-
Foods (Basel, Switzerland) Nov 2022Pit mud, a specific fermented soil, is an essential material for the fermentation of Chinese strong-flavour liquor. However, few studies to date have sought to...
Pit mud, a specific fermented soil, is an essential material for the fermentation of Chinese strong-flavour liquor. However, few studies to date have sought to characterize the spatial profiles of pit mud fungal communities in fermentation cellars from Chinese strong-flavour liquor distilleries. In this analysis, differences in fungal community structures and physicochemical properties in pit mud samples from different spatial positions within fermentation cellars were analyzed, revealing unique characteristic multidimensional pit mud fungal community profiles. , , , , , , , , were dominant in the pit mud samples form the upper cellar wall, whereas , , , , , , , , , were predominant in the middle cellar wall. , , , , , and are majorly present in the down cellar wall layer. , , , , , and were identified as the dominant fungi in pit mud samples from the cellar bottom. Additionally, and are present at notably high levels in all layers of pit mud samples. Moisture, pH, PO, acetic acid, humus, K, Mg, Ca, butyric acid, and caproic acid levels in these different pit mud positions exhibited a rising incremental pattern from the upper wall layer to the bottom layer, whereas lactic acid levels were significantly lower in the bottom pit mud layer relative to these other layers. Moisture, pH, and NH-N were identified as the three most significant factors associated with fungal community composition through a redundancy analysis. Overall, these findings may offer a theoretical foundation for future efforts to improve or standardize artificial pit mud.
PubMed: 36429136
DOI: 10.3390/foods11223544 -
Microorganisms Nov 2021Human living environments and health are seriously affected by the odor produced from fermentation of livestock and poultry manure. In order to reduce the odor pollution...
Human living environments and health are seriously affected by the odor produced from fermentation of livestock and poultry manure. In order to reduce the odor pollution caused by livestock and poultry manure, efficient strains were screened and two methods were tried in this study. The orthogonal test design was used to analyze the gas produced by pig manure under different conditions of temperature, time, wheat straw doping amount and calcium carbonate doping amount. Then, according to ammonia, hydrogen sulfide and comprehensive odor removal effects, the high efficiency of deodorizing strains were screened. The results showed that pig manure produced the least odor when the temperature was 20 °C, added 0% calcium carbonate, 20% wheat straw and waited for 48 h. Three strains were screened to inhibit the odor production of pig manure: , and , showed that their highest removal rate of ammonia and hydrogen sulfide gas could reach 96.58% and 99.74% among them; while for three strains of end-control pig manure stench: , and , the highest removal rate of ammonia and hydrogen sulfide gas reached 85.91% and 90.80% among them. This research provides bacteria resources as the high-efficiency deodorizing function for the source suppression and the end treatment of the odor gas of pig manure, which has high application value for the control of odor pollution.
PubMed: 34946090
DOI: 10.3390/microorganisms9122488 -
Foods (Basel, Switzerland) May 2022Ulcerative colitis (UC) is a chronic inflammatory bowel disease. The purpose of this study was to investigate the ameliorating effects of three yeast strains, I4, 30...
Ulcerative colitis (UC) is a chronic inflammatory bowel disease. The purpose of this study was to investigate the ameliorating effects of three yeast strains, I4, 30 and 11, isolated from traditional fermented dairy food in Xinjiang, China, on the ulcerative colitis symptoms of Balb/c mice treated by dextran sulfate sodium (DSS). Among which, I4 had good tolerance to simulated gastrointestinal juice and strong adhesion to HT-29 cells monolayers. Furthermore, the three yeast strains were oral administered to Balb/c mice with DSS induced colitis. The weight loss, colon shortening and histological injury of colitis mice were ameliorated. Then, oral administration of I4 improved the immune state by reducing the contents of TNF-α, IL-6 and IL-1β and increasing immunoglobulin. The relative expression of intestinal barrier proteins Claudin-1, Occludin and Zonula Occludins-1 (ZO-1) of the mice enhanced, and the short chain fatty acids (SCFAs) content such as Propionic acid, Butyric acid, Isobutyric acid and Isovaleric acid in the feces of the mice increased to varying degrees, after I4 treatment compared with the model group of drinking 3% DSS water without yeast treatment. Moreover, I4 treatment lifted the proportion of beneficial bacteria such as Muribaculaceae, Lactobacillaceae and Rikenellaceae in the intestinal tract of the mice, the abundance of harmful bacteria such as and was decreased. These results suggested that I4 could alleviate DSS induced colitis in mice by enhancing intestinal barrier function and regulating intestinal flora balance.
PubMed: 35627006
DOI: 10.3390/foods11101436 -
Foods (Basel, Switzerland) May 2023Cocoa bean fermentation is carried out in different production areas following various methods. This study aimed to assess how the bacterial and fungal communities were...
Cocoa bean fermentation is carried out in different production areas following various methods. This study aimed to assess how the bacterial and fungal communities were affected by box, ground or jute fermentation methods, using high-throughput sequencing (HTS) of phylogenetic amplicons. Moreover, an evaluation of the preferable fermentation method was carried out based on the microbial dynamics observed. Box fermentation resulted in higher bacterial species diversity, while beans processed on the ground had a wider fungal community. and were observed in all three fermentation methods studied. Moreover, dominated box fermentation and abounded in ground-fermented samples. was the most important yeast in jute and box, while prevailed in the box and ground fermentation. PICRUST analysis was performed to identify potential interesting pathways. In conclusion, there were noticeable differences between the three different fermentation methods. Due to its limited microbial diversity and the presence of microorganisms that guarantee good fermentation, the box method was found to be preferable. Moreover, the present study allowed us to thoroughly explore the microbiota of differently treated cocoa beans and to better understand the technological processes useful to obtain a standardized end-product.
PubMed: 37238842
DOI: 10.3390/foods12102024 -
Food Microbiology Aug 2023Contamination of white-brined cheeses (WBCs) with yeasts is of major concern in the dairy industry. This study aimed to identify yeast contaminants and characterize...
Contamination of white-brined cheeses (WBCs) with yeasts is of major concern in the dairy industry. This study aimed to identify yeast contaminants and characterize their succession in white-brined cheese during a shelf-life of 52 weeks. White-brined cheeses added herbs (WBC1) or sundried tomatoes (WBC2) were produced at a Danish dairy and incubated at 5 °C and 10 °C. An increase in yeast counts was observed for both products within the first 12-14 weeks of incubation and stabilized afterwards varying in a range of 4.19-7.08 log CFU/g. Interestingly, higher incubation temperature, especially in WBC2, led to lower yeast counts, concurrently with higher diversity of yeast species. Observed decrease in yeast counts was, most likely, due to negative interactions between yeast species leading to growth inhibition. In total, 469 yeast isolates from WBC1 and WBC2 were genotypically classified using the (GTG)-rep-PCR technique. Out of them, 132 representative isolates were further identified by sequencing the D1/D2 domain of the 26 S rRNA gene. Predominant yeast species in WBCs were Candida zeylanoides and Debaryomyces hansenii, while Candida parapsilosis, Kazachstania bulderi, Kluyveromyces lactis, Pichia fermentans, Pichia kudriavzevii, Rhodotorula mucilaginosa, Torulaspora delbrueckii, and Wickerhamomyces anomalus were found in lower frequency. Heterogeneity of yeast species in WBC2 was generally larger compared to WBC1. This study indicated that, along with contamination levels, taxonomic heterogeneity of yeasts is an important factor influencing yeast cell counts, as well as product quality during storage.
Topics: Cheese; Yeasts; Polymerase Chain Reaction
PubMed: 37098422
DOI: 10.1016/j.fm.2023.104266 -
Journal of Applied Microbiology May 2015Mineral deficiencies cause several health problems in the world, especially for populations consuming cereal-based diets rich in the anti-nutrient phytate. Our aim was...
AIMS
Mineral deficiencies cause several health problems in the world, especially for populations consuming cereal-based diets rich in the anti-nutrient phytate. Our aim was to characterize the phytate-degrading capacity of the yeast Pichia kudriavzevii TY13 and its secretion of phytase.
METHODS AND RESULTS
The phytase activity in cell-free supernatants from cultures with 100% intact cells was 35-190 mU ml(-1) depending on the media. The Km was 0.28 mmol l(-1) and the specific phytase activity 0.32 U mg(-1) total protein. The phytase activity and secretion of extracellular non-cell-bound phytase was affected by the medium phosphate concentrations. Further, addition of yeast extract had a clearly inducing effect, resulting in over 60% of the cultures total phytase activity as non-cell-bound.
CONCLUSIONS
Our study reveals that it is possible to achieve high extracellular phytase activity from the yeast P. kudriavzevii TY13 by proper composition of the growth medium.
SIGNIFICANCE AND IMPACT OF THE STUDY
TY13 could be a promising future starter culture for fermented foods with improved mineral bioavailability. Using strains that secrete phytase to the food matrix may significantly improve the phytate degradation by facilitating the enzyme-to-substrate interaction. The secreted non-cell-bound phytase activities by TY13 could further be advantageous in industrial production of phytase.
Topics: 6-Phytase; Extracellular Space; Fungal Proteins; Kinetics; Phytic Acid; Pichia
PubMed: 25630750
DOI: 10.1111/jam.12767 -
FEMS Yeast Research May 2019Budding yeasts are distributed across a wide range of habitats, including as human commensals. However, under some conditions, these commensals can cause superficial,...
Budding yeasts are distributed across a wide range of habitats, including as human commensals. However, under some conditions, these commensals can cause superficial, invasive, and even lethal infections. Despite their importance to human health, little is known about the ecology of these opportunistic pathogens, aside from their associations with mammals and clinical environments. During a survey of approximately 1000 non-clinical samples across the United States of America, we isolated 54 strains of budding yeast species considered opportunistic pathogens, including Candida albicans and Candida (Nakaseomyces) glabrata. We found that, as a group, pathogenic yeasts were positively associated with fruits and soil environments, whereas the species Pichia kudriavzevii (syn. Candida krusei syn. Issatchenkia orientalis) had a significant association with plants. Of the four species that cause 95% of candidiasis, we found a positive association with soil. These results suggest that pathogenic yeast ecology is more complex and diverse than is currently appreciated and raises the possibility that these additional environments could be a point of contact for human infections.
Topics: Candida; Fruit; Microbial Sensitivity Tests; Pichia; Plants; Saccharomycetales; Soil Microbiology; United States
PubMed: 31076749
DOI: 10.1093/femsyr/foz032 -
Bioresource Technology Apr 2013D-xylonic acid is one of the top 30 most desirable chemicals to be derived from biomass sugars identified by the US Department of Energy, being applicable as a non-food...
D-xylonic acid is one of the top 30 most desirable chemicals to be derived from biomass sugars identified by the US Department of Energy, being applicable as a non-food substitute for D-gluconic acid and as a platform chemical. We engineered the non-conventional yeast Pichia kudriavzevii VTT C-79090T to express a D-xylose dehydrogenase coding gene from Caulobacter crescentus. With this single modification the recombinant P. kudriavzevii strain produced up to 171 g L(-1) of D-xylonate from 171 g L(-1) D-xylose at a rate of 1.4 g L(-1) h(-1) and yield of 1.0 g [g substrate consumed](-1), which was comparable with D-xylonate production by Gluconobacter oxydans or Pseudomonas sp. The productivity of the strain was also remarkable at low pH, producing 146 g L(-1) D-xylonate at 1.2 g L(-1) h(-1) at pH 3.0. This is the best low pH production reported for D-xylonate. These results encourage further development towards industrial scale production.
Topics: Biomass; Glucose; Hydrogen-Ion Concentration; Intracellular Space; Kluyveromyces; Pichia; Saccharomyces cerevisiae; Sugar Acids; Xylitol; Xylose
PubMed: 23455228
DOI: 10.1016/j.biortech.2013.01.157 -
Scientific Reports Mar 2021Upgrading the nutritive value of rice straw (RS) is necessary to increase its contribution to enhancing meat and milk production. Present work verified whether novel...
Upgrading the nutritive value of rice straw (RS) is necessary to increase its contribution to enhancing meat and milk production. Present work verified whether novel Crabtree negative yeast inoculant could promote RS utilization, rumen fermentation, and milk quality in tropical crossbred lactating Holstein cows. The new stain of Crabtree negative yeasts (Pichia kudriavzevii KKU20 and Candida tropicalis KKU20) was isolated from the rumen of dairy cattle. This study used 6 multiparous crossbreds between Holstein Frisian × Zebu dairy cows in their mid-lactation period. Dairy cows were randomly allocated to three ensiled RS with various yeast stains including Saccharomyces cerevisiae, P. kudriavzevii KKU20, and C. tropicalis KKU20 according to a 3 × 3 replicated Latin square design. Crabtree-negative yeast (P. kudriavzevii and C. tropicalis) increased the apparent digestibility of dry matter by about 6.9% when compared with Crabtree-positive yeast (S. cerevisiae). Bacterial populations were highest with ensiled RS by C. tropicalis KKU20. Ensiled RS with Crabtree-negative yeasts were significantly increased with total volatile fatty acids, but they did not affect volatile fatty acid profiles. Milk protein precentage was highest at 35.6 g/kg when C. tropicalis was fed, and lowest when applied with S. cerevisiae and P. kudriavzevii KKU20 in ensiled RS at 34.5 and 34.1 g/kg, respectively. Thus, feeding ensiled RS with novel Crabtree negative yeast could improve RS digestion, rumen fermentation, and milk protein content in dairy cows.
Topics: Animal Feed; Animals; Candida tropicalis; Cattle; Digestion; Fatty Acids, Volatile; Female; Fermentation; Intestinal Absorption; Lactation; Milk; Milk Proteins; Oryza; Pichia; Rumen; Saccharomyces cerevisiae; Silage
PubMed: 33737628
DOI: 10.1038/s41598-021-85643-2 -
ACS Omega Mar 2023During storage and fermentation of kimchi, white film-forming yeasts (WFY) are generated on the surface of kimchi under various conditions. These yeasts include , , , ,...
During storage and fermentation of kimchi, white film-forming yeasts (WFY) are generated on the surface of kimchi under various conditions. These yeasts include , , , , and . Because of the off-odor and texture-softening properties of WFY that degrade the quality of kimchi, a method to prevent WFY is required. In this study, cinnamaldehyde (CIN) and gold nanoparticles (AuNPs) with a large surface area were grafted on a paper surface, which was termed the "Paper_AuNPs_CIN" film. CIN is an antimicrobial agent that is approved for use in food applications. In the as-fabricated Paper_AuNPs_CIN film, antimicrobial CIN molecules were physically adsorbed to the surface of AuNPs and simultaneously chemically synthesized on the paper surface via the imine reaction. The Paper_AuNPs_CIN film exhibited greater antimicrobial activity against the three WFY strains than a Paper_CIN film (which contains only CIN molecules). Since more CIN molecules were adsorbed to the large surface area of the paper-reduced AuNPs, the Paper_AuNPs_CIN film exhibited a higher antimicrobial activity. Using AuNPs and CIN simultaneously to inhibit the growth of WFY is a novel approach that has not yet been reported. The morphology and elemental mapping of the functionalized films were examined via scanning electron microscopy and energy-dispersive spectroscopy, elemental composition was analyzed via inductively coupled plasma optical emission spectroscopy, and chemical bonding and optical properties were investigated via Fourier transform infrared spectroscopy and diffuse reflectance spectroscopy. Additionally, agar-well diffusion assays were used to determine the antimicrobial activity against three representative WFY strains: , , and .
PubMed: 36910935
DOI: 10.1021/acsomega.2c06323