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Journal of Fungi (Basel, Switzerland) Jan 2023is an emerging non-conventional yeast which has attracted increased attention for its application in food and biotechnology areas. It is widespread in various habitats... (Review)
Review
is an emerging non-conventional yeast which has attracted increased attention for its application in food and biotechnology areas. It is widespread in various habitats and often occurs in the spontaneous fermentation process of traditional fermented foods and beverages. The contributions of in degrading organic acid, releasing various hydrolase and flavor compounds, and displaying probiotic properties make it a promising starter culture in the food and feed industry. Moreover, its inherent characteristics, including high tolerance to extreme pH, high temperature, hyperosmotic stress and fermentation inhibitors, allow it the potential to address technical challenges in industrial applications. With the development of advanced genetic engineering tools and system biology techniques, is becoming one of the most promising non-conventional yeasts. This paper systematically reviews the recent progress in the application of to food fermentation, the feed industry, chemical biosynthesis, biocontrol and environmental engineering. In addition, safety issues and current challenges to its use are discussed.
PubMed: 36836285
DOI: 10.3390/jof9020170 -
Open Forum Infectious Diseases Jan 2023Fungal species have undergone and continue to undergo significant nomenclatural change, primarily due to the abandonment of dual species nomenclature in 2013 and the... (Review)
Review
Fungal species have undergone and continue to undergo significant nomenclatural change, primarily due to the abandonment of dual species nomenclature in 2013 and the widespread application of molecular technologies in taxonomy allowing correction of past classification errors. These have effected numerous name changes concerning medically important species, but by far the group causing most concern are the yeasts. Among common species, , , , , and have been changed to , , , , and , respectively. There are currently no guidelines for microbiology laboratories on implementing changes, and there is ongoing concern that clinicians will dismiss or misinterpret laboratory reports using unfamiliar species names. Here, we have outlined the rationale for name changes across the major groups of clinically important fungi and have provided practical recommendations for managing change.
PubMed: 36632423
DOI: 10.1093/ofid/ofac559 -
Bioinformation 2023It is of interest to isolate the probiotic yeast based on its probiotic characteristics and enzyme production. The isolate was able to withstand high acid, bile...
It is of interest to isolate the probiotic yeast based on its probiotic characteristics and enzyme production. The isolate was able to withstand high acid, bile concentration and showed a high viability. Additionally, it showed auto aggregation ability that increases with time and hydrophobicity with xylene. It was resistant to different antibiotics and showed no hemolytic activity. The isolate was also capable of producing phytase that can break down phytate. Overall, the characteristics of suggest that it could potentially have probiotic properties, and its ability to produce phytase could also make it useful in feed and animal industries.
PubMed: 37822822
DOI: 10.6026/97320630019441 -
World Journal of Microbiology &... Sep 2023Esters were identified as the primary volatile flavor compounds in Chinese Baijiu, exerting a significant influence on its quality and aroma. This study focused on the...
Esters were identified as the primary volatile flavor compounds in Chinese Baijiu, exerting a significant influence on its quality and aroma. This study focused on the yeast strain Pichia kudriavzevii, renowned for its high capacity to produce esters. Whole genome sequences were annotated and analyzed using the GO, KEGG, KOG, CAZy, and Pfam databases to determine the genetic basis underly the enhanced ester production capacity. Results showed that P. kudriavzevii gene function was concentrated in biosynthetic capacity, metabolic capacity, amino acid translocation capacity, glycoside hydrolysis capacity and transfer capacity. Additionally, acyltransferase and kinase were predicted as active sites contributing to P. kudriavzevii high ester production. We further compared the volatile composition differences between P. kudriavzevii and Saccharomyces cerevisiae through Headspace solid-phase microextraction-gas Chromatography-mass spectrometry (HS-SPME-GC-MS), revealing P. kudriavzevii produced 3.5 times more esters than S. cerevisiae. Overall, our findings suggest that P. kudriavzevii had potential applications in the Baijiu brewing industry.
Topics: Saccharomyces cerevisiae; Pichia; Amino Acids; Esters
PubMed: 37713136
DOI: 10.1007/s11274-023-03743-9 -
Food Microbiology Jun 2020In this study, P. kudriavzevii was isolated and identified as an effective antagonistic yeast, which could significantly inhibit the rotting rate, weight loss, and delay...
In this study, P. kudriavzevii was isolated and identified as an effective antagonistic yeast, which could significantly inhibit the rotting rate, weight loss, and delay the color change, with no effect on total soluble solids (TSS), titratable acid (TA), or firmness during cherry tomato storage. High-throughput sequencing was used to survey the effect of P. kudriavzevii on fungal community throughout cold storage. The results showed that the biological succession of predominant pathogens was disrupted by P. kudriavzevii. The abundance of Botrytis and Alternaria was higher in the control than upon P. kudriavzevii treatment at 28 d, but some yeast genera such as Naganishia, Wickerhamomyces, and Cutaneotrichosporon at 14 d, Pichia and Sporidiobolus at 21 d, and Cystofilobasidium at 28 d, had relatively higher abundances in P. kudriavzevii treatments than the control. Oddly, as an antagonist agent, P. kudriavzevii was not the dominant population, indicating that altering the course of succession of the fungal community may be an effective mechanism of antagonistic yeast. Furthermore, the total network correlation analysis of fungal community revealed that the community development was more dependent on similarities in function than on taxonomic relationships.
Topics: Antibiosis; Biological Control Agents; Food Storage; Fruit; Solanum lycopersicum; Microbiota; Mycobiome; Pichia
PubMed: 31997760
DOI: 10.1016/j.fm.2019.103404 -
Archives of Microbiology Sep 2021Soil yeasts exhibit an array of beneficial effects to plants viz., plant growth promotion, phosphate solubilization, nitrogen and sulphur oxidation, etc. Yeasts remain...
Soil yeasts exhibit an array of beneficial effects to plants viz., plant growth promotion, phosphate solubilization, nitrogen and sulphur oxidation, etc. Yeasts remain as poorly investigated group of microorganisms that represent an abundant and dependable source of bioactive/chemically novel compounds and potential bioinoculants. Hence this study holds the key concept of assessing the performance of soil yeasts with potential plant growth promoting ability in soil quality improvement. Sixteen soil yeast isolates with plant growth promoting traits were assessed for biofilm forming potential and five potential soil yeast isolates were selected and identified through molecular technique. Soil incubation study was performed with these isolates to assess their impact on soil physical, chemical and biological properties. Due to inoculation of soil yeasts, notable changes were observed in soil physical, chemical and biological properties. Among the soil yeast isolates, Pichia kudriavzevii gave better results in soil incubation study.
Topics: Pichia; Soil; Soil Microbiology
PubMed: 34165623
DOI: 10.1007/s00203-021-02447-8 -
Frontiers in Microbiology 2022Heterotrophic nitrification is a process of organic nitrogen degradation completed by the participation of heterotrophic nitrifying microorganisms, which can accelerate...
Heterotrophic nitrification is a process of organic nitrogen degradation completed by the participation of heterotrophic nitrifying microorganisms, which can accelerate the nitrogen transformation process. However, the current research mainly focuses on heterotrophic nitrifying bacteria and their ammonium degradation capacities. And there is little accumulation of research on fungi, the main force of heterotrophic nitrification, and their capacities to transform organic nitrogen. In this study, novel heterotrophic nitrifying fungus (XTY1) and bacterium (GS2) were screened and isolated from upland soil, and the strains were identified and registered through GenBank comparison. After 24 h single nitrogen source tests and N labeling tests, we compared and preliminarily determined the heterotrophic nitrification capacities and pathways of the two strains. The results showed that XTY1 and GS2 had different transformation capacities to different nitrogen substrates and could efficiently transform organic nitrogen. However, the transformation capacity of XTY1 to ammonium was much lower than that of GS2. The two strains did not pass through NHOH and NO during the heterotrophic nitrification of organic nitrogen, and mainly generated intracellular nitrogen and low NO. Other novel organic nitrogen metabolism pathways may be existed, but they remain to be further validated.
PubMed: 36569078
DOI: 10.3389/fmicb.2022.1038599 -
Food Microbiology Aug 2022Specialty coffee can be developed by the application of explicit microorganisms or starters to obtain desired fermentation. In the present study, natural fermentation...
Specialty coffee can be developed by the application of explicit microorganisms or starters to obtain desired fermentation. In the present study, natural fermentation (NF) of Arabica coffee was carried out spontaneously, the other set was inoculated with Pichia kudriavzevii (Y) starter culture (isolated, identified and mass cultured). The effect of microbial fermentation, metagenomics, production of functional metabolites, volatiles and their sensorial aspects were studied. The bioprocess illustrated cohesive interface of coffee nutrients and microbial communities like Mycobacterium, Acinetobacter, Gordonia, etc., in NF, Lactobacillus and Leuconostoc were prevailing in Y. The Pichia and Rhodotorula dominated in both the groups. The bioactivity of bacteria and fungi induced complex changes in physicochemical features like pH (4.2-5.2), Brix° (9.5-3.0), and metabolic transition in sugar (3.0-0.7%), alcohol (1.4-2.7%), organic acids modulating flavour precursors and organoleptics in the final brew. In the roasted bean, Y exhibited higher sugar (42%), protein (25%), polyphenol (3.5%), CGA (2.5%), caffeine (17.2%), and trigonelline (2.8%) than NF. The volatile profile exhibited increased flavour molecules like furans, ketones, and pyrazines in Y, besides lactone complexes. The organoleptics in Y were highlighted with honey, malt and berry notes. P. kudriavzevii coffee fermentation could be beneficial in specialty coffee production and enhancement of distinct characteristic flavours.
Topics: Coffee; Fermentation; Flavoring Agents; Pichia; Sugars
PubMed: 35473973
DOI: 10.1016/j.fm.2022.104012 -
Microorganisms Apr 2022Microbial administration has been used successfully to improve host health. However, the positive effects of endogenous microbials are still underexplored. This study...
Microbial administration has been used successfully to improve host health. However, the positive effects of endogenous microbials are still underexplored. This study investigated the effects of bovine Lactic acid bacteria and yeast on the milk production, quality and digestive tract microbiome of dairy cows. Y9, T7 and isolated from high-yielding dairy cows were selected to feed low-yielding Holstein cows. T7 could significantly increase milk yield, meanwhile, T7 and B14 could obviously reduce the number of somatic cell counts (SCC). However, slight differences were found in milk fat, protein, lactose and SNF (solids not fat) percentage. High throughput sequencing showed that the dominant bacteria were and in rumen and feces, respectively, and the dominant fungi were , and in both samples, before and after feeding the microbial addition. Nonetheless, microbial addition changed the abundance and structure of the microbiome in the digestive tract. Our data showed bovine yeast and LAB were beneficial for improving performance and regulating the microbial structure of dairy cows. This study was expected to enrich the knowledge of the digestive tract microbiome in dairy cows and provide a feasible strategy for the further utilization of bovine microorganisms.
PubMed: 35630288
DOI: 10.3390/microorganisms10050842 -
Bioresource Technology Nov 2022This study investigated a newly isolated thermotolerant strain of Pichia kudriavzevii with respect to its stress tolerance and fermentation performance. Response surface...
This study investigated a newly isolated thermotolerant strain of Pichia kudriavzevii with respect to its stress tolerance and fermentation performance. Response surface methodology was applied to evaluate the combined effects of furfural, osmotic and thermal stress on ethanol yield. The proposed model shows that P. kudriavzevii has a natural resistance against multiple stress factors. Further evolutionary adaptation of the isolated strain in lignocellulosic hydrolysates improved the ethanol yield by ≥ 24 %. The adapted strain HYPK213_ELA was able to produce ethanol from wheat straw hydrolysates at a high solid loading of 37 %ww at 40 °C and anaerobic conditions. The highest ethanol concentration of 56.8 ± 1.0 gL was reached at 40°C with an inoculum size of 2.5 × 10cellsmL. The results show that Pichia kudriavzevii has the potential to enable high gravity bioethanol production under conditions where most yeast strains are unable to grow.
PubMed: 36220531
DOI: 10.1016/j.biortech.2022.128079