Changes in soil microbial community structure associated with two types of genetically engineered plants analyzing by PLFA

With the rapid expansion of GEPs(genetically engineered plants), people are more and more concerned about the ecological risks brought by their release. Assessing the effect of GEPs on soil microbial ecology is indispensable to study their ecological risks. In our study, the phospholipids fatty acid(PLFA) method was used to analyze the microbial community of soil samples collected from fields with two types of GEPs-Bt transgenic com and PVY( potato virus Y) cell protein gene transgenic potato. The principal components analysis(PCA) showed all controls were on the right of related GEPs samples along the PC1 (the first principal component) axis, which means a decrease of fungi in soils with genetically engineered crop since most of PLFAs that are strongly positively correlated with PC1 represent fungi. For samples collected from Bt transgenic cornfield, the ratios of gram-positive to gram-negative bacteria were less than those of controls. For samples of transgenic potato field, these ratios were lower than those of controls when soils were collected from deep layer(20-40 cm), but were higher when soils collected from surface layer(0-20 cm). For soils collected from 0-20 cm, the ratios of fungi to bacteria for all GEPs samples were at the same level. So were such rations for all controls. Changes of soil microbial community in two types of GEPs fields were detected in our study, but the causes and more information still needs further study.     

GC-MS分析碱法草浆造纸废水中的有机污染物组成

碱法草浆造纸废水在酸性条件下经乙醚萃取--K-D浓缩器浓缩,采用气相色谱-质谱(GC-MS)联用仪对其有机污染物进行了分析研究.结果表明,该废水中共含有29种有机物,其中主要为有机酸类,占有机物总量的50.84%.其次为难降解的呋喃类和毒性较大的苯环类有机物,它们分别占有机物总量的25.12%和13.53%.