Nitrite reductase genes as functional markers to investigate diversity of denitrifying bacteria during agricultural waste composting

Abstract

The purpose of this study was to investigate the diversity of denitrifier community during agricultural waste composting. The diversity and dynamics of the denitrifying genes (nirK and nirS) were determined using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Relationships between physico-chemical parameters and denitrifying genes structures were simultaneously evaluated by redundancy analysis (RDA). Phylogenetic analysis indicated that nirK clones grouped into six clusters and nirS clones into two major clusters, respectively. The results showed a very high diversity of nir gene sequences within composting samples. RDA showed that the nirK and nirS gene structures were significantly related to pH and pile temperature (P < 0.05). Significant amounts of the variation (49.2 and 38.3 % for nirK and nirS genes, respectively) were explained by pH and pile temperature, suggesting that those two parameters were the most likely ones to influence, or be influenced by the denitrifiers harboring nirK and nirS genes.

Improving green waste composting by addition of sugarcane bagasse and exhausted grape marc

“…Traditional GW disposal has involved incineration or deposition in landfills, which reduce the efficiency of land use and cause environmental problems such as water contamination and odour pollution (Bustamante et al, 2013;Gabhane et al, 2012). As an alternative, composting technology has been considered an effective method for transforming the organic matter into a potentially safe, stable and sanitary product that can be used as a soil amendment, an organic fertilizer, or a substitute for peat in soilless culture (Chen et al, 2014). For biomasses that are high in lignocellulose, however, traditional composting is time consuming, produces odorous gases (i.e., NH 3 and H 2 S), and generates a low quality compost product unsuitable for commercial use (Gabhane et al, 2012).…”

Monitoring influential environmental conditions affecting communities of denitrifying and nitrifying bacteria in a combined anoxic–oxic activated sludge system

“…4). It has been pointed out that pH can affect the denitrifier community as well as the denitrification rate (Chen et al, 2014). Under an acidic pH, the activity of nitrous oxide reductase was lowered ( SImek and Cooper, 2002), whereas alkaline environments (under basic pH condition) led to strong correlations between pH and denitrifier community activity (Chen et al, 2014).…”

A Novel Configuration Fluidized Bed Reactor for Nitrate Reduction and Low Strength Anaerobic Wastewater Treatment

“…Recovering energy from biological gases produced under anaerobic treatment and sludge digestion is more effective than aerobic treatment. Nowadays, many researches focus on the design of anaerobic reactors to achieve high substrate removal efficiency with low operating costs [1,2]. An anaerobic fluidized bed reactor (FBR) is an attached growth wastewater treatment reactor which offers various advantages, such as high substrate removal efficiency due to enhanced contact between microbes adhered onto carrier media and wastewater stream, rapid recovery of stability with changes to operating conditions, and the ability to operate under low hydraulic retention times (HRT) due to the internal recirculation flow rate.…”