Screening of exopolysaccharide producing bacteria strains

This thesis presents a novel improved screening approach in discovering excessive exopolysaccharide producing bacteria strains. Patch isolation method is a rapid
screening technique to reveal exopolysaccharide producing bacteria strains within a short period of time. In the present studies, aniline blue is used as the biological
indicator to identify the production activity of exopolysaccharides. Presence of blue colour intensity indicates the production rate of exopolysaccharides. Excessive exopolysaccharide producing bacteria strains can be found in soil microbial communities. Soil bacteria requires carbon source as metabolic needs to produce
exopolysaccharides. Table sugar used as the lower cost sugar substrate to grow the isolated bacteria. The rate of carbon source required to produce exopolysaccharides
is depends on the types and behaviours of bacterial isolates. To determine whether the carbon source affect the production activity of exopolysaccharides, 1%, 5% and
20% sugar concentration were used as the parameter for cultivation conditions of soil bacterial isolates. The screening bacterial isolates showing positive responses were further to production of exopolysaccharides and the resulting exopolysaccharides were extracted. The extracted exopolysaccharides displayed different characteristics compare to the positive control, Agrobacterium sp. ATCC 31749 and yet to be explored more on the functional properties.