Raman and FT-IR Spectroscopy investigation the cellulose structural differences from bacteria Gluconacetobacter sucrofermentans during the different regimes of cultivation on a molasses media.

Raman and Fourier Transform Infrared (FT-IR) spectroscopy was used for investigation of structural differences of bacterial celluloses (BC), obtained by cultivation native and immobilized cells of Gluconacetobacter sucrofermentans during static and dynamic regimes of cultivation on a molasses media. It was found that the Raman and FT-IR spectra could characterized the groups of the cellulose molecules. The culturing bacterial cellulose in the presence of results in an increase of crystalline and it increased during cultivated on a molasses media with the addition of 1.5% ethanol-75.62%. The degree of BC crystallinity increased during dynamic regime of cultivation is higher than under static regime one. The maximal BC content was observed when 0.5% ascorbic acid was added to the cultivation medium with molasses and native cells. It was found, the degree of BC crystallinity during static regime cultivation on a molasses medium with ethanol, increased significantly to 73.5%, and during dynamic regime-75.6%. So, in this study, the changes of the bacterial cellulose conformation of were revealed during bacterial cultivation in a medium containing molasses in various cultivation modes.

Effect of ultraviolet radiation on physiological and biochemical properties of yeast Saccharomyces cerevisiae during fermentation of ultradispersed starch raw material

Background: Study of correlation between pretreatment of yeast with ultraviolet radiation and efficiency of further fermentation of wort made of ultrafine grain particles to ethanol. Results: We investigated three races of industrial yeast Saccharomyces cerevisiae (native and irradiated by ultraviolet). Physiological properties during fermentation of starchy wort were tested in all variants. It was shown that activation of the yeast by ultraviolet radiation allows to further increase the ethanol yield by 25% on average compared with the native yeast races when using thin (up to micro- and nano-sized particles) or standard grain grinding. Conclusions: Using mechanical two-stage grinding of starchy raw materials and ultraviolet pretreatment of yeast, the efficiency of saccharification of starch and fermentation of wort to ethanol was increased.

Enzymatic hydrolysis and fermentation of ultradispersed wood particles after ultrasonic pretreatment

Background: A study of the correlation between the particle size of lignocellulosic substrates and ultrasound pretreatment on the efficiency of further enzymatic hydrolysis and fermentation to ethanol. Results: The maximum concentrations of glucose and, to a lesser extent, di- and trisaccharides were obtained in a series of experiments with 48-h enzymatic hydrolysis of pine raw materials ground at 380-100 rpm for 30 min. The highest glucose yield was observed at the end of the hydrolysis with a cellulase dosage of 10 mg of protein (204 ±21 units CMCase per g of sawdust). The greatest enzymatic hydrolysis efficiency was observed in a sample that combined two-stage grinding at 400 rpm with ultrasonic treatment for 5-10 min at a power of 10 W per kg of sawdust. The glucose yield in this case (35.5 g glucose l-1) increased twofold compared to ground substrate without further preparation. Conclusions: Using a mechanical two-stage grinding of lignocellulosic raw materials with ultrasonication increases the efficiency of subsequent enzymatic hydrolysis and fermentation.