Microbial carbohydrate-active enzymes influence soil carbon by regulating the of plant- and fungal-derived biomass decomposition in plateau peat wetlands under differing water conditions

Peatlands are important carbon sinks and water sources in terrestrial ecosystems. It is important to explore their microbial-driven water-carbon synergistic mechanisms to understand the driving mechanisms of carbon processes in peatlands. Based on macrogenomic sequencing techniques, located on the peatland of the eastern margin of the Tibetan Plateau with similar stand and different water conditions, we taken soil properties, microbiome abundance, CAZyme abundance and enzyme gene pathways as the object of study, investigated the characterization of soil microbial carbohydrate-active enzymes (CAZymes) under different water gradients in peatland. According to the results, these three phyla (Chloroflexi, Gemmatimonadetes, and Verrucomicrobia) differed significantly between water gradients. Under dried wetlands, the abundance of CAZymes involved in hemicellulose and glucan degradation increased by 3.0 × 10−5 and 3.0 × 10−6, respectively. In contrast, the abundance of CAZymes involved in chitin degradation decreased by 1.1 × 10−5 (p < 0.05). It highlights that regulating plant- and fungus-derived carbon metabolism processes by soil microorganisms in highland peatlands is a crucial mechanism for their response to water changes. Most plant-derived carbon fractions are regulated by soil enzymes (endo-beta 1,4-xylanase, alpha-L-arabinofuranosidase, and alpha-L-fucosidase) containing CAZymes functional genes. Additional findings in this enzyme gene pathway indicate that water changes that affect soil carbon fractions indirectly influence the three enzyme gene metabolic pathways related to plant carbon sources (the glycolysis/gluconeogenesis, other glycan degradation and amino sugar, and nucleotide sugar metabolism). Overall, this study highlights the significance of microbial CAZymes in highland peatland soil carbon processes and indicates that microbial conversion of plant and fungal biomass carbon is more sensitive to water changes

Landslide scales affect soil organic carbon accumulation by influencing microbial decomposition of plant-derived carbon after earthquakes

Geological movements can affect carbon distribution patterns and turnover mechanisms in terrestrial ecosystems by altering surface landscape patterns. However, little is known about how changes in surface landscape features after geological hazards affect the microecological mechanisms of soil carbon. In this study, eight landslides with similar standing conditions and formation times but different scales were selected in the geologically active zone of Southwest China. A macro genome sequencing approach was used to study the microbial changes in the soil carbon functions of landslides after earthquakes. The results indicated that the scale of landslide scale was a significant factor affecting soil carbon stocks after earthquake. Among the landslide scale factors, landslide width had a greater effect on soil carbon storage than length or area. Landslide width corresponded with increased microbial decomposition of plant (lignin, hemicellulose) and fungal (chitin) carbon sources, but both chitinous soil content and its decomposition function gene abundance were low and had a small effect on the total carbon pool. The major bacterial phyla (Actinobacteria, Candidatus Rokubacteria, and Acidobacteria) mineralize carbon sources from plant and fungal biomass fractions through their selective adaptation mechanisms based on the landslide scale. Starch and polysaccharide related metabolic pathways differed significantly between landslides at different scales. Overall, our results emphasize the importance of microbes in surface carbon dynamics driven by geological movements. It is also noted that the scale of landscape degradation following geological disturbance is a key indicator that soil carbon and that microbes influence postdisaster soil carbon recovery and accumulation by regulating their selection and utilization of plant-derived carbon. The findings of this study help to estimate the turnover and distribution of terrestrial ecosystem carbon driven by geological movements at a larger scale

Immunochromatographic paper sensor for ultrasensitive colorimetric detection of cadmium

A novel and highly sensitive immunochromatographic strip based on a monoclonal antibody (3A9) was developed for the detection of cadmium in tap water. The 50% inhibition concentration of the antibody, which showed no cross-reactivity with other heavy metal ions, was 0.45 ng/mL and it recognized Cd(II)–1-(4-isothiocyanobenzyl) ethylenediamine-N,N,N′,N′-tetraacetic acid (EDTA) (Cd(II)–ITCBE) and not metal-free ITCBE and EDTA. The cutoff value for semi-quantitative detection of the strip was 5 ng/mL and the lower limit of detection for quantitative detection was 0.2 ng/mL using a scanning reader. The percent recovery ranged from 107.6% to 132% in tap water samples