Wang Jihui

Biosorption of Cu2+, Pb2+ and Cr6+ by a novel exopolysaccharide from Arthrobacter ps-5

The biosorption behaviors and mechanisms for Cu(2+), Pb(2+) and Cr(6+) by a novel exopolysaccharide (EPS) from Arthrobacter ps-5 have been studied in the paper. The influences of EPS concentration, solution pH and ionic strength on adsorption property were investigated. The EPS showed strong biosorption capability, up to 169.15mg/g of Cu(2+), 216.09mg/g of Pb(2+) and 84.47mg/g of Cr(6+), respectively. With the additional concentration of Ca(2+) and K(+) increased, the biosorption ability on Cu(2+), Pb(2+) and Cr(6+) decreased significantly and followed the order of K(+)<Ca(2+). Infrared spectrometry analysis demonstrated that the groups of OH, CO, COC and COC of the EPS involved in metal biosorption process were the main functional groups for binding metal ions.

Screening and Phylogenetic Analysis of Halophilic Bacteria from the Deep Sea Water at Low Temperature

Three strains of halophilic bacteria were screened from the deep sea water at low temperature. Their phylogenetic positions on the basis of amplification, comparison and analysis of almost complete 16S rRNA gene were cloned and determined by neighboring-joining analyses. Phylogenetic analysis indicated that two strains belong to Pseudomonas.sp. The third stain was classified as genus Acinetobacter .sp. The phylogenetic tree was produced from 16S rRNA of 3 halophilic strains and other 30 strains using 16S rRNA gene as out-group. Two strains (B2 and CY11) were clustered with many Pseudomonas.sp strains. One strain (LT4) was clustered with Acinetobacter baumannii.