Functional metagenomic analysis of quorum sensing signaling in a nitrifying community.
Chuan Hao TanYee Phan YeoMuhammad Hafiz IsmailNoele Kai Jing NgSujatha SubramoniShireen TajMartin TayXie ChaoStaffan KjellebergScott Alan RicePublished in: NPJ biofilms and microbiomes (2021)
Quorum sensing (QS) can function to shape the microbial community interactions, composition, and function. In wastewater treatment systems, acylated homoserine lactone (AHL)-based QS has been correlated with the conversion of floccular biomass into microbial granules, as well as EPS production and the nitrogen removal process. However, the role of QS in such complex communities is still not fully understood, including the QS-proficient taxa and the functional QS genes involved. To address these questions, we performed a metagenomic screen for AHL genes in an activated sludge microbial community from the Ulu Pandan wastewater treatment plant (WWTP) in Singapore followed by functional validation of luxI activity using AHL biosensors and LC-MSMS profiling. We identified 13 luxI and 30 luxR homologs from the activated sludge metagenome. Of those genes, two represented a cognate pair of luxIR genes belonging to a Nitrospira spp. and those genes were demonstrated to be functionally active. The LuxI homolog synthesized AHLs that were consistent with the dominant AHLs in the activated sludge system. Furthermore, the LuxR homolog was shown to bind to and induce expression of the luxI promoter, suggesting this represents an autoinduction feedback system, characteristic of QS circuits. Additionally, a second, active promoter was upstream of a gene encoding a protein with a GGDEF/EAL domain, commonly associated with modulating the intracellular concentration of the secondary messenger, c-di-GMP. Thus, the metagenomic approach used here was demonstrated to effectively identify functional QS genes and suggests that Nitrospira spp. maybe QS is active in the activated sludge community.
Keyphrases
- antibiotic resistance genes
- microbial community
- wastewater treatment
- genome wide
- genome wide identification
- dna methylation
- bioinformatics analysis
- healthcare
- transcription factor
- anaerobic digestion
- genome wide analysis
- mental health
- gene expression
- poor prognosis
- signaling pathway
- escherichia coli
- staphylococcus aureus
- oxidative stress
- biofilm formation
- long non coding rna
- amino acid
- reactive oxygen species
- cystic fibrosis
- heat shock protein