巨大芽孢杆菌D01吸附金(Au3+)的研究

巨大芽孢杆菌（Ｂａｃｉｌｌｕｓ ｍｅｇａｔｅｒｉｕｍ）Ｄ０１菌体吸附ＡＵ＾３＋的最适ｐＨ值为３．０，其生物吸附作用是一种快速的过程，最初５ｍｉｎ 的吸附量可达到最大吸附量的９５％，温度不影响该吸附作用。在ｐＨ３．０和３０℃、起始金离子浓度与菌体浓度之比为３０５ｍｇ／ｇ的条件下，吸附３０ｍｉｎ，吸附率达９９．１％，吸附量为３０２．０ｍｇ／ｇ干菌体。Ｄ０１菌体能将浓度中的Ａｕ＾３＋还原成Ａｕ＾０，在细

STUDIES ON BIOSORPTION OF Au3+ BY BACILLUS MEGATERIUM

Some characteristics of Au3+ biosorption and bioreduction by Bacillus megaterium D01 biomass were reported. The optimum pH value of Au3+ biosorption by strain D01 was 3.0. The biosorption was a rapid process, reaching 95% of the maximal capacity within the first 5 min of contact. Temperature did not affect the biosorption. The biosorptive efficiency(99.1%) and capacity (302.0 mg Au3+/g dry weight biomass) were achieved under the conditions of pH 3.0 and 30 degrees C, both concentration with an initial Au3+/biomass radio of 305 mg/g dry weight for 30 min of the contact. The D01 biomass could reduce Au3+ in the solution to Au0, Au0 on the cells surface and in the contact solution could be crystallized to different forms gold crystals, Au3+ impregnated on SiO2 and alpha-Fe2O3 could be reduced to Au0 by D01 biomass. The results of electrochemical reaction indicated that the strain D01 exhibited a high selectivity for Au3+.