Effect of the chitosan on the proliferation of the microencapsulated Escherichia coli

摘要

Immobilization of microencapsulated cell is a kind of membrane technology. Therefore, the characteristics of membrane have a great impact on the growth of microorganisms. This study is designed to achieve the greatest growth rate of microencapsulated cell, Escherichia coli were immobilized in AC microcapsules made with different type of chitosan and then cultured in the Luria-Bertani medium. Effect of deacetylated degree (DD), molecular weight, membrane formation time and the pH of chitosan on the swelling ratio, cell release and proliferation were investigated at 2, 4, 6, 12, 24 and 48h respectively. The results showed that the DD has no obviously influence on terminal biomass concentration, but the swelling ratio of membrane reached lowest when the DD was 90%. The biomass concentration increased with the rising of chitosan Mw and membrane formation time. Especially, the terminal biomass concentration near to 6.5×10~6·mL in the microcapsules made with 10KDa chitosan Mw ands 15 min membrane formation time. Moreover, the swelling ratio closed to lowest point as the chitosan solution pH was 6.3.