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Methane metabolism in deep subsurface petroleum reservoirs is of paramount interest in the global biogeochemical cycle of carbon. Methanogenesis in such habitats is driven mostly by methanogens in ...

Waste cooking oil is produced in enormous quantities every year, and may have negative effect on people’s health and environment in case of improper treatment. However, it is also a potential feeds...

Essential hypertension is a leading global public health issue, billions of people suffered from it every year. Recently, multiple evidence suggests that DNA methylation play an important role in regulating blood pressure. Here, we tested the risk for essential hypertension conferred by single nucleotide polymorphisms (SNPs) within DNA methyltransferase 1 (DNMT1). Three loci (rs2228611, rs2228612, and rs16999593) were selected to be analyzed in 3410 cases and 1307 normal controls in southern Chinese aged 60 or above. No significant association with essential hypertension was observed for rs2228612 and rs16999593. A higher risk of essential hypertension was found in the minor A allele of rs2228611 in the codominant and recessive model (P < 0.05). After stratified by sex, this association was found in male but not female. Furthermore, this difference was abolished after BMI adjustment in the whole population and reduced in male. In addition, the mutation rate of rs2228611 was higher in the obesity group compared with the normal weight group of male. Intriguingly, rs2228611 was also a risk factor of essential hypertension in normal weight male. These findings indicated that rs2228611 might contribute to male hypertension via BMI-dependent mechanisms in obesity male and BMI-independent mechanisms in normal weight male.

The aim of this work was to isolate and identify the muscovite-solubilizing microorganisms, and then to exploit the mechanism of K-extraction by the isolated microorganisms. Ten strains of microorganisms were isolated from soil sample in K-bearing mineral area (Anhui province, China) using Aleksandov agar medium, which had different degrees of muscovite-solubilizing in the K-extraction experiments. After 15-day incubation, the K-extraction ability was evaluated through dissolved structural element of muscovite in aqueous medium (K, Al, Si) by Inductively Coupled Plasma. Four best muscovite-solubilizing microorganisms were identified by 18S rDNA analysis as Penicillium purpurogenum, Talaromyces radicus, Aspergillus fumigatus and Aureobasidium pullulans, respectively. Furthermore, organic acids in the medium were determined by high performance liquid chromatography, and the surface morphology and composition of original and leached muscovite were evaluated using scanning electron microscopy and energy dispe...

Investigation of petroleum microbes is fundamental for the development and utilization of oil reservoirs' microbial resources, and also provides great opportunities for research and development of bio-energy. Production water from a high-temperature oil reservoir was incubated anaerobically at 55 degrees C for more than 400 days without amendment of any nutrients. Over the time of incubation, about 1.6 mmol of methane and up to 107 micromol of hydrogen (H2) were detected in the headspace. Methane formation indicated that methanogenesis was likely the predominant process in spite of the presence of 23.4 mM SO4(2-) in the production water. Microbial community composition of the incubation was characterized by means of 16S rRNA gene clone libraries construction. Bacterial composition changed from Pseudomonales as the dominant population initially to Hydrogenophilales-related microorganisms affiliated to Petrobacter spp. closely. After 400 days of incubation, other bacterial members detected were related to Anareolineales, beta-, gamma-, and delta-Proteobacteria. The archaeal composition of the original production water was essentially composed of obligate acetoclastic methanogens of the genus Methanosaeta, but the incubation was predominantly composed of CO2-reducing methanogens of the genus Methanothermobacter and Crenarchaeotes-related microorganisms. Our results suggest that methanogenesis could be more active than expected in oil reservoir environments and methane formation from CO2-reduction played a significant role in the methanogenic community. This conclusion is consistent with the predominant role played by H2-oxidizing methanogens in the methanogenic conversion of organic matter in high-temperature petroleum reservoirs.

Methanogenic microbial community is responsive to the availability of hydrocarbons and such information is critical for the assessment of hydrocarbon degradation in remediation and also in biologically enhanced recovery of energy from non-producing oil reserves. In this study, methanogenic enrichment cultures from oily sludge amended with n-alkanes (C15-C20) showed a development of active methanogenic alkanes-degrading consortium for over a total of 1000 days of incubation at 37°C. Total genomic DNAs were extracted from three types of samples, the original oily sludge (OS), the sludge after incubation for 500 days under methanogenic condition without any external carbon addition (EC), and the enrichment culture from the EC amended with n-alkanes (ET) incubated for another 500 days. The phylogenetic diversities of microbial communities of the three samples were analyzed by PCR amplification of partial 16S rRNA genes. The catabolic genes encoding benzylsuccinate synthase (bssA) and alkylsuccinate synthase (...