关键词: 地肤, 多环芳烃, 降解, ACC脱氨酶, 根内生细菌

Abstract: We explored the diversity and composition of soil microbial community in 0-10 and 10-20 cm soil layers in the reclaimed woodland (R-S) and reclaimed grassland (R-G) in Lu’an coal waste pile, Changzhi, Shanxi Province, using the method of phospholipid fatty acid (PLFA). The effects of environmental factors on the soil microbial community composition were analyzed. The results showed that: (1) PLFA richness index (S) and Shannon diversity index (H) of 0-10 cm and 10-20 cm soil layers in R-G were all higher than that in R-S (P<0.05), but there was no significant difference in Pielou evenness index (E) in both soil layers between the two plots. (2) In both soil layers, the contents of total microbial PLFAs, fungi PLFAs (F), actinomycetes PLFAs (A), Grampositive bacteria PLFAs (G+), Gram-positive bacteria/Gramnegative bacteria and fungi/bacteria were all higher in R-S than that in R-G (P<0.05). However, the contents of bacteria PLFAs (B) and Gram-negative bacteria (G-) in those plots were different for the two soil layers, being higher in 0-10 cm in R-S than that in R-G (P<0.05), but lower in 10-20 cm soil layer in R-S than that in R-G. (3) The principal component analysis indicated that the soil microbial community structure and composition were significantly affected by the types of reclamation. The redundancy analysis  showed that the soil physicochemical properties affected the contents of soil microbial PLFAs. Among them, soil available phosphorus (AP), soil pH and cation exchange capacity (CEC) were the main factors affecting microbial community composition. The contents of soil microbial PLFAs were positively correlated with AP and CEC, while negatively correlated with soil pH.

Key words: degradation., ACC deaminase, Kochia scoparia, polycyclic aromatic hydrocarbons, endophytic bacteria