[Sorption behavior of PCB28 to phosphatidylcholine and triglyceride].

Sorption behaviors of PCB28 to phosphatidylcholine (PC)and triglyceride (TG) were studied. Results showed that sorption equilibrium could be achieved in 8 h for PCB28, and the sorption amount on PC was higher than that of TG when the initial PCB28 concentration is in the range of 50-250 microg x L(-1). As the initial PCB28 concentration increases, the absolute sorption amount and relative sorption amount on PC and TG enhances. And linear isotherm is suggested as the most appropriated fitting type, sorption constants K(d) calculated from linear isotherm for PC and TG are 38.84 L x g(-1) and 20.14 L x g(-1) respectively, which suggested that PC had a higher sorption ability to PCB28 than that of TG, and the fatty acid chain length might be important factors to influence the sorption mechanism of PC and TG.

[Phytoremediation of polychlorinated biphenyls contaminated soil by leguminosae-gramineae intercropping: a field trial].

Phytoremediation of polychlorinated biphenyls (PCBs) contaminated soil by leguminosae (alfalfa) and gramineae (ryegrass and tall fescue) was studied in a field trial. All planted treatments had significantly higher PCBs removal efficiency compared with those of unplanted control after 270 days of in-situ phytoremediation. Alfalfa monoculture received the highest removal efficiency of soil PCBs by 59.6%. Analysis of PCBs congeners composition showed that the percentage of di-chlorinated biphenyl decreased in all planted treatments. Alfalfa produced the maximum biomass among the 3 plants. Total PCBs concentration in alfalfa roots reached 355.1 microg/kg, which was significantly higher than those in ryegrass and tall fescue. The phytoextraction efficiency of different treatment was in order of alfalfa > alfalfa-ryegrass-tall fescue > alfalfa-ryegrass > ryegrass > alfalfa-tall fescue > tall fescue. The results suggest that alfalfa may be an ideal candidate for the phytoremediation of PCBs contaminated soil.

A new stromata-producing Neotyphodium species symbiotic with clonal grass Calamagrostis epigeios (L.) Roth. grown in China.

We describe a new stromata-producing Neotyphodium species symbiotic with clonal Calamagrostis epigeios (L.) Roth. Stromata on the grass, 47.5-186 mm long, occurred frequently, but neither perithecium nor mature ascus was observed. Morphology of fungal isolates obtained from symptomatic and asymptomatic tillers were identical to each other and similar to those of epichloë endophytes. In phylogenetic analysis all selected five fungal isolates clustered into a significantly distinct clade based on sequences of beta-tubulin gene (tubB) introns and translation elongation factor 1-alpha gene (tefA) introns with bootstrap values of 99%, supporting erection of a new species. Concerning the production of extremely long stromata on the host plants and absence of sexual spores, we propose the name Neotyphodium stromatolongum Y. Ji, L. Zhan et Z. Wang, sp. nov.