Identification And Primary Application Of Microorganisms From Putrid Alkaline Silicasol

Silicasol is a kind of fine chemical product. It is a kind of colloidal solution which formed by silica particle uniformly dispersed in water. Silicasol has been widely used in chemical industry, textile, precision casting, electronics and other industries. However, silicasol often be putrescent as a result of microbial pollution during production and storage. It declines quality of the products, losses using value, causing severe economic losses.Six strains were isolated from different lot number alkaline silicasol samples by pH and Salt tolerance choice. To take a series of physiological and biochemical tests, such as morphological characteristic, sugar fermentation, ammonium dextrose test, litmus milk test, catalase test, urease test, triple sugar iron agar test, citrate test, starch hydrolysis test were conducted. Salt tolerance, temperature tolerance, pH tolerance and API 50 CH had been carried out too. In addition, 16S rDNA gene sequence analysis had used to identify isolated strains. The strains were identified as Exiguobacterium aurantiacum,Cyclobacteriaceae bacterium,Microbacterium sp., Acinetobacter sp., Stenotrophomonas maltophilia and Bacillus thuringiensis.The ability of above six isolates for the production of alkaline protease and alkaline amylase were studied. Of the six isolates, five strains were capable of producing alkaline protease, the strongest one was Stenotrophomonas maltophilia. Of the six isolates, Acinetobacter sp. and Bacillus thuringiensis could product alkaline amylase, and Acinetobacter sp. was stronger .To determine the optimum growth medium of Exiguobacterium aurantiacum, single-factor experiment was taken. The optimum growth medium from strongest to the weakest was LB, nutrient agar and peptone water. The optimum neutralize condition was add 15mL 2.7×1010cfu/mL bacteria liquid to 100mL alkaline wastewater, pH less than 11 and room temperature.In this study, isolates were identified, clarifies the reason of the corruption, and provides a basis for silicasol quality control. The ability of for the production of alkaline protease and alkaline amylase were studied. To explore the possibilities the treatment of alkaline wastewater. Reveals potential value of industrial development.