Production of Pullulan Polysaccharide from Aureobasidium pullulan and to Study its Properties

Pullulan, which is made of linear α-d-glucan maltotriose and maltotetrose repeating units interconnected by α (1→6) and α (1→4) linkages, is a water-soluble homopolysaccharide produced extracellularly by Aureobasidium pullulans. A. pullulanis the anamorphic yeast-like fungus and routinely found on leaves and various surfaces; it is ubiquitous and a cosmopolitan saprophyte. The fungus was isolated from guava leaves and was confirmed by colony characteristics and biochemical test. Isolates obtained showed colouration from off-white to yellow and then to black. Pullulan was extracted from the fungus using a pullulan producing medium. Fourier transform infrared spectroscopy was the technique used for confirmation of the product. This work also reports the flocculating, antioxidant, emulsifying activities of pullulan; it can also be used as reducing agent for synthesising silver nanoparticles.