Effects of oxytetracycline on archaeal community, and tetracycline resistance genes in anaerobic co-digestion of pig manure and wheat straw.

In this study, the effects of different concentrations of oxytetracycline (OTC) on biogas production, archaeal community structure, and the levels of tetracycline resistance genes (TRGs) were investigated in the anaerobic co-digestion products of pig manure and wheat straw. PCR denaturing gradient gel electrophoresis analysis and real-time quantitative polymerase chain reaction (RT-qPCR) (PCR) were used to detect the archaeal community structure and the levels of four TRGs: tet(M), tet(Q), tet(W), and tet(C). The results showed that anaerobic co-digestion with OTC at concentrations of 60, 100, and 140 mg/kg (dry weight of pig manure) reduced the cumulative biogas production levels by 9.

Effects of different bulking agents on the maturity, enzymatic activity, and microbial community functional diversity of kitchen waste compost.

Aerobic composting is an effective method for the disposal and utilization of kitchen waste. However, the addition of a bulking agent is necessary during kitchen waste composting because of its high moisture content and low C/N ratio. In order to select a suitable bulking agent, we investigated the influence of leaf litter (LL), sawdust (SD), and wheat straw (WS) on the enzymatic activity, microbial community functional diversity, and maturity indices during the kitchen waste composting process.

[Effects of biological organic fertilizer on microbial community's metabolic activity in a soil planted with chestnut (Castanea mollissima)].

A field experiment was conducted in Zhashui County of Shaanxi Province, Northwest China in 2011 to study the effects of biological organic fertilizer on the microbial community's metabolic activity in a soil planted with chestnut (Castanea mollissima). Three treatments were installed, i. e.

[Effects of heavy metals pollution on soil microbial communities metabolism and soil enzyme activities in coal mining area of Tongchuan, Shaanxi Province of Northwest China].

This paper studied the metabolism of soil microbes, functions of soil microbial communities, and activities of soil enzymes in a coal mining area of Tongchuan. In the coal mining area, the concentrations of soil Cu, Zn, Cd, and Pb were significantly higher than those in the non-mining area, of which, Cd contributed most to the heavy metals pollution. By adopting Biolog method combining with principal component analysis (PCA) and cluster analysis, it was found that the metabolic characteristics of different soil microbial communities varied significantly with increasing soil heavy metals pollution, and the variation was mainly manifested in the metabolic patterns of carbon sources such as saccharides and amino acids.

Effects of Cu on metabolisms and enzyme activities of microbial communities in the process of composting.

With the compost matrix of pig manure, wheat straw, and spent mushroom substrate, and then inoculated with the Compound Microbe Preparation, the study investigated the effects of the heavy metal Cu on the process of composting. Biolog EcoPlate™ test revealed that at a low content, Cu could improve the capacities of microbial communities to transform and exploit carbon sources in the form of polymer, thus speeding up the decomposition of agricultural wastes, and at a high content, Cu presented inhibiting effect on microbial communities to exploit complex macromolecular carbon sources, thus extending the decomposition of agricultural wastes. Enzyme activity testing showed that at a low content, Cu presented enzyme activity-activating effect at the early period of composting and inhibiting effect in the late period of composting, and at a high content, Cu presented enzyme activity-inhibiting effects through the process of composting.