| Pichia pastoris has been utilized widely as an excellent heterologous gene expression system recently. In this research, the media of PP-NP~m-8 was studied, The highest phytase activity could reach 5.5×10~4u/ml, which was 1.17 times as high as that of before optimizing. The price relations of substrate cost and enzyme yield under the optimal conditions was 0.006 yuan/10~7u, which decrease by 14 times than that of zhaohaixia (0.009yuan/10~6u) and decreased by 3283 times than that of BMGY/BMMY cultural medium (the price relations of substrate cost and enzyme yield was 1.97104yuan/10~6u) .The cultural conditions of PP-NP~m-8 strain in baffled flask were studied to ascertain the optimal conditions for growth and culturing of PP-NP~m-8 strain. The phytase activity could reach 1.1×10~5u/ml when it finished inducing, which was 2.35 times as high as that of before optimizing and increased by 6.33 times than 1.5× 10~4u/ml reported by Yao Bin etc.Some factors influencing the growth and expression of recombinant pichia pastoris were investigated to decide the optimal fermenting conditions in 10L automatic fermenter. Under the optimal conditions, phytase was accumulated and its activity could reach 2.63×10~5u/ml, which was 5.52 times as high as that of before optimizing and increased by 9.11 times than the activity of KM71 2.6×10~4u/ml reported by Yanming Han.After being filtrated and condensed, mix fermentation broth and the complement in the same proportion, phytase product was gained.In this research we bring out phytase fermentation and product procession, which increase phytase activity and provide scientific base for its fermentational production and substrate cost decreasing as well.
|
PDF Full Text Request