[Effects of earthworm (Eisennia foetida ) on As, P uptake by maize and As, P fractional transformation in the rhizosphere].

A pot experiment was conducted to examine the roles of earthworm in As uptake from original As-polluted soil by maize (Zea mays L.), and their effects on As, P fractions in the rhizosphere. The As-polluted soils with three As levels were collected from the arable soil near As mine. The plants were harvested after 10 weeks of growth. Dry weight (DW) and P, As concentrations of plants, as well as As and P fractions of the rhizospheric soil, were determined. The results showed that inoculated earthworm or appended rice straw increased maximal 149%, 222% DW of root and shoot, respectively. At the medium and high soil As levels, root As concentration in the soil treated by earthworm and rice straw was highest among all treatments, and earthworm increased more As concentration of shoot than rice straw did. In different soil As levels, root P concentration in the soil treated by earthworm was highest, and shoot P by rice straw. Ca-P affected maize absorbing As at the low soil As level(r = 0.981), and maize absorbing Al-P was restrained by As involved in well-crystallized hydrous oxides of Fe and Al at the medium (r = 0.953)and high (r = 0.997)soil As levels. The concentration of non-specially absorbed As and As combined with Fe or Al and of O-P increased at the soil inoculated earthworm or/and appended rice straw at the same time. These results indicated that earthworm was more valuable for plant developing than rice straw was.

Halomonas shengliensis sp. nov., a moderately halophilic, denitrifying, crude-oil-utilizing bacterium.

A moderately halophilic bacterium, designated strain SL014B-85(T), was isolated from a crude-oil-contaminated saline soil from Shengli oilfield, Shandong Province, China. Cells were Gram-negative, aerobic, short rods with lateral flagella. Growth occurred at NaCl concentrations of 0-15 % (optimum 5-15 %), at 10-42 degrees C (optimum 30 degrees C) and at pH 8.0-9.0 (optimum pH 8.5). The only respiratory quinone was Q9, and the main cellular fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(19 : 0) cyclo omega8c. The G+C content of the DNA was 66.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SL014B-85(T) belonged to the genus Halomonas in the Gammaproteobacteria, with highest sequence similarity of 98.1 and 97.8 % to Halomonas alimentaria DSM 15356(T) and Halomonas ventosae DSM 15911(T), respectively. DNA-DNA relatedness values were below 40 % with members of closely related Halomonas species. Results of phenotypic, biochemical and phylogenetic analyses revealed that strain SL014B-85(T) could be classified as representing a novel species of the genus Halomonas, for which the name Halomonas shengliensis sp. nov. is proposed. The type strain is SL014B-85(T) (=CGMCC 1.6444(T)=LMG 23897(T)).