Efficient Ammonium Removal by Bacteria Rhodopseudomonas Isolated from Natural Landscape Water: China Case Study

Xuejiao Huang,Chong Yang,Deti Xie,Mi Feng,Jiupai Ni,Zhenlun Li

doi:10.3390/w10081107

Abstract

In this study, we isolated a strain of photosynthetic bacteria from landscape water located in Southwest University, Chongqing, China, and named it Smobiisys501. Smobiisys501 was Rhodopseudomonas sp. according to its cell morphological properties and absorption spectrum analysis of living cells. The analysis of the 16S rDNA amplification sequence with specific primers of photosynthetic bacteria showed that the homology between Smobiisys501 and Rhodopseudomonas sp. was 100%, and the alignment results of protein sequences of the bacterial chlorophyll Y subunit showed that Smobiisys501 and Rhodopseudomonas palustris were the most similar, with a similarity of more than 92%. However, Smobiisys501 could not utilize glucose and mannitol as a carbon source and had a low fatty acid content, which were different from the related strains of the genus Rhodopseudomonas. Moreover, the DNA-DNA relatedness was only 42.2 ± 3.3% between Smobiisys501 and the closest strain Rhodopseudomonas palustris. Smobiisys501 grew optimally at 30 °C and pH 7.0 in the presence of yeast extract, and it could efficiently remove ammonium (99.67% removal efficiency) from synthetic ammonium wastewater. All the results indicated that Smobiisys501 was a novel species of Rhodopseudomonas, with the ability to remove ammonium.

Highlights

The genus Rhodopseudomonas was first described by Czurda and Maresch [1] and is one of the photosynthetic bacteria (PSB), known as purple nonsulfur bacteria
This study reports a new member of the genus Rhodopseudomonas, named Smobiisys501, as an anaerobic bacterium
Smobiisys501 belongs to the genus Rhodopseudomonas according to the morphological and absorption spectra analysis, as well as the alignment result of the 16S rDNA

Summary

Introduction

The genus Rhodopseudomonas was first described by Czurda and Maresch [1] and is one of the photosynthetic bacteria (PSB), known as purple nonsulfur bacteria. Delineating species of the genus Rhodopseudomonas is taxonomically challenging due to the poor correlation between phenotypic and genotypic traits, hampering the identification and classification of newly isolated strains [6]. Many molecular biological methods including the sequence alignment, G+C content determination, DNA-DNA hybridization, and phospholipid fatty acid analysis have been successfully employed to identify the genus Rhodopseudomonas [2,7,8]. An example of this is PPF2/PPR2, a pair of specific primers designed according to the particular sequence of 16S rDNA of Rhodopseudomonas that could accurately identify Rhodopseudomonas [9]

Methods

Discussion

Conclusion