Cultivation of nitrite-dependent anaerobic methane-oxidizing bacteria: impact of reactor configuration

Abstract

Nitrite-dependent anaerobic methane oxidation (n-damo) is mediated by bacteria that anaerobically oxidize methane coupled with nitrite reduction and is a potential bioprocess for wastewater treatment. In this work, the effect of reactor configuration on n-damo bacterial cultivation was investigated. A magnetically stirred gas lift reactor (MSGLR), a sequencing batch reactor (SBR), and a continuously stirred tank reactor (CSTR) were selected to cultivate the bacteria. Microbial community was monitored by using quantitative PCR, 16S rRNA gene sequencing, pmoA gene sequencing, and fluorescence in situ hybridization (FISH). The effects of substrate inhibition, methane mass transfer, and biomass washout in the three reactors were focused on. The results indicated that the MSGLR had the best performance among the three reactor systems, with the highest total and specific n-damo activities. Its maximum volumetric nitrogen removal rate was up to 76.9 mg N L(-1) day(-1), which was higher than previously reported values (5.1-37.8 mg N L(-1) d(-1)).

Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria

“…The correlated increases in the number of NC10 bacteria and the activity of methane oxidation indicated that NC10 bacteria were responsible for the everincreasing methane oxidation activity. The specific cell activity of the NC10 bacteria in the final marine denitrifying methanotrophic culture was 0.14 Ϯ 0.02 fmol CH 4 day Ϫ1 cell Ϫ1 , which corresponded to the previous measurements (0.09 to 0.34 fmol CH 4 day Ϫ1 cell Ϫ1 ) (8,26,38). Furthermore, the qPCR and FISH results showed that NC10 bacteria could grow in seawater media (20.5‰ of salinity) and that their apparent doubling times (38.7 to 48.9 days) were slightly longer than the doubling times previously observed in freshwater enrichment cultures (14 to 25 days) (3,29).…”

“…During the enrichment, the biomass samples (0.25 g) were harvested on a regular basis, and DNA extraction and PCR amplification were performed as previously described (25). PCR products were evaluated by agarose gel (1.0%) electrophoresis and cloned by the use of pMD19-T vector (TaKaRa, Bio Inc., Shiga, Japan) as previously described (26). Clones with successful ligation were checked via a blue-white screening technique, and approximately 30 positive clones from each sample (inoculum and en- richment culture after 16 months) were randomly selected and sequenced by BGI-Shanghai (China).…”

Effect of electricity on microbial community of microbial fuel cell simultaneously treating sulfide and nitrate

“…The MEGA Software version 6.0 was used to construct phylogenetic trees based on the neighbor-joining method. Bootstrap re-sampling analysis of 1000 replicates was performed to estimate the degree of confidence in the tree topologies [24]. All nucleotide sequences data reported in this study were deposited in the GenBank database under accession numbers KM925019-KM925039.…”

Effect of inoculum sources on the enrichment of nitrite-dependent anaerobic methane-oxidizing bacteria

“…DNA extraction of each sample was performed as described previously (Hu et al 2014a). The primers (Table S2) and amplification conditions used in this study were previously described by Luesken et al (2011c).…”