Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 3: 67 - 75. Published March 2008.
Comparison of forest soils and waste-contaminated soils as sources of polysaccharide-degrading microbes
Ting ASY*^, de Cruz G. and Chan HY
*Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Setapak Campus, Jalan Genting Kelang, Setapak 53300, Kuala Lumpur, Malaysia
^Corresponding author: tingsy@mail.utar.edu.my
ABSTRACT
Objective: This study was conducted to determine the suitable soil types that can be used as sources of polysaccharide-degrading microbes. A comparison was done of the potential of isolating such microbes from non-polluted areas (forest soils) and waste-contaminated soils.
Methodology and Results: Waste-contaminated soils have more isolates producing polysaccharide-degrading enzymes (polysaccharases) than forest soils. In vitro plate screening using dye-labeled substrate detected 78 isolates producing polysaccharases from waste-contaminated soils, compared to 59 isolates from forest soils. Xylanase was the most common polysaccharase produced by isolates from both soil samples, followed by amylase and cellulase. Enzyme assay using dinitrosalicylic acid further established that bacteria from waste-contaminated soils produced the most xylanase (2.355 U ml-1), amylase (1.420 U ml-1) and cellulase (0.910 U ml-1) activities, while bacteria isolated from forest soil samples have comparatively less xylanase (0.776 U ml-1), amylase (0.223 U ml-1) and cellulase (0.024 U ml-1) activities. Similarly, polysaccharase activities in fungal isolates from waste-contaminated soils were higher than that of isolates from forest soils, except for cellulase activity.
Application of findings: Waste-contaminated soils are better sources for selection of candidates for bioremediation of solid wastes and for extraction of polysaccharases for industrial applications.
Key words: amylase, cellulase, industrial applications, polysaccharases, xylanase
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