compounds profiles. In general, the sensory evaluation score of adding non- yeast-fermented wine was better than that of , and SLY-4 fermentation received the highest one, followed by F2-24, F2-16, and HX-13 from high to low. The research results provide a theoretical basis for the breeding of non- yeast and its application in wine making.
PubMed: 34539588
DOI: 10.3389/fmicb.2021.626920 -
Eukaryotic Cell Oct 2012A draft genome sequence of Pichia kudriavzevii M12 is presented here. The genome reveals the presence of genes encoding enzymes involved in xylose utilization and the...
A draft genome sequence of Pichia kudriavzevii M12 is presented here. The genome reveals the presence of genes encoding enzymes involved in xylose utilization and the pentose phosphate pathway for bioethanol production. Strain M12 is also a potential producer of phytases, enzymes useful in food processing and agriculture.
Topics: 6-Phytase; Base Sequence; Ethanol; Genome, Fungal; Molecular Sequence Data; Pichia; Sequence Analysis, DNA
PubMed: 23027839
DOI: 10.1128/EC.00229-12 -
Journal of Food Science and Technology Jun 2023Kombucha is a fermented tea with a combination of yeast and bacteria. Kombucha teas may have a variable microbiota based on geographic origin and cultural conditions....
UNLABELLED
Kombucha is a fermented tea with a combination of yeast and bacteria. Kombucha teas may have a variable microbiota based on geographic origin and cultural conditions. The microbial flora of kombucha has been studied with culture-dependent methods. But, the improvement of the metataxonomic approach has broadened our perspective on fermented foods. In this study, a kombucha mother was procured from an artisanal supplier in Türkiye. High-throughput new-generation sequencing (16S rRNA and Internal Transcribed Spacer (ITS)) was carried out to investigate the microbial communities of kombucha after 7 days of fermentation in both liquid tea (L) and pellicle (P). Microbial counts, pH (4.42 ± 0.01 and 3.50 ± 0.02), and TA% (0.26 ± 0.02 and 0.60 ± 0.04) were also detected on the first and 7 days of fermentation. According to metataxonomic results, the dominant bacteria were (%21.13), an acetic acid-producing bacteria, and the dominant fungal genus was (64.35%) in L while sp. CE17 was the dominant bacteria (7%) and was also the dominant yeast in P. This study also revealed different species which were not common in kombucha including propionic acid and butyric acid-producing bacteria such as and , a butyrivibriocin producing bacteria. Accordingly, different yeast species were detected such as and .
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13197-023-05725-z.
PubMed: 37187981
DOI: 10.1007/s13197-023-05725-z -
Food Science and Biotechnology 2017Thermotolerant yeast strains were isolated from , a traditional Korean fermentation starter in which variety of microorganisms are present. Among the isolates, the...
Thermotolerant yeast strains were isolated from , a traditional Korean fermentation starter in which variety of microorganisms are present. Among the isolates, the MBY1358 identified as yeast showed significantly higher growth rate (0.59 ± 0.00 1/h) at 44 °C than other strains. Maximum ethanol concentration of 8.35 ± 0.03 g/L was obtained from 20 g/L glucose with yield of 0.44 ± 0.01 g/g at 44 °C, which is 1.14 times ethanol production of the control strain of . The MBY1358, which was significantly more thermotolerant than the control strain and fermented 200 g/L glucose to 107.33 ± 5.03 g/L ethanol at 44 °C, was deposited to Korean Collection for Type Cultures (KCTC) under the accession number 27654.
PubMed: 30263670
DOI: 10.1007/s10068-017-0155-6 -
Journal of Dairy Science Oct 2022Bovine mastitis, a major infectious disease affecting milking cows, leads to reduced milk yield and quality, reduced animal welfare, and an increased need for culling....
Bovine mastitis, a major infectious disease affecting milking cows, leads to reduced milk yield and quality, reduced animal welfare, and an increased need for culling. Although its major causative agents are bacteria, yeast species and achlorophyllous algae of the Prototheca genus are well known as causative agents of bovine refractory mastitis. Nevertheless, few studies have analyzed specific yeasts and Prototheca in this context. Herein, we present survey data of yeast species and Prototheca species isolated from bulk tank milk in the Tokachi district of Japan from April 2020 through March 2021. The species of 276 isolates were determined. Yeast species accounted for 184 isolates, of which Pichia kudriavzevii was the most prevalent species. Regarding Prototheca species, only Prototheca bovis was isolated (92 isolates). Prototheca bovis and Pichia kudriavzevii were detected throughout the year and were detected repeatedly on the same farm. Kluyveromyces marxianus was the second most frequently isolated yeast species after Pichia kudriavzevii. Candida parapsilosis, the fourth most frequently isolated yeast species, was found discontinuously. Analysis of monthly data indicated that Kluyveromyces marxianus and Candida parapsilosis were mainly found during the winter and summer months, respectively. Candida akabanensis and Pichia cactophila were the third and fifth most frequently isolated yeast species, respectively. They were detected repeatedly in bulk tank milk samples from the same farms. Results obtained from bulk tank milk underscore the prevalence of these species. These study results are expected to contribute to the elucidation of problematic yeast and Prototheca species.
Topics: Animals; Cattle; Cattle Diseases; Female; Japan; Kluyveromyces; Mastitis, Bovine; Milk; Phylogeny; Pichia; Prototheca
PubMed: 35965121
DOI: 10.3168/jds.2022-21781 -
ELife Apr 2021Bacterial members of the infant gut microbiota and bacterial-derived short-chain fatty acids (SCFAs) have been shown to be protective against childhood asthma, but a...
Bacterial members of the infant gut microbiota and bacterial-derived short-chain fatty acids (SCFAs) have been shown to be protective against childhood asthma, but a role for the fungal microbiota in asthma etiology remains poorly defined. We recently reported an association between overgrowth of the yeast in the gut microbiota of Ecuadorian infants and increased asthma risk. In the present study, we replicated these findings in Canadian infants and investigated a causal association between early life gut fungal dysbiosis and later allergic airway disease (AAD). In a mouse model, we demonstrate that overgrowth of within the neonatal gut exacerbates features of type-2 and -17 inflammation during AAD later in life. We further show that growth and adherence to gut epithelial cells are altered by SCFAs. Collectively, our results underscore the potential for leveraging inter-kingdom interactions when designing putative microbiota-based asthma therapeutics.
Topics: Animals; Asthma; Bacteria; Bacterial Physiological Phenomena; Case-Control Studies; Child; Child, Preschool; Gastrointestinal Microbiome; Humans; Infant; Mice, Inbred C57BL; Pichia; Specific Pathogen-Free Organisms; Mice
PubMed: 33876729
DOI: 10.7554/eLife.67740 -
Journal of Advanced Research Jan 2020Olfactory cues have a large impact on insect behaviour and fitness consequently showing potential in pest management. Yeast released volatiles are used by insects as...
Olfactory cues have a large impact on insect behaviour and fitness consequently showing potential in pest management. Yeast released volatiles are used by insects as olfactory cues for finding feeding and oviposition sites. The yeast strain SB-16-15 was isolated from spontaneous fermentation of berries and identified as . Thirty-nine volatiles were sampled from the headspace of yeasts by solid phase micro extraction and identified by gas chromatography and mass spectrometry techniques. Ten of those volatiles elicited antennal responses of flies, one of the most serious pest of berries. In the two-choice experiments, flies preferred the mixture composed of nine synthetic compounds analogous to electroanntenographic active volatiles released by the yeasts compare to the solvent control. Female flies were significantly attracted to the mixture at the concentration 0.1 µL mL and showed no preference to the mixture at the concentration 1 µL mL versus control while males reacted positively to the synthetic blend at the concentration 1 µL mL. Herein, for the first time, behaviour modifying effect of berry related yeast volatiles was shown suggesting these semiochemicals have potential in use for monitoring flies.
PubMed: 32071775
DOI: 10.1016/j.jare.2019.08.001 -
Molecules (Basel, Switzerland) Jan 2021This study aimed to identify the volatile compounds in the fermented and dried cocoa beans conducted with three distinct inoculants of yeast species due to their high...
This study aimed to identify the volatile compounds in the fermented and dried cocoa beans conducted with three distinct inoculants of yeast species due to their high fermentative capacity: , , the mixture in equal proportions 1:1 of both species, and a control fermentation (with no inoculum application). Three starter cultures of yeasts, previously isolated and identified in cocoa fermentation in the municipality of Tomé-Açu, Pará state, Brazil. The seeds with pulp were removed manually and placed in wooden boxes for the fermentation process that lasted from 6 to 7 days. On the last day of fermentation, the almonds were packaged properly and placed to dry (36 °C), followed by preparation for the analysis of volatile compounds by GC-MS technique. In addition to the control fermentation, a high capacity for the formation of desirable compounds in chocolate by the inoculants with was observed, which was confirmed through multivariate analyses, classifying these almonds with the highest content of aldehydes, esters, ketones and alcohols and low concentration of off-flavours. We conclude that the addition of mixed culture starter can be an excellent alternative for cocoa producers, suggesting obtaining cocoa beans with desirable characteristics for chocolate production, as well as creating a product identity for the producing region.
Topics: Cacao; Chocolate; Fermentation; Food Industry; Pichia; Saccharomyces cerevisiae; Seeds; Volatile Organic Compounds
PubMed: 33440885
DOI: 10.3390/molecules26020344 -
Microorganisms May 2022The aim of this study was to reveal the sites of yeast contamination in dairy production and perform taxonomic characterization of potential yeast spoilers in cheese...
The aim of this study was to reveal the sites of yeast contamination in dairy production and perform taxonomic characterization of potential yeast spoilers in cheese making. Occurrence of spoilage yeasts was followed throughout the manufacture of white-brined cheese at a Danish dairy, including the areas of milk pasteurization, curd processing, and packaging (26 sites in total). Spoilage yeasts were isolated from whey, old cheese curd, and air samples in viable counts of 1.48-6.27 log CFU/mL, 5.44 log CFU/g, and 1.02 log CFU/m, respectively. Yeast isolates were genotypically classified using (GTG)-PCR fingerprinting and identified by sequencing of the D1/D2 region of the 26S rRNA gene. The largest yeast heterogeneity was found in old curd collected under the turning machine of molds, where 11 different yeast species were identified. The most frequently isolated yeast species were , , and . The less abundant yeast species included , , , , , , , , , and . The awareness on occurrence and taxonomy of spoilage yeasts in cheese production will contribute to a knowledge-based control of contaminating yeasts and quality management of cheese at the dairies.
PubMed: 35744597
DOI: 10.3390/microorganisms10061079