一株产胞外多糖海洋弧菌的分离鉴定及其多糖抗肿瘤活性初步研究

Isolation and Identification of Marine Vibrio Producing Extracellular Polysaccharide(EPS)and the Preliminary Study on Anti-tumor Activity of the EPS

为初步探究广西北部湾海洋细菌所产胞外多糖(Extracellular polysaccharide,EPS)的生物学活性,通过LB-苯胺蓝培养基分离产EPS的海洋细菌,苯酚-硫酸法测定EPS产量,16S r DNA法鉴定多糖产量较高的菌株,通过凝胶渗透色谱测定多糖分子量,红外光谱分析该多糖的结构;最后运用MTT(噻唑蓝)法测定该EPS对Vero细胞的毒性,以及对He La细胞的抑制作用。结果显示,从海水及红树林泥样中共分离获得167株产EPS的海洋细菌,其中一株BHc-09 EPS产量较高,达0.306 mg/m L,通过16S r DNA序列分析鉴定BHc-09为弧菌属,其EPS分子量约为184.5 k D,结构中含有糖醛酸;该胞外多糖对正常Vero细胞无毒性而对肿瘤细胞的生长具有明显的抑制作用。

In order to investigate the bio-activities of the extracellular polysaccharide（EPS）from the marine bacteria in the GuangxiBeibu Gulf,the marine bacteria of EPS-producing were isolated from water/mud samples by LB-aniline blue medium. Phenol-sulfuric acidmethod was used for measuring the yield of the EPS. The marine bacterial strains with high-yield of ESP were further identified by the sequenceanalysis of 16 S r DNA. The molecular weight and the preliminary structure of the EPS were tested by Gel permeation chromatography（GPC）and infrared spectrometry,respectively. Finally,the cytotoxicity of the EPS on Vero cells and the inhibitory effect of the EPS on Hela cellswere tested by the MTT method. The results showed that totally 167 marine bacteria producing EPS were isolated from sea water/mud ofmangrove,one of which（named BHc-09）yielded ESP as high as 0.306 mg/m L and was identified to be Vibrio by the analysis of its 16 S r DNAsequence. The molecular weight of the EPS from BHc-09 was 184.5 k D,and there was uronic acid in the EPS structure. The EPS produced byBHc-09 presented no cytotoxicity on Vero cell,but significantly inhibitory effects on tumor cells. The results suggested that an EPS-producingmarine Vibrio was successfully isolated and identified,and its extracellular polysaccharide has anti-tumor activity.