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Journal of Fungi (Basel, Switzerland) Oct 2022The aim of this study was to investigate the effects of purified β-glucosidases from SLY-4, F2-24, and HX-13 (named as SLY-4E, F2-24E, and HX-13E, respectively) on...
The aim of this study was to investigate the effects of purified β-glucosidases from SLY-4, F2-24, and HX-13 (named as SLY-4E, F2-24E, and HX-13E, respectively) on the flavor complexity and typicality of wines. Cabernet Sauvignon wines were fermented by with the addition of SLY-4E, F2-24E, and HX-13E; the fermentation process and characteristics of wines were analyzed. The addition of SLY-4E, F2-24E, and HX-13E into must improved the contents of terpenes, higher alcohols, and esters, and decreased the contents of C compounds and fatty acids, which enhanced the fruity, floral, and taste aspects, reducing the unpleasant green of wines with no significant difference in their appearance. β-glucosidases from different yeast species produced different aroma compound profiles which presented different flavor and quality. F2-24EW had the best effect on flavor and quality of wine followed by SLY-4EW and HX-13EW. These research results can provide references for the use of β-glucosidases from non- yeasts to improve the flavor complexity, typicality, and quality of wines.
PubMed: 36294622
DOI: 10.3390/jof8101057 -
Foods (Basel, Switzerland) Feb 2023This study explored the effect of the combination of yeast, non- yeast (), and during cider fermentation on physicochemical properties, antioxidant activities, flavor...
This study explored the effect of the combination of yeast, non- yeast (), and during cider fermentation on physicochemical properties, antioxidant activities, flavor and aroma compounds, as well as sensory qualities. Ciders fermented with the triple mixed-cultures of these three species showed lower acid and alcohol content than those fermented with the single-culture of . The antioxidant activities were enhanced by the triple mixed-culture fermentation, giving a higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate and total antioxidant capacity; specifically, the SPL5 cider showed the highest DPPH radical scavenging rate (77.28%), while the SPL2 gave the highest total antioxidant capacity (39.57 mmol/L). Additionally, the triple mixed-culture fermentation resulted in improved flavor and aroma with a lower acidity (L-malic acid) and higher aroma compounds (Esters), when compared with the single-culture fermented ciders (); more specifically, the SPL4 cider resulted in the highest total flavor and aroma compounds. In addition, sensory evaluation demonstrated that ciders produced using the triple mixed-cultures gained higher scores than those fermented using the single-culture of , giving better floral aroma, fruity flavor, and overall acceptability. Therefore, our results indicated that the triple mixed-cultures (, , and ) were found to make up some enological shortages of the single fermented cider. This study is believed to provide a potential strategy to enhance cider quality and further give a reference for new industrial development protocols for cider fermentation that have better sensory qualities with higher antioxidant properties.
PubMed: 36766182
DOI: 10.3390/foods12030655 -
Food Chemistry Feb 2021The use of starters during fermentation has been gaining momentum as it can warrant high-quality chocolate. The objective of this study was to investigate the influence...
The use of starters during fermentation has been gaining momentum as it can warrant high-quality chocolate. The objective of this study was to investigate the influence of Saccharomyces cerevisiae (Sc) and Pichia kudriavzevii (Pk) during on-farm fermentation on physico-chemical and microbiological characteristics and levels of methylxanthines and bioactive amines of cocoa. Four treatments were used: ScPk (1:1), only Sc, only Pk, and no starter (control). The starters lead to changes throughout fermentation, but provided fermented cocoa with similar pH, titratable acidity, reducing sugars and phenolic compounds. ScPk shortened fermentation time by 24 h. The ScPk fermented and dried cocoa had higher levels of monomeric phenols, methylxanthines, phenylethylamine and lower levels of the putrefactive amines - putrescine and cadaverine (p < 0.05). The results were confirmed by multivariate analysis. Based on these results, the mixture of both yeasts species is a promising starter for cocoa fermentation decreasing duration time and modulating high-quality components.
Topics: Amines; Cacao; Caffeine; Catechin; Chocolate; Farms; Fermentation; Food Microbiology; Hydrogen-Ion Concentration; Phenols; Pichia; Saccharomyces cerevisiae; Temperature; Theobromine; Theophylline; Time Factors
PubMed: 32810810
DOI: 10.1016/j.foodchem.2020.127834 -
Journal of Bioscience and Bioengineering Dec 2020The non-conventional yeast Pichia kudriavzevii is considered to be a promising biotechnological host for the production of organic acids under low-pH conditions....
The non-conventional yeast Pichia kudriavzevii is considered to be a promising biotechnological host for the production of organic acids under low-pH conditions. However, little is known about the low-pH stress response in P. kudriavzevii, which significantly restricts its future development. In this study, P. kudriavzevii N-X showed great tolerance to low-pH stress, but the cell aggregation upon extremely acidic conditions might be unfavorable for low-pH fermentation. We therefore conducted RNA-Seq to compare global gene expression of P. kudriavzevii N-X in response to different pH stresses. Totally 434 genes were identified to be differentially expressed genes (DEGs), and annotation and enrichment analysis suggested that multiple genes associated with regulation of membrane lipid composition, filamentous growth and arginine metabolism were differentially expressed. The increased specific activity of arginase and intracellular ammonia concentration of P. kudriavzevii cultured at pH 2.0 further implied potential roles of arginine in response to extreme low-pH conditions. Extracellular supplementation of 5 mM arginine resulted in increased pHi and cell growth at pH 2.0, meanwhile the cell aggregation was partially suppressed. Additionally, overexpression of ARG J involving in arginine synthesis can also enhance the cell growth and reduce the aggregation effect. These results suggested that increasing arginine flux might be an alternative approach in the developing of P. kudriavzevii as a platform host for production of organic acids under low-pH conditions.
Topics: Arginine; Fermentation; Hydrogen-Ion Concentration; Oxidative Stress; Pichia; Transcription, Genetic
PubMed: 32798135
DOI: 10.1016/j.jbiosc.2020.07.014 -
Biotechnology Advances 2023The conventional yeast (Saccharomyces cerevisiae) is the most studied yeast and has been used in many important industrial productions, especially in bioethanol... (Review)
Review
The conventional yeast (Saccharomyces cerevisiae) is the most studied yeast and has been used in many important industrial productions, especially in bioethanol production from first generation feedstock (sugar and starchy biomass). However, for reduced cost and to avoid competition with food, second generation bioethanol, which is produced from lignocellulosic feedstock, is now being investigated. Production of second generation bioethanol involves pre-treatment and hydrolysis of lignocellulosic biomass to sugar monomers containing, amongst others, d-glucose and D-xylose. Intrinsically, S. cerevisiae strains lack the ability to ferment pentose sugars and genetic engineering of S. cerevisiae to inculcate the ability to ferment pentose sugars is ongoing to develop recombinant strains with the required stability and robustness for commercial second generation bioethanol production. Furthermore, pre-treatment of these lignocellulosic wastes leads to the release of inhibitory compounds which adversely affect the growth and fermentation by S. cerevisae. S. cerevisiae also lacks the ability to grow at high temperatures which favour Simultaneous Saccharification and Fermentation of substrates to bioethanol. There is, therefore, a need for robust yeast species which can co-ferment hexose and pentose sugars and can tolerate high temperatures and the inhibitory substances produced during pre-treatment and hydrolysis of lignocellulosic materials. Non-conventional yeast strains are potential solutions to these problems due to their abilities to ferment both hexose and pentose sugars, and tolerate high temperature and stress conditions encountered during ethanol production from lignocellulosic hydrolysate. This review highlights the limitations of the conventional yeast species and the potentials of non-conventional yeast strains in commercialization of second generation bioethanol.
Topics: Saccharomyces cerevisiae; Pentoses; Xylose; Genetic Engineering; Fermentation
PubMed: 36669745
DOI: 10.1016/j.biotechadv.2023.108100 -
Applied Biochemistry and Biotechnology Jun 2024Deoxynivalenol (DON) is a mycotoxin that significantly threatens the food and feed industry. Corn steep liquor (CSL) is an acidic byproduct of the corn starch industry,...
Deoxynivalenol (DON) is a mycotoxin that significantly threatens the food and feed industry. Corn steep liquor (CSL) is an acidic byproduct of the corn starch industry, and DON is concentrated in CSL once the material is contaminated. In this work, a Pichia kudriavzevii strain that could remove DON from CSL was isolated and characterized. The strain P. kudriavzevii E4-205 showed detoxifying activity in a pH range of 4.0~7.0 and temperature of 25~42 °C, and 39.4% DON was reduced by incubating this strain in CSL supernatant diluted by 2-fold (5 μg/mL DON) for 48 h at pH 5.0 and 30 °C. Further mechanism studies showed that P. kudriavzevii E4-205 could adsorb DON by the cell wall and degrade DON by intracellular enzymes with NADH as a cofactor. The degradation product was identified as 3,7,8,15-tetrahydroxyscirpene by liquid chromatography-tandem mass spectrometry. DON adsorption by inactivated cells was characterized, and the adsorption followed pseudo first-order kinetics. This study revealed a novel mechanism by which microbes degrade DON and might serve as a guide for the development of DON biological detoxification methods.
Topics: Trichothecenes; Pichia; Cell Wall; Adsorption; Hydrogen-Ion Concentration; Zea mays; Temperature; Kinetics
PubMed: 37624506
DOI: 10.1007/s12010-023-04712-6 -
Archives of Microbiology Aug 2023Recently, there has been growing interest in the characterization of native yeasts for their use in production of wines with regional characteristics. This study aimed...
Recently, there has been growing interest in the characterization of native yeasts for their use in production of wines with regional characteristics. This study aimed to investigate Saccharomyces and non-Saccharomyces yeasts present in the spontaneous fermentation of Tannat and Marselan grape musts collected from Concordia (Entre Ríos, Argentina) over 2019, 2020, and 2021 vintages. The evolution of these fermentative processes was carried out by measuring total soluble solids, total acidity, volatile acidity, pH, ethanol concentration, and total carbon content. Isolated Saccharomyces and non-Saccharomyces yeasts were identified based on colony morphology in WL medium, 5.8S-ITS-RFLP analysis, and 26S rDNA D1/D2 gene sequencing. Two hundred and ten yeast colonies were isolated and identified as Pichia kudriavzevii, Saccharomyces cerevisiae, Hanseniaspora uvarum, Metschnikowia pulcherrima, Candida albicans, Candida parapsilosis, Pichia occidentalis, Pichia bruneiensis, Hanseniaspora opuntiae, Issatchenkia terricola, and Hanseniaspora vineae. P. kudriavzevii isolated from all vintages was associated with the spontaneous fermentation of grape musts from the Concordia region.
Topics: Vitis; Fermentation; Yeasts; Wine; Saccharomyces cerevisiae; DNA, Ribosomal
PubMed: 37550458
DOI: 10.1007/s00203-023-03646-1 -
Colloids and Surfaces. B, Biointerfaces May 2023In this research, CuZnSnS (CZTS) particles were successfully fabricated via the molten salt approach from the copper, zinc and tin sulphides as raw precursors. SEM...
In this research, CuZnSnS (CZTS) particles were successfully fabricated via the molten salt approach from the copper, zinc and tin sulphides as raw precursors. SEM analysis revealed that CZTS particles are tetragonal-shaped with sharp edges, smooth flat plane morphology, and crystal size varying from 10.8 to 28.7 µm. The phase and crystalline structure of synthesized powders were investigated using XRD analysis, which confirms the presence of a tetragonal crystal structure kesterite phase. The chemical composition of CZTS particles was evaluated by EDX spectroscopy, which identified the nearly stoichiometric composition with an averaged formula of CuZnSnS. The TG/DTA-MS and ICP-OES analysis showed the possible decomposition pathways and predicted their degradation rate in aqueous solutions. The CZTS particles possessed highly effective concentration and time-dependent antimicrobial properties against medically relevant bacteria and yeast strains. The CZTS particles (1 g L) exhibited over 95.7 ± 1.9% killing efficiency towards M. luteus. In contrast, higher dosages (3.5 and 5 g L) led to its complete inactivation and reduced the P. aeruginosa cell viability to 43.2 ± 3.2% and 4.1 ± 1.1%, respectively. Moreover, the CZTS particles (0.5 g L) are responsible for causing 54.8 ± 1.8% of C. krusei and 89.7 ± 2.1% of C. parapsilosis yeasts death within the 24 h of exposure, which expanded to almost 100% when yeasts were treated with two times higher CZTS concentration (1.0 g L). The mechanism of action has been proposed and evidenced by monitoring the 2',7'-dichlorofluorescein (DCF) fluorescence, which revealed that the overproduction of reactive oxygen species (ROS) is responsible for microorganism death.
Topics: Anti-Infective Agents; Candida parapsilosis; Cell Survival; Copper; Pseudomonas aeruginosa; Saccharomyces cerevisiae
PubMed: 36965333
DOI: 10.1016/j.colsurfb.2023.113275 -
Current Microbiology Mar 2023Arsenic (As) exists widely in the environment and its strong toxicity endangers human health, causing widespread concern. Microbial adsorption technology plays an...
Arsenic (As) exists widely in the environment and its strong toxicity endangers human health, causing widespread concern. Microbial adsorption technology plays an important role in As removal due to its advantages of high safety, low pollution, and low cost. The removal of As by active microorganisms requires not only good accumulation characteristics but also high As tolerance. The effect of salt preincubation on arsenate [As(V)] tolerance and bioaccumulation of Pichia kudriavzevii A16 and the possible mechanisms were studied. Salt preincubation improved the As(V) tolerance and bioaccumulation ability of the yeast. After NaPO preincubation, the proportion of dead cells and cells with high reactive oxygen species (ROS) accumulation decreased from 50.88% and 16.54% to 14.60% and 5.24%, respectively. In addition, the As removal rate significantly increased from 26.20% to 57.98%. The preincubated cells showed stronger As(V) tolerance and removal ability. The potential of use in complex environment to remove As(V) as well as the mechanisms involved in As(V) tolerance by yeast will be discussed.
Topics: Humans; Arsenic; Saccharomyces cerevisiae; Sodium Chloride; Pichia
PubMed: 36862180
DOI: 10.1007/s00284-023-03216-0 -
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