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Microbial Pathogenesis Dec 2021Mycotoxins are the secondary metabolites of certain toxigenic fungi which pose severe health stress in humans, animals and poultry. Certain biological agents and...
Mycotoxins are the secondary metabolites of certain toxigenic fungi which pose severe health stress in humans, animals and poultry. Certain biological agents and components are used to adsorb mycotoxins in poultry industry which provide promising results in this regard. Pichia kudriazevii (PK), a novel yeast, has the ability to enhance the immune status of poultry chicks. The present study was designed to investigate the ameliorative potential of PK against aflatoxins associated immunosuppression and oxidative stress in broiler chicks. 180-one day old broiler chicks were equally divided into six groups and given different combinations of aflatoxins (300 and 600 μg/kg) and PK (1 g/kg). Parameters studied were antibody response to sheep red blood cells, lymphoproliferative response to PHA-P; phagocytic response by carbon clearance assay system, total antioxidant capacity and total oxidant status of chicks. Results of this experiment confirmed the immunomodulation and antioxidant capacity of PK against 300 μg/kg aflatoxin level. However such amelioration was partial when PK was used with 600 μg/kg aflatoxins. Moreover, the exact ratio of aflatoxin: PK to cause such amelioration still needs to be investigated.
Topics: Aflatoxins; Animal Feed; Animals; Chickens; Dietary Supplements; Oxidative Stress; Pichia; Poultry Diseases; Sheep
PubMed: 34742894
DOI: 10.1016/j.micpath.2021.105279 -
Low-pH production of d-lactic acid using newly isolated acid tolerant yeast Pichia kudriavzevii NG7.Biotechnology and Bioengineering Sep 2018Lactic acid is a platform chemical for the sustainable production of various materials. To develop a robust yeast platform for low-pH production of d-lactic acid (LA),...
Lactic acid is a platform chemical for the sustainable production of various materials. To develop a robust yeast platform for low-pH production of d-lactic acid (LA), an acid-tolerant yeast strain was isolated from grape skins and named Pichia kudriavzevii NG7 by ribosomal RNA sequencing. This strain could grow at pH 2.0 and 50°C. For the commercial application of P. kudriavzevii NG7 as a lactic acid producer, the ethanol fermentation pathway was redirected to lactic acid by replacing the pyruvate decarboxylase 1 gene (PDC1) with the d-lactate dehydrogenase gene (d-LDH) derived from Lactobacillus plantarum. To enhance lactic acid tolerance, this engineered strain was adapted to high lactic acid concentrations, and a new transcriptional regulator, PAR1, responsible for acid tolerance, was identified by whole-genome resequencing. The final engineered strain produced 135 g/L and 154 g/L of d-LA with productivity over 3.66 g/L/hr at pH 3.6 and 4.16 g/L/hr at pH 4.7, respectively.
Topics: Acids; DNA, Fungal; DNA, Ribosomal; Drug Tolerance; Hydrogen-Ion Concentration; Lactic Acid; Metabolic Engineering; Metabolic Networks and Pathways; Phylogeny; Pichia; Sequence Analysis, DNA; Temperature; Vitis
PubMed: 29896854
DOI: 10.1002/bit.26745 -
Translational Animal Science Jul 2020Growth performance, liver and spleen weight, plasma, and ceca digesta metabolites and incidences of diarrhea were investigated in growing pigs fed spent biomass of...
Growth performance, liver and spleen weight, plasma, and ceca digesta metabolites and incidences of diarrhea were investigated in growing pigs fed spent biomass of Ninety six barrows (~25 kg, 4 pigs/pen) were fed 1 of 4 experimental diets ( = 6) for 7 weeks. The diets were control, corn-, and soybean meal-based diet or control plus 2.5%, 3.75%, or 5.0% . Diets were formulated to be isocaloric and iso nitrogenous. Feed intake and body weight (BW) were recorded weekly for calculation of average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F). Fecal scores were taken 3 d/wk to assess incidence and severity of diarrhea. One pig/pen close to pen average was bled for plasma metabolites on days 7 and 49 and subsequently euthanized for spleen and liver weight, ileal and cecum digesta samples for concentration of short-chain fatty acids (SCFA). The concentration of crude protein, crude fat, and non-fiber carbohydrates in biomass was 36.4%, 9.6%, and 50.8% DM, respectively. Inclusion of tended ( = 0.06) to linearly reduce ADG from days 8 through 49 resulting in a trend ( = 0.06) for linear reduction in the final BW. The final BW was 79.0, 79.2, 76.8, and 75.5 kg for the 0%, 2.5%, 3.75%, and 5.0% , respectively. Diets had no effect ( > 0.10) on ADFI, G:F, spleen, and liver weight throughout the entire experiment. On day 7, there was cubic ( = 0.03) decrease and quadratic ( = 0.02) increase in plasma concentration of creatinine and urea N, respectively. However, there were no ( > 0.10) diet effects on plasma metabolites on day 49. There was a tendency ( = 0.08) for linear increase in cecum digesta concentration of acetic acid. There were no diet effects ( > 0.10) on fecal score in the first 4 wk of feeding. In conclusion, feeding yeast tended to depress growth and stimulate cecum fermentation at higher dose and had no detrimental effects on organ weights or plasma metabolites in growing pigs.
PubMed: 32904991
DOI: 10.1093/tas/txaa152 -
AMB Express Nov 2018Food spoilage and its contamination with yeast and mold is a serious problem of food industry. Despite the high fat content, mayonnaise is an attractive substrate for...
Food spoilage and its contamination with yeast and mold is a serious problem of food industry. Despite the high fat content, mayonnaise is an attractive substrate for food spoilage microorganisms. The aim of this study was to develop a method for yeast identification in mayonnaise and to test commercially available mayonnaises for the presence of these contaminating microorganisms. Based on the sequencing of intergenic regions ITS1 and ITS2, we identified a yeast microorganism that causes mayonnaise spoilage. We found that DNA sequences were more than 99% identical to the GenBank DNA sequences from Pichia kudriavzevii. We developed a specific to P. kudriavzevii TaqMan probe and primers. The reaction conditions were optimized regarding to the components concentration and temperature cycle. The minimum amount of P. kudriavzevii DNA that could be detected by developed method was 50 fg. The minimal number of P. kudriavzevii cells that could be detected by developed method without pre-enrichment was 50. We tested verified method with DNAs from microorganisms of different taxonomic groups that were obtained from three collections of microorganisms. Finally, we analyzed 20 different brands of mayonnaise from 14 producers and 10 different brands of mayonnaise sauce from seven producers. We determined the Cq parameter that characterizes transition of the fluorescence curve to the logarithmic phase and, therefore, correlates with the extent of sample contamination with P. kudriavzevii yeast. P. kudriavzevii was detected in six analyzed samples of mayonnaise and one sample of mayonnaise sauce.
PubMed: 30467735
DOI: 10.1186/s13568-018-0716-y -
Nutrition Research (New York, N.Y.) May 2017There is a common agreement on the important role of the gastrointestinal microbiota in the etiology of cancer. Benign probiotic yeast strains are able to ameliorate...
There is a common agreement on the important role of the gastrointestinal microbiota in the etiology of cancer. Benign probiotic yeast strains are able to ameliorate intestinal microbiota and regulate the host metabolism, physiology, and immune system through anti-inflammatory, antiproliferative, and anticancer effects. We hypothesized that Pichia kudriavzevii AS-12 secretion metabolites possess anticancer activity on human colorectal cancer cells (HT-29, Caco-2) via inhibiting growth and inducing apoptosis. This study aimed to assess the anticancer effect of P. kudriavzevii AS-12 secretion metabolites and the underlying mechanisms. The cytotoxicity evaluations were performed via 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay; 4',6-diamidino-2-phenylindole staining; and FACS-flow cytometry tests. Also, the effects of P. kudriavzevii AS-12 secretion metabolites on the expression level of 6 important genes (BAD, Bcl-2, Caspase-3, Caspase-8, Caspase-9 and Fas-R) involved in the extrinsic and intrinsic apoptosis pathways were studied by real-time polymerase chain reaction method. P. kudriavzevii AS-12 secretion metabolites showed significant (P < .0001) cytotoxic effects on HT-29 cells (57.5%) and Caco-2 (32.5%) compared to KDR/293 normal cells (25%). Moreover, the cytotoxic effects of examined yeast supernatant on HT-29 cells were comparable with 5-fluorouracil, as a positive control (57.5% versus 62.2% respectively). Flow cytometric results showed that the induction of apoptosis is the main mechanism of the anticancer effects. Also, according to the reverse transcriptase polymerase chain reaction results, the expression level of proapoptotic genes (BAD, Caspase-3, Caspase-8, Caspase-9, and Fas-R) in treated HT-29 and Caco-2 cells was higher than untreated and normal cells, whereas the antiapoptotic gene (Bcl-2) was downregulated. P. kudriavzevii AS-12 secretion metabolites exert its anticancer effects by inhibiting cell proliferation and inducing intrinsic and extrinsic apoptosis in colon cancer cells.
Topics: Apoptosis; Caco-2 Cells; Caspase 3; Caspase 8; Caspase 9; Cell Proliferation; Colorectal Neoplasms; Fluorouracil; HT29 Cells; Humans; Indoles; Pichia; Probiotics; Tetrazoles; Tetrazolium Salts; Thiazoles; bcl-2-Associated X Protein; bcl-Associated Death Protein
PubMed: 28477945
DOI: 10.1016/j.nutres.2017.04.001 -
Mycopathologia Aug 2022Revealing the phylogenetic relationships of Candida krusei strains (sexual form Pichia kudriavzevii) is a prerequisite for understanding the evolution of its...
Revealing the phylogenetic relationships of Candida krusei strains (sexual form Pichia kudriavzevii) is a prerequisite for understanding the evolution of its virulence-associated mechanisms and ecological lifestyles. Molecular phylogenetic analyses based on entire internal transcribed spacer region (ITS) and multilocus sequence typing (MLST) data were carried out with sequences available in public databases and Hungarian isolates from animals obtained for the study. The ITS haplotype network yielded a high frequency haplotype at the centre of the network (H1; n = 204) indicating that various selective pressure might resulted in population expansion from H1. MLST analysis identified three new genotypes among animal-derived isolates, therefore overall 203 sequence types were investigated to determine the population structure of C. krusei. The most commonly encountered sequence types were ST 17 and ST 67. Phylogenetic analyses showed diverse genetic construction of C. krusei population. Evidence of potential recombination events were also observed that might play some role in high intraspecies genetic variability among strains, however, the limited data of C. krusei genotypes from different countries prevented us to identify accurate evolutionary routes of commensal and pathogenic strains or species-specific lineages. Further expansion of C. krusei MLST database may promote the better understanding of the mixed evolutionary history of this species.
Topics: Candida; Multilocus Sequence Typing; Phylogeny; Pichia
PubMed: 35689765
DOI: 10.1007/s11046-022-00640-x -
Brazilian Journal of Microbiology :... 2018High potential, thermotolerant, ethanol-producing yeasts were successfully isolated in this study. Based on molecular identification and phylogenetic analysis, the...
High potential, thermotolerant, ethanol-producing yeasts were successfully isolated in this study. Based on molecular identification and phylogenetic analysis, the isolated thermotolerant yeasts were clustered in the genera of Pichia kudriavzevii, Candida tropicalis, Candida orthopsilosis, Candida glabrata and Kodamea ohmeri. A comparative study of ethanol production using 160g/L glucose as a substrate revealed several yeast strains that could produce high ethanol concentrations at high temperatures. When sugarcane bagasse (SCB) hydrolysate containing 85g/L glucose was used as a substrate, the yeast strain designated P. kudriavzevii RZ8-1 exhibited the highest ethanol concentrations of 35.51g/L and 33.84g/L at 37°C and 40°C, respectively. It also exhibited multi-stress tolerance, such as heat, ethanol and acetic acid tolerance. During ethanol fermentation at high temperature (42°C), genes encoding heat shock proteins (ssq1 and hsp90), alcohol dehydrogenases (adh1, adh2, adh3 and adh4) and glyceraldehyde-3-phosphate dehydrogenase (tdh2) were up-regulated, suggesting that these genes might play a crucial role in the thermotolerance ability of P. kudriavzevii RZ8-1 under heat stress. These findings suggest that the growth and ethanol fermentation activities of this organism under heat stress were restricted to the expression of genes involved not only in heat shock response but also in the ethanol production pathway.
Topics: Biotransformation; Candida; Ethanol; Hot Temperature; Pichia; Plant Extracts; Saccharum; Stress, Physiological
PubMed: 29154013
DOI: 10.1016/j.bjm.2017.09.002 -
Journal of Basic Microbiology Aug 2015Application of growing microorganisms for cadmium removal is restricted by high cadmium toxicity. The effects of sodium chloride (NaCl) preincubation on the cadmium...
Application of growing microorganisms for cadmium removal is restricted by high cadmium toxicity. The effects of sodium chloride (NaCl) preincubation on the cadmium tolerance and removal ability of Pichia kudriavzevii and Saccharomyces cerevisiae were investigated in this study. NaCl preincubation improved the biomass of P. kudriavzevii under cadmium stress, while no obvious effect was observed in S. cerevisiae. The improved activities of peroxidase (POD) and catalase (CAT) after NaCl preincubation might be an important reason for the decrease of the reactive oxygen species (ROS) accumulation, cell death, and oxidative damage of proteins and lipids induced by cadmium, contributing to the improvement of the yeast growth. The cadmium bioaccumulation capacity of P. kudriavzevii decreased significantly after NaCl preincubation, which played an important role in mitigating the cadmium toxicity to the yeast. The cadmium removal rate of P. kudriavzevii was obviously higher than S. cerevisiae and was significantly enhanced after NaCl preincubation. The results suggested that NaCl preincubation improved the cadmium tolerance and removal ability of P. kudriavzevii.
Topics: Cadmium; Catalase; Oxidative Stress; Peroxidase; Pichia; Reactive Oxygen Species; Saccharomyces cerevisiae; Sodium Chloride
PubMed: 25721585
DOI: 10.1002/jobm.201400847 -
International Journal of Food... Mar 2022Certain yeast species belonging to the Pichia genus are known to form a distinctive film on grape must and wine. In a mixed-culture type fermentation, Pichia spp. (P....
The film-forming Pichia spp. in a winemaker's toolbox: A simple isolation procedure and their performance in a mixed-culture fermentation of Vitis vinifera L. cv. Gewürztraminer must.
Certain yeast species belonging to the Pichia genus are known to form a distinctive film on grape must and wine. In a mixed-culture type fermentation, Pichia spp. (P. kluyveri in particular) are known to impart beneficial oenological attributes. In this study, we report on an easy isolation method of Pichia spp. from grape must by exploiting their film-forming capacity on media containing 10% ethanol. We isolated and identified two Pichia species, namely Pichia kudriavzevii and Pichia kluyveri, and subsequently co-inoculated them with Saccharomyces cerevisiae to ferment Gewürztraminer musts. Noteworthy differences included a significant increase in the 2-phenethyl acetate levels with the P. kluyveri co-fermentation and a general increase in ethyl esters with the P. kudriavzevii co-fermentation. Both Pichia co-inoculations yielded higher levels of glycerol in the final wines. Based on all the wine parameters we tested, the P. kluyveri strain that was isolated performed similarly to a commercial P. kluyveri strain.
Topics: Fermentation; Pichia; Saccharomyces cerevisiae; Vitis; Wine
PubMed: 35074659
DOI: 10.1016/j.ijfoodmicro.2022.109549 -
Animals : An Open Access Journal From... Apr 2020The objective of this study was to determine the effect of supplementing CPY1, RSY5 and YSY2 isolated from ruminal fluid of dairy cows on transfer of aflatoxin B...
The objective of this study was to determine the effect of supplementing CPY1, RSY5 and YSY2 isolated from ruminal fluid of dairy cows on transfer of aflatoxin B (AFB) from feed into aflatoxin M (AFM) in milk, DMI, milk production and nutrient digestibility. Four multiparous Holsteins in mid-lactation were used in a 4 × 4 Latin square design trial consisting of 14 days in each experimental period for sample collection. Between each period, 14 clearance days prior to the next treatment were allowed to minimize carryover effects. In each treatment, subsequent supplementation of isolated yeast was compared, i.e., (1) control (without yeast supplementation), (2) CPY1 (K1Y), (3) RSY5 (K2Y) and (4) YSY2 (PY). All diets contained 22.28 µg of AFB/kg. Treatments were individually fed at the rate of 2 g/day (1 × 10 CFU/g) of yeast biomass or corn meal in the control group. Concentrations of AFM in milk was reduced with yeast and averaged 1.54, 0.36, 0.43 and 0.51 µg/L for control, K1Y, K2Y and PY, respectively ( < 0.01). The transfer of AFB from feed into AFM in milk was higher in control compared with K1Y, K2Y and PY (7.26% vs. 1.18%, 1.44% and 1.69% respectively, < 0.01). Supplementation of yeast also improved DMI and milk compositions, but no differences were observed in nutrient digestibility or milk yield among treatments. Concentration and yield of milk protein, fat, lactose, solid-not-fat (SNF) and total solids were greater in cows fed yeast compared with the control ( < 0.01). These results indicate that CPY1, RSY5 and YSY2 shows promise as a dietary supplementation to detoxify AFB and improve DMI and yield of milk components.
PubMed: 32325721
DOI: 10.3390/ani10040709