COMMUNITY DYNAMICS OF MICROORGANISMS DURING CATTLE MANURE COMPOSTING PROCESS

• Main Author: Safika
• Format: Dissertations
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/32810
• Institution: Institut Teknologi Bandung

Cattle manure, the waste product of cattle farm, nowadays has been used in small amount as fertilizer, biogas and compost. Manure composting process in Indonesia is generally carried out based on traditional method in which process a lot of nutrients has lost and the process itself takes a long time. Composting depends on the quality of organic materials, site of compost, composting methods, temperature, aeration systems, water content, C/N ratio and microorganisms that play role in the process. The unique cattle manure can be in good habitat for the communities of microorganisms degrading organic compounds. The understanding of community structure dynamics of microorganisms that play a role in the degradation of organic compounds in each composting phase is important to control the composting process effectively. The objective of this reseach was to determine biodiversity and community dynamics of bacteria, eukaryotes and archaea during cattle manure composting process. In the long term the outcomes of this study are expected to improve the composting process more effective. Culture-independent approaches were used to analyze biodiversity of compost microorganisms, based on differences in the 16S or 18S rRNA gene fragment sequences. The gene fragments were obtained by PCR amplification of total DNA and the different sequences were separated by DGGE apparatus. Each strip of DGGE bands was targeted for nucleotide sequencing. Homology of the nucleotide sequences were analyzed phylogenetically. Community diversity of microorganisms can be revealed by grouping the microorganisms represented by DGGE bands. The DGGE bands pattern showed that a number of microorganisms bands appear and disappear during composting process. The variety of DGGE bands from bacteria and eukaryotes at mesophilic to thermophilic phase was more diverse than that of archaea. However at the end of thermophilic phase methanogenic archaea bands were more dominant than these of bacteria and eukaryotes. While at maturation phase bacterial bands were more dominant compared to those of eukaryotes and archaea. During composting process, physicochemical changes observed include temperature, moisture content, pH, and the C/N ratio. Temperatures of 28 °C at initial mesophilic phase increase to 60 °C at the peak of the thermophilic phase, then decreased to 35 °C at the maturation phase. Water content of 88, 32% at the mesophilic phase gradually decreased at thermophilic phase and reach to 43.46% at the maturation phase. The pH increased from 7.8 to 8.9 at the peak of thermophilic phase, and decreased to 7.3 at the maturation phase. At mesophilic phase C/N ratio of 17.99 was observed then increase at the early of thermophilic phase to 33.08 and decreased to 22.31 at maturation phase. The results of this study found that the communities of microorganisms during the composting process changes, due to the changes in environmental factors of the compost. Microorganisms that play a role in the degradation of the compost at mesophilic phase included Pseudomonas, Providencia, Peptostreptococcus, Clostridium, Methanobacteriales, Methanosarcinales, Eimeriidae, Penicillium and Ascomycota. An increasing temperature was observed as a consequence of the degradation of the compost material during the mesophilic phase. This leads to the next phase of composting process, which in thermophilic phase. Microorganisms that found at the early of thermophilic phase were Pseudomonas, compost bacterium (Gammaproteobacteria), Bacillus, Methanobacteriales, Methanosarcinales, Apicomplexa, Eimeriidae, Aspergillus, Penicillium and Ascomycota. At the peak of the thermophilic phase with the temperature of 60 °C, microorganisms observed were Bacillus, Ureibacillus, compost bacterium (Gammaproteobacteria), Methanosarcinales, Methanobacteriales, Eimeriidae Gregarina and uncultured eukaryote (Ascomycota). At the end of the thermophilic phase, the structure at microorganisms change by revealing of Clostridia that was previously disappear. The existance of Bacillus, Methanobacteriales, Methanosarcinales, Eimeriidae, Gregarina and uncultured eukaryote (Ascomycota) also enriched the structure of microorganism at this phase. While at the maturation phase showed that the microorganisms observed were Clostridia, Gammaproteobacteria, Methanobacteriales, Methanosarcinales, Ascomycota and uncultured eukaryote (Apicomplexa), which is different to that found in the mesophilic phase. The discovery of a new clusters of bacteria, archaea and eukaryotes during the composting process, leading to the discovery of a new type of microorganisms. These microorganisms are unique microorganisms that play a role typically during the composting process that was conducted and has not been reported previously. Bacteria that formed new cluster have close relations with the Gammaproteobacteria and Clostridia. While the Methanosarcinales and Methanobacteriales the order of methanogenic archaea, were form a new cluster. Methanobacteriales were found in all phases, but it was a dominant order for both mesophilic and maturation phase whose temperature were between 28-35 0C. In addition, Eimeriidae and Ascomycota families found in this composting process were different to those in the GenBank database and has a close similarity to Eimeriidae environmental and Aspergillus. This study also revealed that family of Eimeriidae and Gregarina were dominant protozoa found in the composting process. Communities of microorganisms either bacteria, archaea and eukaryotes dynamically changes in each phase during the composting process as a result of a complex interaction between microorganisms and their environment. Physicochemical of compost changes which in turn will affect the community composition of microorganisms, that depend on the composition of the substrate. On the other hand, the composition of the substrate is also greatly influenced by the metabolic activity of microorganisms.