北极海洋放线菌R-527F的抗菌活性筛选、鉴定及其抗菌物质发酵条件研究

对分离自北冰洋73°N以北海域沉积物中的一株放线菌R-527F进行分子鉴定及生物活性研究.通过对菌株的形态特征、培养性状、生理生化特征以及16S rDNA序列进行综合分析,确定该株菌为链霉菌属,暂定名为Streptomyces sp.R-527F.其含有聚酮类Ⅰ型(PKS Ⅰ)和非核糖体含硫多肽类(nonribosomal peptide synthetase,NRPS)化合物的合成基因.对其抗菌活性及活性物质发酵条件进行了研究,实验结果表明,该菌株所产生的抗菌物质对枯草芽孢杆菌具有显著抑制效果,抑菌圈直径达到18.2 mm.适合其抗菌物质的发酵条件:种子液接种量为4％,培养基初始pH为8.0,培养温度为28℃,培养时间为6d,摇床转速为180 r·min-1,装液量为40％,为该菌株抗菌物质的进一步研究奠定发酵条件参数基础.

STUDIES ON THE ANTI-BACTERIA ACTIVITY, IDENTIFICATION AND FERMENTATION CONDITION OF ANTIBIOTIC SUBSTANCES OF STREPTOMYCES SP. R-527F ISOLATEDFROM ARCTIC MARINE SEDIMENT

An actinobacteria strain,R-527F,was isolated from a marine sediment sample taken north of 73°N in the Arctic Ocean.According to the morphological and physiological characteristics and 16S rDNA sequence,this strain was temporarily named Streptomyces sp.R-527F,which belongs to the species within the genus of Streptomyces,in the Globisporus taxa.Amplification of the biosynthetic genes and a bacteria-inhibition assay were carried out.The results show that it contain Polyethylene ketone type Ⅰ(PKS Ⅰ) and non ribosome-bound sulfur-containing peptides(NRPS) compound synthesis genes,and that the antibacterial substances produced by the strain on Bacillus subtilis has remarkable inhibition effect,with an antibacterial circle diameter of 18.2 mm.Based on the variation of single factor experiments,the optimal fermentation conditions for antibacterial substance biosynthesis are: the fermentation medium containing starch 10 g,sucrose 10 g,soybean powder 6 g,MgSO4 0.5 g and sea water 1 000 mL,the seed liquid inoculum for 4%,medium initial pH is 8,the culture temperature of 28℃,culture time for 6 days,shaking speed is 180 r·min-1,liquid volume 40%.