Research On Selection And Fermentation Of Erythrose Alcohol Strains

Using microbial fermentation production of erythritol is one of the hot topics in the studyof modern fermentation engineering. The yeast which make a resistance to high osmoticpressure in a suitable medium were in aerobic fermentation, and then fermented liquid wasseparated, extracted and purified to get erythritol. The synthetic reaction of microorganisms inbioreactors is a complex biochemical process, affected by not only its own productionperformance, but also by the culture medium composition, culture medium proportion, seedquality and fermentation conditions and other factors affecting the control. Therefore, it isvery important that breeding good strains and determine the fermentation level environmentalfactors for the improvement of production capacity.The purpose of this work is to improve yields of erythritol and reduce the cost ofproduction of erythritol. In Shandong-edge collective suburban orchard soil, brewing food,pollen, etc. were extracted substances, microbial screening, and get a high yield strains of L-3-2. This strain was researched under single factor experiments to determine the main factorsof culture and fermentation, the effects of fermentation conditions on the production oferythritol such as carbon sources, nitrogen sources, initial pH, temperature and other factorswere studied. The results show that the culture medium of nutrient factor has a great influenceon erythritol production, and the ratio of medium condition is: glucose30%（w/w）, yeastextract,1%（w/w）,2g/L KH₂PO₄, MgSO₄10g/L, is suitable for bacteria growth,reproduction and synthesis of target products; The optimal reaction condition for synthesis oftarget products as follows: temperature30℃, initial pH4, speed200r/min, fluid volume60ml, the average erythritol production can reach119.2g/L.