Development And Application Of Efficient Compound Probiotics

Probiotics are new products to take place of the antibiotics. It has been widely used in aquaculture, animal breeding, planting, disease treatment and other fields, because of the advantages including no residue, no resistance, no toxic side effects and remarkable effect.This study focused on screening of microorganisms, the preparation of compound probiotics and specifically applied in aquaculture industry. The main results are:1、Eight effective sediment samples were collected from CangZhou and TianJin region,and eleven strains were isolated by selected medium. With initial performance testing, four strains were deemed to the best strains, and separately numbered 21-B、31-A、33-A、41-A.2、Through the molecular and physiological-biochemical experiments to identify the screening of strains, the result was that the four strains were identified as Cronobacter sakazakii, Bacillus subtilis, Lysinibacillus sphaericus and Bacillus cereus.3、The Cronobacter sakazakii was detected performance alone. The results found the removal rate of nitrite nitrogen was 97.6%, and removal rate of ammonia nitrogen was as high as 98.3%.4 、 Single function strains were mixed cultured. The best medium of the strain was glucose 10 g ? L-1, casein 10 g ? L-1, potassium hydrogen phosphate 2 g ? L-1 and beef liver extract powder 1 g ? L-1. The optimum temperature of growth of the strains was 37 oC, the optimum pH was 8.0 and the optimum rotation rate was 120 r?min-1. The best mixture ratio :31-A: 33-A: 41-A was 2: 1: 1(ie 7 combination).5、7th combination preparation was used in different ammonia-nitrogen wastewater. In the simulation experment, the removal rate of nitrite nitrogen was 75%, and removal rate of ammonia nitrogen was as high as 40%. In the collected water experiment, the results found the removal rate of COD was about 30%.