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Journal of Applied Microbiology Feb 2024To assess the capability of Pichia kudriavzevii strains isolated from wine, cider, and natural environments in North Patagonia to produce ciders with reduced malic acid...
AIMS
To assess the capability of Pichia kudriavzevii strains isolated from wine, cider, and natural environments in North Patagonia to produce ciders with reduced malic acid levels.
METHODS AND RESULTS
Fermentation kinetics and malic acid consumption were assessed in synthetic media and in regional acidic apple musts. All P. kudriavzevii strains degraded malic acid and grew in synthetic media with malic acid as the sole carbon source. Among these strains, those isolated from cider exhibited higher fermentative capacity, mainly due to increased fructose utilization; however, a low capacity to consume sucrose present in the must was also observed for all strains. The NPCC1651 cider strain stood out for its malic acid consumption ability in high-malic acid Granny Smith apple must. Additionally, this strain produced high levels of glycerol as well as acceptable levels of acetic acid. On the other hand, Saccharomyces cerevisiae ÑIF8 reference strain isolated from Patagonian wine completely consumed reducing sugars and sucrose and showed an important capacity for malic acid consumption in apple must fermentations.
CONCLUSIONS
Pichia kudriavzevii NPCC1651 strain isolated from cider evidenced interesting features for the consumption of malic acid and fructose in ciders.
Topics: Malus; Fructose; Wine; Saccharomyces cerevisiae; Fermentation; Acetic Acid; Sucrose; Malates; Pichia
PubMed: 38268424
DOI: 10.1093/jambio/lxae019 -
Indian Journal of Microbiology Dec 2020The search for promising yeasts that surpass the fermentative capacity of commercial strains, such as CAT-1, is of great importance for industrial ethanol processes in...
The search for promising yeasts that surpass the fermentative capacity of commercial strains, such as CAT-1, is of great importance for industrial ethanol processes in the world. Two yeasts, BB2 and BB9, were evaluated in comparison to the industrial yeast CAT-1. The objective was to evaluate the performance profile of the three studied strains in terms of growth, substrate consumption, and metabolite formation, aiming to determine their behaviour in different media and pH conditions. The results showed that under cultivation conditions simulating the medium used in the industrial process (must at 22° Brix at pH 3.0) the highest ethanol productivity was 0.41 g L h for CAT-1, compared to 0.11 g L h and 0.16 g L h for and BB2, respectively. CAT-1 produced three times more ethanol in must at pH 3.0 (28.30 g L) and in mineral medium at pH 3.0 (29.17 g L) and 5.0 (30.70 g L) when compared to the value obtained in sugarcane must pH 3.0 (9.89 g L). It was concluded that CAT-1 was not limited by the variation in pH in the mineral medium due to its nutritional composition, guaranteeing better performance of the yeast even in the presence of stressors. Only CAT-1 expressed he constitutive invertase enzyme, which is responsible for hydrolysing the sucrose contained in the must.
PubMed: 33087999
DOI: 10.1007/s12088-020-00891-6 -
Journal of Industrial Microbiology &... Apr 2012In this study, simultaneous saccharification and fermentation (SSF) was employed to produce ethanol from 1% sodium hydroxide-treated rice straw in a thermostatically...
In this study, simultaneous saccharification and fermentation (SSF) was employed to produce ethanol from 1% sodium hydroxide-treated rice straw in a thermostatically controlled glass reactor using 20 FPU gds⁻¹ cellulase, 50 IU gds⁻¹ β-glucosidase, 15 IU gds⁻¹ pectinase and a newly isolated thermotolerant Pichia kudriavzevii HOP-1 strain. Scanning electron micrograph images showed that the size of the P. kudriavzevii cells ranged from 2.48 to 6.93 μm in diameter while the shape of the cells varied from oval, ellipsoidal to elongate. Pichia kudriavzevii cells showed extensive pseudohyphae formation after 5 days of growth and could assimilate sugars like glucose, sucrose, galactose, fructose, and mannose but the cells could not assimilate xylose, arabinose, cellobiose, raffinose, or trehalose. In addition, the yeast cells could tolerate up to 40% glucose and 5% NaCl concentrations but their growth was inhibited at 1% acetic acid and 0.01% cyclohexamide concentrations. Pichia kudriavzevii produced about 35 and 200% more ethanol than the conventional Saccharomyces cerevisiae cells at 40 and 45°C, respectively. About 94% glucan in alkali-treated rice straw was converted to glucose through enzymatic hydrolysis within 36 h. Ethanol concentration of 24.25 g l⁻¹ corresponding to 82% theoretical yield on glucan basis and ethanol productivity of 1.10 g l⁻¹ h⁻¹ achieved using P. kudriavzevii during SSF hold promise for scale-up studies. An insignificant amount of glycerol and no xylitol was produced during SSF. To the best of our knowledge, this is the first study reporting ethanol production from any lignocellulosic biomass using P. kudriavzevii.
Topics: Biofuels; Cellulase; Ethanol; Fermentation; Hydrolysis; Industrial Microbiology; Oryza; Pichia; Saccharomyces cerevisiae; beta-Glucosidase
PubMed: 22131104
DOI: 10.1007/s10295-011-1060-2 -
Letters in Applied Microbiology Jan 2016This work explores the potential for the development of orange peel based ethanol bioprocesses through isolation of the thermotolerant Pichia kudriavzevii KVMP10. A...
UNLABELLED
This work explores the potential for the development of orange peel based ethanol bioprocesses through isolation of the thermotolerant Pichia kudriavzevii KVMP10. A model solution of hydrolysed Valencia orange peel was employed to determine the ethanologenic potential of the yeast, which was maximized at 42°C producing 54 g l(-1) of ethanol. The effect of orange peel oil on bioethanol formation was investigated at 30 and 42°C confirming that the minimum inhibitory peel oil content was 0·01% (v/v). Pichia kudriavzevii KVMP10 demonstrated significant technological advantages for the production of sustainable bioenergy, such as utilization of both hexoses (glucose, sucrose, fructose and galactose) and pentoses (xylose) at high temperatures, exemplifying its great potential for application in orange peel based biorefineries for ethanol production.
SIGNIFICANCE AND IMPACT OF THE STUDY
Citrus peel waste is one of the most underutilized and geographically diverse residues in the planet. In attempt to develop a citrus peel based biorefinery we report here the isolation of a yeast which exhibited favourable technological characteristics for the production of ethanol through utilization of the specific food waste. Pichia kudriavzevii KVMP10 was highly thermotolerant and utilized both hexoses and pentoses for ethanol production, which was achieved at elevated rates, highlighting its great potential for application in ethanol production processes from citrus peel.
Topics: Bioreactors; Citrus sinensis; Ethanol; Fermentation; Fructose; Fruit; Galactose; Glucose; Hot Temperature; Hydrolysis; Kluyveromyces; Molecular Sequence Data; Pichia; Saccharomyces cerevisiae; Soil Microbiology; Sucrose; Xylose; Zymomonas
PubMed: 26510181
DOI: 10.1111/lam.12514 -
Molecules (Basel, Switzerland) Jan 2021This study aimed to identify the volatile compounds in the fermented and dried cocoa beans conducted with three distinct inoculants of yeast species due to their high...
This study aimed to identify the volatile compounds in the fermented and dried cocoa beans conducted with three distinct inoculants of yeast species due to their high fermentative capacity: , , the mixture in equal proportions 1:1 of both species, and a control fermentation (with no inoculum application). Three starter cultures of yeasts, previously isolated and identified in cocoa fermentation in the municipality of Tomé-Açu, Pará state, Brazil. The seeds with pulp were removed manually and placed in wooden boxes for the fermentation process that lasted from 6 to 7 days. On the last day of fermentation, the almonds were packaged properly and placed to dry (36 °C), followed by preparation for the analysis of volatile compounds by GC-MS technique. In addition to the control fermentation, a high capacity for the formation of desirable compounds in chocolate by the inoculants with was observed, which was confirmed through multivariate analyses, classifying these almonds with the highest content of aldehydes, esters, ketones and alcohols and low concentration of off-flavours. We conclude that the addition of mixed culture starter can be an excellent alternative for cocoa producers, suggesting obtaining cocoa beans with desirable characteristics for chocolate production, as well as creating a product identity for the producing region.
Topics: Cacao; Chocolate; Fermentation; Food Industry; Pichia; Saccharomyces cerevisiae; Seeds; Volatile Organic Compounds
PubMed: 33440885
DOI: 10.3390/molecules26020344 -
Food Science & Nutrition Nov 2015Probiotic strains contribute to the functionality of foods during fermentation. In this present work, cereal-mix was fermented with probiotic Pichia kudriavzevii OG32....
Probiotic strains contribute to the functionality of foods during fermentation. In this present work, cereal-mix was fermented with probiotic Pichia kudriavzevii OG32. Selected fermentation parameters and functional properties of the product were determined. The growth of Pichia kudriavzevii OG32 was supported by the cereal-mix containing 1% salt and 0.2% red chili powder to counts of between 7.46 and 8.22 Log10 cfu/mL within 24 h. Pichia kudriavzevii OG32 increased the viscosity of cereal-mix with the highest inoculum size (1.84x105cfu/ml) giving the highest viscosity of 1793.6 mPa.S. An inoculum size of 1.98 × 10(4) cfu/mL gave the most acceptable product based on the sensory evaluation by the panelist. Forty volatile compounds were identified in the fermented product, while acids (32.21%) and esters (32.37%) accounted for the largest proportions. The cereal-based fermented product scavenged DPPH from 200 μmol/L methanolic solution by 55.71%. Probiotic yeast improved the sensory and some functional properties of cereal-based substrate during fermentation. This is one of the first reports on the volatile composition of cereal-based functional food produced with probiotic yeast.
PubMed: 26788290
DOI: 10.1002/fsn3.239 -
Bioprocess and Biosystems Engineering Jul 2017The importance of non-Saccharomyces yeast species in fermentation processes is widely acknowledged. Within this group, Pichia kudriavzevii ITV-S42 yeast strain shows...
The importance of non-Saccharomyces yeast species in fermentation processes is widely acknowledged. Within this group, Pichia kudriavzevii ITV-S42 yeast strain shows particularly desirable characteristics for ethanol production. Despite this fact, a thorough study of the metabolic and kinetic characteristics of this strain is currently unavailable. The aim of this work is to study the nutritional requirements of Pichia kudriavzevii ITV-S42 strain and the effect of different carbon sources on the growth and ethanol production. Results showed that glucose and fructose were both assimilated and fermented, achieving biomass and ethanol yields of 0.37 and 0.32 gg, respectively. Glycerol was assimilated but not fermented; achieving a biomass yield of 0.88 gg. Xylose and sucrose were not metabolized by the yeast strain. Finally, the use of a culture medium enriched with salts and yeast extract favored glucose consumption both for growth and ethanol production, improving ethanol tolerance reported for this genre (35 g L) to 90 g L maximum ethanol concentration (over 100%). Furthermore Pichia kudriavzevii ITV-S42 maintained its fermentative capacity up to 200 g L initial glucose, demonstrating that this yeast is osmotolerant.
Topics: Carbon; Ethanol; Fermentation; Pichia; Sorghum; Xylose
PubMed: 28447168
DOI: 10.1007/s00449-017-1769-z -
Genome Announcements Apr 201765, 129, and 131 have been isolated from the microbiota of fermented masau fruits. and especially harbor promising features for biotechnology and food applications....
65, 129, and 131 have been isolated from the microbiota of fermented masau fruits. and especially harbor promising features for biotechnology and food applications. Here, we present the draft annotated genome sequences of these isolates.
PubMed: 28385833
DOI: 10.1128/genomeA.00064-17 -
Yeast (Chichester, England) Aug 2016The present research was undertaken to study the probiotic characteristics of Pichia kudriavzevii isolated from frozen idli batter. Polymerase chain reaction...
The present research was undertaken to study the probiotic characteristics of Pichia kudriavzevii isolated from frozen idli batter. Polymerase chain reaction amplification with 18S rRNA primers confirmed Pichia kudriavzevii, a xylose-utilizing probiotic strain. It was resistant to physiological concentrations of bile salts, pepsin and pancreatic enzyme. It also showed efficient auto-aggregation as well as co-aggregation ability with four commercial probiotic yeasts and exhibited good hydrophobicity in xylene and toluene. The strain inhibited the growth of 13 enteropathogens and showed a commensal relationship with four commercial probiotic yeast and bacteria. Moreover, it was resistant to 30 antibiotics with different modes of action. The yeast exhibited thermotolerance up to 95 °C for 2 h. The cell-free supernatants were also found to be heat stable, indicating the presence of thermostable secondary metabolites. Hence it could be exploited as starter culture, co-culture or probiotic in the preparation of fermented products or incorporated in heatable foods as well. Copyright © 2016 John Wiley & Sons, Ltd.
Topics: Anti-Bacterial Agents; Antibiosis; Bile Acids and Salts; Coculture Techniques; Drug Resistance, Microbial; Fermentation; Food Microbiology; Hot Temperature; Hydrogen-Ion Concentration; Hydrophobic and Hydrophilic Interactions; Microbial Viability; Phenotype; Pichia; Probiotics; Xylose
PubMed: 27370793
DOI: 10.1002/yea.3181 -
Current Opinion in Critical Care Oct 2023The increasing incidence of drug-resistant Candida brings a new challenge to the treatment of invasive candidiasis. Although cross-resistance among azoles and... (Review)
Review
PURPOSE OF REVIEW
The increasing incidence of drug-resistant Candida brings a new challenge to the treatment of invasive candidiasis. Although cross-resistance among azoles and echinocandins was generally uncommon, reports of multidrug-resistant (MDR) Candida markedly increased in the last decade. The purpose of this review is to understand mechanisms and risk factors for resistance and how to tackle antifungal resistance.
RECENT FINDINGS
The paper describes the action of the three main classes of antifungals - azoles, echinocandins and polyenes - and Candida's mechanisms of resistance. The current evolution from cross-resistance to multiresistance among Candida explains the modern glossary - multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) - imported from bacteria. MDR Candida most commonly involves acquired resistance in species with intrinsic resistance, therefore it mostly involves C. glabrata, C. parapsilosis, C. krusei, C guilliermondii or C. auris , which is intrinsically multidrug resistant. Finally, strategies to tackle antifungal resistance became clearer, ideally implemented through antifungal stewardship.
SUMMARY
Avoiding antifungal's overuse and selecting the best drug, dose and duration, when they are needed, is fundamental. Knowledge of risk factors for resistance, microbiological diagnosis to the species, use of susceptibility test supported by antifungal stewardship programs help attaining effective therapy and sustaining the effectiveness of the current antifungal armamentarium.
Topics: Humans; Candida; Antifungal Agents; Candidiasis, Invasive; Echinocandins; Azoles
PubMed: 37641511
DOI: 10.1097/MCC.0000000000001077