Pullulan production utilizing various carbon sources by Aureobasidium melanogenum DSM 2404 as biotherapeutic tool in biomedical applications

Abstract

Introduction: Pullulan is a biodegradable biopolymer made up of maltotriose subunits that are water-soluble. It has a direct glucan structure comprising α-1,4 and α-1,6 linkages in a 2:1 ratio, which gives it exceptional physical and structural properties, making it a suitable choice for application in biomedical applications. Despite its potential benefits, the price of production is expansive, and productivity is low, which are significant drawbacks. Therefore, the objective of this work is to identify the ideal carbon source for Aureobasidium melanogenum DSM 2404 to produce high pullulans. Methods: In shake flask studies, the effects of different carbon sources, such as maltose, glucose, sucrose, lactose, and xylose, on cell growth and pullulan generation by Aureobasidium melanogenum DSM 2404 were examined. Results: The highest pullulan production was obtained from sucrose (13.38 g L-1) compared to other types of carbon sources used in the fermentation medium. The maximal pullulan production rate of 0.112 [g-1 L-1 h-1] was obtained in sucrose culture. This suggests that sucrose provides favorable conditions for the microorganisms to produce pullulan at a faster rate compared to other sugars. Conclusion: Sucrose was found to be the most efficient carbon source for the synthesis of pullulan using Aureobasidium melanogenum DSM 2404 generating 13.38 g L-1 of pullulan.