The Influencing Factors on the Production of Alcoholic Drinking from Jackfruit (Artocarpus heterophyllus L.)

The large amount of jackfruit (Artocarpus heterophyllus Lam) harvested and their short use time caused many difficulties for the farmers. Fortunately, the high sugar content in jackfruit meat is a hopeful substance for wine production. This study aimed to consider the effect of yeast strains and their concentration on fermented jackfruit solution. Jackfruit juice with 14 °Brix is ​​fermented using 0.005 to 0.015% (w/v) Saccharomyces cerevisiae RV002, Mauri Instant Dry Yeast yeast under anaerobic conditions for 1 to 4 days at 30 °C. Survey samples were checked once a day to analyze the indicators. The functional report of the sugar in the fermentation time, shows that the higher incidence of yeast cultures and the initial sugar concentration inhibited yeast growth. The results showed that fermentation from jackfruit meat with 25 °Brix using Saccharomyces cerevisiae RV002 yeast with concentration of 0.01% for 3 days is the best to create a good quality with ethanol content 4,9% and characteristic aroma of jackfruit.

Micro-Bioreactors in Space: Case Study of a Yeast (Saccharomyces cerevisiae) Bioreactor With a Non-Invasive Monitoring Method

Bioreactors in space have applications from basic science to microbial factories. Monitoring bioreactors in microgravity has challenges with respect to fluidics, aeration, sensor size, sample volume and disturbance of medium and cultures. We present a case study of the development of small bioreactors and a non-invasive method to monitor dissolved oxygen, pH, and biomass of yeast cultures. Two different bioreactor configurations were tested for system volumes of 60 ml and 10.5 ml. For both configurations, the PreSens SFR vario, an optical sensor array, collected data autonomously. Oxygen and pH in the cultures were monitored using chemically doped spots, 7 mm in diameter, that were fixed to the bottom of sampling chambers. Spots emitted a fluorescent signal for DO and pH when reacted with oxygen molecules and hydrogen ions, respectively. Biomass was sensed using light reflectance at centered at 605 nm. The, optical array had three light detectors, one for each variable, that returned signals that were pre- and post-calibrated. For heterotrophic cultures requiring oxygen and respiring carbon dioxide, a hollow fiber filter, in-line with the optical array, oxygenated cells and remove carbon dioxide. This provided oxygen levels that were sufficient to maintain aerobic respiration for steady state conditions. Time series of yeast metabolism in the two bioreactors are compared and discussed. The bioreactor configurations can be easily be modified for autotrophic cultures such that carbon dioxide is enhanced and oxygen removed, which would be required for photosynthetic algal cultures.

Increase of Non-Albicans Candida Species and Their Antifungal Susceptibility in Intensive Care Unit Patients (Mexico)

In Mexico little is known about candidemia by non-albicans Candida species and regarding their antifungal susceptibility. Besides without antifungal tests, fluconazole is one of the most used in empirical therapy. In the present study, we included patients from intensive care unit of one hospital in Mexico (2019–2020) with compatible yeast infection clinical signs, symptoms. Based on cultivable isolates, yeasts were identified by automated instrument and by molecular method (PCR), and their susceptibilities to six antifungals were characterized at different concentrations. From 105 patients, yeast cultures were recovered and identified mainly non-albicans Candida species (57.2%); and the most prevalent was C. glabrata (41.9%). Followed by C. albicans, C. krusei, C. parapsilosis, C. tropicalis and Cryptococcus neoformans. The most common infection site was urine (56%), followed by the bronchial aspirate (30%). Mostly the isolated fungi were susceptible to 5-flucytosine (98%) and to amphotericin B. Mainly C. glabrata followed by C. krusei and C. tropicalis were resistant to different concentrations of itraconazole, miconazole, and fluconazole. The present investigation contributes to the knowledge of non-albicans Candida species infections in patients and, opens the possibility for a better understanding and management in antifungal empirical therapy.in Mexico.

Development of starters for dairy products based on goat's milk

For milk and dairy products, 70 % of the Kazakh market accounts for the products of foreign companies. Geographically, the problem of the production of domestic products, the ecology of which is characteristic of the population of the country, has not yet been solved. The existing starter cultures are currently mainly intended for cow's milk, and are not adapted to the milk of other animal species. However, the production and processing of camel, mare and goat milk is a dairy farm with a history and traditions in the Republic of Kazakhstan. The fermentation process with the help of lactic acid bacteria is the basis for the preparation of products such as kefir, koumiss and shubat. There are data on the use of lactic acid bacteria in starters, but there is little data in studies on their use as starter cultures for camel, mare and goat milk, there are no scientific experimental results. Despite the economic rates of production of fermented products based on camel, mare and goat milk in the Republic of Kazakhstan, their production is slowed down at the industrial level due to the lack of yeast cultures and dairy technology for these types of milk. In this scientific work, fermenting consortia based on goat's milk was developed from active strains of microorganisms isolated from traditional fermented milk products, taking into account their compatibility, biochemical characteristics and scientific foundations. The technological, nutritional and microbiotic properties of the finished starters were adapted to the probiotic effect of camel, mare and goat milk by changing their composition. As a result of the study, a consortium of starters with a very high probiotic effect, safe for life, prone to survival in the digestive system was proposed.

Methods for Oxygenation of Continuous Cultures of Brewer’s Yeast, Saccharomyces cerevisiae

Maintaining steady-state, aerobic cultures of yeast in a bioreactor depends on the configuration of the bioreactor system as well as the growth medium used. In this paper, we compare several conventional aeration methods with newer filter methods using a novel optical sensor array to monitor dissolved oxygen, pH, and biomass. With conventional methods, only a continuously stirred tank reactor configuration gave high aeration rates for cultures in yeast extract peptone dextrose (YPD) medium. For filters technologies, only a polydimethylsiloxan filter provided sufficient aeration of yeast cultures. Further, using the polydimethylsiloxan filter, the YPD medium gave inferior oxygenation rates of yeast compared to superior results with Synthetic Complete medium. It was found that the YPD medium itself, not the yeast cells, interfered with the filter giving the low oxygen transfer rates based on the volumetric transfer coefficient (KLa). The results are discussed for implications of miniaturized bioreactors in low-gravity environments.

Antimicrobial Properties of Lyophilized Extracts of Olive Fruit, Pomegranate and Orange Peel Extracts against Foodborne Pathogenic and Spoilage Bacteria and Fungi In Vitro and in Food Matrices

Several novel antimicrobials with different concentrations of olive, pomegranate, and orange fruit pulp extracts were produced from agricultural byproducts and, after lyophilization, their antimicrobial activity and potential synergistic effects were evaluated in vitro and in food samples against foodborne pathogenic and spoilage bacteria and fungi. The Minimum Inhibitory of the tested bacteria was 7.5% or 10%, while fungi were inhibited at a concentration of 10% or above. The optical density of bacterial and yeast cultures was reduced to a different extent with all tested antimicrobial powders, compared to a control without antimicrobials, and mycelium growth of fungi was also restricted with extracts containing at least 90% olive extract. In food samples with inoculated pathogens and spoilage bacteria and fungi, the 100% olive extract was most inhibitory against E. coli, S. typhimurium, and L. monocytogenes in fresh burger and cheese spread samples (by 0.6 to 1.8 log cfu/g), except that S. typhimurium was better inhibited by a 90% olive and 10% pomegranate extract in burgers. The latter extract was also the most effective in controlling the growth of inoculated fungi (Αspergillus niger, Penicillium italicum, Rhodotorula mucilaginosa) in both yogurt and tomato juice samples, where it reduced fungal growth by 1–2.2 log cfu/g at the end of storage period. The results demonstrate that these novel encapsulated extracts could serve as natural antimicrobials of wide spectrum, in order to replace synthetic preservatives in foods and cosmetics.

Investigation of probiotic potential of yeasts isolated from sourdoughs from different regions of Turkey

In this study, 14 yeast cultures from 62 isolates from traditional sourdoughs collected from 6 different regions of Turkey were selected by FT-IR identification and characterised to reveal their probiotic properties. Four yeast strains were genotypically identified and compared with FT-IR identification. In all analyses, it was observed that mostly Saccaromyces cerevisiae strain exhibited high hydrophobicity, auto-aggregation feature, and all yeast isolates in this study showed tolerance to 0.3%, even salt concentration. In addition, all yeast strains were susceptible to anti-yeasts agents, although they were resistant to all antibiotics used in the study. All selected yeast isolates exhibited high antimicrobial activity against the Staphylococcus aureus. In conclusion, this study investigated the potential probiotic properties of yeast strains isolated from sourdough.

Moniliophthora perniciosa, the Causal Agent of Cacao Witches’ Broom Disease Is Killed in vitro by Saccharomyces cerevisiae and Wickerhamomyces anomalus Yeasts

Cacao plantations from South America have been afflicted with the severe fungal disease known as Witches’ Broom Disease (WBD), caused by the basidiomycete Moniliophthora perniciosa. Yeasts are increasingly recognized as good fungal biocides, although their application is still mostly restricted to the postharvest control of plant and fruit decay. Their possible utilization in the field, in a preharvest phase, is nevertheless promising, particularly if the strains are locally adapted and evolved and if they belong to species considered safe for man and the environment. In this work, a group of yeast strains originating from sugarcane-based fermentative processes in Brazil, the cacao-producing country where the disease is most severe, were tested for their ability to antagonize M. perniciosa in vitro. Wickerhamomyces anomalus LBCM1105 and Saccharomyces cerevisiae strains LBCM1112 from spontaneous fermentations used to produce cachaça, and PE2 widely used in Brazil in the industrial production of bioethanol, efficiently antagonized six strains of M. perniciosa, originating from several South American countries. The two fastest growing fungal strains, both originating from Brazil, were further used to assess the mechanisms underlying the yeasts’ antagonism. Yeasts were able to inhibit fungal growth and kill the fungus at three different temperatures, under starvation, at different culture stages, or using an inoculum from old yeast cultures. Moreover, SEM analysis revealed that W. anomalus and S. cerevisiae PE2 cluster and adhere to the hyphae, push their surface, and fuse to them, ultimately draining the cells. This behavior concurs with that classified as necrotrophic parasitism/mycoparasitism. In particular, W. anomalus within the adhered clusters appear to be ligated to each other through roundish groups of fimbriae-like structures filled with bundles of microtubule-sized formations, which appear to close after cells detach, leaving a scar. SEM also revealed the formation of tube-like structures apparently connecting yeast to hypha. This evidence suggests W. anomalus cells form a network of yeast cells connecting with each other and with hyphae, supporting a possible cooperative collective killing and feeding strategy. The present results provide an initial step toward the formulation of a new eco-friendly and effective alternative for controlling cacao WBD using live yeast biocides.

Characterization of Episomal Replication of Bovine Papillomavirus Type 1 DNA in Long-Term Virion-Infected Saccharomyces Cerevisiae Culture

We have previously reported that bovine papillomavirus type 1 (BPV-1) DNA can replicate its genome and produce infectious virus-like particles in short term virion-infected S. cerevisiae (budding yeast) cultures (Zhao and Frazer 2002, Journal of Virology, 76:3359–64 and 76:12265–73). Here, we report the episomal replications of BPV-1 DNA in long term virion-infected S. cerevisiae culture up to 108 days. Episomal replications of the BPV-1 DNA could be divided into three patterns at three stages, early active replication (day 3–16), middle weak replication (day 23–34/45) and late stable replication (day 45–82). Two-dimensional gel electrophoresis analysis and Southern blot hybridization have revealed further that multiple replication intermediates of BPV-1 DNA including linear form, stranded DNA, monomers and higher oligomers were detected in the virion-infected yeast cells over the time course. Higher oligomers shown as covalently closed circular DNAs (cccDNAs) are the most important replication intermediates that serve as the main nuclear transcription template for producing all viral RNAs in the viral life cycle. In this study, the cccDNAs were generated at the early active replication stage with the highest frequencies and then at late stable replication, but they appeared to be suppressed at the middle weak replication. Our data provided a novel insight that BPV-1 genomic DNA could replicate episomally for the long period and produce the key replication intermediates cccDNAs in S. cerevisiae system.