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International Journal of Food... Aug 2016Terroir concept includes specific soil, topography, climate, landscape characteristics and biodiversity features. In reference to the last aspect, recent studies...
Terroir concept includes specific soil, topography, climate, landscape characteristics and biodiversity features. In reference to the last aspect, recent studies investigating the microbial biogeography (lately called 'microbial terroir') have revealed that different wine-growing regions maintain different microbial communities. The aim of the present work was to identify potential autochthonous fermentative yeasts isolated from native plants in North Patagonia, Schinus johnstonii, Ephedra ochreata and Lycium chilense, that could be associated to the specific vitivinicultural terroir of this region. Different Pichia kudriavzevii isolates were recovered from these plants and physiologically and genetically compared to regional wine isolates and foreign reference strains of the same species. All isolates were subjected to molecular characterization including mtDNA-RFLP, RAPD-PCR and sequence analysis. Both wine and native P. kudriavzevii isolates from Patagonia showed similar features, different from those showed by foreign strains, suggesting that this species could be part of a specific regional terroir from North Patagonia.
Topics: Anacardiaceae; Argentina; Biodiversity; Chile; DNA, Mitochondrial; DNA, Ribosomal Spacer; Ephedra; Fermentation; Lycium; Pichia; Polymorphism, Restriction Fragment Length; Random Amplified Polymorphic DNA Technique; Saccharomyces cerevisiae; Wine
PubMed: 27124468
DOI: 10.1016/j.ijfoodmicro.2016.04.017 -
Letters in Applied Microbiology Jun 2024Yeasts are unicellular eukaryotic microorganisms extensively employed in various applications, notably as an alternative source of protein in feeds, owing to their...
Yeasts are unicellular eukaryotic microorganisms extensively employed in various applications, notably as an alternative source of protein in feeds, owing to their nutritional benefits. Despite their potential, marine and mangrove yeast species used in the aquaculture industry have received little attention in the Philippines. Pichia kudriavzevii (A2B R1 ISO 3), sourced from bark samples, was selected and mass-produced due to its high protein content and amino acid profile. The dried biomass of P. kudriavzevii were incorporated in diets of Nile tilapia (Oreochromis niloticus) juveniles at varying inclusion levels (0, 1, 2 and 4 g/kg diet) and its effect on their growth performance, body composition, and liver and intestinal morphology were assessed after 40 days of feeding. The groups that received P. kudriavzevii at a concentration of 2 g/kg diet exhibited higher final body weight, % weight gain, and specific growth rate in comparison to the other treatment groups. Whole body proximate composition did not vary among the dietary groups. Intestinal and liver histopathology also indicated no abnormalities. These findings suggest the potential of ascomycetous P. kudriavzevii as a beneficial feed additive in Nile tilapia diets, warranting further investigation into its long-term effects and broader applications in fish culture.
PubMed: 38906842
DOI: 10.1093/lambio/ovae057 -
Microorganisms Apr 2023There is an expanding market for beer of different flavors. This study aimed to prepare a craft Belgian-style pale ale with a non- yeast. 4A was used as a sole starter...
There is an expanding market for beer of different flavors. This study aimed to prepare a craft Belgian-style pale ale with a non- yeast. 4A was used as a sole starter culture, and malted barley as the only substrate. The ingredients and brewing process were carefully monitored to ensure the quality and innocuousness of the beverage. During fermentation, the yeast consumed 89.7% of total sugars and produced 13.8% / of ethanol. The product was fermented and then aged for 8 days, adjusted to 5% / alcohol, and analyzed. There were no traces of mycotoxins, lead, arsenic, methanol, or microbiological contamination that would compromise consumer health. According to the physicochemical analysis, the final ethanol concentration (5.2% /) and other characteristics complied with national and international guidelines. The ethyl acetate and isoamyl alcohol present are known to confer sweet and fruity flavors. The sensory test defined the beverage as refreshing and as having an apple and pear flavor, a banana aroma, and a good level of bitterness. The judges preferred it over a commercial reference sample of Belgian-style pale ale made from . Hence, 4A has the potential for use in the beer industry.
PubMed: 37110400
DOI: 10.3390/microorganisms11040977 -
Food Chemistry May 2023Pichia kudriavzevii was one of the important aroma-producing fungi in the solid-state fermentation of Baijiu, and immobilization was an effective strategy for improving...
Pichia kudriavzevii was one of the important aroma-producing fungi in the solid-state fermentation of Baijiu, and immobilization was an effective strategy for improving microbial performance. Herein, P. kudriavzevii cells were immobilized in a gel network that crosslinked by chitosan and sodium alginate to form sodium alginate/chitosan-P. kudriavzevii microspheres (SA/CS-PMs). Their structural characteristics and formation processes were characterized by SEM and FT-IR. The effect of synthesis conditions on the performance of microspheres were determined by single-factor experiments. Under the optimal conditions, the SA/CS-PMs could increase the amylase activity of the fermentation broth by 57.18%, the esterase activity by 66.13%, the content of ester by 67.04%, and could be reused at least three times. Further research results indicated that the content of ester could be increased significantly in Baijiu solid-state fermentation with the SA/CS-PMs. In conclusion, the SA/CS-PMs could improve the ester production ability of P. kudriavzevii by increasing the esterase activity, which was a valuable exploration of directional biosynthesis and a feasible strategy to improve solid-state fermentation quality.
Topics: Fermentation; Chitosan; Alginates; Esters; Microspheres; Spectroscopy, Fourier Transform Infrared; Pichia; Esterases
PubMed: 36502727
DOI: 10.1016/j.foodchem.2022.135154 -
l-Lactic Acid Production via Sustainable Neutralizer-Free Route by Engineering Acid-Tolerant Yeast .Journal of Agricultural and Food... Jul 2023l-Lactic acid (l-LA) is a platform chemical obtained via microbial fermentation at a near-neutral pH value. Large amounts of neutralizers are required during this...
l-Lactic acid (l-LA) is a platform chemical obtained via microbial fermentation at a near-neutral pH value. Large amounts of neutralizers are required during this process, which increases the production costs in downstream processing as well as environmental burden. To address this challenge, an acid-tolerant yeast E1 was isolated and metabolically engineered to produce l-LA without neutralizers. The genome of strain E1 was sequenced and a CRISPR-Cas9 system was developed in this newly isolated strain. Subsequently, the gene encoding pyruvate decarboxylase () was knocked out to subdue ethanol formation. Furthermore, the l-lactate dehydrogenase gene from 2-6 and the codon-optimized gene from were introduced into E1 chromosome to redirect the ethanol fermentation pathway to l-LA production. Deletion of the () gene further increased the optical purity of l-LA. After optimizing fermentation conditions, the maximum titer of l-LA in the 5 L fermenter reached 74.57 g/L without any neutralizers, with an optical purity of 100% and a maximum yield of 0.93 g/g glucose. This is the first report of optically pure l-LA production without neutralizers and the engineered acid-tolerant yeast paves the way for the sustainable production of l-LA via a green route.
Topics: Animals; Cattle; Saccharomyces cerevisiae; Lactic Acid; Acids; Pichia; Fermentation; Ethanol
PubMed: 37439413
DOI: 10.1021/acs.jafc.3c03163 -
Journal of Medical Microbiology Dec 2017Fungaemia is associated with substantial morbidity and mortality in neonates admitted to neonatal intensive care units (NICUs). We report an outbreak of fungaemia in a...
PURPOSE
Fungaemia is associated with substantial morbidity and mortality in neonates admitted to neonatal intensive care units (NICUs). We report an outbreak of fungaemia in a NICU due to rare yeast, Pichia kudriavzevii (a teleomorph of Candida krusei). To the best of our knowledge, this is the first report of neonatal sepsis due to P. kudriavzevii.
METHODOLOGY
Between August and September 2014, blood cultures from nine neonates diagnosed with late-onset sepsis in the NICU yielded yeast-like organisms. The molecular identification and typing of these isolates was performed by sequencing the D1/D2 region of 26S rDNA and fluorescent amplified fragment length polymorphism (FAFLP) respectively. Antifungal susceptibility was tested by broth microdilution as per the Clinical Laboratory Standards Institute (CLSI) guidelines. Sampling from environmental sources and the hands of healthcare workers (HCWs) in the NICU was performed.
RESULTS
Of the nine neonates, eight were preterm and six had very low birth weight (VLBW). Thrombocytopenia was present in two neonates. Sequencing identified all the isolates as P. kudriavzevii and FAFLP showed their clonal origin. Antifungal susceptibility testing revealed the susceptibility of all isolates to the antifungals tested. Treatment with voriconazole was advised. However, only seven neonates were treated successfully and discharged after improvement, whereas two were lost for follow-up. Cultures from the environment and the hands of HCWs were negative. The outbreak was controlled by the strict implementation of infection control practices.
CONCLUSION
This study emphasizes the importance of accurate identification of the aetiological agent of sepsis and vigilant monitoring for the possibility of an outbreak in NICUs.
Topics: Amplified Fragment Length Polymorphism Analysis; Antifungal Agents; DNA, Fungal; Disease Outbreaks; Drug Resistance, Multiple, Fungal; Female; Fungemia; Humans; Infant; Infant, Premature; Infant, Very Low Birth Weight; Infection Control; Intensive Care Units, Neonatal; Male; Microbial Sensitivity Tests; Morbidity; Pichia; Thrombocytopenia; Voriconazole
PubMed: 29134932
DOI: 10.1099/jmm.0.000645 -
Antonie Van Leeuwenhoek 1976Pichia kudriavzevii and P. terricola were found to be heterothallic, but not interfertile with one another; nor did they mate with P. membranaefaciens, P. scutulata,...
Pichia kudriavzevii and P. terricola were found to be heterothallic, but not interfertile with one another; nor did they mate with P. membranaefaciens, P. scutulata, Candida lambica, C. diversa, C. ingens, C. silvae, C. valida, C. vini, C. norvegensis, or Torulopsis inconspicua. Limited conjugation occurred between mating types of P. kudriavzevii and C. krusei and conjugation and sporulation occurred in mixtures with C. sorbosa. The data indicate C. krusei and C. sorbosa to be the same species and to represent imperfect forms of P. kudriavzevii.
Topics: Ascomycota; Conjugation, Genetic; Mutation; Pichia; Species Specificity; Spores, Fungal
PubMed: 1086649
DOI: 10.1007/BF00394135 -
Bioresource Technology Apr 2016Heavy metal bioaccumulation by growing microorganisms is a potential technique for treating the heavy metal pollution in food materials, e.g. fishery processing wastes....
Heavy metal bioaccumulation by growing microorganisms is a potential technique for treating the heavy metal pollution in food materials, e.g. fishery processing wastes. In this study, a multi-stress-tolerant yeast with high Zn tolerance and efficient Zn removal ability was screened and renamed as Pichia kudriavzevii A16 after identification. High salinity and low pH obviously increased the Zn bioaccumulation capacity of P. kudriavzevii A16, contributing to the increasing Zn removal rate of P. kudriavzevii A16 at 0.5 mmol/L Zn from 67.69% to 77.03% and 96.09%, respectively. P. kudriavzevii A16 displayed high specificity of Zn removal at high concentrations of Cu, while high concentrations of Cd significantly inhibited the Zn removal by restraining the yeast growth. P. kudriavzevii A16 possessed more powerful Zn removal ability than Saccharomyces cerevisiae CICC1211 under various environmental stresses. The multi-stress-tolerant P. kudriavzevii A16 can be developed into a potential Zn removal agent using in complex food environments.
Topics: Biodegradation, Environmental; Hydrogen-Ion Concentration; Metals, Heavy; Pichia; Salinity; Stress, Physiological; Zinc
PubMed: 26845218
DOI: 10.1016/j.biortech.2016.01.057 -
Endogenous Ethanol and Triglyceride Production by Gut , and Yeasts in Non-Alcoholic Steatohepatitis.Cells Oct 2022Nonalcoholic steatohepatitis (NASH) increases with fructose consumption and metabolic syndrome and has been recently linked with endogenous ethanol production, notably...
Nonalcoholic steatohepatitis (NASH) increases with fructose consumption and metabolic syndrome and has been recently linked with endogenous ethanol production, notably by high alcohol-producing (HiAlc Kpn). yeasts are the main causes of auto-brewery syndromes but have been neglected in NASH. Here, the fecal ethanol and microbial content of 10 cases and 10 controls were compared. Ethanol was measured by gas chromatography-mass spectrometry. Species identification was performed by MALDI-TOF MS, and triglyceride production was assessed by a colorimetric enzymatic assay. The fecal ethanol concentration was four times higher in patients with NASH (median [interquartile range]: 0.13 [0.05-1.43] vs. 0.034 [0.008-0.57], = 0.037). Yeasts were isolated from almost all cases but not from controls (9/10 vs. 0/10, = 0.0001). was the most frequent (four patients), while , and were identified in two cases each. The concentration of ethanol produced by yeasts was 10 times higher than that produced by bacteria (median, 3.36 [0.49-5.60] vs. 0.32 [0.009-0.43], = 0.0029). Using a 10% D-fructose restricted medium, we showed that NASH-associated yeasts transformed fructose in ethanol. Unexpectedly, yeasts isolated from NASH patients produced a substantial amount of triglycerides. strains produced the maximal ethanol and triglyceride levels in vitro. Our preliminary human descriptive and in vitro experimental results suggest that yeasts have been neglected. In addition to , gut and yeasts could be linked with NASH pathophysiology in a species- and strain-specific manner through fructose-dependent endogenous alcohol and triglyceride production.
Topics: Humans; Pichia; Ethanol; Non-alcoholic Fatty Liver Disease; Candida albicans; Candida glabrata; Triglycerides; Candida; Fructose
PubMed: 36359786
DOI: 10.3390/cells11213390 -
Annals of Saudi Medicine 2019A 23-year-old female, who had undergone a sleeve gastrectomy two weeks earlier, presented with abdominal complaints. A CT scan showed portal vein thrombosis, bowel...
A 23-year-old female, who had undergone a sleeve gastrectomy two weeks earlier, presented with abdominal complaints. A CT scan showed portal vein thrombosis, bowel ischemia, and intra-abdominal sepsis. Anastomosis and antibiotic therapy were not successful, and the patient went into multi-organ failure and died. Multiple cultures revealed a yeast fungus confirmed as Pichia kudriavzevii using rRNA gene sequencing. We report the first case of peritonitis in association with P kudriavzevii. In addition to the abdominal complications and surgical interventions, the yeast was found to have significantly contributed to the patient's death. SIMILAR CASES PUBLISHED: None. CONFLICT OF INTEREST: None.
Topics: Fatal Outcome; Female; Gastrectomy; Humans; Multiple Organ Failure; Mycoses; Peritonitis; Pichia; Tomography, X-Ray Computed; Young Adult
PubMed: 31215216
DOI: 10.5144/0256-4947.2019.205