1
|
Zhao Y, Zhang J, Ni M, Pan Y, Li L, Ding Y. Cultivation of phosphate-accumulating biofilm: Study of the effects of acyl-homoserine lactones (AHLs) and cyclic dimeric guanosine monophosphate (c-di-GMP) on the formation of biofilm and the enhancement of phosphate metabolism capacity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 928:172408. [PMID: 38608880 DOI: 10.1016/j.scitotenv.2024.172408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/05/2024] [Accepted: 04/09/2024] [Indexed: 04/14/2024]
Abstract
This study investigated the mechanisms of microbial growth and metabolism during biofilm cultivation in the biofilm sequencing batch reactor (BSBR) process for phosphate (P) enrichment. The results showed that the sludge discharge was key to biofilm growth, as it terminated the competition for carbon (C) source between the nascent biofilm and the activated sludge. For the tested reactor, after the sludge discharge on 18 d, P metabolism and C source utilization improved significantly, and the biofilm grew rapidly. The P concentration of the recovery liquid reached up to 157.08 mg/L, which was sufficient for further P recovery via mineralization. Meta-omics methods were used to analyze metabolic pathways and functional genes in microbial growth during biofilm cultivation. It appeared that the sludge discharge activated the key genes of P metabolism and inhibited the key genes of C metabolism, which strengthened the polyphosphate-accumulating metabolism (PAM) as a result. The sludge discharge not only changed the types of polyphosphate-accumulating organisms (PAOs) but also promoted the growth of dominant PAOs. Before the sludge discharge, the necessary metabolic abilities that were spread among different microorganisms gradually concentrated into a small number of PAOs, and after the sludge discharge, they further concentrated into Candidatus_Contendobacter (P3) and Candidatus_Accumulibacter (P17). The messenger molecule C-di-GMP, produced mostly by P3 and P17, facilitated P enrichment by regulating cellular P and C metabolism. The glycogen-accumulating organism (GAO) Candidatus_Competibacter secreted N-Acyl homoserine lactones (AHLs), which stimulated the secretion of protein in extracellular polymeric substances (EPS), thus promoting the adhesion of microorganisms to biofilm and improving P metabolism via EPS-based P adsorption. Under the combined action of the dominant GAOs and PAOs, AHLs and C-di-GMP mediated QS to promote biofilm development and P enrichment. The research provides theoretical support for the cultivation of biofilm and its wider application.
Collapse
Affiliation(s)
- Yimeng Zhao
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Jun Zhang
- Suzhou Drainage Company Limited, Suzhou 215009, China
| | - Min Ni
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; Jiangsu Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Yang Pan
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China.
| | - Lu Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Yanyan Ding
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China
| |
Collapse
|
2
|
Huang K, He Y, Wang W, Jiang R, Zhang Y, Li J, Zhang XX, Wang D. Temporal differentiation in the adaptation of functional bacteria to low-temperature stress in partial denitrification and anammox system. ENVIRONMENTAL RESEARCH 2024; 244:117933. [PMID: 38097061 DOI: 10.1016/j.envres.2023.117933] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/08/2023] [Accepted: 12/10/2023] [Indexed: 12/18/2023]
Abstract
Despite reliable nitrite supply through partial denitrification, the adaptation of denitrifying bacteria to low temperatures remains elusive in partial denitrification and anammox (PDA) systems. Here, temporal differentiations of the structure, activity, and relevant cold-adaptation mechanism of functional bacteria were investigated in a lab-scale PDA bioreactor at decreased temperature. Although distinct denitrifying bacteria dominated after low-temperature stress, both short- and long-term stresses exerted differential selectivity towards the species with close phylogenetic distance. Species Azonexus sp.149 showed high superiority over Azonexus sp.384 under short-term stress, and long-term stress improved the adaptation of Aquabacterium sp.93 instead of Aquabacterium sp.184. The elevated transcription of nitrite reductase genes suggested that several denitrifying bacteria (e.g., Azonexus sp.149) could compete with anammox bacteria for nitrite. Species Rivicola pingtungensis and Azonexus sp.149 could adapt through various adaptation pathways, such as the two-component system, cold shock protein (CSP), membrane alternation, and electron transport chain. By contrast, species Zoogloea sp.273 and Aquabacterium sp.93 mainly depended on the CSP and oxidative stress response. This study largely deepens our understanding of the performance deterioration in PDA systems during cold shock and provides several references for efficient adaptation to seasonal temperature fluctuation.
Collapse
Affiliation(s)
- Kailong Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China; Institute of Environmental Research at Greater Bay/ Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China; Nanjing Jiangdao Institute of Environmental Research Co., Ltd., Nanjing, 210019, China
| | - Yang He
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Wuqiang Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China; LingChao Supply Chain Management Co., Ltd., Shenzhen, 518000, China
| | - Ruiming Jiang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Yujie Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Jialei Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China
| | - Depeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China.
| |
Collapse
|
3
|
Ni M, Pan Y, Li D, Huang Y, Chen Z, Li L, Bi Z, Wu R, Song Z. Metagenomics, metatranscriptomics, and proteomics reveal the metabolic mechanism of biofilm sequencing batch reactor with higher phosphate enrichment capacity under low phosphorus load. ENVIRONMENTAL RESEARCH 2023; 238:117237. [PMID: 37793587 DOI: 10.1016/j.envres.2023.117237] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/21/2023] [Accepted: 09/25/2023] [Indexed: 10/06/2023]
Abstract
The biofilm sequencing batch reactor (BSBR) process has higher phosphate recovery efficiency and enrichment multiple when the phosphorus load is lower, but the mechanism of phosphate enrichment at low phosphorus load remains unclear. In this study, we operated two BSBR operating under low and high phosphorus load (0.012 and 0.032 kg/(m3·d)) respectively, and used metagenomic, metatranscriptomic, and proteomics methods to analyze the community structure of the phosphorus accumulating organisms (PAOs) in the biofilm, the transcription and protein expression of key functional genes and enzymes, and the metabolism of intracellular polymers. Compared with at high phosphorus load, the BSBR at low phosphorus load have different PAOs and fewer types of PAOs, but in both cases the PAOs must have the PHA, PPX, Pst, and acs genes to become dominant. Some key differences in the metabolism of PAOs from the BSBR with different phosphorus load can be identified as follows. When the phosphorus load is low, the adenosine triphosphoric acid (ATP) and NAD(P)H in the anaerobic stage come from the TCA cycle and the second half of the EMP pathway. The key genes that are upregulated include GAPDH, PGK, ENO, ppdk in the EMP pathway, actP in acetate metabolism, phnB in polyhydroxybutyrate (PHB) synthesis, and aceA, mdh, sdhA, and IDH1 in the TCA cycle. In the meantime, the ccr gene in the PHV pathway is inhibited. As a result, the metabolism of the PAOs features low glycogen with high PHB, Pupt, Prel, and low PHV. That is, more ATP and NAD(P)H flow to phosphorus enrichment metabolism, thus allowing the highly efficient enrichment of phosphorus from low concentration phosphate thanks to the higher abundance of PAOs. The current results provide theoretical support and a new technical option for the enrichment and recovery of low concentrations of phosphate from wastewater by the BSBR process.
Collapse
Affiliation(s)
- Min Ni
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; Jiangsu Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Yang Pan
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
| | - Dapeng Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Yong Huang
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Zhiqiang Chen
- Harbin Institute of Technology, Harbin, 150006, China
| | - Lu Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Zhen Bi
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Ruijing Wu
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China
| | | |
Collapse
|