利用基因工程菌E.coli SE5000对水体中的镍离子进行富集研究。菌体细胞对Ni2+ 的富集速率很快，富集过程满足Langmuir等温线模型。经基因改造的基因工程菌不仅最大镍富集容量与原始宿主菌相比增加了4倍多，而且对pH值的变化呈现出更强的适应性。对离子强度及其它共存重金属离子的影响的实验结果表明：Na+，Ca2+，Cd2+，Pb2+ 的影响较小，但Mg2+，Hg2+，Cr3+ 和Cu2+ 所引起的负面效应较大。金属螯合剂EDTA 的存在对基因工程菌的富集行为影响很大。

The aerobic and anaerobic biodegradation of polyethylene glycols (PEGs) in a model wastewater was investigated employing sludge microbes from Xiamen Terylene plant. The effect of molecular weight (MW) on the aerobic/anaerobic biodegradation of PEGs was assessed by performing shake flasks/sealed flasks experiments, respectively, using organic model wastewater containing PEG 600, 6000 and 20,000. In aerobic biodegradation, although there were differences between the degradation processes, the three kinds of PEG were all degraded by about 80% in 5 days, regardless of the wide diversity of MW. In anaerobic biodegradation, about 50% degradation of PEG 600 in 9 days, 40% degradation of PEG 6000 in 10 days and 80% degradation of PEG 20,000 in 6 days were obtained. The effect of nutrition on anaerobic degradation was also investigated. The biodegradation rate of PEG 6000 increased sequentially in the organic, inorganic and enriched organic media. The latter two were similar to each other. In the enriched organic media PEG 6000 was degraded by 50% in 10 days and 70% in 14 days, while in the organic media the degradation rate was 23% in 10 days and 50% in 14 days. It was notable that the anaerobic microbes could use PEG 6000 as sole carbon source, and PEGMWup to 20,000 was efficiently biodegraded in this study, either in aerobic or anaerobic way.

This study constructed a genetically engineered Escherichia coli JM109 which simultaneously expressednickel transport system andmetallothionein to remove andrecover Ni2+ from aqueous solution. Bioaccumulation process was rapidandfollowedlinearized Langmuir isotherm. A more than six-fold increase of Ni2+ binding capacity was obtainedby genetically engineered E. coli cells comparedwith original host E. coli cells. A pH assay showedgenetically engineered E. coli cells accumulatedNi 2+ effectively over a broadrange of pH (4-10). The presence of 1000mg/L Na+ andCa 2+, or 50mg/L Cd2+ or Pb2+ did not have a significant effect on Ni2+ bioaccumulation, while Mg2+, Hg2+ and Cu2+ poseda severe adverse influence on Ni2+ uptake by genetically engineered E. coli. Furthermore, genetically engineered E. coli cells did not require extra nutrients for Ni2+ bioaccumulation.

Corynebacterium strain SH09 separated from a silver mine was used for biosorption and bioreduction of diamine silver complex. The biosorption of the diamine silver complex was better than that of silver ions and the maximum of the former was about 350 (mg Ag) (g dried biomass)−1. After dried cells of SH09 were resuspended in the aqueous solution of diamine silver complex in the dark at 60℃ for more than 72h, transmission electron microscopy (TEM) observations showed that a large quantity of black particles whose diameter ranged from 10 to 15nm were formed on the cell wall. The particles were identified as being silver nanoparticles by X-ray diffraction (XRD) and UV-vis spectroscopy. Under the same conditions, no bioreduction of silver nitrate was found. According to IR spectra, some functional groups, such as the amide of the proteins, were involved in the processes of biosorption and bioreduction.

The growth of Phanerochaete chryrosporium (ATCC 24725) in pellets was influenced by colture time, medium pH. CN, surlactant concentration, spote number in inoculum, and shaking rale. The reroval of Pb2+ from aqueous solution by this kind of mycellal pellets was studied. The results indicated that many factors affected biosorption. These factors included pH. Pb2+ concentration, co-ion, adsorption time, and chemical pretreatments of biomass. Under optimum biosorption conditions (pH 4.5, 27℃， 16H)，the higheat lead uptake of 108mg/g, was observed with mycelial pellets of 1.5-1.7mm in diameter which were treated with 0.1mol/L NaOH solution before adsorption. Pretreatment of biomass with NaOH frther increased its biosorption capacity.