Bacterial Community Dynamics and Influencing Variables during Composting with Different Initial Raw Materials (Pig Manure and Tea Waste)

Research Article

J Bacteriol Mycol. 2020; 7(2): 1129.

Bacterial Community Dynamics and Influencing Variables during Composting with Different Initial Raw Materials (Pig Manure and Tea Waste)

Ren L, Xiao W, Zhang L, Zhang J*, Huang H

College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China

*Corresponding author: Zhang J, College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China

Received: April 29, 2020; Accepted: May 14, 2020; Published: May 21, 2020


This research was carried out to determine the structure dynamics and shaping factors of bacterial community during agricultural waste composting with pig manure or tea waste. Bacterial community structure was determined by Denaturing Gradient Gel Electrophoresis (DGGE). Redundancy analysis was used to estimate the relationship between bacterial community structure and environmental parameters. Results showed that Firmicutes, Proteobacteria, Acidobacteria, and Bacteroidetes were the dominant bacterial phyla and varied in samples with different initial materials. Anoxybacillus toebii, Keratinibaculum paraultunense, Peptoniphilus methioninivoras, were remarkable observed during the cooling and maturation stages of pig manure piles. While Clostridium bytyricum, Halanaerobium salsuginis were widely distributed during the whole composting process for tea waste. Redundancy analysis indicated that EC, pH, TN, and TOC showed predominant influence on the bacterial community structure. Significant amounts of the variation (47.0%) of community structure were explained by those parameters. These parameters might be the most responsive ones influencing the succession of bacterial communities during agricultural waste composting for pig manure and tea waste.

Keywords: Composting; Bacterial Community; Redundancy Analysis; Shaping Factor; Initial Raw Material


Composting has been considered as a resourceful treatment technology to stabilize agricultural solid wastes [1-5]. Under controlled conditions, the biodegradable components in solid waste were utilized and transformed by the widespread microorganisms in nature, including bacterial and fungal communities. Bacterial communities play crucial roles during agricultural waste composting process. They are important drivers for the organic matter decomposition and stabilization during composting [6, 7].

Physico-chemical factors have various influences on the bacterial community dynamics during agricultural waste composting [7]. Previous study found that the properties of the raw material causes differences in microbiological parameters [8]. Many researchers found that different raw materials in composting system had an important impact on bacterial populations. Bacterial populations adapting to the physiological and biochemical properties of available carbon substrates will have higher biological activity [9, 10]. Inoculation of Pichia kudriavzevii RB1 accelerated composting process and changed the microbial community structure [11]. The multistage inoculation could influence the duration of high pile temperature and diversity of bacterial community during municipal solid waste composting [12].

Many studies suggested that the abundance and diversity of bacterial population are influenced by their initial composition originating from different raw material [12, 13], and inoculation with different bacteria [14-16] or fungi [13, 14]. Different raw materials induced different physico-chemical parameters and different initial microbial communities, thus affecting microbial community dynamics during the composting process, especially in the early stage [11]. The different microbial community structure will react to composting process [11, 12]. It is of great importance to determine the interaction between raw material and microorganism (especially bacterial community). Up to now, it is lack and incomplete that the environmental factors have been analyzed with the changes of microbial community structure to separate out their relative importance.

Thus, pig manure and tea waste were used in this study as the main initial materials for composting, respectively. The changes of physico-chemical parameters with different starting materials were determined. The structure dynamics of bacterial communities in different piles was characterized by PCR-Denaturing Gradient Gel Electrophoresis (DGGE). The relationship between changes in physico-chemical factors and structure changes of bacterial community were determined by Redundancy analysis. Variation partitioning analysis was also conducted to relate changeable environment to the succession in community structure, and present statistical analysis for mining potential relations. It is necessary to determine the dynamic changes and shaping factors of bacterial communities during composting system with different starting materials, and to provide theoretical guidance and assistance for the composting of agricultural wastes.

Materials and Methods

Composting piles set-up

Pig Manure (PM) and Tea Waste (TW) were used as the main difficult-degradable materials for different treatments, respectively. They were gathered from the countryside of Changsha, Hunan, China. These materials were chopped into about 15 mm pieces after air-dried. The discarded vegetables were gathered from food market around Changsha. Vegetable waste was cut into about 15 mm pieces and supplied as easy decomposable materials. The properties and homogenized ratios of those wastes are shown in Table 1.