The Coaggregation Of The Bacteria In The Waste Water Treatment Processes Biofilm

The definition of the coaggregation is that the process of different strains of bacteria are conglutinated together each other by special molecule .This conglutination influences the biofilm's formation of complex multi-bacteria .The biofilm is the nature's immobilized microflora in which bacteria can live more eternal and steady in circumstances.Most of bacteria have a certain ability of biofilm formation,but the strong and the weak differ greatly .The bacteria living by biofilm have Highly resistant to disinfectant, severe environment, Host Immune Response and so on.In the wastewater treatment processes,In order to increase the probability of degrading bacteria entering to biofilm ,we mix Bridging bacterium and degrading bacteria with extensive coaggregation ability ,this way can solve the problem that degrading bacteria can't permanently plant in the wastewater treatment processes.Isolate 22 strains of bacteria from different wastewater treatment processes biofilm, quantitatively determined their coaggregation ability, and identify unknown bacteria by 16S rRNA sequence analysis. 22 strains of bacteria can combine 263 pairing, the result shows that the coaggregation percentage of Bacillus cereus G5 with other 21 strains reached more than 30% and 45%, and Bacillus megaterium T1 with other 17 strains of bacteria reached more than 34% and 45% in the 2h and 20h. The coaggregation percentage of H2 and H3 belonging to Shewanella with other 16 strains of bacteria reached 30%~75% in the 2h, and 40%~82% in the 20h; The ability of biofilm formation co-cultured by G5 and T1 with other 21 strains further shows that the G5 and T1 improved the biofilm formation of single bacteria. The ability of biofilm formation of the 2 strains of bacteria generally exceeds in 5% LB culture medium . The experiment results shows that the 2 strains of bacteria with ability of extensive coaggregation can fix multi-bacteria on biofilm.