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目的对一株分离自东海海水样品中的菌株(编号P12008)进行鉴定和生物学活性研究。方法对P12008进行革兰染色、形态观察及耐盐实验,结合16S rDNA序列测定确立其进化地位。采用体外细胞毒模型MTT法测定菌株发酵液对HepG2细胞及HL60细胞的抑制作用;采用DPPH和ABTS模型对菌株发酵液的乙酸乙酯提取液进行抗氧化作用研究。结果P12008为G~-菌,光镜下呈椭圆或圆形。该菌株在不含NaCl的培养基中不能生长,最适生长盐度为12.5%。16S rDNA序列分析的结果表明P12008菌株与Halomonas sp.MZ0306A1(EU124745.1)相似度最高,为99%。生物学活性研究发现,该菌株的发酵液对HepG2细胞的抑制率为17.1%,对ABTS清除率达到40.71%(100μg·mL~(-1)),而对DPPH的抑制率达到59.06%(375μg·mL~-)抗氧化活性较强。结论研究表明,P12008是一株中等嗜盐的盐单胞菌,其发酵液具有一定的体外细胞毒活性和较强的抗氧化作用,值得进一步研究其活性代谢产物。
Objective To identify and study the biological activity of a strain (P12008) isolated from seawater samples from the East China Sea. Methods Gram stain, morphology and salt tolerance experiments were performed on P12008. The evolutionary status of P12008 was determined by 16S rDNA sequencing. The in vitro cytotoxicity assay was used to determine the inhibitory effect of the strain fermentation broth on HepG2 cells and HL60 cells. The DPPH and ABTS models were used to study the antioxidant activity of the ethyl acetate extract of the fermentation broth. Results P12008 was G ~ - bacteria, which was oval or circular under light microscope. The strain can not grow in NaCl-free medium, the optimum growth salinity is 12.5%. The results of 16S rDNA sequence analysis showed that the similarity between P12008 strain and Halomonas sp. MZ0306A1 (EU124745.1) was 99%. The biological activity study showed that the strain of the fermentation broth of HepG2 cells was 17.1%, the ABTS clearance rate was 40.71% (100μg · mL -1), while the inhibition rate of DPPH reached 59.06% (375μg · ML ~ -) Antioxidant activity is strong. Conclusion The study shows that P12008 is a halophilic halophilic bacteria. The fermentation broth of P12008 has certain cytotoxicity in vitro and strong antioxidant activity, which deserves further study of its active metabolites.