Improved Production and Purification of Pectinase from Streptomyces sp. GHBA10 isolated from Valapattanam mangrove habitat, Kerala, India

Pectinases are enzymes that catalyze the hydrolysis of pectin (polygalacturonic acid) to galacturonic acid residues. Actinomycetes are efficient degraders of plant debris as they produce extracellular enzymes like cellulase, xylanase and pectinase. The present investigation focuses on improvement of pectinase production through media optimization, followed by its purification. Submerged fermentation was carried out using a mangrove isolate of Streptomyces sp. GHBA10, identified by 16S rDNA sequencing. The highest yield of the enzyme was obtained from 0.3% (w/v) pectin and 0.1% (w/v) tryptone at an initial medium pH of 8.5, when incubated at 30°C and 150 rpm for 6 days with an inoculum size of 5% (v/v). The effect of surfactants such as sodium dodecyl sulphate, Triton X-100, Tween-20, Tween-80 and cetrimide on the enzyme production revealed that cetrimide significantly enhanced the enzyme secretion. The crude pectinase was purified by salt precipitation, dialysis and gel filtration chromatography. The specific activity of the purified pectinase was estimated to be 2610 U/mg of enzyme protein. Purification revealed 3.5-fold increase in specific activity of the enzyme. Sodium dodecyl sulphate polyacrylamide gel electrophoresis revealed an apparent molecular weight of 32 kDa. This pectinase may be industrially used in extraction and clarification processes.