Abstract: A sponge-associated actinobacterium FH with strong bioactivity was isolated from marine sponge Hymeniacidon perlevis,and identified by 16S rDNA gene sequence analysis as Streptomyces globisporus.The inhibition of Vibrio harveyi and Vibrio splendidus by FH strain was studied and the fermentation condition of FH strain was optimized,including influence of preservation temperature and time on the antibacterial effect of fermented product. The dry weight of mycelium revealed that the growth curve of FH strain showed a lag phase in 0-15 h,log phase in 15-72 h,stationary phase in 72-120 h and decline phase after 120 h.The optimal fermentation of FH strain was observed under conditions of temperature 25℃,pH 7.5 and loading volume 30 mL in the orthogonal experiment, with the best antibacterial effect on Vibrio harveyi and Vibrio splendidus by the crude extracts of FH strain fermented in 72 h under this condition.However,there was no significant difference in the antibacterial effects in the crude extracts of FH strain stored at 4℃and-20℃for 60 days and stored 7 days at room temperature(P＞0.05).Addition of 2 mL fermentation product of FH strain in 100 mL sterilized seawater led to effectively inhibit the growth of Vibrio harveyi and Vibrio splendidus.The findings indicated that the sponge-associated actinobacterium FH and its fermentation product had potential application in the field of mariculture.
2017, Vol. 32 
