Insights into antibiotic resistance gene abundances and regulatory mechanisms induced by ionic liquids during composting.

This study investigated the regulatory mechanism of the evolution of antibiotic resistance genes (ARGs) during the composting process with sawdust and cow manure as raw materials using ionic liquids (ILs) pretreatment. The results showed that genes of MLS, chloramphenicol, tetracycline, beta - lactam as composting gradually decreased. From day0 to day3, MLS in control group (CK) and experimental group (T) decreased by 25.62% and 26.66%, respectively. Tetracycline decreased by 7.21% in CK and by 7.86% in T. Chloramphenicol decreased by 2.85% in CK and 3.34% in T. Beta-lactam decreased by 1.95% in Ck and by 3.69% in T. Mechanism studies have shown that ILs can effectively decompose extracellular polymeric substances (EPS) and enhance lactose dehydrogenase (LDH) release, resulting in ARGs release and elimination. Meanwhile, ILs pretreatment can inhibit growth of some ARGs hosts, especially Firmicutes, resulting in decreased ARGs. Moreover, metabolic pathways and related genes take part in ARGs transmission were down regulated, leading to decreased ARGs.

Diversity of lignocellulolytic functional genes and heterogeneity of thermophilic microbes during different wastes composting.

The goal of this study was to investigate the heterogeneity of thermophilic microorganisms and their lignocellulose-degrading gene diversity during composting. In this study, bagasse pith/dairy manure (BAG) and sawdust/dairy manure (SAW) were used as experimental subjects. The pour plate method indicated that thermophilic bacteria and thermophilic actinobacteria were more culturable than thermophilic fungi. Metagenomics analysis showed that the Actinobacteria, Firmicutes and Proteobacteria were the dominant phyla during composting. In addition, auxiliary activity and glycoside hydrolase families were critical for lignocellulosic degradation, which were found to be more abundant in BAG. As a result, the degradation rates of cellulose, hemicellulose and lignin in BAG (7.36%, 13.99% and 5.68%) were observably higher than those in SAW (6.13%, 12.09% and 2.62%). These findings contribute to understanding how thermophilic microbial communities play a role in the deconstruction of different lignocelluloses and provide a potential strategy to comprehensively utilize the resources of lignocellulosic biomass.

Mechanism analysis of humification coupling metabolic pathways based on cow dung composting with ionic liquids.

This study focused on how adding ionic liquids (IL) affects composting humification. During the warming and thermophilic phases, addition of IL increased precursors content, and increased the polymerization of humus (HS) at later stages. Furthermore, the final HS and humic acid (HA) content of experimental groups (T) groups 129.79 mg/g and 79.91 mg/g were higher than in control group (CK) 118.57 mg/g and 74.53 mg/g, respectively (p < 0.05). IL up-regulated the gene abundance of metabolism for carbohydrate and amino acid (AA), and promoted the contributions of Actinobacteria and Proteobacteria, which affected humification. The redundancy analysis (RDA) results showed that the citrate-cycle (TCA cycle)(ko0020), pentose phosphate pathway (ko00030), pyruvate metabolism (ko00620), glyoxylate and dicarboxylate metabolism (ko00630), propanoate metabolism (ko00640), butanoate metabolism (ko00650) positively correlated with HA and HI. HA and humification index (HI) positively correlated with AA metabolic pathways, and fulvic acid (FA) was negatively correlated with these pathways. Overall, metabolism for carbohydrate and AA metabolism favored compost humification. ILs improved metabolism for carbohydrate and amino acid metabolism, thus enhancing humification.

Metagenomics analysis revealed the coupling of lignin degradation with humus formation mediated via shell powder during composting.

This study was the first to explore the effect of shell powder (SP) on lignin degradation and humus (HS) formation during composting. The results showed that the treatment group (T) with SP consumed more polyphenols, reducing sugar and amino acids than the control group (CK), especially the rate of reducing sugar consumption in T (50.61 %) was significantly higher than CK (28.40 %). SP greatly enhanced the efficiency of lignin degradation (T:45.47 %; CK:24.63 %) and HS formation (T:34.93 %; CK:20.16 %). The content of HA in T was 12.94 mg/g while CK was 12.06 mg/g. SP maintained a continuous increase in the relative abundance of AA1, AA3 after cooling phase. Meanwhile, T (48.98 %) significantly increased the abundance of Actinobacteria compared with CK (37.19 %). Actinobacteria, AA1 and AA3 were identified as the main factors promoting lignin degradation and HS formation by correlation analysis. Therefore, adding SP could be a novel strategy to improve compost quality.

Upregulated keratin 15 links to the occurrence of lymphovascular invasion, stromal cervical invasion as well as unfavorable survival profile in endometrial cancer patients.

Keratin 15 (KRT15) overexpression links with tumor initiation, metastasis, and poor survival in several solid carcinomas. While its clinical relevance is scarcely reported in endometrial cancer (EC). Therefore, the current study aimed to investigate the abnormal expression of KRT15 and its correlation with clinical characteristics, survival in EC patients. Totally, 135 surgical EC patients were enrolled. KRT15 protein expression in formalin-fixed and paraffin-embedded tumor and adjuvant tissues was detected by immunohistochemical staining; meanwhile, KRT15 mRNA expression in fresh-frozen tumor and adjacent tissues was detected by reverse transcription-quantitative polymerase chain reaction. KRT15 protein and mRNA expressions were higher in tumor tissue compared with adjacent tissue (both P < .001). Elevated KRT15 protein expression was correlated with the occurrence of lymphovascular invasion (P = .010) and more advanced International Federation of Gynecology and Obstetrics stage (P = .018); meanwhile, elevated KRT15 mRNA expression was linked with more advanced International Federation of Gynecology and Obstetrics stage (P = .038) and marginally associated with the occurrence of stromal cervical invasion (P = .052). Besides, KRT15 protein and mRNA expressions were not correlated with other clinical features (all P > .05). KRT15 protein high was marginally correlated with poor accumulating disease-free survival (DFS) (P = .091) and overall survival (OS) (P = .059); meanwhile, the correlation of KRT15 mRNA expression with accumulating DFS (P = .212) and OS (P = .092) was even weaker. However, multivariate Cox's regressions showed that tumor KRT15 protein (high vs low) was independently correlated with poor DFS (P = .045) and OS (P = .043). KRT15 is abnormally increased in EC tissue, meanwhile, its upregulation links to the occurrence of lymphovascular invasion, stromal cervical invasion, and poor prognosis in EC patients.

Exploring the effects of heavy metal passivation under Fenton-like reaction on the removal of antibiotic resistance genes during composting.

This study aims to explore the succession of microbes carrying antibiotic resistance genes (ARGs), the relationship between heavy metal speciation and ARGs via Fenton-like reaction during composting. The results indicated that the passivation of Cu and Ni was more prominent, and the Fenton-like reaction promoted exceptionally the passivation of Zn, Ni and Mn. The removals of macrolides-lincosamids-streptogramins (MLS), aminoglycoside and tetracycline resistance genes were induced with the composting process, but the relative abundance of bacitracin resistance genes increased. Additionally, Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes were main carriers and disseminators of ARGs, and the Fenton-like reaction improved the contribution degree of Proteobacteria to bacitracin, tetracycline and aminoglycoside resistance genes. Redundancy analysis revealed the passivation of heavy metal contributed to the removal of tetracycline, MLS and aminoglycoside resistance genes. Conclusively, the Fenton-like reaction promoted the passivation of Zn, Ni and Mn, and controlled the abundance of bacitracin resistance genes in composting.

Lignocellulosic depolymerization induced by ionic liquids regulating composting habitats based on metagenomics analysis.

The application of ionic liquids with sawdust and fresh dairy manure was studied in composting. The degradation of organic matter (OM), dissolved organic matter (DOM), and lignocellulose was analyzed. The DOM decreased by 14.25 mg/g and 11.11 mg/g in experimental group (ILs) and control group (CK), respectively. OM decreased by 7.32% (CK) and 8.91% (ILs), respectively. The degradation rates of hemicellulose, lignin, and cellulose in ILs (56.62%, 42.01%, and 23.97%) were higher than in CK (38.39%, 39.82%, and 16.04%). Microbial community and carbohydrate-active enzymes (CAZymes) were analyzed based on metagenomics. Metagenomic analysis results showed that ionic liquids enriched Actinobacteria and Proteobacteria in composting. Compared with CK, the total abundance values of GH11, GH6, AA6, and AA3_2 in ILs increased by 13.98%, 10.12%, 11.21%, and 13.68%, respectively. Ionic liquids can improve the lignocellulosic degradation by regulating the environmental physicochemical parameters (temperature, pH, C/N) to promote the growth of Actinobacteria and Proteobacteria and carbohydrate-active enzymes (CAZymes) abundance. Therefore, ionic liquids are a promising additive in lignocellulosic waste composting.

In-situ generation of H2O2 by zero valent iron to control depolymerization of lignocellulose in composting niche.

Lignocellulosic degradation is a bottleneck of bioconversion during the composting process. In-situ generation of H2O2 in the composting system was an ideal method for efficiently promoting lignocellulase degradation, and zero valent iron (ZVI) was concerned because it can generate H2O2 by reducing dissolved oxygen. This study focused on the effects of ZVI treatment on lignocellulose degradation, microbial communities, and carbohydrate-active enzymes (CAZymes) genes during composting. Its results indicated that ZVI increased H2O2 content during composting, accompanied by the formation of •OH. The degradation rates of lignin, cellulose and hemicellulose in ZVI group (20.77%, 30.35% and 44.7%) were significantly higher than in CK group (17.01%, 26.12% and 38.5%). Metagenomic analysis showed that ZVI induced microbial growth that favored lignocellulose degradation, which increased the abundance of Actinobacteria and Firmicutes but reduced Proteobacteria. At the genus level, the abundance of Thermomonospora, Streptomyces, and Bacillus significantly increased. In addition, glycoside hydrolases and auxiliary activities were important CAZymes families of lignocellulose degradation, and their abundance was higher in the ZVI group. Redundancy analysis showed that the increased H2O2 and •OH content was a critical factor in improving lignocellulose degradation. Overall, H2O2 as a co-substrate enhanced the enzymatic efficiency, •OH unspecifically attacked lignocellulose, and the increase in functional microbial abundance was the main reason for promoting lignocellulose degradation in composting.

Signature of dissolved organic matter and microbial communities based on different oxygen levels response during distillers dried grains with solubles plus sugarcane pith co-fermentations.

The objective of this study was to investigate the relationship between dissolved organic matter (DOM) and microbial communities during the co-fermentation of distillers dried grains with solubles (DDGS) and sugarcane pith at different oxygen levels. In aerobic fermentation (AF), the content of DOM decreased from 32.61 mg/g to 14.14 mg/g, and decreased from 32.61 mg/g to 30.83 mg/g in anaerobic fermentation (ANF). Phenols and alcohols were consumed first in AF, while lipids and proteins were consumed first in ANF. Degradation rates of cellulose, hemicellulose and lignin in AF (6.67%, 39.93%, 36.50%) were higher than those in ANF (0.69%, 18.36%, 9.12%). Firmicutes, Actinobacteriota and Ascomycota were the main phyla in community. Distance-based redundancy analysis showed that pH, organic matter (OM) and DOM were the main driving factors of microbial community succession.

Biochar-based solid acid accelerated carbon conversion by increasing the abundance of thermophilic bacteria in the cow manure composting process.

This study investigated the effects of biochar-based solid acids (SAs) on carbon conversion, alpha diversity and bacterial community succession during cow manure composting with the goal of providing a new strategy for rapid carbon conversion during composting. The addition of SA prolonged the thermophilic phase and accelerated the degradation of lignocellulose; in particular, the degradation time of cellulose was shortened by 50% and the humus content was increased by 22.56% compared with the control group (CK). In addition, high-throughput sequencing results showed that SA improved the alpha diversity and the relative abundance of thermophilic bacteria, mainly Actinobacteria, increased by 12.955% compared with CK. A redundancy analysis (RDA) showed that Actinobacteria was positively correlated with the transformation of carbon.

Red mud conserved compost nitrogen by enhancing nitrogen fixation and inhibiting denitrification revealed via metagenomic analysis.

The objective of this study was to investigate the effects of adding red mud (RM) on denitrification and nitrogen fixation in composting. The results revealed that the retentions of NH4+-N and NO3--N in experimental group (T) with RM were 16.20% and 7.27% higher than that in control group (CK) at the mature stage, respectively. The composition and structure of RM can effectively inhibit denitrification and enhance nitrogen fixation. Moreover, metagenomic analysis revealed that Actinobacteria and Proteobacteria were the main microorganisms in denitrification process, while Firmicutes were the main microorganisms in nitrogen fixation process. In T, denitrifying genes nirK and nosZ were 11% and 18% lower than those in CK, respectively, while nitrogen-fixing genes nifK and nifD were 18% and 34% higher than those in control group, respectively. Therefore, adding RM could reduce nitrogen loss and improve the quality of compost via enhancing nitrogen fixation and inhibiting denitrification process.

Humification process and mechanisms investigated by Fenton-like reaction and laccase functional expression during composting.

This study aims to explore the impacts of the Fenton-like reaction on hydrogen peroxide, hydroxyl radicals, humic substance (HS) formation, laccase activity and microbial communities during composting to optimize composting performances. The results indicated that the activity of laccase in the presence of the Fenton-like reaction (HC) (35.92 U/g) was significantly higher than that in the control (CP) (29.56 U/g). The content of HS in HC (151.91 g/kg) was higher than that in CP (131.73 g/kg), and amides, quinones, aliphatic compounds and aromatic compounds were promoted to form HS in HC by 2D-FTIR-COS analysis. Proteobacteria contributed most greatly to AA1 at phylum level, Pseudomonas and Sphingomonas abundances increased in HC. Redundancy analysis indicated that there was a strong positive correlation among the Fenton-like reaction, laccase and HS. Conclusively, the Fenton-like reaction improved the activity of laccase, promoted the formation of HS and enhanced the quality of compost.

4-Hydr-oxy-3-nitro-phenyl penta-noate.

In the title compound, C(11)H(13)NO(5), an intra-molecular O-H⋯O hydrogen bond is formed between the hydr-oxy and the nitro groups, which results in the formation of a six-membered ring. The valer-oxy group shows a torsioned conformation, and connects to the aryl ring with a C-C-O-C torsion angle of 102.34 (1)°.