No abstract

Bacillus accelerates lignocellulose degradation, promotes the stabilization and resource utilization of compost by secreting enzymes, and plays an important role in compost formation and quality control. This study evaluated enzyme activity, lignocellulosic degradation, and bacterial succession in composting inoculated with different microbial Bacillus agents. They were identified as B. licheniformis, B. subtilis, B. thermoamylovorans, B. thermoruber, and B. hisashii. Four treatments were established, including a CK (uninoculated microorganisms), A (B. licheniformis, B. subtilis, B. thermoamylovorans,and B. hisashii), B (B. subtilis, B. thermoamylovorans, B. thermoruber, and B. hisashii), and C (B. subtilis, B. thermoamylovorans, and B. hisashii), and the composting lasted 7–14 days. Lignin and cellulose degradation rates in B during composting were 17.1% and 36.7% at the cooling stage, respectively. Redundancy analysis showed that degradation of lignocellulose in the thermophilic stage was mainly related to the secretion of lignocellulose-degrading enzymes after microbial inoculation. 16S rRNA sequencing revealed that Bacillus (20.3%) and Thermobifida (20.2%) were the dominant genera. Inoculation with a combination including B. thermoruber was a feasible way to increase lignocellulose degradation and promote maturity in sewage sludge composting.

Atmospheric particulate matter with a diameter <2.5 µm (PM2.5) and pollution are worldwide environmental problems and may have negative effects on cardiovascular disease through the lung and gut. The dynamics of intestinal microflora in response to particulate pollutants is unclear. The present study investigated changes in the gut microbiota related to pollutant exposure using spontaneously hypertensive rats (SHR). DNA was extracted from fecal samples. Amplicon Generation and the quality control of PCR products were performed. PCR products was sequenced on an Illumina HiSeq 2500 platform. Data analysis included: operational taxonomic unit (OTU) clustering and species annotation, alpha diversity, beta diversity, principal coordinates analysis (PCoA), and the use of PICRUSt bioinformatics software. The microbial diversity of the SHR rats was inversely associated with exposure to pollutants. In terms of relative abundance, 24 bacterial genera and 2 genera in particular (Actinobacillus and Fusobacterium) significantly declined, and one genus (Treponema) increased. Moreover, pollutant exposure was associated with the accumulation of genes from the gut microbiota that are implicated in cardiovascular diseases. From the long-term exposure experiment, rats appeared to respond to pollutant injury. In conclusion, these results suggest that the effects of atmospheric pollutants on organisms are not limited to the respiratory tract, but also include the gastrointestinal tract. Pollutants are likely to influence the intestinal microbiota and promote the progression of cardiovascular disease.