Diversity of cultivated bacteria from Pekan peat swamp forest and the lignocellulosic biodegradation potential /
Tropical peat swamp forests were known to provide huge terrestrial carbon storage due to substantial accumulation of organic matter mainly derived from vegetation residues recognized as peat. Previously characterized as non-favourable-microbial habitat due to the extremely acidic, poor in nutrient,...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Kuantan, Pahang :
Kulliyyah of Science, International Islamic University Malaysia,
2019
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| Subjects: | |
| Online Access: | Click here to view 1st 24 pages of the thesis. Members can view fulltext at the specified PCs in the library. |
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| Summary: | Tropical peat swamp forests were known to provide huge terrestrial carbon storage due to substantial accumulation of organic matter mainly derived from vegetation residues recognized as peat. Previously characterized as non-favourable-microbial habitat due to the extremely acidic, poor in nutrient, water-logged, and anoxic conditions, recent study has proven that peat soils comprised of unexplored diversity of microbial community regardless of the harsh condition. Therefore, this project aims to isolate and identify the bacterial diversity from the soil sample of Pekan peat swamp forest, one of the biggest peat swamp forest in Peninsular Malaysia, and determine their lignocellulosic biodegradation potential. Apart of direct isolation on variety of growth medium, soil was also subjected to dry heat and wet heat pretreatments as well as enrichment with cellulose for the isolation of actinomycetes and other lignocellulose-degrading bacteria. Prior to molecular identification through 16S rRNA gene analysis, bacterial isolates were primary screened for decolourization zone on agar medium supplemented with Azo-CMC, Azure B and Azo-Xylan. Two isolates with the highest measurement of decolourization zone were subjected to the biomass degradation potential analysis using oil palm frond (OPF) bagasse, a natural lignocellulose substrate. The analysis includes biochemical assay and high-performance liquid chromatography (HPLC) verification. From the total of 7953 isolates which have been successfully cultivated from 5 sampling sites of Pekan peat swamp forest soil, 3447 actinomycetes were obtained from dry heat and wet heat pretreatments, while 4506 of other bacteria were isolated from enrichment method, peat and M1 agars. Based on morphological differences, 40 isolates were meticulously selected and molecularly identified via 16S rRNA analysis. Proteobacteria, Actinobacteria and Firmicutes with various genera such as Burkholderia, Achromobacter, Pantoea, Pandoraea, Stenotrophomonas, Curtobacterium, Streptomyces and Bacillus are among the cultivable bacteria identified from this ecological niche. Among the 40 isolates, 67.50% isolates showed positive decolourization zone on Azure B dyed-agar, 62.50% isolates on Azo-CMC dyed-agar and 57.50% isolates on Azo-Xylan dyed-agar with the mean of hydrolyzing capacity index (HCI) were 2.21 cm, 3.08 cm and 4.53 cm, respectively. Isolate 15-B (PC) identified as closely related to Achromobacter insuavis demonstrated a promising potential in the biomass degradation analysis of OPF bagasse in terms of production of glucose and ferulic acid with 0.99 mg/mL and 0.70 µg/mL, respectively, compared to 16-W (O) which is affiliated to Streptomyces misionensis. This present study indicates fascinating lignocellulosic degradation capabilities of the selected bacteria and successfully validates the diversity and potential of Pekan peat swamp forest as the source of lignocellulose-degrading bacteria. |
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| Physical Description: | xix, 114 leaves : colour illustrations ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 88-96). |