Bacterial community shifts evaluation in the sediments of Puyang River and its nitrogen removal capabilities exploration by resuscitation promoting factor.

Identifying indigenous bacterial community and exploring the potential of native microorganisms are crucial for in situ bioremediation of nitrogenous pollutants in water bodies. This study evaluated the bacterial communities of sediment samples from a nitrogen polluted river, and revealed the possible environmental factors shaping the bacterial populations. Importantly, viable but non-culturable bacteria which possessed nitrogen removal capabilities in indigenous population of the sediments were explored by resuscitation promoting factor (Rpf). It was found that the sediments from upstream (URS) and lower stream (LRS) of Puyang river showed both different pollutants levels and bacterial community. Nitrate nitrogen, organic carbon and ammonium nitrogen probably had a significant effect on bacterial compositions between URS and LRS. From URS and LRS, a total of thirteen strains with heterotrophic nitrification ability were resuscitated by Rpf addition, which belonged to genera Bacillus, Pseudomonas, Stenotrophomonas and Acinetobacter. Among them, the strain Pseudomonas sp. SSPR1 was found to display high removal capabilities of simultaneous nitrification and denitrification, and the average ammonium and nitrate removal rates were 2.23 and 0.86 mg/(L·h), respectively. These resuscitated strains could be considered to be used for biological nitrogen removal in rivers and their receiving water bodies.

Resuscitation of functional bacterial community for enhancing biodegradation of phenol under high salinity conditions based on Rpf.

This study assumed that key degraders of functional bacterial community were prone to enter into the viable but non-culturable (VBNC) state under high saline phenolic conditions, and resuscitation-promoting factor (Rpf) could strengthen these degraders for better performances. Based on these assumptions, Rpf was used to enhance salt-tolerant phenol-degrading capability of functional populations in activated sludge. Results suggested that Rpf accelerated the start-up process during sludge domestication, and significantly enhanced salt-tolerant phenol-degrading capability. High-throughput sequencing showed that the resuscitation and stimulation functions of Rpf linked mainly to the genus Corynebacterium within the phylum Actinobacteria, and the genera Proteiniphilum and Petrimonas within the phylum Bacteroidete. These key functional populations contributed to better phenol-degrading capabilities under high salinity conditions. This study indicated that Rpf is a promising additive for improving biological treatment performance of saline phenolic wastewater.