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Trehalose (Trehalose) is widely found in microorganisms, vertebrates, invertebrates and plants. Studies have shown that cells not only can be used as trehalose carbon source such stockpiles, also can be used as a highly efficient protective agents increase the cellular components of the adverse environmental conditions (such as high temperatures, starvation, freezing, dehydration, radiation, toxic reagents, high osmotic pressure and high alcohol concentration ) resistance. Trehalose can not only function in the living body, and external trehalose can also be of biological macromolecules having a protective effect, which makes it having a wide range of applications in many aspects, such as in medicine, molecular biology and microbiology cells antifreeze The active ingredient of the agent, cosmetics, diagnostic reagents, and biological products stabilizer, as well as serving as a fresh food preserving agent. Therefore, with a cheap and efficient method to produce trehalose has become a current research focus. Starch low prices, wide variety of sources, starch as raw material, Enzymatic production of trehalose, cheap starting materials, conversion rate, very promising, is considered to be the best material used to produce trehalose. In past studies also found Saccharomycopsis fibuligera sdu, the use of the starch converting production trehalose good strains. But the yeast can be synthesized in vivo acidic and neutral trehalase, these enzymes in cells can be decomposed to the synthesis of trehalose, which will not be conducive to the accumulation of trehalose. Accordingly, in order to improve the yield of trehalose from this strain, it is necessary to remove or reduce acid and neutral trehalase activity. Later, the use of chemical mutagenesis techniques for acidic and neutral trehalase activity greatly reduced A11 mutant, the mutant strain is cultured in a soluble starch medium the amount of bacteria in vivo accumulation of trehalose reaches 19.1% (w / w), in the the cumulative amount of the bacteria in vivo trehalose cultured maize starch medium reached 24.0% (w / w). This study found that tapioca starch instead of corn starch to produce trehalose can trehalose lower production costs, A11 mutant cassava starch medium of 2.0% (w / v) 2-L fermenter 48 h fermentation bacteria in vivo seaweed the cumulative amount of sugar to 25.8% (w / w). The use of soluble starch, and corn starch as a carbon source to convert the trehalose is not economical. Cassava as a non-food crop, is used as a food and fermentation industry, starch material, large-scale cultivation of many provinces and cities in southern China. Study, we found that in shake flask experiments, A11 strains using cassava starch conversion trehalose content higher than soluble starch, corn starch and the like. For 48 h, and 2.0% cassava starch, 4.0% soybean meal hydrolyzate, pH 5.5, 30 ℃ condition trehalose accumulated amounted to 24.8% (w / w). This paper also use of the 2-L fermentor study the fermentation tapioca starch production of trehalose, trehalose accumulation in an A11 strain 48-h fermentor an amount of 25.8%, the residual reducing sugar concentration and residual total sugar concentration were 1.2 mg / mL and 2.1 mg / mL. This is the highest strains of the currently reported by the amount of trehalose accumulation. Trehalose extraction and purification process, the paper mainly with the bacterial cells of the trehalose trichloroacetic acid extraction and ethanol precipitation method, the extract was separated after further purification, to obtain trehalose crystals. Obtained by chemical mutagenesis mutant A83 for the extraction method of the present trehalose are deficiencies, the present study, this strain in the 37 ° C under the conditions of the cell wall permeability changes can be automatically released trehalose and trehalose-releasing rate reached 44.7% . This study is in the current environment pollution, resource consumption situation is grim social context, in response to the call of energy saving and environmental protection as well as low-cost, non-toxic industrial production of trehalose to make a positive explore and try.
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