Study and Applications of Pullulan Produced from Fungal Isolates Garud Abha, Raut Savanta V. Department of Microbiology, Bhavan ’s College, Andheri [W], Mumbai-400 058 *E-mail: svrmicro@yahoo.co.in
Online published on 16 February, 2013. Abstract The two fungal cultures, one isolated from painted wet wood and the other from the surface of PVC pipes, after identification, were used to synthesize and extract EPs which was confirmed as pullulan using preliminary tests, precipitation tests and chromatographic techniques. Characterization of the EPS was carried out on the basis of preliminary physical tests, and the colorimetric estimation of the total carbohydrate and protein content, present in the EPS samples, which was 47.9%, 83.8%, 62.1% and 0.075%, 0.088%. 0.085% respectively, for the standard strain, isolate 1 and isolate 2 and gave respective per cent yields of 49.9%, 57,6% and 42.6% after incubation in defined synthetic glucose media. Optimization of medium for pullulan production proved that the optimum initial pH of the medium for effective growth and pullulan production is 6.5. Using 3 crude substrates – acid hydrolyzed juices of sugarcane, beetroot and corn shows EPS production was 32.48 ± 0.4%, 38.91 ± 0.3%, 32.5 ± 0.35%; 33.6 ± 0.4%, 39.4 ± 0.6%, 23.6 ± 5.2% and 47.0 ± 0.7%, 55.2 ± 0.6%; 40 ± 0.07% for the standard strain, isolate 1 and 2 respectively. The antimicrobial activity (antibacterial and antifungal) was tested using different organisms. Application of the polysaccharide, pullulan, as a thickening agent in water based paints and use as a cold insulator for prolonged availability of cooling effects has been carried out effectively. Top Keywords Aureobasidium pullulans, pullulan, Antimicrobial sensitivity, cold insulator. Top |