Organic aggregate-attached bacterial community composition and dynamics of the shallow hypertrophic freshwater Lake Taihu, revealed by T-RFLP analysis Bacterial community structure and composition in Lake Poyang: a case study in the Songmenshan Region, China Effect of intercropping on bacterial community composition in rhizoshpere of wheat (Triticum aestivum L.), maize(Zea mays L.) and faba bean (Vicia faba L.)