Abstract:In this study,A strain,named Lactobacillus plant JD.L which could tolerate low pH and high shearing was selected.Then the nutrient and environmental conditions were optimized and listed as follows: hydrolysate of cottonseed-meal as fermentation medium,temperature 51 ℃,pH 6.2,ORP was-100mv,fed-batch rate 0.05/h Giving the characteristics of the liquid which was produced by continuous fermentation of cell recycling sodium salt method,microfiltration membrane whose diameter is 1μm was choosed to do protecting filtration.Then,the basic parameter of embrane filtration was determined by ultrafiltration whose diameter is 100nm and nano-filtration equipments whose molecular weight is 300.