Structural dynamics and transcriptomic analysis of Dehalococcoides mccartyi within a TCE-Dechlorinating community in a completely mixed flow reactor

Abstract

A trichloroethene (TCE)-dechlorinating community (CANAS) maintained in a completely mixed flow reactor was established from a semi-batch enrichment culture (ANAS) and was monitored for 400 days at a low solids retention time (SRT) under electron acceptor limitation. Around 85% of TCE supplied to CANAS (0.13 mmol d −1) was converted to ethene at a rate of 0.1 mmol d −1 , with detection of low production rates of vinyl chloride (6.8 × 10− 3 mmol d −1) and cisdichloroethene (2.3 × 10− 3 mmol d −1). Two distinct Dehalococcoides mccartyi strains (ANAS1 and ANAS2) were stably maintained at 6.2 ± 2.8 × 10 8 cells mL −1 and 5.8 ± 1.2 × 10 8 cells mL −1 , respectively. Electron balance analysis showed 107% electron recovery, in which 6.1% were involved in dechlorination. 16S rRNA amplicon sequencing revealed a structural regime shift between ANAS and CANAS while maintaining robust TCE dechlorination due to similar relative abundances of D. mccartyi and functional redundancy among each functional guild supporting D. mccartyi activity. D. mccartyi transcriptomic analysis identified the genes encoding for ribosomal RNA and the reductive dehalogenases tceA and vcrA as the most expressed genes in CANAS, while hup and vhu were the most critical hydrogenases utilized by D. mccartyi in the community.

Recent Advanced Technologies for the Characterization of Xenobiotic-Degrading Microorganisms and Microbial Communities

“…This study suggested a strain-level discrepancy between the Cryptococcus fungal species and their in-situ mock communities. Thus, transcriptomic analysis provides a large amount of gene information about the potential function of microbial communities in adaptation and survival in extreme environments (Singh D. P. et al, 2018 ; Mao et al, 2019 ; Marcelino et al, 2019 ).…”

“…Therefore, the study of microbial population existing in contaminated environments provides a significant knowledge of specific microbial characteristics that improve degradation rates. However, effective implementation of microbial remediation strategies needs advanced technical approaches, which provide an in-depth understanding about the dynamics aspects of microbial activity and survival under stressed environment (Rastogi and Sani, 2011 ; Lima-Morales et al, 2016 ; Mao et al, 2019 ). The development in molecular, biotechnological, bioinformatics and system biology tools pertaining to bio-remedial problems have provided gene level mechanisms of bioremediation (Ahmad and Ahmad, 2014 ; Aora and Bar, 2014 ; Singh D. P. et al, 2018 ; Jaiswal and Shukla, 2020 ; Nkongolo and Kotha, 2020 ; Wolf et al, 2020 ).…”

Recent advances and trends of trichloroethylene biodegradation: A critical review

“…Therefore, more efforts should be devoted to exploring the actual mechanisms of anaerobic reductive dechlorination. Overall, pceA , tceA (TCE to DCE), tceA , dceA , vcrA , bvcA (cis-DCE to VC), and tceA , vcrA , bvcA (VC to ethene) are crucial RDases involved in TCE reductive dechlorination process ( Figure 2B ; Ise et al, 2011 ; Popat and Deshusses, 2011 ; Dugat-Bony et al, 2012 ; Zinder, 2016 ; Dolinova et al, 2017 ; Mao et al, 2019 ; Yan et al, 2021 ; Rossi et al, 2022b ). Furthermore, the recently discovered new strain Dehalococcoides mccartyi NIT01 contains 19 rdhA genes (including NIT01 - rdhA7 and rdhA13 ), which are basically the same as the encoded vcrA and pceA ( Asai et al, 2022 ).…”

Advanced Bioremediation Technologies and Processes for the Treatment of Synthetic Organic Compounds (SOCs)

“…This study suggested a strain-level discrepancy between the Cryptococcus fungal species and their in-situ mock communities. Thus, transcriptomic analysis provides a large amount of gene information about the potential function of microbial communities in adaptation and survival in extreme environments (Singh D. P. et al, 2018;Mao et al, 2019;Marcelino et al, 2019).…”

“…Therefore, the study of microbial population existing in contaminated environments provides a significant knowledge of specific microbial characteristics that improve degradation rates. However, effective implementation of microbial remediation strategies needs advanced technical approaches, which provide an in-depth understanding about the dynamics aspects of microbial activity and survival under stressed environment (Rastogi and Sani, 2011;Lima-Morales et al, 2016;Mao et al, 2019). The development in molecular, biotechnological, bioinformatics and system biology tools pertaining to bioremedial problems have provided gene level mechanisms of bioremediation (Ahmad and Ahmad, 2014;Aora and Bar, 2014;Singh D. P. et al, 2018;Nkongolo and Kotha, 2020;Wolf et al, 2020).…”