Studies On Isolation, Screening, Identification Of Symbiotic And Epiphyte Bacteria With Anti-TMV From Marine Fish

10 samples of seven marine fish were collected from Pingtan sea area in Fujian provience. 6 different media were used as isolation media. A total of 119 symbiotic and epiphyty bacteria of marine fish were isolated. The fermentation broth of the 91 marine bacteria were used to determine their inhibitory activities Anti-TMV replication by leaf-disk methods. The results showed that a total of 36 marine bacteria were able to inhibit the replication of TMV with the inhibition rate over 60%. The crude extracts of the fermentation broth were acquired and used for further screening test for the 36 marine bacteria. The 8 marine bacteria's crude extracts at a concentration of 1 mg/mL inhibited the TMV replication with the inhibition rate over 60%. The inhibition rate of the 8 marine bacteria's crude extracts at the concentration of 0.5 mg/mL and 0.25 mg/mL were tested, respectively. The inhibition rate of the 3 marine bacteria's crude extracts in the 8 marine bacteria were over 50% at the concentration of 0.5 mg/mL, especially the crude extracts of the two bateria: 0167B and 0110B, showed high inhibition rate. It was 66.81% and 58.87% at the concentration of 0.5 mg/mL, 48.18% and 39.19% at the concentration of 0.25 mg/mL, respectively.As to the 36 active strains described above whose crude extracts were used to test their inhibition rate Anti-TMV replication at the concentration of 1 mg/mL, the 14 of which showed the inhibition rate higher than 50%. The 14 strains were cultrured with liquid medium subsequently, the fermentation broth were diluted to 10-fold, and then the dilution were used to examine their inhibitory activities Anti-TMV infection by half-leave method. Each strain's inhibition rate was tested 5 times. The result showed that the mean inhibition rate of all the 14 strains was higher than 98%, most of the 14 stains, inhibition rate Anti-TMV infection were 100%.Five active strains were identified by morphology characterization. The cluster analysis between identified bacteria and other bacteria from GenBank were deduced from sequences of 16S rDNA. The results showed that 0110B was identified as Bacillus pumilus, 0111B was identified as Serratia marcescens, 0134B was identified as bacillus subtilis, 0165B was identified as Brevibacterium linens, 0167B was identified as Arthrobacter sp..