Isolation and Identification of Thermophilic-Mesophilic Microbial Diversity in Chicken Manure Compost

Kong, Joshophine Pei Ning (2024) Isolation and Identification of Thermophilic-Mesophilic Microbial Diversity in Chicken Manure Compost. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

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Abstract

Compost manure is known to harbor diverse microbial communities due to the presence of rich organic compounds and lignocellulolytic components where they are broken down by mesophilic and thermophilic microorganisms. Consequently, the composting product can be used as organic fertilizer, soil amendment and reduce the negative impacts of chicken manure to the environment. The aim of this study is to isolate and identify thermophilic fungus and mesophilic microorganisms that may be present in the chicken manure compost with the ability to improve composting efficiency. For molecular analysis, DNA extraction was performed on compost samples using QIAamp PowerFecal Pro DNA Kit. The concentration obtained was 240.4 ng/μl. The DNA extract was then sent for fungus ITS1 metagenomic analysis. Isolation of ‘thermophilic fungi’ from three sets of samples were performed through serial dilutions and spread plate method onto Potato Dextrose agar and 4% Sabouraud Dextrose Agar plates containing 0.025% chloramphenicol plates. However, after incubation, all plates showed no growth. Isolation of ‘mesophilic microorganisms’ were performed from three sets of new samples, with differing amounts of diatomaceous earth, expressed as DE (0g, 8g and 16g respectively), together with Nutrient agar and MRS agar for bacterial isolation. For bacterial isolation, cfu/mL for each dilution plate were determined and calculated the log10 average cfu/mL, however there were no significant differences between the means of the samples with different DE amounts using ANOVA analysis. Pure culture of isolates were obtained and identified via colony morphology and spore characteristics using appropriate staining methods then categorized according to their morphotypes. To detect production of extracellular cellulase, the isolates were allowed to grow on carboxymethylcellulose-sodium agar and the plates were visualized for hydrolysis zones on the agar surface. 10 isolates have shown hydrolysis zones on the agar surface around their respective colonies. To investigate the cellular respiration of microorganisms isolated, the catalase test was performed. All 23 isolates showed positive results except for 3 isolates. The isolated fungus and bacteria may be further identified by DNA sequencing to confirm their taxonomy and abundance. The common suspected genus assigned to bacterial isolates are Staphylococcus and Bacillus based on the characterization and biochemical test results. For fungus, the common phylum assigned are Ascomycota and Basidiomycota based on the characterization results.