Anaerolineaceae and Methanosaeta turned to be the dominant microorganisms in alkanes-dependent methanogenic culture after long-term of incubation

Abstract

The methanogenic alkanes-degrading enrichment culture which had been incubated for over 1,300 days amended with n-alkanes (C15–C20) was investigated through clone libraries of bacteria, archaea and assA, mcrA functional genes. These enrichment cultures were obtained from oily sludge after an initial incubation of the oily sludge without any carbon source and then an enrichment transfer with n-alkanes (C15–C20) for acclimation. Activation of alkanes, methane precursor generation and methanogenic pathways are considered as three pivotal stages for the continuous methanogenesis from degradation of alkanes. The presence of functional genes encoding the alkylsuccinate synthase α-subunit indicated that fumarate addition is most likely the one of initial activation step for degradation of n-alkanes. Degradation intermediates of n-alkanes were octadecanoate, hexadecanoate, butyrate, isobutyrate, acetate and propionate, which could provide the appropriate substrates for acetate formation. Both methyl coenzyme M reductase gene and 16S rRNA gene analysis showed that microorganisms of Methanoseata were the most dominant methanogens, capable of using acetate as the electron donor to produce methane. Bacterial clone libraries showed organisms of Anaerolineaceae (within the phylum of Chloroflexi) were predominant (45.5%), indicating syntrophically cooperation with Methanosaeta archaea was likely involved in the process of methanogenic degradation of alkanes. Alkanes may initially be activated via fumarate addition and degraded to fatty acids, then converted to acetate, which was further converted to methane and carbon dioxide by methanogens.Electronic supplementary materialThe online version of this article (doi:10.1186/s13568-015-0117-4) contains supplementary material, which is available to authorized users.

Methanogenic paraffin degradation proceeds via alkane addition to fumarate by ‘Smithella’ spp. mediated by a syntrophic coupling with hydrogenotrophic methanogens

“…Since the seminal work in Zengler et al . (), several studies have provided evidence that these taxa are important in methanogenic alkane biodegradation (Gieg et al ., ; Siddique et al ., ; Wang et al ., ; Cheng et al ., ; Tan et al ., ; Liang et al ., ).…”

Salt Marsh Bacterial Communities before and after the Deepwater Horizon Oil Spill

“…5F). The Chloroflexi are associated with natural hydrocarbon seeps (100), anaerobic pipelines (101), and oil contaminated experiments (81,102,103). The relative abundances of Chloroflexi positively correlated to the concentration of total inland n-alkanes (rho ϩ 0.46, P ϭ 0.002), to total aromatics (rho ϭ ϩ0.66, P Ͻ 0.0001) and, interestingly, to the presence of J. roemerianus (rho ϭ ϩ0.31, P ϭ 0.04).…”

Active prokaryotic population dynamics exhibit high correlation to reactor performance during methane production from acid hydrolysates ofAgave tequilanavar.azulbagasse

“…; Liang et al . ). The increase in biological variables as ACE diversity index and relative abundances of syntrophic populations, and those associated to methane production indicated a positive effect of OLR disturbances during stages 1 and 2.…”

“…In the inoculum, the dominant OTUs were affiliated to many fermentative and syntrophic acetate-producing populations (Table 3). In this context, the family Anaerolineaceae (39Á8%), characterized by a fermentative metabolism and syntrophic relationships with acetotrophic methanogens (Brenner et al 2005;Liang et al 2015;McIlroy et al 2017), was represented by six OTUs. Between them, two OTUs belonged to unclassified Anaerolineaceae (19Á6%), three OTUs were affiliated to Anaerolinea thermolimosa (16Á9%) and one OTUs related to Bellilinea caldifistulae (3Á3%).…”