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Foods (Basel, Switzerland) Jan 2024In this study, changes in volatile compounds co-fermented by different with were analyzed using GC-IMS and compared with fermentation, to investigate the production...
In this study, changes in volatile compounds co-fermented by different with were analyzed using GC-IMS and compared with fermentation, to investigate the production of aroma in mulberry wine during the fermentation process. A total of 61 compounds were accurately identified, including 21 esters, 10 alcohols, 8 aldehydes, 6 ketones, and 19 other volatiles. Compared with the single strain fermentation (), the content of 2-methylpropyl acetate, allyl Isothiocyanate, ethyl crotonate, isobutyl propanoate, and butyl 2-methylbutanoate, co-fermentation groups ( with different ) showed a significant decrease. Alcohols, aldehydes, ketones, and organic acid were lower in both the F(S-P1) and F(S-P2) groups than in the F(S) group throughout fermentation. The 2-methylpentanoic acid only was contained in the F(S) group. The co-fermentation with different could also be well distinguished. The content of Benzaldehyde and 4-methylphenol in the F(S-P1) group was significantly lower than that in the F(S-P2) group. The PCA results revealed effective differentiation of mulberry wine fermented by different fermentation strains from GC-IMS. The result showed that could establish a new flavor system for mulberry wine, which plays a crucial role in enhancing the flavor of fruit wine.
PubMed: 38338556
DOI: 10.3390/foods13030422 -
Mycobiology 2020Citric acid is a commercially valuable organic acid widely used in food, pharmaceutical, and beverage industries. In this study, 260 yeast strains were isolated from...
Citric acid is a commercially valuable organic acid widely used in food, pharmaceutical, and beverage industries. In this study, 260 yeast strains were isolated from soil, bread, juices, and fruits wastes and preliminarily screened using bromocresol green agar plates for their ability to produce organic acids. Overall, 251 yeast isolates showed positive results, with yellow halos surrounding the colonies. Citric acid production by 20 promising isolates was evaluated using both free and immobilized cell techniques. Results showed that citric acid production by immobilized cells (30-40 g/L) was greater than that of freely suspended cells (8-19 g/L). Of the 20 isolates, two (KKU-L42 and KKU-L53) were selected for further analysis based on their citric acid production levels. Immobilized KKU-L42 cells had a higher citric acid production rate (62.5%), while immobilized KKU-L53 cells showed an ∼52.2% increase in citric acid production compared with free cells. The two isolates were accurately identified by amplification and sequence analysis of the 26S rRNA gene D1/D2 domain, with GenBank-based sequence comparison confirming that isolates KKU-L42 and KKU-L53 were and , respectively. Several factors, including fermentation period, pH, temperature, and carbon and nitrogen source, were optimized for enhanced production of citric acid by both isolates. Maximum production was achieved at fermentation period of 5 days at pH 5.0 with glucose as a carbon source by both isolates. The optimum incubation temperature for citric acid production by was 32 °C, with NHCl the best nitrogen source, while maximum citric acid by was observed at 27 °C with (NH) SO as the nitrogen source. Citric acid production was maintained for about four repeated batches over a period of 20 days. Our results suggest that apple and banana wastes are potential sources of novel yeast strains; and which could be used for commercial citric acid production.
PubMed: 32363040
DOI: 10.1080/12298093.2020.1726854 -
Data in Brief Aug 2023strain APC 11.10 B was isolated from apple bark in Switzerland and exhibited strong antagonistic activity against plant pathogenic fungi (e.g., or isolates). In...
strain APC 11.10 B was isolated from apple bark in Switzerland and exhibited strong antagonistic activity against plant pathogenic fungi (e.g., or isolates). In order to identify the mechanisms underlying this antagonism, we have sequenced the genome of this isolate by long- and short-read sequencing technologies. The sequence data were assembled into nine scaffolds and a fully resolved circularized mitogenome. The total genome size was 10.9 Mbp and 7451 potential open reading frames (ORFs) and 202 tRNA genes were predicted. In comparison to two genomes deposited at the NCBI (of strains X31-10 and CBA6002), the APC 11.10 B strain seemed to represent a hybrid because backmapping of sequencing reads resulted in a high rate of heterozygous and structural variants in the nuclear genome (this was not observed for the mitochondrial genome). The (APC 11.10 B) draft genome represents a first step and resource for genome mining, comparative and functional genomics (e.g., identifying the biocontrol mode of action), and evolutionary studies. Since the genus comprises many biotechnologically relevant yeasts, the genome data may be used in a variety of fields and disciplines.
PubMed: 37496519
DOI: 10.1016/j.dib.2023.109394 -
Current Microbiology Sep 2019Seven endophytic yeast strains were isolated from tangerine peel (Citrus reticulata Blanco) and genotyped through clustering with D1/D2 and ITS1-5.8S-ITS2 sequences from...
Seven endophytic yeast strains were isolated from tangerine peel (Citrus reticulata Blanco) and genotyped through clustering with D1/D2 and ITS1-5.8S-ITS2 sequences from GenBank. Phenotypic characteristics were obtained through commercial kits and through assisted species identification. Indole-3-acetic acid (IAA) production by the yeast strains was assessed using Salkowski reagent and High-Performance Liquid chromatography (HPLC). The growth-promoting effects of the yeast were evaluated using the 'ragdoll' method. CRYb1, CRYb2 and CRYb7 isolates were identified as the closest species Hanseniaspora opuntiae. CRYb3 was identified as Pichia kluyveri. CRYb4, CRYb5 and CRYb6 were identified as Meyerozyma guilliermondii. CRYb1, CRYb5, CRYb6 and CRYb7 were found to be capable of IAA production. The most promising yeast strains now require further evaluation for their ability to promote plant growth in vitro and in vivo. These data increase our knowledge of the distribution and biological properties of endophytic yeast. This is important information that will be required to fully harness the growth-promoting properties of yeast strains.
Topics: Citrus; Endophytes; Fruit; Indoleacetic Acids; Phylogeny; Pichia
PubMed: 31243536
DOI: 10.1007/s00284-019-01721-9 -
Food Microbiology Feb 2022Cocoa fermentation is the key and most relevant process in the synthesis of aroma and flavor precursor molecules in dry beans or raw material for producing chocolate....
Cocoa fermentation is the key and most relevant process in the synthesis of aroma and flavor precursor molecules in dry beans or raw material for producing chocolate. Because this process occurs in an uncontrolled manner, the chemical and sensory quality of beans can vary and be negatively affected. One of the strategies for the standardization and improvement of the sensory quality of chocolate is the introduction of microbial starter cultures. Among these, yeasts involved in fermentation have been studied because of their pectinolytic and metabolic potential in the production of volatile compounds. This study was aimed at isolating and characterizing, both sensory and chemically, yeasts involved in cocoa fermentation that could be used as starter cultures from two agro-ecological regions for the cultivation of cocoa in Colombia. The microbiological analyses identified 22 species represented mostly by Saccharomyces cerevisiae, Wickerhamomyces anomalus and Pichia sp. The preliminary sensory analysis of eight of these species showed that Hanseniaspora thailandica and Pichia kluyveri presented sensory profiles characterized by high intensity levels of fruity notes, which could be ascribed to the production of ethyl acetate, isoamyl acetate, and 2-phenylethyl acetate.
Topics: Bioprospecting; Cacao; Chocolate; Fermentation; Hanseniaspora; Pichia; Saccharomyces cerevisiae; Saccharomycetales; Yeasts
PubMed: 34579856
DOI: 10.1016/j.fm.2021.103896 -
World Journal of Microbiology &... Mar 2024Probiotic microorganisms are used to improve the health and wellness of people and the research on this topic is of current relevance and interest. Fifty-five yeasts,...
Probiotic microorganisms are used to improve the health and wellness of people and the research on this topic is of current relevance and interest. Fifty-five yeasts, coming from honeybee's ecosystem and belonging to Candida, Debaryomyces, Hanseniaspora, Lachancea, Metschnikowia, Meyerozyma, Starmerella and Zygosacchromyces genera and related different species, were evaluated for the probiotic traits. The resistance to gastrointestinal conditions, auto-aggregation, cell surface hydrophobicity or biofilm formation abilities as well as antimicrobial activity against common human pathogenic bacteria were evaluated. The safety analysis of strains was also carried out to exclude any possible negative effect on the consumer's health. The influence of proteinase treatment of living yeasts and their adhesion to Caco-2 cells were also evaluated. The greatest selection occurred in the first step of survival at the acidic pH and in the presence of bile salts, where more than 50% of the strains were unable to survive. Equally discriminating was the protease test which allowed the survival of only 27 strains belonging to the species Hanseniaspora guilliermondii, Hanseniaspora uvarum, Metschnikowia pulcherrima, Metschnikowia ziziphicola, Meyerozyma caribbica, Meyerozyma guilliermondii, Pichia kluyveri, Pichia kudriavzevii and Pichia terricola. An integrated analysis of the results obtained allowed the detection of seven yeast strains with probiotic aptitudes, all belonging to the Meyerozyma genus, of which three belonging to M. guillermondii and four belonging to M. caribbica species.
Topics: Bees; Animals; Humans; Ecosystem; Caco-2 Cells; Yeasts; Candida; Probiotics
PubMed: 38538981
DOI: 10.1007/s11274-024-03941-z -
Journal of Insect Physiology 2019A healthy gut microbiota generally improves the performance of its insect host. Although the effects can be specific to the species composition of the microbial...
A healthy gut microbiota generally improves the performance of its insect host. Although the effects can be specific to the species composition of the microbial community, the role of gut microbiota in determining water balance has not been well explored. We used axenic and gnotobiotic (reared with a known microbiota) Drosophila melanogaster to test three hypotheses about the effects of gut yeasts on the water balance of adult flies: 1) that gut yeasts would improve desiccation survival in adult flies; 2) that larval yeasts would improve adult desiccation survival; 3) that the effects would be species-specific, such that yeasts closely associated with D. melanogaster in nature are more likely to be beneficial than those rarely found in association with D. melanogaster. We used Saccharomyces cerevisiae (often used in Drosophila cultures, but rarely associated with D. melanogaster in nature), Lachancea kluyveri (associated with some species of Drosophila, but not D. melanogaster), and Pichia kluyveri (associated with D. melanogaster in nature). Adult inoculation with yeasts had no effect on survival of desiccating conditions. Inoculation with P. kluyveri as larvae did not change desiccation survival in adults; however, rearing with L. kluyveri or S. cerevisiae reduced adult desiccation survival. We conclude that adult inoculation with gut yeasts has no impact on desiccation survival, but that rearing with yeasts can have either no or detrimental effect. The effects appear to be species-specific: P. kluyveri did not have a negative impact on desiccation tolerance, suggesting some level of co-adaptation with D. melanogaster. We note that S. cerevisiae may not be an appropriate species for studying the effects of gut yeasts on D. melanogaster.
Topics: Animals; Drosophila melanogaster; Female; Gastrointestinal Microbiome; Male; Pichia; Saccharomyces cerevisiae; Water
PubMed: 31170408
DOI: 10.1016/j.jinsphys.2019.103893 -
Applied Bionics and Biomechanics 2022Detection of food spoilage with simple and fast methods is an important issue in food security and safety. The present study is mainly aimed at identifying and...
Detection of food spoilage with simple and fast methods is an important issue in food security and safety. The present study is mainly aimed at identifying and quantifying four yeast species in white fresh soft cheese using an electronic nose (EN). The yeast species , , , and were used. Six concentrations of each yeast species (100, 200, 400, 600, 800, and 1000 cells/g cheese) were inoculated in 100 g of fresh soft cheese and incubated for 48 h at 25°C. The EN was used to identify and quantify different yeast species in cheese samples. It was found that EN was able to discriminate between four yeast species using principal component analysis (PCA). Moreover, EN was able to quantify in good precision three (, , and ) of the four tested yeasts presented in cheese samples using partial least squares (PLS) models. It seems that EN is a reliable tool that can be used as a fast technique to identify and quantify cheese spoilage in the cheese industry.
PubMed: 35082918
DOI: 10.1155/2022/8472661 -
Brazilian Journal of Microbiology :... Dec 2021Yeast isolates from flowers and fruits from a Brazilian forest were studied. The yeasts were identified at species and strain level by PCR-RFLP and PCR-RAPD,...
Yeast isolates from flowers and fruits from a Brazilian forest were studied. The yeasts were identified at species and strain level by PCR-RFLP and PCR-RAPD, respectively. The 46 isolated yeasts were classified into 11 different species belonging to the genera Candida, Diutina, Hanseniaspora, Meyerozyma, Pichia, Rhodotorula, and Torulaspora. A total of 20 different strains were found. In order to ascertain the probiotic potential, the resistance to gastrointestinal conditions, autoaggregation, and hydrophobicity assays were studied, along with the capacity to form biofilm. The results indicate that, although most of the strains presented better results than Saccharomyces boulardii (the only strain recognized as a probiotic yeast), four strains were the most promising, namely, Rhodotorula mucilaginosa 32, Meyerozyma caribbica 35, and Diutina rugosa 12 and 45, according to the Duncan test. Several biotechnological properties were evaluated. D. rugosa inhibited Dekkera bruxellensis. The assimilation or fermentation of seven sugars was tested, and only five of the yeasts did not show a capacity to assimilate any of the sugars under aerobic conditions. However, all strains were able to ferment at least one of the sugars under anaerobic conditions. As far as enzyme production is concerned, positive results were only found for the enzymes' amylase, pectinase, and protease. D. rugosa 42 and Hanseniaspora opuntiae 18, followed of Pichia kluyveri 26, showed high values for the production of melatonin. In conclusion, the results of this study show that several non-Saccharomyces present probiotic characteristics, and these have good potential for industrial applications in the food or biotechnology industries.
Topics: Biotechnology; Ecosystem; Fermentation; Fruit; Probiotics; Random Amplified Polymorphic DNA Technique; Sugars; Yeasts
PubMed: 34595728
DOI: 10.1007/s42770-021-00541-z -
World Journal of Microbiology &... Feb 2021This study aimed to assess the microbial diversity in Coffea canephora grown in four different environments of Espirito Santo state, Brazil. Coffee cherries of two...
This study aimed to assess the microbial diversity in Coffea canephora grown in four different environments of Espirito Santo state, Brazil. Coffee cherries of two different altitudes (300 and 600 m) and two terrain aspects (Southeast-facing and Northwest-facing slopes) were processed by the dry method. Samples were collected during the drying/fermentation process. Microorganisms were counted, isolated, and identified by MALDI-TOF, followed by sequencing of the ribosomal region. Sugars and organic acids were quantified by HPLC and volatile compounds of the roasted coffees were evaluated by GC-MS. Bacteria population presented a significant number of isolates as well as higher counts during the drying/fermentation process with respect to the population of yeasts. The principal genera of microorganisms found were Bacillus, Pichia, Candida, and Meyerozyma. Meyerozyma guilliermondii was the most frequent yeast in all environments. On the other hand, Pichia kluyveri was found only in coffee cherries from the 600 m altitude. The highest concentration of acetic and succinic acids observed was 6.06 mg/g and 0.84 mg/g, respectively. Sucrose concentrations ranged from 0.68 to 5.30 mg/g, fructose from 1.30 to 4.60 mg/g, and glucose from 0.24 to 1.25 mg/g. Thirty-six volatile compounds, belonging to the groups of pyrazines, alcohols, aldehydes, ketones, and furans were identified in roasted coffee, with differences between altitude and terrain aspects. Information about microbial diversity is crucial to better understand the coffee quality and distinct characteristics of coffee produced in different environments.
Topics: Alcohols; Bacteria; Brazil; Coffea; Coffee; Desiccation; Fermentation; Food Handling; Fungi; Gas Chromatography-Mass Spectrometry
PubMed: 33594606
DOI: 10.1007/s11274-021-03017-2