2株海洋细菌对镉的吸附作用

Adsorption of Heavy Metal Cadmium by Two Marine Bacterial Strains

用高质量浓度镉培养液单独和联合培养2株海洋细菌J2和J6,3、7、10、14、17d后,采用原子吸收法分别测定培养液上清液和菌细胞中Cd2+的质量浓度,以确定2株菌对镉的吸附性能;通过测定菌体细胞内半胱氨酸脱巯基酶的活性,初步研究了2株菌对镉的转化作用机理。试验结果表明,2株菌均可将细胞外的Cd2+吸收到细胞内,在培养至第7d时,上清液中Cd2+的含量达到最低值,随着培养时间的增加逐渐趋于稳定,J2和J6菌体细胞中Cd2+的含量分别在培养到第10d和14d时达最大值,联合培养对镉的吸附作用优于单独培养;J2和J6在镉处理后细胞内的半胱氨酸脱巯基酶活性均显著增高,提示Cd2+的吸附与细胞内半胱氨酸脱巯基酶作用产生的S2-有关。

Two marine bacterial strains J2（Vibrio pacinii）and J6（V.alginnolyticus）were incubated in culture medium containing high concentration of cadmium.The cadmium concentration and bacterial cells were determined by Atomic Absorption Spectroscopy（AAS） 3,7,10,14 and 17 days after culture.The mechanism about transformation of heavy metals Cd by the strains was studied by detection of the activity of cysteine desulfhydrase in bacterial cells.The results showed that Cd2＋ consistency in culture medium was reduced by J2 and J6 exposed to the metal for a week,compared with the control,the minimal Cd content in the 7th day.The maximum content of Cd2＋ in cells of J2 and J6 was observed in the 10th day and 14th day,respectivesy.The activity of cysteine desulfhydrase in cells of J2 and J6 was shown to be increased by supplementation with Cd.The findings suggest that the transformation mechanism of J2 and J6 to Cd be S-2 produced under the effect of cysteine desulfhydras and combined with Cd.