Bioprocess optimization for biomass production of probiotics yeast Saccharomyces boulardii in semi-industrial scale (original) (raw)

Yeasts, especially Saccharomyces cerevisiae, are one of the oldest organisms with broad spectrum of applications, owing to their unique genetics and physiology. Yeast extract, i.e. the product of yeast cells, is extensively used as nutritional resource in bacterial culture media. The aim of this study was to develop a simple, rapid and cost benefit process to produce the yeast extract. In this procedure mechanical methods such as high temperature and pressure were utilized to produce the yeast extract. The growth of the bacteria feed with the produced yeast extract was monitored in order to assess the quality of the product. The results showed that the quality of the produced yeast extract was very promising concluded from the growth pattern of bacterial cells in media prepared from this product and was comparable with that of the three commercial yeast extracts in terms of bacterial growth properties. One of the main advantages of the current method was that no chemicals and enzyme...

In this study, an effort was made to create a model cell factory of Saccharomyces cerevisiaeusing bacterial cellulose (BC) and Aspergillus awamori for consolidated bioprocessing (CBP)of starch. This work suggested development of a cell factory for consolidated bioprocess-ing of starch in one bioreactor, performing three bioprocesses, i.e. production of amylolyticenzymes by fungal culture, hydrolysis of starch and fermentation to ethanol productionusing S. cerevisiae without its genetic modification. The microorganisms were separatelyimmobilized on different amounts of BC and their mixture was used for the fermentationof 5% w/v starch. The mixture of BC/A. awamori and BC/S. cerevisiae was used for starchfermentation both in wet and freeze-dried (lyophilized) form in the same ratio (3:1). A1.75-fold increase in maximum ethanol production was observed using freeze-dried BCimmobilized biocatalysts compared to wet cell factory. The ethanol production yield wasexamined progressively by the effect of (i) initial ratios of both freeze-dried BC/S. cerevisiaeand BC/A. awamori, (ii) different weight of the freeze-dried cell factory and (iii) A. awamoricells concentration, reaching the 82% of the theoretical yield encouraging us to use this cellfactory model for further fermentations of starch in higher concentration. Ethanol produc-tion of 26.69 mL/L and the maximum ethanol yield (0.42 g ethanol/g starch) or 82% of thetheoretical yield was achieved by increasing cells of A. awamori inoculum during its immo-bilization on BC to 109cells/mL. The results of this work are satisfactory compared withother systems of starch fermentation from literature. SEM, TEM and FTIR spectra analysiswere carried out in order to prove the successful preparation of cell factory. SEM showed theimmobilization of cells on the BC netting, and TEM showed on BC fibrils. Finally, a repeatedfermentation batch was performed, proving the operational viability and stability of thecell factory. The results indicated that the objective of designed cell factory was success-fully performer, and the results of starch fermentation are promising for the developmentof an innovation in brewing industry. Likewise, these have prospects of their application in White-Biotechnology.

The development of the application of the science of biotechnology is not only based on biology alone, but also on other applied sciences such as computer microbiology, molecular biology, and so forth. Seeing this took researcher of issues on which the growth Sacharomyces cerevisiae yeast or yeast genus that has the ability to change glucose into alcohol and CO2 by fermentation processes. Growth of microorganisms Sacharomyces cerevisiae in the graphs form and provide information about the nature characteristics from growth of microorganisms Sacharomyces cerevisiae in fed-batch or bait-bulk fermentation process. In the graphic representation process of the growth microorganisms Saccharomyces cerevisiae, there are several stages of the process such as by inserting the initial values of the biomass concentration, initial substrate concentration entering values, enter the initial value of the broth volume, enter the value of the incoming substrate concentration during the fermentation process, and the initial value . Limit time spent in the growth graphic representation of microorganisms on the fed-batch fermentation process is 44 hours.From the simulations that have been conducted, obtained by the above chart of growth microorganisms, can be used as an overview and comparison of the actual breeding, so as to facilitate researchers in testing the breeding of microorganisms in the laboratory.

The purpose of this study was to yield high ethanol production by yeast under optimized condition. Glucose Yeast Extract medium was used for isolation, growth and preservation of yeast. A sequential study has been done by consecutive pH levels of 3, 4, 5, 6, 7, 8, 9, 10 and 11. The best ethanol production was obtained at pH 5.0. The various sucrose concentrations examined were 2.5%, 5%, 7.5%, 10%, 12.5%, 15%, 17.5% and 20%. The maximum ethanol production was at 10% (36g/L). In case of yeast extract various concentrations examined were 0.25%, 0.75%, 0.5%, 1.0%, 1.25%, 1.5%, 1.75% and 2.0%. The highest specific ethanol production after 48hr was observed in flask containing 1% yeast extract concentration which was 47g/L.

Biological systems are very complex regarding their kinetic behavior. There are many models that intend to predict fermentation performance, although Monod equation remains the best model. A detailed investigation of batch fermentation process at room temperature for two different types of yeast Saccharomyces carlsbegensis and Saccharomyces cerevisiae was carried out. Batch fermentation experiments were carried in 1 liter bioreactors, in the same medium, time and fermentation conditions. Kinetic constants were used to compare fermentation performance under similar conditions. Kinetic parameters investigation was done based on growth kinetics, ethanol productivity and substrate consumption (glucose) using computer simulation for different kinetic models. There are some notable differences based on kinetic models. Although two types of yeast strain leave the same remain extract in the end of fermentation, fermentation dynamics differ from each other. Saccharomyces carlsbengensis has h...