SYNTHESIS AND CHARACTERIZATION OF MICROBIAL ALGINATE ISOLATED FROM RHIZOSPHERE
Ramyaa Lakshmi T. Selvaraj, Meena Sethu
Thiagarajar College, Madurai Kamaraj University, India
Alginate is an exopolysaccharide secreted by selective microbes and also by seaweeds. In seaweeds they occur in the form of calcium, magnesium or sodium salts whereas, in microbes it is in the form of alginic acid. Bacterial alginate is a linear exopolysaccharide consisting of β-1,4-linked β-D-mannuronic acid and its C-5 epimer α-L-guluronic acid. Although seaweed alginates are commercially produced, its mechanical instability caused because of seasonal variation and osmotic swelling due to physiological conditions create variations in its productivity. Hence bacterial alginate is preferred which has high pseudoplasticity. The versatile nature of alginate may help the bacteria in nature to adhere the rhizosphere and act as an absorbant. In this study alginate producing microbes were isolated and 16sRNA sequencing was done to confirm the bacterial strains. The media composition was standardized for better yield of the polymer. Different batch cultures were done and the polymer production found was not uniform, the yield and appearance of the polymer varied among batches. It was found that the concentration of iron gave an impact in the yield and appearance. The synthesized alginate was characterized my DSC, GCMS, NMR, MALDI and FTIR spectra. The characterized alginate was successfully subjected to gel formation. Commercially alginates gain the importance because of the gelling property and its high viscosity. The gelling property is achieved in normal temperature of water and it doesn’t require temperature variations.