Zoige wetland of Tibetan plateau is characterized by being located at a low latitude (33 degrees 56'N, 102 degrees 52'E) region and under the annual temperature around 1 degrees C. Previous studies indicated that Zoige wetland was one of the CH(4) emission centres in Qinghai-Tibetan plateau; in this study, the methanogen community in this low-latitude wetland was analysed based on the homology of 16S rRNA and mcrA genes retrieved from the soil. The results indicated that members of Methanosarcinales and Methanomicrobiales constituted the majority of methanogens, and a novel uncultured methanogen cluster, Zoige cluster I (ZC-I) affiliated to Methanosarcinales, could be dominant. Using quantitative polymerase chain reaction (qPCR) assay, ZC-I methanogens were estimated to be 10(7) cells per gram of soil, accounting for about 30% of the total Archeae. By combining culturable enrichment with qPCR assay, the quantity of ZC-I methanogens in the methanogenic enrichment with acetate, H2/CO(2), methanol or trimethylamine was determined to increase to 10(8) cells ml(-1), but not with formate, which indicated that ZC-I methanogens could use the four methanogenic substrates. The growth rates at 30 degrees C and 15 degrees C were not pronounced different, implying ZC-I to be the cold-adaptive methanogens. The broad substrate spectrum identified the ZC-I methanogens to be a member of Methanosarcinaceae, and could represent a novel sub-branch specifically inhabited in cold ecosystems. Fluorescence in situ hybridization (FISH) images also visualized ZC-I methanogens the sarcina-like aggregate of the spherical cells. The prevalence and flexibility in substrate utilization and growth temperature suggested ZC-I methanogens to be an important player in the methanogenesis of Zoige wetland.

The Zoige wetland of the Tibetan plateau is at permanent low temperatures and is a methane emission heartland of the plateau; however, cold-adaptive methanogens in the soil are poorly understood. In this study, a variety of methanogenic enrichments at 15°C and 30°C were obtained from the wetland soil. It was demonstrated that hydrogenotrophic methanogenesis was the most efficient type at 30°C, while methanol supported the highest methanogenesis rate at 15°C. Moreover, methanol was the only substrate to produce methane more efficiently at 15°C than at 30°C. A novel psychrophilic methanogen, strain R15, was isolated from the methanol enrichment at 15°C. Phylogenetic analysis placed strain R15 within the genus Methanolobus, loosely clustered with Methanolobus taylorii (96.7% 16S rRNA similarity). R15 produced methane from methanol, trimethylamine, and methyl sulfide and differed from other Methanolobus species by growing and producing methane optimally at 18°C (specific growth rate of 0.063 ؎ 0.001 h ؊1 ) and even at 0°C. Based on these characteristics, R15 was proposed to be a new species and named "Methanolobus psychrophilus" sp. nov. The K m and V max of R15 for methanol conversion were determined to be 87.5 ؎ 0.4 M and 0.39 ؎ 0.04 mM h ؊1 at 18°C, respectively, indicating a high affinity and conversion efficiency for methanol. The proportion of R15 in the soil was determined by quantitative PCR, and it accounted for 17.2% ؎ 2.1% of the total archaea, enumerated as 10 7 per gram of soil; the proportion was increased to 42.4% ؎ 2.3% in the methanol enrichment at 15°C. This study suggests that the psychrophilic methanogens in the Zoige wetland are likely to be methylotrophic and to play a role in methane emission of the wetland.Wetlands in cold areas, such as permafrost and tundra, contribute a large proportion of global methane emission, since about 75% of the Earth's biosphere is cold (3). The Zoige wetland of the Tibetan plateau is such a wetland. Although it is located in a low-latitude region (33°56ЈN, 102°52ЈE), its average annual temperature is around 1°C due to the high altitude (3,400 to 3,600 m). Previous studies estimated the annual methane emission in the Tibetan plateau to be in the range of 0.56 to 1 Tg (8, 9), and the Zoige wetland and the headstreams of the Yangtze and Yellow rivers could be the CH 4 emission flux heartlands of the plateau (17 Studies on methane production in cold terrestrial ecosystems, using radiolabeled methanogenic precursors and stable isotope signatures, indicated that the acetoclastic methanogenesis pathway was strongly prevalent (11,12,32,41), possibly due to psychroactive homoacetogenesis supplying extra acetate in addition to fermentation-derived acetate (22, 23). Methanogen population structure analysis in boreal wetlands, such as a Siberia peat bog, based on unculturable approaches also showed that Methanosarciaceae, Methanomicrobiaceae, and rice cluster II presented as the dominant group (23). A study on methanogenic community shifting in a cellulose-fermenting enrichm...

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The global COVID-19 pandemic is affecting the health of individuals and leading to psychological problems. Students in higher education who are graduating, facing online learning challenges, and future job opportunities are among the most at-risk group for psychological issues. Due to the new normal of the COVID-19 pandemic, limited studies have been conducted concerning the mental health of students, especially in the Asia-Pacific region. Therefore, this study aimed to assess student’s depression, anxiety, and stress status in four countries in the Asia Pacific region, namely, Malaysia, Indonesia, Thailand, and China. This study employed a quantitative research design with a pool of 1,195 student participants. The DASS-21 questionnaire was used for data collection through an online platform to measure the severity of depression, anxiety, and stress. Descriptive statistics were conducted to achieve the research objectives, and all reliability values were reported greater than 0.70. Findings revealed that up to 38% of the students reported mild or moderate depression, anxiety, and stress, while 20.5% reported severe or extremely severe anxiety. Overall, anxiety was reported to be the most significant problem among the students, followed by depression and stress. Students are at risk of mental health challenges during the coronavirus pandemic, likely due to unexpected life changes. This study contributes an overview report of students’ mental health problems and discusses the support and services in preventing students’ psychological problems. The comprehensive discussion has provided scientific information and suggestion to policymakers in maintaining the student academic and welfare.

Accelerated by global climate changing, retreating glaciers leave behind soil chronosequences of primary succession. Current knowledge of primary succession is mainly from studies of vegetation dynamics, whereas information about belowground microbes remains unclear. Here, we combined shifts in community assembly processes with microbial primary succession to better understand mechanisms governing the stochastic/deterministic balance. We investigated fungal succession and community assembly via high-throughput sequencing along a well-established glacier forefront chronosequence that spans 2-188 years of deglaciation. Shannon diversity and evenness peaked at a distance of 370 m and declined afterwards. The response of fungal diversity to distance varied in different phyla. Basidiomycota Shannon diversity significantly decreased with distance, while the pattern of Rozellomycota Shannon diversity was unimodal. Abundance of most frequencies OTU2 (Cryptococcus terricola) increased with successional distance, whereas that of OTU65 (Tolypocladium tundrense) decreased. Based on null deviation analyses, composition of the fungal community was initially governed by deterministic processes strongly but later less deterministic processes. Our results revealed that distance, altitude, soil microbial biomass carbon, soil microbial biomass nitrogen and NH + 4 -N significantly correlated with fungal community composition along the chronosequence. These results suggest that the drivers of fungal community are dynamics in a glacier chronosequence, that may relate to fungal ecophysiological traits and adaptation in an evolving ecosystem. The information will provide understanding the mechanistic underpinnings of microbial community assembly during ecosystem succession under different scales and scenario.