This paper reports about experimental results concerning the influence of 30 nm ZnO nanoparticles on biomass, carbohydrates, β-glucans, proteins accumulation and catalase enzyme activity at Saccharomyces cerevisiae CNMN-Y-20 yeast strain exposed to alcohol action. Alcohol in concentrations of 2%, 5% and 10% added to culture medium has been reported to stimulate β-glucans biosynthesis and to inhibit protein synthesis. Low biomass production, with 71% less that control, was detected in the experiments with 10% alcohol. ZnO nanoparticles in combination with alcohol do not offer sufficient protection for the proteins biosynthesis, but efficiently protect the carbohydrates and β-glucans biosynthetic processes, which contents in the biomass are with 16.6% and 19.9% higher than control, respectively. The maximum value of β-glucans content was established in case of cultivation of selected yeast strain on YPD medium supplemented with 5 mg/L nanoparticles ZnO and 2% alcohol. The obtained results allowed the elaboration of new procedure for directed synthesis of β -glucans that contributed to an increase of this component with 30.7%, compared to control.

Currently, special attention is paid to the use of industrial by-products, in particular those obtained in huge quantities in the brewing and wine making process, as a source for the production of natural preparations with high biological value. In this study are presented results related to the recovery of beer yeast biomass from the sediments of the beer industry, by obtaining lipid extracts with valuable biochemical composition. Thus, applying the optimized autolysis method, with the use of sodium phosphate buffer at 45°C for the destruction of the cell wall and fractional extraction with hydric, alkaline and acidic solutions, various liquid and solid fractions were obtained from the biomass of brewer’s yeast with varied lipid content. So, in order to optimize the waste processing process of the beer industry and the complex recovery of yeast biomass, it is reasonable to include the lipid fraction extraction stage in the technological flow, after obtaining protein and mannoprotein extracts, which will be useful and as an additional step of purification of the β-glucan fraction.

In this study, the procedure of obtaining new biologically active mannoprotein preparation based on the yeast biomass from the residues of the wine industry, namely the production of Merlot dry red wine is presented. The process for obtaining of the preparation includes lysis of the yeast cell wall with sodium phosphate buffer, extraction of anthocyanins by treatment with 50% alcohol solution, hydrolysis with 1N NaOH, sedimentation of mannoproteins with ethyl alcohol, centrifugation and dissolution of purified sediment in distilled water, standardization of the preparation obtained up to a concentration of 10 mg/ml. As a result, it has been established that the mannoprotein preparation possesses a valuable biochemical composition characterized by a high content of proteins, carbohydrates, anthocyanins, and a wide range of minerals, macro, microelements, and does not practically contain heavy metals. Due to its biochemical composition, the preparation, also, possessed antioxidant activities and high catalase and superoxide dismutase activity. In conclusion, we can mention that the varied biochemical composition, antioxidant, and enzymatic activity highlight the high biological value of the mannoprotein preparation and the enormous potential for implementation in various fields, especially in animal husbandry and viticulture, food and cosmetic industry.

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