Diversity and abundance of aerobic anoxygenic phototrophic bacteria in two cyanobacterial bloom-forming lakes in China

Abstract

-Aerobic anoxygenic phototrophic (AAP) bacteria are widely distributed in marine and freshwater ecosystems. The aims of this study were to investigate the diversity and abundance of AAP bacteria in cyanobacterial bloom-forming eutrophic lakes and to study the association of AAP bacteria with the bloomforming cyanobacteria. Analysis of pufM gene (the light-reaction center gene) clone libraries indicated that in eutrophic lakes (Lake Taihu and Lake Chaohu, China) with cyanobacterium Microcystis blooms, the AAP bacteria were related to members of Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. In Lake Taihu and Lake Chaohu, Alphaproteobacteria accounted for 81.5% and 75.0% of Microcystisassociated AAP bacteria, respectively, and 84.6% and 72.5% of free-living AAP bacteria, respectively. The predominance of Alphaproteobacteria in the two lakes was different from the previously reported predominance of Betaproteobacteria in freshwater lakes. Quantitative real-time PCR analysis indicated that in Lake Taihu and Lake Chaohu, AAP bacteria represented an important part of the bacterial community associated with Microcystis, and the abundance of Microcystis-associated AAP bacteria (18.3% and 11.7%, respectively) was higher than that of free-living AAP bacteria (5.1% and 7.9%, respectively). The abundance of AAP bacteria in the two bloom-forming lakes was higher than the previously reported level in other eutrophic freshwater bodies.

Distribution of Aerobic Anoxygenic Phototrophs in Freshwater Plateau Lakes

“…The high abundance of puf M gene from eutrophic DC and CH was consistent with the previous study by Shi et al [14] on eutrophic lakes Taihu and Chaohu in China. Result showed that free-living AAP bacteria were separately 2.3 (±0.69) × 10 6 cells mL -1 in Lake Taihu and 1.3 (±0.29) × 10 5 cells mL -1 in Lake Chaohu, which was higher than the previously reported levels in other eutrophic freshwater bodies [14].…”

“…Result showed that free-living AAP bacteria were separately 2.3 (±0.69) × 10 6 cells mL -1 in Lake Taihu and 1.3 (±0.29) × 10 5 cells mL -1 in Lake Chaohu, which was higher than the previously reported levels in other eutrophic freshwater bodies [14]. The abundance of AAP bacteria was highly variable with copies of puf M gene ranging from 1.1 × 10 2 to 1.4 × 10 5 mL -1 [21] and 0.3 to 12.04 × 10 5 cells mL −1 in the surface layers of peat-bog lakes by epifluorescence microscopy numbering [13].…”

“…However, information on the AAP abundance that relates to the trophic status is inadequately recorded. Though research studies on AAP bacteria have been frequently reported [12][13][14][15], the distribution of AAP bacteria in specific areas remains unclearly and inadequately understood, e.g., freshwater plateau lakes. The populations of anoxygenic phototrophic bacteria are morphologically and physiologically diverse, indicating an adaptation to the local stratified environments [16].…”

High turnover rates of aerobic anoxygenic phototrophs in European freshwater lakes

“…AAP bacteria are abundant in various marine environments (Kolber et al, , Cottrell et al, , Sieracki et al, , Jiao et al, , Yutin et al, , Boeuf et al, ) and also in many freshwater lakes and rivers (Mašín et al, , Mašín et al, , Ruiz‐González et al, , Čuperová et al, , Caliz and Casamayor, , Fauteux et al, , Lew et al, ). Freshwater AAP bacteria seem to represent a diverse assemblage of species belonging exclusively to different subgroups of Alpha‐ and Betaproteobacteria (Waidner and Kirchman, , Shi et al, , Salka et al, , Čuperová et al, , Caliz and Casamayor, ).…”

Cyanobacteria as Potential Options for Wastewater Treatment

“…Different reports on eutrophic lakes of China (Taihu, Chaohu and Ulungur Lakes) revealed the invariable predominance of Microcystis sp. (Ye et al 2009 ;Shi et al 2010 ;Lin et al 2011 ). Magana-Arachchi et al ( 2011 ) studied the cyanobacterial diversity of Gregory Lake, Nuwara Eliya, Sri Lanka which is eutrophied due to agricultural and industrial activities.…”