污染土壤中耐镉菌株的筛选、鉴定及吸附试验研究

Screening and identification of cadmium-tolerant bacteria in polluted soil and characteristics

从镉含量超标的土壤中分离驯化出具有耐镉能力的菌株14株。16S rDNA序列鉴定,可知铜绿假单胞菌占72%,属于优势菌群。对耐镉菌株分别进行镉和铅的吸附试验研究,选出吸附效果最好的两株菌Z11和Z13,同时观察温度和pH对两株菌生长量的影响,在最佳生长条件时绘制菌的生长曲线。结果表明,菌Z11对污染土中镉和铅的吸附率分别达到40%和47%,菌Z13分别达到47%和33%。两株菌生长最适温度均为20～25℃,都不能耐高温。Z11和Z13最适生长pH分别为7～9和5～7。

Total 14 cadmium-tolerant strains were isolated from coking plant soil which cadmium content exceeds the standard.The 16S rDNA sequence analysis showed that Pseudomonas aeruginosa took the percentage of 72% and was the dominant microorganisms.These strains were further used to study the adsorption efficiency to Cd2＋ and Pb2＋.Among these strains,two cadmium-tolerant strains labeled as Z11 and Z13 had good adsorption efficiency to Cd2＋ and Pb2＋ were screened.Effects of pH and temperature on the growth of the strains Z11 and Z13 was studied and drew the growth curve of the strains under the optimal growing conditions.The results showed that the adsorption of Z11 for Cd2＋ and Pb2＋ reached 40% and 47%,respectively and that of Z13 reached 47% and 33%,respectively.The optimum growth temperature of the two strains were 20-25 ℃,both of them can＇t tolerate high temperature.The optimum growth pH of the strain Z11 and Z13 were 7-9 and 5-7,respectively.