Bacterial community composition in lakes

Abstract Bacteria are ubiquitous organisms, inhabiting almost every part of earth including the extreme habitats, and in aquatic ecosystems they represent dense assemblages with varied morphological, physiological and ecological preferences. In these freshwater ecosystems bacterial community composition is determined by using various culture-dependent as well as culture-independent techniques (DNA isolation, PCR amplifications, amplified ribosomal DNA restriction analysis, sequencing, and phylogenetic profiling). The chapter deals with the bacterial community composition of lakes, their diversity, distribution, functional annotations, and their relationship with other organisms in aquatic ecosystem. Later in the chapter the bacterial community's responses to disturbance (natural as well as anthropogenic) are discussed. The chapter further reviews the bacterial community composition of various lakes, novel species obtained from these lakes, and the dominant phyla (Actinobacteria, Cyanobacteria, Acidobacteria, Caldeserica, Calditrichaeota, Verrucomicrobia, Chlorobi, Planctomycetes, Nitrospirae, Chloroflexi, Bacteriodetes, Firmicutes, and Proteobacteria) found in these freshwater ecosystems.