Comparative metatranscriptomic analysis of anaerobic digesters treating anionic surfactant contaminated wastewater.
THE SCIENCE OF THE TOTAL ENVIRONMENT 2019;
649:482-494. [PMID:
30176460 DOI:
10.1016/j.scitotenv.2018.08.328]
[Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/23/2018] [Accepted: 08/24/2018] [Indexed: 06/08/2023]
Abstract
Three distinct biological reactors fed with synthetic medium (UASB_Control), synthetic medium and linear alkylbenzene sulfonate (LAS; UASB_SL), and real laundry wastewater (UASB_LW) were compared using a metatranscriptomic approach to determine putative bioindicator genes and taxonomies associated to all steps of anaerobic LAS biodegradation pathway. A homemade bioinformatics pipeline combined with an R workflow was developed to perform the RNAseq data analysis. UASB_SL and UASB_LW showed similar values of LAS biological degradation (~47%) and removal (53-55%). Rarefaction analysis revealed that 1-2 million reads were sufficient to access the whole functional capacity. In the first step of LAS biodegradation pathway, fumarate reductase subunit C was detected and taxonomically assigned to the genus Syntrophobacter (0.002% - UASB_SL; 0.0015% - UASB_LW; not detected - UASB_Control). In the second step, many enzymes related to beta-oxidation were observed and most of them with low relative abundance in UASB Control and taxonomically related with Smithella, Acinetobacter and Syntrophorhabdus. For the ring cleavage step, the abundance of 6 OCH CoA hydrolase putative gene was ten times higher in UASB_SL and UASB_LW when compared to UASB_Control, and assigned to Desulfomonile and Syntrophorhabdus. Finally, the adenylylsulfate reductase, taxonomically related with Desulfovibrio and Desulfomonile, was observed in the desulfonation step with the highest relative abundance in UASB_LW.
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