Resuscitation Of Viable But Non-culturable Bacteria And Its Effect On The Quorum Sensing Of Pseudomonas Aeruginosa In Mangrove Soil

Mangrove forest,as a treasure house of microbial resources,has the special environment of salty and fresh water alternation,strong acid,strong reducing and high salt characteristics,which makes it contains variety of bacteria with special function including viable but non-culturable(VBNC)bacteria.But the traditional method can only isolate 0.01%-10%microbes in environment,which greatly limits the understanding of mangrove microbial resources and the associated functions.In this paper,the resuscitation promoting factor(Rpf)produced by Micrococcus luteus was combined with MPN culture system to resuscitate and isolate VBNC bacteria in Shenzhen mangrove soil,screen the strains which inhibit quorum sensing,and try to explore the relationship between VBNC phenomenon and quorum sensing.Total of 144 strains were isolated,including 83 VBNC bacteria belonged to 4 phylum(Actinobacteria,Firmicutes,Proteobacteria and Bacteroidetes)12 order,12 family and 22 genus.Based on the reporters of CV026(Chromobacterium violaceum ATCC 31532)and VIR07(Chromobacterium violaceum ATCC 12472)which used to detect quorum sensing,comparison and screening of isolated 51 strains were processed.A strain of LQC3M004(Lactobacillus brevis)with a significant inhibition effect on quorum sensing was identified.It is found that the lysate of the strain induced by a signal molecule can significantly reduce the production of pyocyanin and biofilm in Pseudomonas aeruginosa.The inhibition rate for pyocyanin was 25.16%and for biofilm was 16.93%after treated by lysate protein of 1 mg/mL,while the inhibitory rate for pyocyanin was 30,75%and for biofilm was 33.00%after treated by lysate protein of 2 mg/mL.The whole genome sequencing of the strain LQC3M004 was analyzed but there were no genes were found associated with QS degradation,and the mechanism needs to be further studied.This study not only enriches the database of bacteria,but also provides new ideas and scientific basis for returnation of VBNC state bacteria and screening of quorum sensing related bacteria by Rpf.