pichia kudriavzevii
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2022 ◽  
Vol 11 (1) ◽  
pp. e17311124783
Author(s):  
Samara Teodoro dos Santos ◽  
Marcelo Fossa da Paz ◽  
Ângela Dulce Cavenaghi Altemio

Beer production is an ancient biotechnological process and since yeast as discovered to be responsible for the transformation of barley wort into beer, studies have been carried out with the aim of understanding the behavior of these microorganisms. This work aimed to study the application of two strains of yeasts of the species Pichia kudriavzevii, isolated in the Brazilian Midwest for the production of craft beer and to analyze the occurrence of bioaromatization, with the production of volatile organic compounds (VOC) and to evaluate the sensory perception of the results with untrained end consumers through a quick sensory methodology called Check All That Apply (CATA). For this purpose, three batches of beer were produced and inoculated with commercial yeast (Saccharomyces cerevisiae, the control) and two strains of the same species, called Pichia kudriavzevii BB1 and Pichia kudriavzevii BB2. A total of 28 volatile organic compounds that differentiated the control of the Pichia BB1/BB2 group were detected, being 20 esters, 2 alcohols, 5 carboxylic acids and 1 hydrocarbon. There was no difference among the Pichia kudriavzevii BB1 and BB2 samples (p>0.05) in the sensory analysis using the CATA methodology. It was possible to distinguish two clusters between the tasters according to the habit of consuming craft beer, and those who consumed frequently, assigned a higher score in the hedonic test. It was concluded that Pichia kudriavzevii BB1 and BB2 influenced the beer bioaromatization, improving the acceptance test score with the tasters.


2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Keyu Sun ◽  
Ziwuzhen Wang ◽  
Xuanqing Zhang ◽  
Ze Wei ◽  
Xue Zhang ◽  
...  

Antagonistic yeast is a promising way to control postharvest fruit decay because of its safety and broad-spectrum resistance. However, the biocontrol efficacy of yeast is limited by environmental stress, such as oxidative stress.


2021 ◽  
Vol 12 (4) ◽  
pp. 950-966
Author(s):  
Phakamani H. Tsilo ◽  
Albertus K. Basson ◽  
Zuzingcebo G. Ntombela ◽  
Tsolanku S. Maliehe ◽  
Rajasekhar V. S. R. Pullabhotla

Biolocculants are gaining attention in research due to their environmental friendliness and innocuousness to human in comparison to the conventional flocculants. The present study aimed to investigate the ability of fungi from Kombucha tea SCOBY to produce effective bioflocculant in bulk. A 16S rRNA gene sequence analysis was utilized to identify the isolate. The medium composition (carbon and nitrogen sources) and culture conditions (inoculum size, temperature, shaking speed, pH, and time) were optimized using one-factor-at-a-time method. The functional groups, morphology, and crystallinity of the bioflocculant were evaluated using Fourier transform infrared (FT-IR), scan electron microscope (SEM) and X-ray diffractometry (XRD). The fungus was found to be Pichia kudriavzevii MH545928.1. It produced a bioflocculant with flocculating activity of 99.1% under optimum conditions; 1% (v/v) inoculum size, glucose and peptone as nutrient sources, 35 °C, pH 7 and the shaking speed of 140 rpm for 60 h. A cumulus-like structure was revealed by SEM; FT-IR displayed the presence of hydroxyl, carboxyl, amine, and thiocynates. The XRD analysis demonstrated the bioflocculant to have big particles with diffraction peaks at 10° and 40° indicating its crystallinity. Based on the obtained results, P. kudriavzevii MH545928.1 has potential industrial applicability as a bioflocculant producer.


2021 ◽  
Vol 7 (12) ◽  
pp. 1038
Author(s):  
Hao Ji ◽  
Ke Xu ◽  
Xiameng Dong ◽  
Da Sun ◽  
Libo Jin

Improving the comprehensive utilization of sugars in lignocellulosic biomass is a major challenge for enhancing the economic viability of lignocellulose biorefinement. A robust yeast Pichia kudriavzevii N-X showed excellent performance in ethanol production under high temperature and low pH conditions and was engineered for ᴅ-xylonate production without xylitol generation. The recombinant strain P. kudriavzevii N-X/S1 was employed for sequential production of ᴅ-xylonate and ethanol from ᴅ-xylose, feeding on ᴅ-glucose without pH control in a two-stage strategy of aerobic and shifting micro-aerobic fermentation. Acid-pretreated corncob without detoxification and filtration was used for ᴅ-xylonate production, then simultaneous saccharification and ethanol fermentation was performed with cellulase added at pH 4.0 and at 40 °C. By this strategy, 33.5 g/L ᴅ-xylonate and 20.8 g/L ethanol were produced at yields of 1.10 g/g ᴅ-xylose and 84.3% of theoretical value, respectively. We propose a promising approach for the sequential production of ᴅ-xylonate and ethanol from non-detoxified corncob using a single microorganism.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Ítalo Thiago Silveira Rocha Matos ◽  
Vanderly Andrade de Souza ◽  
Giovana do Rosário D’Angelo ◽  
Spartaco Astolfi Filho ◽  
Edson Júnior do Carmo ◽  
...  

Considering the high biotechnological potential of yeasts associated to edible fruits, a screening for these microorganisms, capable of alcoholic fermentation, was performed in ripe fruits of camu-camu (Myrciaria dubia, Kunth). The fruits were collected from north of Brazilian Amazon, in the floodplain of the Cauamé River. Yeasts were isolated, and fermentation capability was evaluated using Durham tubes. Quantitative assays were performed to calculate ethanol yield (g g−1), specific growth rate (h−1), and ethanol productivity (g L−1·h−1). Taxonomic identification was performed by ribosomal gene nucleotide sequence analysis by alignment using BLASTN. A total of fifteen yeast colonies were isolated, and three of them presented promising ability to ferment glucose to ethanol. These isolates were identified as Candida orthopsilosis, Pichia kudriavzevii, and Meyerozyma caribbica. When cultured in broth containing 180 g·L−1 of glucose, M. caribbica CC003 reached 91.7 percent of the maximum theoretical ethanol concentration (84.4 g·L−1), presenting an ethanol yield and productivity of 0.4688 g·g−1 and 0.781 g·L−1·h−1, respectively. These results indicate a promising potential of this isolate for bioprocess applications. This paper is a rare report of C. orthopsilosis with endophytic habit because most of the references indicate it as a human pathogen. Besides this, M. caribbica is a promising fermenter for alcoholic beverages due to its osmotolerance and high ethanol yield. This is the first paper reporting endophytic yeasts associated with fruits of Myrciaria dubia.


2021 ◽  
pp. 1-12
Author(s):  
A.P. Magnoli ◽  
V. Poloni ◽  
L.A. Cristofolini ◽  
C.I. Merkis ◽  
F.M. Escobar ◽  
...  

The aim of this study was to evaluate the effects of aflatoxin B1 (AFB1) and monensin (MONS) interaction on the liver and intestinal histological changes in poultry, and the influence of Pichia kudriavzevii RC001. One-day-old commercial line (Ross 308) broilers (n=120) were individually weighed and randomly assigned to 8 treatments (15 broilers/treatment, 5 broilers per cage and 3 replicates/treatment). The experimental diets were: Group 1: basal diet (BD); Group 2: BD + MONS (50 mg/kg); Group 3: BD + P. kudriavzevii RC001 (1 g/kg); Group 4: BD + AFB1 (100 μg/kg); Group 5: BD + MONS + P. kudriavzevii RC001; Group 6: BD + AFB1 + P. kudriavzevii RC001; Group 7: BD + AFB1 + MONS + P. kudriavzevii RC001; Group 8: BD + AFB1 + MONS. When MONS was added, the typical AFB1 macroscopic and microscopic alterations were intensified. The P. kudriavzevii RC001 cytotoxicity and genotoxicity assays with Vero cells and with broiler chicken’s erythrocytes, demonstrated that P. kudriavzevii RC001 neither were non-cytotoxic nor genotoxic. When MONS was added in the presence of P. kudriavzevii RC001, the toxic effect of AFB1 on liver was not prevented. When P. kudriavzevii was present alone, the same prevention of the pathological damage was observed in the intestine of poultry fed with AFB1. The smallest apparent absorption area was obtained when AFB1 and MONS were added in the feed (P<0.05). AFB1 and MONS interaction demonstrated important toxic effects. Although P. kudriavzevii was effective in ameliorating the adverse effects of AFB1 alone on liver pathology and gut morphology, it was not able to diminish the toxic effects of AFB1 in presence of MONS. It suggests that P. kudriavzevii could be used as feed additive or counteracting the toxic effects of AFB1 in poultry production in the absence of MONS.


2021 ◽  
Vol 9 (12) ◽  
pp. 2488
Author(s):  
Haixia Ma ◽  
Feier Li ◽  
Evode Niyitanga ◽  
Xicun Chai ◽  
Shipeng Wang ◽  
...  

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: Paracoccus denitrificans, Bacillus licheniformis and Saccharomyces cerevisiae, 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: Pichia kudriavzevii, P. denitrificans and Bacillus subtilis, 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.


Author(s):  
K. F. Williams ◽  
O. K. Agwa ◽  
G. O. Abu ◽  
O. Akaranta

Aim: This study investigated the screening, characterization and identification of sophorolipid-producing yeast isolated from palm oil effluent polluted soil. Place and Duration: Two soil samples impacted with palm oil mill effluent were obtained from Elibrada and Rumuche in Emohua Local Government Area, Rivers State, Nigeria, between March 2020 and September 2021. Methodology: The soil samples were analyzed for physicochemical, geotechnical and microbiological qualities. The yeast isolates were identified using biochemical and 16S ITS molecular approaches. The isolates were screened for hydrocarbon degradation and sophorolipid production. The sophorolipid production was evaluated using emulsification index (E24), haemolytic activity, oil spread activity, drop collapse and blue agar plate assay (Cetyl trimethyl ammonium bromide CTAB Method). Results: The pH of the Palm oil mill effluent -impacted soil ranged between pH 6.18 to 6.34 the electrical conductivity value for Elibrada and Rumuche were 20.84 µS/cm and 80.19 µS/cm respectively while that of the unpolluted soil was 220.13 µS/cm. Permeability of the soil from Elibrada was 2.7 cm/s, Rumuche had 1.3 cm/s while the unpolluted soil had 5.6 cm/s. Total organic carbon for soil samples from Rumuche was 4.92%, Elibrada had 6.13% while the unpolluted soil had 8.74%. Oil and grease component for the Rumuche soil was 10500 mg/kg, Elibrada had 7200 mg/kg and the unpolluted soil had 28.0 mg/kg. Total fungal count for Rumuche soil samples was 3.8 × 104 CFU/g while Elibrada had 3.2 × 104 CFU/g. Eighty percent (80%) of the isolates were Candida spp. while 20% were Saccharomyces sp. There were four bands separated which were denoted as ITS 600bp and a Ladder L which was 500bp. The phylogenetic construct showed that the Y8 was 70.2% similar to Candida parapsilosis. The isolate Y3 was 95.8% similar to Candida haemulonis. Isolate Y9 had 100% similarity with Pichia kudriavzevii while Y13 had a 97.4% identity with Saccharomyces cerevisiae the GENBANK accession numbers were Candida haemulonis MW182014, Candida parapsilosis MW182015, Pichia kudriavzevii MW182016 and Saccharomyces cerevisiae MW182017. Conclusion: There is an increasing concern to develop a process for microbial isolation and characterization for effective biotechnological advancement using impacted environmental media as a bioresource.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Chunsheng Li ◽  
Qiuying Liu ◽  
Yueqi Wang ◽  
Xianqing Yang ◽  
Shengjun Chen ◽  
...  

Abstract Background High-temperature bioethanol production benefits from yeast thermotolerance. Salt stress could induce obvious cross-protection against heat stress of Pichia kudriavzevii, contributing to the improvement of its thermotolerance and bioethanol fermentation. However, the underlying mechanisms of the cross-protection remain poorly understood. Results Salt stress showed obvious cross-protection for thermotolerance and high-temperature ethanol production of P. kudriavzevii observed by biomass, cell morphology and bioethanol production capacity. The biomass and ethanol production of P. kudriavzevii at 45 °C were, respectively, improved by 2.6 and 3.9 times by 300 mmol/L NaCl. Metabolic network map showed that salt stress obviously improved the key enzymes and intermediates in carbohydrate metabolism, contributing to the synthesis of bioethanol, ATP, amino acids, nucleotides, and unsaturated fatty acids, as well as subsequent intracellular metabolisms. The increasing trehalose, glycerol, HSPs, and ergosterol helped maintain the normal function of cell components. Heat stress induced serious oxidative stress that the ROS-positive cell rate and dead cell rate, respectively, rose from 0.5% and 2.4% to 28.2% and 69.2%, with the incubation temperature increasing from 30 to 45 °C. The heat-induced ROS outburst, oxidative damage, and cell death were obviously inhibited by salt stress, especially the dead cell rate which fell to only 20.3% at 300 mmol/L NaCl. The inhibiting oxidative damage mainly resulted from the abundant synthesis of GSH and GST, which, respectively, increased by 4.8 and 76.1 times after addition of 300 mmol/L NaCl. The improved bioethanol production was not only due to the improved thermotolerance, but resulted from the up-regulated alcohol dehydrogenases and down-regulated aldehyde dehydrogenases by salt stress. Conclusion The results provide a first insight into the mechanisms of the improved thermotolerance and high-temperature bioethanol production of P. kudriavzevii by salt stress, and provide important information to construct genetic engineering yeasts for high-temperature bioethanol production. Graphical Abstract


Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 260
Author(s):  
Jong-Beom Park ◽  
Jun-Su Choi ◽  
Hye-Won Park ◽  
Sae-Byuk Lee ◽  
Heui-Dong Park

Yakju, a traditional fermented beverage in Korea, is prepared using various raw materials and methods, and, hence, exhibits various characteristics. Low-temperature-fermented yakju can inhibit the growth of undesirable bacteria and is known for its unique flavor and refreshing taste. To increase the production of volatile aromatic compounds in yakju, strains with strong resistance to low temperatures and excellent production of volatile aromatic compounds were screened from indigenous fruits (grape, persimmon, plum, aronia, wild grape) and nuruk in Korea. One Saccharomyces cerevisiae and three non-Saccharomyces strains were finally screened, and yakju was fermented at 15 °C through mono/co-culture. The analysis of volatile aromatic compounds showed that S. cerevisiae W153 produced 1.5 times more isoamyl alcohol than the control strain and reduced the production of 2,3-butanediol by a third. Similarly, a single culture of Pichia kudriavzevii N373 also produced 237.7 mg/L of ethyl acetate, whereas Hanseniaspora vineae G818 produced ~11 times greater levels of 2-phenethyl acetate than the control. Alternatively, Wickerhamomyces anomalus A159 produced 95.88 mg/L of ethyl hexadecanoate. During principal component analysis, we also observed that the co-culture sample exhibited characteristics of both volatile aroma compounds of the single cultured sample of each strain. Our results suggest that yakju with unique properties can be prepared using various non-Saccharomyces strains.


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