Effect of Fermentation Temperature on Mannatide Production by alpha-hemolytic StreptococcusAU Xu, Cui Zhang, Jialan Xiong, Qiu Chen, Yali Gao, Mengxiang (mxgao0398@163.com)

摘要

Temperature is one of the most important environmental factors for cell growth and product formation. Batch microbial mannatide fermentations by alpha-hemolytic Streptococcus H1S-33 at various temperatures, ranging from 28 to 39 degrees C, were studied. The lag time was shorter and the specific cell growth rate and specific mannatide production rate in the early stages of growth were higher at 30 degrees C or higher temperature. The average cell growth rate was higher and the biomass reached the maximum earlier than other temperature at 37 degrees C during fermentation 0-11 h and declined obviously after 11 h, but they remained at a higher level at 33 degrees C after 11 h. Therefore the two-phase temperature control strategy was presented. The temperature control strategy was that the temperature was 37 degrees C during 0-11 h, it Was adjusted to 33 degrees C with the descending 1 degrees C an hour after 11 h. The biomass (dry cell weight) and mannatide production yield reached 9.24 g.L-1 and 1.16 g.L-1 at the variable temperature, respectively, which were higher than those at other temperatures.C1 Gao, Mengxiang; 266 Jingmi Rd, Jinzhou 434025, Hubei, Peoples R ChinaSC Biotechnology & Applied Microbiology