Search

The main reason for selecting whey as a substrate of research and raw material for alcohol production is to reduce industrial waste that adversely impacts the environment, as well as to make a profit on it. The environmental impact of whey is related to its biological oxygen demand (BOD = 230 mg/ml) and chemical oxygen demand (COD = 70 mg / ml). Whey is mainly composed of disaccharide lactose, and the activity of yeast strains plays an important role in its conversion to bioethanol. Lactic acid bacteria, whey composition, and fermentation conditions also play an important role. In this work, the physicochemical properties of milk and cheese whey were studied, and microbiological analysis was carried out. The results show the high quality of the whey of the two selected producers of cottage cheese and cheese. The uniformity of consistency and normal appearance, taste, and smell, corresponding to the whey, testify to the observance of all sanitary norms and rules at the stage of whey collection. No significant differences were found between the characteristics of two different whey samples. The cells of yeast strains isolated from whey had different natures. 4 strains of alcohol-resistant yeasts and 2 strain of lactic acid bacteria Lactobacillus plantarum W1 and Leuconostocmesenteroides W1 were isolated, which could be promising biocatalysts for bioethanol production. [ABSTRACT FROM AUTHOR]

The aim of this study is determination of the quality of red wines from grape varieties Vranec, Merlot and Frankovka fermented by wine yeasts from the French manufacturer SELECTYS® LA DÉLICIEUSE and baker’s yeast seeded in a ratio of 0.25 g/L. The research was done during 2020 and 2021 in the Vinica vineyard, where the three grape varieties are grown at an altitude from 400 to 520 m. Regarding enological parameters, the highest amount of alcohol was measured for Merlot wines fermented by French yeast (13.07%), Frankovka wine fermented by baker’s yeast had the highest amount of sugar (9.71 g/L), Vranec wine produced by baker’s yeast had the highest total acidity (7.37 g/L) while the highest concentration of volatile acids was determined for Frankovka wine fermented by French yeast SELECTYS® LA DÉLICIEUSE (1.58 g/L). The impact of wine yeast to the quantity of particular elements was the most statistically significant for Fe57 in Merlot and Vranec wines, Cu65 in Frankovka wines and Pb208 in Merlot. Vranec and Merlot wines fermented by baker’s yeast indicated higher amounts of phenolic compounds while Frankovka wines produced by SELECTYS® LA DÉLICIEUSE showed opposite tendency with significantly higher amounts of polyphenols. [ABSTRACT FROM AUTHOR]

The purpose of this work was to evaluate the effects of applying cassava starch coating with the addition of different concentrations of coconut oil in minimally processed strawberries. The strawberries were selected and sanitized, had their leaves and peduncles removed, and were submerged in the coatings (40°C) for three minutes. Four treatments were obtained: T1 - control (strawberries without coating); T2 - coconut oil (1.0%) + cassava starch (3.0%); T3 - coconut oil (1.5%) + cassava starch (3.0%); T4 - coconut oil (2.0%) + cassava starch (3.0%). After receiving the coatings, the strawberries were placed in PET (polyethylene terephthalate) containers and stored at 5±1°C for 12 days. Physical, chemical, sensory analysis and microbiological evaluations were performed. T2 and T3 samples were more efficient in reducing mass loss (14.59% and 14.52%). They were also effective in maintaining texture and color for longer, as they influenced sensory and microbiological analysis, increasing shelf life and slowing growth, especially of molds and yeasts. The study may help small-scale establishments to increase the shelf life of minimally processed strawberries. The use of small concentrations of coconut oil prolonged the quality of strawberries during refrigerated storage. [ABSTRACT FROM AUTHOR]

Yeasts are important microorganisms used in different fermentation processes. The cocoa beans must go through a correct fermentation process to obtain good-quality chocolate, which involves the action of yeasts and bacteria, and yeasts play a crucial role since they act in the first days of fermentation. In coffee, several studies have shown that the microbiota in the fruits is also a relevant factor. The fermentation process (regardless of the processing type) improves the beverage's quality. In this sense, studies using starter cultures in these two raw materials are important for better control of the process, and optimization of fermentation time, in addition to the improvement and diversification of volatile and non-volatile compounds produced by yeasts. Thus, this review discusses the importance and role of yeasts during fermentation, their metabolism, the produced compounds, and how yeast and the different chemical reactions help increase the quality of chocolate and coffee. Yeasts have a crucial role during coffee and cocoa fermentation in enhancing the quality. [ABSTRACT FROM AUTHOR]

Ethnic Indian people have been domesticating beneficial microorganisms (bacteria, yeasts, and moulds) by their wisdom of ethno-microbiological knowledge for production of flavoured and socio-culturally preferred fermented foods and alcoholic beverages for more than 8000 years. The purpose of this review is to collate the available literatures of diversity of Saccharomyces and non-Saccharomyces species associated with Indian fermented foods and alcoholic beverages. A colossal diversity of enzyme- and alcohol-producing yeasts under the phylum Ascomycota has been reported from Indian fermented foods and alcoholic beverages. The distributions of yeast species show 13.5% of Saccharomyces cerevisiae and 86.5% of some non-Saccharomyces spp. in Indian fermented foods and alcoholic beverages, based on the reported literatures available till date. There is a research gap on prospect of yeasts research in India. Hence, we suggest that validation of traditional knowledge of domestication of functional yeasts needs to be studied to develop the functional genomics platforms for Saccharomyces and non-Saccharomyces spp. in Indian fermented foods and alcoholic beverages. The purpose of this review is to collate the available literatures of diversity of Saccharomyces and non-Saccharomyces spp. in Indian fermented foods and alcoholic beverages. [ABSTRACT FROM AUTHOR]

Parabens are substances with antifungal and antibacterial properties, suspected to be endocrine disruptors and widely used as preservatives in cosmetics. In this case, exposure to these compounds is mainly dermal and interactions may occur with skin components including cutaneous mycobiota. In this work, we have explored the in vitro reciprocal interactions between three parabens (methylparaben, ethylparaben, and propylparaben) and yeasts from the human cutaneous mycobiota (Candida parapsilosis, Cryptococcus uniguttulatus , and Rhodotorula mucilaginosa) by studying the effect of these parabens on fungal growth and the fungal ability to metabolize the tested compounds. Our results showed that, at the tested concentrations, the growth of three strains of C. parapsilosis was not influenced by the presence of parabens. Whereas, using the same parabens concentrations, growth of C. uniguttulatus and R. mucilaginosa was completely inhibited by ethylparaben since the first day of contact, whereas these same fungi were not sensitive to the two other parabens, even after seven days of incubation. The presence of a lamellar wall in these basidiomycete fungi as well as the physico-chemical properties of ethylparaben could explain this selective inhibition. Additionally, C. parapsilosis and R. mucilaginosa degraded 90% to 100% of propylparaben after seven days of incubation but had no effect on the other tested parabens. Thus, their enzymes seem to only degrade long chain parabens. In the same conditions, C. uniguttulatus did not degrade any paraben. This inability may be due to the absence of fungal enzymes able to degrade parabens or to the possible inaccessibility of intracellular enzymes due to the polysaccharide capsule. Our work has shown that parabens can act differently from one fungus to another within the cutaneous mycobiota. These preliminary results have evidenced that in vitro parabens, contained in cosmetic products, could be involved in the occurrence of a state of dysbiosis. The tested yeasts from the cutaneous mycobiota can also be involved in the degradation of parabens and thereby reduce, according to the produced metabolites and their activities, the risk of endocrine disruption they can induce. [ABSTRACT FROM AUTHOR]

Introduction: The fungal nail infection (onychomycosis) involves 18%-40% of all nail disorders, which, although not fatal, can cause mechanical, aesthetic, occupational, and economic problems. Drug treatments due to prolonged treatment periods, drug interactions, adverse effects, and slow progression may associate with numerous negative outcomes. This study aimed to evaluate the long-pulsed 1064-nm Nd: YAG laser effect on fungal colonies and subsequently possible change in the minimum inhibitory concentrations (MICs) of common antifungals compared with the same non-lasered colonies as a novel way to investigate laser and antifungal interaction. Methods: Sixty onychomycosis samples consisting of saprophyte (n = 20), dermatophyte (n = 20), and yeast (n = 20) duplicate colonies were isolated. A series was treated by a long-pulsed 1064-nm Nd: YAG laser. Afterward, the MIC (CLSI-M38-A2 and CLSI-M27-A3) of two series against common antifungals were compared. Results: After 1064-nm Nd: YAG laser irradiation in all 20 tested saprophytes, the MICs of terbinafine (P value < 0.035) were changed, and in all 20 tested dermatophytes, the MICs of voriconazole (P value < 0.021) were changed. Also, in all 20 tested yeasts, the MICs of caspofungin (P value < 0.037) were changed. Moreover, in saprophytes, dermatophytes, and yeasts, significant changes in the MICs of itraconazole (P value < 0.032), terbinafine (P value < 0.025), and caspofungin (P value < 0.037) were detected. Our result showed the GM MICs of the 1064-nm Nd: YAG laser in all saprophyte, dermatophyte, and yeast groups were lower than in the control group. Conclusion: The present study indicated that the long-pulsed 1064-nm Nd: YAG laser significantly changes the MICs of antifungals in onychomycosis clinical samples. [ABSTRACT FROM AUTHOR]

Non-conventional yeasts can be isolated from a wide range of environmental sources and are often found in the beverage industry in mixed fermentations, in which the microbial community is usually not fully known. However, it is important to know the compositions of these starter cultures because in addition to enabling reproducibility during fermentation, other properties can be discovered. Thus, the objective of this work was to identify and characterize non-conventional yeasts isolated from the environment, evaluating their probiotic potential and possible use in beer brewing. Isolates were obtained from flowers, fruits, leaves and mixed-fermentation beers, with the species being identified by PCR. Yeasts with promising activity were evaluated regarding their growth under different pHs, temperature and the presence of organic acids. To explore probiotic potential, in vitro tests were performed for antimicrobial activity and co-aggregation with food-spoiling microorganisms, auto-aggregation and survival in simulated gastrointestinal tract conditions. In this study, Pichia kluyveri (LAR001), Hanseniaspora uvarum (PIT001) and Candida intermedia (ORQ001) were selected among 20 isolates for further study. P. kluyveri was the only strain that tolerated pH 2.5. Lactic acid was not inhibitory, but acetic acid and incubation at 37 °C had partially inhibitory effects on yeast growth. All yeasts tolerated α-acids from hops and up to 1% NaCl. Our results also suggest that these isolates are able to adhere to intestinal cells and positively influence the host to combat pathogens, as they showed auto-aggregation rates > 99% and antagonistic activity to pathogenic bacteria. The yeasts tolerated gastric environment conditions, but were more sensitive to pancreatic conditions. We conclude that these non-conventional yeasts have probiotic potential and promising application in beer fermentation. [ABSTRACT FROM AUTHOR]

Sourdough is the result of a fermentation process involving mainly LAB and yeasts. The present microbiota increase acidification, leavening and flavour. Moreover, consumers demand for more nutritious, healthy and clean-label products, has increased the use of sourdough in bread-making. Generally, LAB rapidly acidify the sourdough medium due to organic acids production (lactic and acetic acid, mostly). Nevertheless, different process parameters may influence sourdough microbiota, inducing changes in both sourdough and the resulting bread. Finally, sourdough fermentation involving probiotics can provide extra health benefits to its consumers. Also, long fermentations can reduce FODMAPs and phytate content, besides lowering the glycemic index. [ABSTRACT FROM AUTHOR]

Medium to large evergreen Corymbia citriodora (Eucalyptus citriodora) trees have smooth, powdery bark that is light grey, cream, or pink in color. It is frequently grown as an ornamental tree and is widely cultivated in Australia for its timber and essential oil. Herbal remedies are made from its foliage. It produces an essential oil that can be used to treat a variety of ailments, including clogged nasal passageways, cuts wounds, sore throats, and skin infections. The aim of the study was to determine the antimicrobial activity of Corymbia citriodora essential oil (CCEO) against ten microorganisms Candida albicans CCM 8186, C. glabrata CCM 8270, C. krusei CCM 8271, C. tropicalis CCM 8223, Staphylococcus aureus subsp. aureus CCM 4223, Micrococcus luteus CCM 732, Listeria monocytogenes CCM 4699, Escherichia coli CCM 3954, Pseudomonas putida CCM 1977, and Enterobacter aerogenes CCM 2531. The antimicrobial activity of CCEOs was evaluated using the disc diffusion method. The best antibacterial activity of CCEO against yeasts was found against C. tropicalis (17.33±0.58 mm). CCEO was most effective against Gram-positive bacteria M. luteus (9.33±0.58 mm) and Gram-negative bacteria E. coli (12.67±0.58 mm). In conclusion, Candida species were most sensitive against Corymbia citriodora essential oil. [ABSTRACT FROM AUTHOR]

Copyright of Compendium of Veterinary Sciences / Compendio de Ciencias Veterinarias is the property of Facultad de Ciencias Veterinarias de la Universidad Nacional de Asuncion and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cuaderno Activa is the property of Tecnologico de Antioquia, Institucion Universitari and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The black yeast-like fungi Aureobasidium spp. are ubiquitous microorganisms found in a wide variety of extreme and benign environments as saprophytes, endophytes, and pathogens. Since this diverse genus includes species with potential uses in agriculture and the food industry, it is important that we explore their evolution and spread in the context of climate change. Aureobasidium spp. are known to be capable of producing a plethora of various metabolites, many of which find applications in the field in the control of plant pathogens. The present review aims to explain how these microorganisms can provide ecological and safe strategies that might be adopted in agricultural production systems and food processing. The versatility and potential of the Aureobasidium genus lie perfectly within the Sustainable Development Goals Agenda 2021–2030 by opening new horizons that are respectful to the environment and human health. [ABSTRACT FROM AUTHOR]

Species of the Candida genus represent the third most common cause of onychomycosis, the most frequent and difficult to treat nail infection. Onychomycosis has been attributed to fungi organized in biofilm and some natural products have proved promising for its treatment. This study aimed to evaluate the antibiofilm activity of propolis extract (PE) and its by-product (WPE) on 7-day preformed biofilms produced by Candida albicans in polystyrene microplates, as well as in an ex vivo model on human nail fragments. The cytotoxicity and permeation capacity were also assessed. Firstly, multiple parameters were evaluated over 7 days to elucidate the dynamics of biofilm formation by C. albicans. The cell viability and total biomass did not vary much from the beginning; however, days 3 and 4 were crucial in terms of metabolic activity, which was significantly increased, and the levels of extracellular matrix components, wherein proteins and nucleic acids experienced an increase, but polysaccharide levels dropped. Architecturally, one-day biofilm showed a monolayer of organized cells (blastoconidia, hyphae, and pseudohyphae), while in the seven-day biofilm there was a three-dimensional well-structured and complex biofilm. This yeast was also able to form a biofilm on both surfaces of the nail, without an additional nutritional source. Both extracts showed excellent antibiofilm activity against the 7-day preformed biofilm and were not toxic to Vero cells at concentrations compatible with the antifungal and antibiofilm activities. Both extracts permeated the experimentally infected nail, with WPE being more efficient. The results of this study, taken together, reinforce the potential of these natural products, containing propolis, as a safe option for the topical treatment of onychomycosis. [ABSTRACT FROM AUTHOR]

Kopanisti is a Greek PDO cheese, which is traditionally produced by the addition of an amount of over-mature Kopanisti, called Mana Kopanisti, to initiate cheese ripening. The aim of this study was the production of four types of Kopanisti cheese (A–D) using pasteurized cow milk, and a combination of the following starters/adjuncts in order to test their ability to be used in Kopanisti cheese production: A: Lactococcus lactis subsp. lactis and Lacticaseibacillus paracasei, B: L. lactis and Lc. paracasei/Mana Kopanisti, C: L. lactis and Lc. paracasei/Ligilactobacillus acidipiscis and Loigolactobacillus rennini, D: Lig. acidipiscis and Loig. rennini. Throughout production and ripening, classical microbiological, metataxonomics and physicochemical analyses were employed, while the final products (Day 35) were subjected to sensory analysis as well. Most interestingly, beta-diversity analysis of the metataxonomics data revealed the clusters constructed among the Kopanisti types based on the different inoculation schemes. On day 35, Kopanisti A–C types clustered together due to their similar 16S microbiota, while Kopanisti D was highly differentiated. On the contrary, ITS data clustered Kopanisti B and C together, while Kopanisti A and D were grouped seperately. Finally, based on the sensory evaluation, Kopanisti C appeared to have the most suitable bacteria cocktail for the Kopanisti cheese production. Therefore, not only were the conventional starters used, but also the Lig. acidipiscis and Loig. rennini strains could be used in a standardized Kopanisti cheese production that could lead to final products of high quality and safety. [ABSTRACT FROM AUTHOR]

Simple Summary: Guinea pigs are reared not only to be kept as pets, but also for human consumption. This happens mostly in the Andean countries (Ecuador, Bolivia, and Peru), where guinea pig meat is one important source of animal protein. In this region, animal husbandry is performed usually by small farmers, who enter into frequent and close contact with guinea pigs. This poses a potential threat to human health because these (and other domestic) animals carry opportunistic human pathogens in their tissues and organs. Using traditional microbiological procedures and molecular biology techniques, we show here that the nasal mucosa of guinea pigs may contain up to 11 species of potentially pathogenic yeasts. Several of these yeasts are resistant to compounds used to treat fungal infections, which warns against their virulence potential if acquired by humans or other animals. We suggest that more attention should be given to this situation to prevent the risk of infectious diseases caused by microbes that are transmitted from animals to humans (=zoonoses). Guinea pigs (Cavia porcellus) have been reared for centuries in the Andean region for ceremonial purposes or as the main ingredient of traditional foods. The animals are kept in close proximity of households and interact closely with humans; this also occurs in western countries, where guinea pigs are considered pets. Even though it is acknowledged that domestic animals carry pathogenic yeasts in their tissues and organs that can cause human diseases, almost nothing is known in the case of guinea pigs. In this work we used traditional microbiological approaches and molecular biology techniques to isolate, identify, and characterize potentially zoonotic yeasts colonizing the nasal duct of guinea pigs raised as livestock in Southern Ecuador (Cañar Province). Our results show that 44% of the 100 animals studied were colonized in their nasal mucosa by at least eleven yeast species, belonging to eight genera: Wickerhamomyces, Diutina, Meyerozyma, Candida, Pichia, Rhodotorula, Galactomyces, and Cryptococcus. Noticeably, several isolates were insensitive toward several antifungal drugs of therapeutic use, including fluconazole, voriconazole, itraconazole, and caspofungin. Together, our results emphasize the threat posed by these potentially zoonotic yeasts to the farmers, their families, the final consumers, and, in general, to public and animal health. [ABSTRACT FROM AUTHOR]

The function of the Saccharomyces cerevisiae Ppz1 phosphatase is controlled by its inhibitory subunit Hal3. Hal3 is a moonlighting protein, which associates with Cab3 to form a decarboxylase involved in the CoA biosynthetic pathway. Hal3 is composed by a conserved core PD region, required for both Ppz1 regulation and CoA biosynthesis, a long N‐terminal extension, and an acidic C‐terminal tail. Cab3 has a similar structure, but it is not a Ppz1 inhibitor. We show here that deletion or specific mutations in a short region of the N‐terminal extension of Hal3 compromise its function as a Ppz1 inhibitor in vivo and in vitro without negatively affecting its ability to interact with the phosphatase. This study defines a R‐K‐X(3)‐VTFS‐ sequence whose presence explains the unexpected ability of Cab3 (but not Hal3) to regulate Ppz1 function in Candida albicans. This sequence is conserved in a subset of fungi and it could serve to estimate the relevance of Hal3 or Cab3 proteins in regulating fungal Ppz enzymes. We also show that the removal of the motif moderately affects both Ppz1 intracellular relocalization and counteraction of toxicity in cells overexpressing the phosphatase. Thus, our work contributes to our understanding of the regulation of Ppz phosphatases, which are determinants for virulence in some pathogenic fungi. [ABSTRACT FROM AUTHOR]

The antimicrobial properties of essential oil from Lavandula sp. raise hopes related to its use in phytotherapy. This study aimed to evaluate the antimicrobial activity of essential oils from cultivars of L. angustifolia ('Hidcote Blue Strain', 'Hidcote Blue') and L. × intermedia ('Phenomenal', 'Grosso') grown in central-eastern Poland, that is, at the border of the northern lavender cultivation range. The chemical composition of the essential oils was determined by GC/MS. Essential oil concentrations (20, 10, 5, 2.5, 1.25, 0.6, 0.3, 0.16, 0.08, and 0.04 mg/mL) were tested to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) towards ten strains of Gram-positive bacteria, five Gram-negative bacteria, and eight yeasts in vitro culture. Essential oils from the Lavendula cultivars showed antimicrobial activity against all microorganisms analysed. The yeasts were characterised by higher sensitivity to lavender oil compared to bacteria, while Gram-positive bacteria were more sensitive than Gram-negative bacteria. The lowest MIC values for bacteria and fungi were obtained for 'Grosso'. Furthermore, the 'Grosso' oil showed the highest fungicidal activity, while the highest bactericidal activity was found in 'Hidcote Blue' and 'Grosso'. Using Staphylococcus aureus as an example, it was shown that different bacterial strains of the same species show varying sensitivity to the essential oil. A higher oil content was noted for the cultivars L. × intermedia, especially for the 'Phenomenal'. Linalyl acetate and linalool were the main components of the essential oil in all cultivars. However, in the 'Grosso' oil, a high content of terpinen-4-ol (18.08%) was also recorded. An analysis of the relationships between the content of the main components in the analysed essential oils and the antimicrobial activity of essential oils suggested that linalool and terpinen-4-ol were compounds potentially responsible for antimicrobial activity. The obtained results allow us to conclude that essential oil with significant antimicrobial activity can be obtained from Lavandula sp. plants harvested in the northern part of the cultivation range. [ABSTRACT FROM AUTHOR]

We demonstrate that zoogleal mats of kombucha exhibit spikes of electrical resistance. A kombucha is a sugared tea fermented by a symbiotic community of over 20 species of bacteria and yeasts which produce cellulosic gelatinous zoogleal mats. We recorded electrical resistance of the zoogleal mats via platinum electrodes placed at a distance 1 cm of each other. We found that the mats show temporal variations in electrical resistance in a range 0.13–0.19 M Ω. We discovered spikes of the mats resistance morphologically similar to action potential spikes. Average duration of a resistance spike is 1.8 min, average amplitude is 2.2 k Ω. Average interval between resistance spikes is c. 20 min. The discovered resistive spiking of kombucha mats might indicate on their memfractive properties, and thus, open pathways towards prototyping neuromorphic devices with living zoogleal mats. [ABSTRACT FROM AUTHOR]

In this study, coffee pulp was examined as a starting material to make alcoholic beverages (coffee pulp wine) and yeast fermentation ability. We have evaluated five yeasts, three of which were previously isolated from the coffee cherry, and the other two were commercial yeasts. The pH, °Brix, viable yeast cells, and color parameters of coffee pulp wines were measured. The antioxidant activity of coffee pulp wine were measured using the 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays. Relatively, the 2,2-diphenyl-1-picrylhydrazyl inhibition percentage of Saccharomycopsis fibuligera (strain KNU18Y4) fermented coffee pulp wine was higher than that of other yeasts. Coffee pulp wine fermented with Saccharomyces cerevisiae (strain Fermivin) had higher ferric reducing antioxidant power values. Coffee pulp wine fermented with S. fibuligera (strain KNU18Y4) produced higher total phenolic content and total flavonoid content. Coffee pulp wine fermented with S. cerevisiae (strain KNU18Y12) had lower total tannin content compared to other treatments. The citric and malic acid contents were higher in coffee pulp wine fermented with S. cerevisiae (strain Fermivin). On the other hand, high lactic and acetic acid produced, with coffee pulp wine fermented with S. fibuligera (strain KNU18Y4). Ethyl alcohol was the most abundant volatile compound found in all treatments. [ABSTRACT FROM AUTHOR]

Introduction. Banknotes are a potential means of transmitting microorganisms capable of producing diseases, such as Staphylococcus aureus, a bacterium distributed throughout Latin America, causing infections and resistant to commonly used antibiotics. The objective of the study is to carry out a bacterial and fungal characterization of banknotes circulating in the city of Bucaramanga, and especially to identify some that may be related to public health problems. Methodology. Observational and quantitative study, with a sample of 50 banknotes (5 different denominations of 2 issue dates). Microorganisms were identified and quantified by seeding in peptone broth, later in Reasoner's 2A agar (R2A), nutritious and selective, in addition to the use of analytical profile index (API) and light microscopy techniques. A statistical analysis of the connection of variables was performed using the Statistical Package for the Social Sciences (SPSS) software. Results. 21 genera and 12 species of bacteria were identified, as well as 3 genera and 2 species of filamentous fungi, including some that can cause infections such as Klesiella, Enterobacter, Listeria, Staphylococcus, Cryptococcus and Aspergillus. Discussion. In relation to international studies, in this study fewer types of microorganisms were identified, which is explained by the limitations of the techniques used and the level of local contamination. Conclusion. It was possible to establish that the degree of microbial contamination does not depend of pathogens suggests measures to limit their transmission through this route. [ABSTRACT FROM AUTHOR]

The use of milling by-products as ingredients in food formulations has increased gradually over the past years, due to their well-recognized health properties. Fermentation performed with selected microbial strains or microbial consortia is the most promising way to reduce antinutritional factors of cereals and bran, while increasing their nutritional and functional properties. This work, developed within the BBI project INGREEN, was aimed to study the functional, nutritional and technological features of a pre-fermented ingredient obtained from the fermentation of a mixture of rye bran and wheat germ by a selected microbial consortium composed of yeasts (Kazachstania unispora and Kazachstania servazii) and lactic acid bacteria (Latilactobacillus curvatus) using as reference the unfermented mixture and the same mixture fermented by a baker's yeast. The selected microbial consortium improved the complexity of the volatile molecules such as acids, alcohols and esters. A better retention of color parameters was maintained compared to the product fermented by a baker's yeast. In addition, the fermentation by the selected consortium showed a significant increase in short chain fatty acids (more than 5-fold), antioxidant activity (22–24%), total phenol content (53–71%), bioactive peptides (39–52%), a reduction of 20–28% in phytic acid content and an increase in prebiotic activity not only compared to the unfermented product but also compared to the preferment obtained with a baker's yeast. Overall, the fermentation by the selected microbial consortium can be considered a valuable way to valorize milling by-products and promote their exploitation as food ingredients. [ABSTRACT FROM AUTHOR]

Dahi and chhurpi are the homemade, mildly acidic and mouthfeel fermented dairy products of Sikkim in India. Since yeasts co-exist among traditional fermented dairy foods, we believe that some species of yeasts may have some probiotic properties. Hence, the present study is aimed at screening some probiotic yeasts from dahi and chhurpi. A total of 3438 yeasts were isolated from 40 samples of dahi (1779 isolates) and 40 chhurpi (1659 isolates) and were preliminarily screened for probiotic properties on the basis of survival in low pH, resistance to bile salts and the percentage of hydrophobicity, out of which only 20 yeasts were selected for in vitro and genetic screening of probiotic properties. Saccharomyces cerevisiae DJT-2 and Debaryomyces prosopidis CPA-55 showed the highest hydrophobicity of 97.54% and 98.33%, respectively. S. cerevisiae DRC-42 and S. cerevisiae CGI-29 showed 93.88% and 91.69% auto-aggregation, respectively. All yeasts showed co-aggregation properties against pathogenic bacteria. Kluyveromyces marxianus DPA-41 and Pichia kudriavzevii CNT-3 showed excellent deconjugation activities. Probiotic genes for acid tolerance, bile tolerance, adhesion and antimicrobial activity were detected in S. cerevisiae DAO-17, K. marxianus DPA-41, S. cerevisiae CKL-10 and P. kudriavzevii CNT-3. Based on the results of in vitro and genetic screening of probiotic yeasts strains, S. cerevisiae DAO-17 (dahi), S. cerevisiae CKL-10 (chhurpi), P. kudriavzevii CNT-3 (chhurpi) and K. marxianus DPA-41(dahi) were selected as the potential probiotic yeasts. [ABSTRACT FROM AUTHOR]

The taxonomic composition and spatial localization of yeast and bacteria in kefir grains (KG) obtained for study from different regions of the planet were investigated. The diversity of their microbiome has been demonstrated by high-throughput sequencing of bacterial 16S rRNA genes and the ITS1 region of the 18S-ITS1-5.8S-ITS2-28S complex of yeast rRNA. It has been established that the main representatives of the complex community of KG from different regions are lactic acid bacteria (LAB; lactobacilli, lactococci, and Leuconostoc spp. in different ratios) and different types of yeast of the genus Kazachstania (family Saccharomycetaceae). Acetic acid bacteria and a small percentage of yeast Kluyveromyces marxianus were detected in the KG from Tibet, and yeast Pichia kluyveri was detected in the KG from Ossetia. [ABSTRACT FROM AUTHOR]

In order to evaluate the effect of complex fermentation of different yeasts and Lactobacillus plantarum on the fermentation quality of Xinhui citrus, three kinds of yeasts and Lactobacillus plantarum were used as raw materials for compound fermentation of fresh fruit pulp of Xinhui citrus. The changes of yeast viable count, total sugar content, pH and total acidity in fermentation broth were tracked during the fermentation process, and the bioactive substances and antioxidant activities of Xinhui citrus fermentation liquor in different fermentation systems were compared. The results showed that all the three strains of yeast could grow normally in Xinhui citrus, but the growth rate of Saccharomyces cerevisiae (Sc) and Kluyveromyces marxianus (Km) in Xinhui citrus was higher than that of Kazachstania unispora (Ku). Fermentation could increase the contents of total flavonoids, polyphenols and γ-aminobutyric acid of Xinhui citrus fermentation liquor and its antioxidant activity in vitro, but it could partially degrade crude polysaccharides. The contents of crude polysaccharide and γ-aminobutyric acid were the highest in the yeast fermentation system, which could reach 4.37 g/kg and 82.85 mg/kg. The content of total flavonoids in the yeast fermentation system was the highest, which was 1.54 g/kg. In addition, the hydroxyl radical scavenging rate and total reducing power of K. marxianus fermentation broth were 82.48% and 1.09, respectively, which were significantly higher than those of other yeast fermentation(P

The hybrid material between the functional elements particularly with the polymer compounds as a nanocomposites are attractive in numerous fields. In the current work, chitosan/Fe 2 O 3 /CuO-nanocomposite has been successfully synthesized in situ via a coprecipitation method and characterized by several apparatuses. The X-ray diffraction cleared that chitosan/Fe 2 O 3 /CuO-nanocomposite was crystalline. Transmission Electron Microscopy (TEM) showed that the size of chitosan/Fe 2 O 3 /CuO-nanocomposite was of 17–85 nm. Candida albicans , Candida tropicalis , and Geotrichum candidum were inhibited employing the chitosan/Fe 2 O 3 /CuO-nanocomposite with inhibition areas of 25 ± 0.1 and 30 ± 0.1, and 23 ± 0.2 mm, respectively. Minimum inhibitory concentration (MIC) of chitosan/Fe 2 O 3 /CuO-nanocomposite was 15.62, 31.25, and 62.5 μg/mL for C. tropicalis , C. albicans, and G. candidum , respectively. Biofilm formation of C. albicans , C. tropicalis and G. candidum was inhibited at level of 95.31, 96.65, and 93.63 %, respectively at 75 % MIC of chitosan/Fe 2 O 3 /CuO-nanocomposite. The exposed C. tropicalis to chitosan/Fe 2 O 3 /CuO-nanocomposite showed severe damag of cytoplasm membrane with cell wall rupture. Chitosan/Fe 2 O 3 /CuO-nanocomposite reflected anticancer potential against human skin cancer (A-431) cells with IC 50 of 77.79 ± 1.37 μg/mL. Moreover, wound heals was induced by chitosan/Fe 2 O 3 /CuO-nanocomposite with closure level 92.76 %. Molecular docking studies suggested strong binding of C. tropicalis (PDB ID: 8BH8) and A-431 (PDB ID: 5JJX) proteins with CuO nanoparticles and FeO nanoparticles. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of using different probiotic microorganisms in the composition of the synbiotic system fertilizer on microbial composition, nitrification process, and growth of Penaeus vannamei in the nursery phase. An intensive nursery was carried out (stocking density: 2000 shrimp m−3) for 40 days, using synbiotic fertilization protocols with different probiotic microorganisms in the following treatments: CW – clear water (control), B – Bacillus , BLP – Bacillus + Lactobacillus + Pediococcus , BLPY – Bacillus + Lactobacillus + Pediococcus + Yeasts (Saccharomyces cerevisiae), BY – Bacillus + Yeasts. In addition to probiotic, the fertilizer used rice bran as the main organic carbon source, molasses, sodium bicarbonate (as a buffer), and water in its composition. The Plankton community was analyzed by direct counting. The abundance of ammonia-oxidizing (AOB) and nitrite-oxidizing (NOB) bacteria were determined using fluorescent in situ hybridization. During the experimental time, a faster control of total ammonia nitrogen (TAN) was observed in BLP treatment. Throughout the trial, the control of nitrite through the nitrification process was not observed in the treatments where synbiotic systems were used. In these treatments, water changes were carried out to keep the concentration below the safe level for the species. The phytoplankton and zooplankton communities were basically dominated by Bacillariophyta and protozoans, respectively. On day 21 of the trial, BLP treatment had a higher abundance of AOB bacteria than CW, BLPY, and BY treatments. On day 39 of the experiment, BLP treatment had more NOB than BLPY and BY. Shrimp had a higher final weight in CW and BLP treatments than in the BY. Yield was higher in BLP, B, and BLPY treatments than in the CW. The use of Bacillus , Lactobacillus , and Pediococcus (BLP treatment) in synbiotic system fertilization promoted rapid control of TAN, a higher abundance of AOB and NOB, and improved shrimp growth performance in intensive nurseries. • Probiotic microorganisms in synbiotic improve ammonia control in shrimp nurseries. • Probiotic inoculation in shrimp nursery with synbiotic system increases AOB and NOB. • Probiotic inoculation improves growth and FCR in shrimp nurseries with synbiotic. [ABSTRACT FROM AUTHOR]

This work highlights the biosurfactant production potential of yeasts from mangroves in northeastern Brazil. The biosurfactants were evaluated by their emulsifying capacity (EI24), with 6 isolates showing values between 50% and 62%. Surfactant properties from crude extract were measured using drop collapse, oil displacement, Parafilm® M, surface tension and critical micellar concentration tests. The effects of temperature, salinity, pH, and the ability to emulsify different hydrocarbons were analyzed, showing a promising potential of the yeast species investigated to tolerance to high temperatures and acidic pH, in addition to emulsifying different sources of hydrocarbons with environmental impact. It is important to note that the Pichia pseudolambica isolates showed a remarkable ability to reduce the surface tension of water, from 70.82 mN/m to 36.47 mN/m. In addition, the critical micellar concentration (CMC) values ranged from 7 to 16 mg/mL, highlighting the promising surfactant activity of these isolates for future applications. It was identified that the biosurfactant adhered to the yeast cell wall, and FTIR and 1H NMR spectroscopy analysis was carried out on the yeast biomass and its post-sonication supernatant. The results indicate the presence of characteristic functional groups and peaks found in biosurfactants of a glycolipid nature. Taking together the results reveals the promising potential of biosurfactant biosynthesis of P. pseudolambica yeast, a trait not reported in the literature so far for this species. P. pseudolambica presents a relevant metabolic potential for alternative substrate use and resilience to adverse conditions that could enable it to produce biosurfactants for the biotechnological remediation of areas contaminated by oil derivatives. The metabolic properties herein investigated, together with their presence in Brazilian mangroves, make P. pseudolambica an emerging candidate for developing industrial processes and sustainable strategies for the recovery of ecosystems impacted by oil spills, being positioned as a sustainable alternative to conventional surfactants. [Display omitted] • Mangroves can be a source of biosurfactants-producing yeasts with applications in bioremediation. • Pichia pseudolambica strains emulsified diverse hydrocarbon sources. • Biosurfactants from the mangrove yeasts can be used in high-temperature processes. • Pichia pseudolambica glycolipids can be applied to remediate recalcitrant hydrocarbon pollutants. [ABSTRACT FROM AUTHOR]

Excessive levels of higher alcohols have negative impacts on the quality of Baijiu. Understanding the key microorganisms responsible for producing higher alcohols and their assembly processes is crucial for controlling higher alcohols in multi-species Baijiu fermentation. This study investigated the changes in volatile compounds, including higher alcohols, and microbial communities in the four fermentation cycles of Jiang -flavor Baijiu. Higher alcohols were the most abundant in the first cycle. Through metatranscriptomic and culture-dependent analysis, Saccharomyces cerevisiae and four non- Saccharomyces yeasts (Pichia kudriavzevii , Zygosaccharomyces bailii , Schizosaccharomyces pombe , and Torulaspora delbrueckii) were demonstrated to be the main contributors to higher alcohol (isobutanol, isoamylol, and 1-propanol) production, with S. cerevisiae producing the highest levels. A higher abundance of Saccharomyces resulted in the highest levels of higher alcohols in the first cycle. Moreover, our results revealed that yeast community was assembled from stochastic to deterministic processes with the increase of fermentation cycles, driven by lactic acid. These findings provide valuable insights into controlling higher alcohol production in Baijiu fermentation. • Isobutanol, isoamylol, and 1-propanol were the main higher alcohols with significant differences between cycles. • S. cerevisiae and four non- Saccharomyces yeasts were the contributors for higher alcohol production. • Higher level of higher alcohols in the first cycle is produced by high abundance of Saccharomyces. • Yeast community was assembled from stochastic to deterministic processes, driven by lactic acid. [ABSTRACT FROM AUTHOR]

• We developed a new assay for chitin content analysis in yeasts. • Our assay classified 12 yeast species based on chitin patterns and morphology. • These species were classified into the phylogenetic clades identified by Tsui. • The imaging-cytometry assay exhibited 85 % accuracy. Pathogenic fungi are a major threat to public health, and fungal infections are becoming increasingly common and treatment resistant. Chitin, a component of the fungal cell wall, modifies host immunity and contributes to antifungal resistance. Moreover, chitin content is regulated by chitin synthases and chitinases. However, the specific roles and mechanisms remain unclear. In this study, we developed a cytometric imaging assay to quantify chitin content and identify the distribution of chitin in the yeast cell wall. The Candida albicans SC5314 and Nakaseomyces glabratus (ex. C. glabrata) ATCC2001 reference strains, as well as 106 clinical isolates, were used. Chitin content, distribution, and morphological parameters were analysed in 12 yeast species. Moreover, machine learning statistical software was used to evaluate the ability of the cytometric imaging assay to predict yeast species using the values obtained for these parameters. Our imaging-cytometry assay was repeatable, reproducible, and sensitive to variations in chitin content in C. albicans mutants or after antifungal stimulation. The evaluated parameters classified the yeast species into the correct clade with an accuracy of 85 %. Our findings demonstrate that this easy-to-use assay is an effective tool for the exploration of chitin content in yeast species. [ABSTRACT FROM AUTHOR]

Aquatic animals are continually being exposed to stressors under farming conditions, increasing risks to gut health that result in dysbiosis. Since restrictions are imposed on the frequent use of antibiotics in aquaculture, there is emerging demand for economically viable, environmentally safe, and sustainable alternatives for the intensive production of aquaculture species. The application of beneficial microorganisms as probiotics has been suggested and widely practiced in recent times. Bacteria and fungi are ubiquitous microorganisms that can grow in various environments where organic substrates are available. Being rich in nutrients, a fish’s aquatic environment and gastrointestinal tract confer a favorable culture milieu for the microorganisms. However, the colonization and probiotic potential of fungi and mycelial bacteria resembling fungi (actinobacteria), either in the culture environment or within the gastrointestinal tracts of fish, have received less emphasis. Apart from bacilli and lactic acid bacteria, as the most conventionally used probiotics in aquaculture, numerous studies have focused on other promising alternatives. Diverse species of yeasts and molds belonging to the kingdom ‘Fungi’ have been characterized for their prospective roles in nutrition, immunomodulation, and disease prevention in fish. Bioactive compounds such as manno-oligosaccharides and β-glucans are recognized as fungal postbiotics that improve innate immunity and disease resistance in fish. Actinobacteria are known to possess different hydrolytic enzymes and novel secondary metabolites representing their probiotic attributes. The application of these groups in water quality amelioration has also been explored. Thus, this paper presents an overview of the present status of knowledge pertaining to the effects of yeasts (Candida, Cryptococcus, Debaryomyces, Geotrichum, Leucosporidium, Pichia, Rhodosporidium, Rhodotorula, Saccharomyces, Sporidiobolus, Sporobolomyces, Trichosporon and Yarrowialipolytica), molds (Aspergillus spp.) and actinobacteria (Streptomyces) as probiotics in finfish aquaculture, as well as their occurrence within the gastrointestinal tracts of finfish. Furthermore, probiotic mechanisms, selection criteria, and future perspectives on using fungi and actinobacteria as promising probiotics are discussed.

The union of aquaculture and hydroponics is named aquaponics—a system where microorganisms, fish and plants coexist in a water environment. Bacteria are essential in processes which are fundamental for the functioning and equilibrium of aquaponic systems. Such processes are nitrification, extraction of various macro- and micronutrients from the feed leftovers and feces, etc. However, in aquaponics there are not only beneficial, but also potentially hazardous microorganisms of fish, human, and plant origin. It is important to establish the presence of human pathogens, their way of entering the aforementioned systems, and their control in order to assess the risk to human health when consuming plants and fish grown in aquaponics. Literature analysis shows that aquaponic bacteria and yeasts are mainly pathogenic to fish and humans but rarely to plants, while most of the molds are pathogenic to humans, plants, and fish. Since the various human pathogenic bacteria and fungi found in aquaponics enter the water when proper hygiene practices are not applied and followed, if these requirements are met, aquaponic systems are a good choice for growing healthy fish and plants safe for human consumption. However, many of the aquaponic pathogens are listed in the WHO list of drug-resistant bacteria for which new antibiotics are urgently needed, making disease control by antibiotics a real challenge. Because pathogen control by conventional physical methods, chemical methods, and antibiotic treatment is potentially harmful to humans, fish, plants, and beneficial microorganisms, a biological control with antagonistic microorganisms, phytotherapy, bacteriophage therapy, and nanomedicine are potential alternatives to these methods.

The paper’s aim is to emphasize the variety of the yeasts populations which are present in the musts from inland and Tokaj areas. The study is based on the alcoholic fermentation on the four strains which were selected for this purpose, the isolation of the specific yeasts and the quantification of the obtained results through in the data base. From the fermentative dynamics’ point of view, the differences occur depending on the growing environment and on the strain types which were considered.The minerals play an important role in increasing the biotechnological properties of the wine yeasts Saccharomyces bayanus, Saccharomyces ellipsoideus regarding the fermentative activity and multiplication speed.

Many genera and species of microorganisms can be found in grape musts and wines at various times during the winemaking process. For instance, Saccharomyces, Brettanomyces, and Pediococcus can be found together in wine. There are many species of yeast involved in wine spoilage during storage. Aim of this study was to isolate the spoilage yeasts from wine samples with using special selective agar media and identified on species level by Matrix-Assisted Laser Desorption/Ionization-Time of Fly Mass Spectrometry (MALDI-TOF MS). Six red wines used in this study. We identified 10 yeast species from 152 isolates. The most common species in wine samples was Saccharomyces cerevisiae. We also identified four Candida species, two Zygosaccharomyces species and one species from genus Rhodotorula, Saccharomycodes and Dekkera.

To examine the antimicrobial and antioxidant activity of 15 natural honeys, honey samples were collected from different locations of Slovakia, Poland and Serbia. For antimicrobial activity determination honey solutions were prepared at three concentrations: 50, 25 and 12.5 % (by mass per volume). The potential antimicrobial activity of selected samples against four species of bacteria (Escherichia coli CCM 3988, Pseudomonas aeroginosa CCM 1960, Staphylococcus epidermis CCM 4418, Bacillus cereus CCM 2010) and two species of yeasts (Saccharomyces cerevisiae CCM 8191, Candida albicans CCM 8216) was studied using the disc diffusion method. After incubation, the zones of inhibition of the growth of the microorganisms around the disks were measured. The strongest antimicrobial activity was shown at honey samples of 50 % concentration against Escherichia coli, Pseudomonas aeroginosa and Staphylococcus epidermis. Against Saccharomyces cerevisae and Candida albicans very low (at 50 %, 25 % concentration) or zero antifugal (at 12.5 % concentration) activity was determined. From the results obtained it was shown the variable ability of honey samples to scavenge stable free radical DPPH. TEACDPPH values ranged between 0.1-1.0 mmol.kg-1. As the antioxidative best source buckwheat honey was manifested and the lowest antioxidant activity was shown at acacia honey.

Fungal contamination was observed in 46 milk samples. Contamination level was 100% for Candida and Rhodotorula (yeasts). Contamination is attributed to deficiencies in milking dairy cows. In the samples of Telemea cheese, the predominant microflora belonged to the species Candida and Rhodotorula. In milk and cheese samples was not detected aflatoxin M1. Many types of cheese are excellent substrates for the growth of fungi. Fungi more important are Penicillium, Aspergillus, Cladosporium, Mucor and Trichoderma. Mycotoxins, produced by certain fungi as toxic metabolic substances can be found in dairy products, either from indirect sources when dairy cows consume feeds with mycotoxin (Aflatoxin B1 and its metabolite that passes into milk - AFM1) or from direct sources as a result of growth intentional or accidental fungi. Many feed from farm crops are consumed later. In the course of vegetative growth but especially during the flowering period, Fusarium fungi may infect grains or other fodder crops and produce fusarium toxins, deoxynivalenol, nivalenol, zearalenone, fumonisins and HT2 and T toxins. Aflatoxins are mainly produced by two species: Aspergillus flavus and A. parasiticus. Aflatoxin B1 is metabolized by ruminants resulting aflatoxin M1, and this metabolite can be transferred to cows’ milk.

Grape pomace is a winery industry residue of skins, seeds and stems of grapes used in agriculture for animal feed and production of food with biological activity. The aim of this study was to evaluate antimicrobial activity of Vitis vinifera L. pomace extract on growth of microscopic fungi and bacteria. The four strains of bacteria (two Gram-positive bacteria Staphylococcus aureus CCM 2461, Bacillus cereus CCM 2010; two Gram-negative bacteria Escherichia coli CCM 3988, Pseudomonas aeruginosa CCM 1959) and four yeasts strains (Candida albicans CCM 8186, Candida glabrata CCM 8270, Candida krusei CCM 8271 and Candida tropicalis CCM 8223) were studies. For detection of antimicrobial activity, the grape pomace extracts of white variety Pálava and red variety Dornfelder were used. Pálava pomace extracts were less efficient against the microorganisms tested and Dornfelder extracts were more active against Gram-positive bacteria and yeasts.

This study was focused on monitoring of antimicrobial activity of selected medicinal plants: Artemisia vulgaris, Geum urbanum, Euphorbia peplus, Rumex hydrolapathum, Portulaca oleracea, Geranium pratense, Polygonum aviculare. The selected medicinal plants were evaluated for antimicrobial activity with disc diffusion method. Ethanolic extracts against 3 Gram-positive (G+) bacteria (Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis), 3 Gram-negative (G-) bacteria (Salmonella enterica, Pseudomonas aeruginosa, Yersinia enterocolitica) and 3 yeasts (Candida tropicalis, Candida krusei, Candida glabrata, Candida albicans) were used as model microorganisms to determine antimicrobial activity. The Portulaca oleracea extract showed the largest zone of inhibition against Staphylococcus aureus, Pseudomonas aeruginosa and Yersinia enterocolitica. Artemisia vulgaris extract formed the largest zone of inhibition against Bacillus subtilis, Enterococcus faecalis and one yeast Candida krusei. The extract from Geum urbanum and Euphorbia peplus did not create the maximum inhibition zone against any of the microorganisms that were tested.

The aim of this study was to isolate and identify yeast species in wine samples from five different countries, and determine the genera of spoilage yeasts. One hundred and thirty four (no. 134) wine samples (86 white and 48 red wine); (30 bottled, 104 tank wine) from five countries Slovakia (no. 53), Czech Republic (no. 17), Hungary (no. 6), Spain (no. 32) and Italy (no. 26) were used in this study. Yeasts were cultivated on Malt extract agar supplemented with bromocresol green. After cultivation, yeasts were identified on species level by MALDI-TOF mass spectrometry. We identify 10 yeasts genera from total of 285 isolates; Saccharomyces (97 isolates, 1 species), Pichia (120 isolates, 5 species), Kregervanrija (6 isolates, 1 species), Zygosaccharomyces (32 isolates, 2 species), Candida (13 isolates, 2 species), Rhodotorula (4 isolates, 1 species), Wickerhamomyces (7 isolates, 1 species) Meyerozyma (4 isolates, 1 species) and genera with only 1 isolate and species: Torulaspora, and Cyberlindnera.

To generate a comprehensive profile of viable yeasts on cheese as it is purchased by consumers, 40 samples of locally produced cheese were obtained from four Slovakian farms and sampled. The samples were cultured on Malt extract agar with bromocresol green and cultivated for 5 days at 25 °C. Selected colonies were cultured overnight on TSA agar aerobically and used for identification. Pure cultures were obtained and identified by mass spectrometry, as well as growth characteristics and colony morphology. The yeast Candida kefyr was the most abundant yeast, present in 90 % of all cheese samples. From the non-smoked and smoked cheese a total of 10 species of 5 yeast genera were identified with MALDI-TOF Mass Spectrometry.

Yeasts are ubiquitously present in different natural sources. Some of these yeasts have interesting characteristics for the production of fermented food products. This study characterized Lachancea thermotolerans and L. quebecensis isolated from insects to determine their brewing potential. The yeasts were evaluated according to their fermentative potential in glucose and maltose-defined media and their resistance to ethanol and hop. Finally, craft beer was elaborated at a laboratory scale (10 L). The yeasts utilized glucose as the only carbon source and produced 3.25 ± 1.77, and 4.25 ± 1.06% (v/v), of ethanol for L. thermotolerans and quebecensis, respectively. While in the maltose-defined medium, ethanol content reached 3.25 ± 0.45, and 3.92 ± 0.36, respectively. The presence of alpha acids and ethanol affected the growth of L. quebecensis, which showed lower growth at 90 IBU and 8 ethanol% (v/v) mixtures. The craft beer brewed with L. quebecensis in monoculture experiments showed fruity flavors associated with ethyl acetate and isoamyl acetate. The ethanol content reached 3.50 ± 0.46% (v/v). The beer pH was 4.06 ± 0.20, with a lactic acid concentration of 1.21 ± 0.05 g/L. The sensory panel identified the beer as “fruity”, “floral”, “hoppy”, “sweet”, and “sour”. To our knowledge, this is the first time L. quebecensis was reported as a potential candidate for sour beer production with reduced ethanol content.

A serious global problem with the increasing resistance of microorganisms to currently used antimicrobials has opened up the promotional research in the identification of new, more effective drugs with a broad spectrum of antimicrobial activities. Plant essential oils, due to the large biological and structural diversity of their components, are known to have many potential benefits. This study aimed to evaluate the antimicrobial and anti-adhesion activity of fifteen essential oils and their compounds against two bacterial and two yeast species responsible for food spoilage and infectious diseases. Antimicrobial activity was determined by testing the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC) and the minimum fungicidal concentration (MFC) of essential oils and compounds. The essential oils of Cinnamomum zeylanicum and Eugenia caryophyllus showed the highest antimicrobial activity with MICs ranging from 0.078 to 1.25 mg/mL, and 0.039 to 1.25 mg/mL, respectively. On the other hand, essential oils of Eucalypti aetheroleum and Salvia officinalis had significantly weaker antimicrobial properties than the others. Further, MICs were used to assess the inhibition of adhesion of bacteria Salmonella Typhimurium ATCC 25923 and Staphylococcus aureus ATCC 14208, and yeasts Candida albicans ATCC 10231 and Saccharomyces cerevisiae ATCC 9763 in a microtiter plate using the crystal violet staining method. Based on the percentage of adhesion inhibition, yeast S. cerevisiae ATCC 9763 showed a high level of antimicrobial resistance. E. caryophyllus had the strongest effect with inhibition up to 73%. Consistent with the antimicrobial susceptibility results, the most active anti-adhesion compounds were carvacrol and thymol. Considering the role of biofilm in food spoilage and clinical diseases, inhibition of the initial phase of biofilm formation by natural antimicrobial agents may be an alternative to commonly used synthetic ones.

Protein phosphorylation is the most common and versatile post-translational modification occurring in eukaryotes. In yeast, protein phosphorylation is fundamental for maintaining cell growth and adapting to sudden changes in environmental conditions by regulating cellular processes and activating signal transduction pathways. Protein kinases catalyze the reversible addition of phosphate groups to target proteins, thereby regulating their activity. In Saccharomyces cerevisiae, kinases are classified into six major groups based on structural and functional similarities. The NPR/Hal family of kinases comprises nine fungal-specific kinases that, due to lack of similarity with the remaining kinases, were classified to the “Other” group. These kinases are primarily implicated in regulating fundamental cellular processes such as maintaining ion homeostasis and controlling nutrient transporters’ concentration at the plasma membrane. Despite their biological relevance, these kinases remain poorly characterized and explored. This review provides an overview of the information available regarding each of the kinases from the NPR/Hal family, including their known biological functions, mechanisms of regulation, and integration in signaling pathways in S. cerevisiae. Information gathered for non-Saccharomyces species of biotechnological or clinical relevance is also included.

In this research, the LAB and yeast isolations and identifications of homemade traditional sourdoughs were investigated. Both LAB and yeasts were identified by the PCR method and used in the production of sourdough bread (SDB). Twelve types of SDB were produced from combinations of isolated LAB and yeasts. Eleven LAB and yests were identified from 36 sourdoughs. The most frequently isolated LAB species were Lactobacillus brevis (45.0%), Pediococcus acidilactici (20.0%) and Lactobacillus plantarum (18.3%) while other LAB species were isolated by only 1.7–3.5%. On the other hand, 27.5% of the isolates were Saccharomyces cerevisiae, which was followed by Pichia kudriavzevii (25.0%) and Kluyveromyces marxianus (12.5%). The total titratable acidity and pH of the sourdough ranged from 3.10 to 34.45% and from 4.05 to 4.80 respectively. High acceptable loaf height (7.2 cm), moisture (30.05%), dry matter (69.95%), volume (1370 cm3), specific volume (4.35 cm3 g−1) and sensory value (62 scores) were determined for SDB12. Isolated LAB is mainly composed of heterofermentative species (75%). Among the bread produced with the combination of LAB and yeasts, the SDB12 was the most preferred SDB in terms of sensory analysis and other quality characteristics. The use of homofermentative and heterofermentative LAB and yeast combinations provided high-quality SDB. This would be due to the symbiotic growth of these microorganisms. The use of L. plantarum by L. brevis and by other species resulted in high-quality SDB.