ARS | Publication request: CHARACTERIZATION OF EXOPOLYSACCHARIDES PRODUCED FROM AUREOBASIDIUM PULLULANS

Submitted to: Society Of Industrial Microbiology Annual Meeting
Publication Acceptance Date: July 29, 2004
Publication Date: July 29, 2004
Citation: Prasongsuk, S., Leathers, T.D., Kuhirun, M., Eveleigh, D.E., Punnapayak, H. 2004. Characterization Of Exopolysaccharides Produced From Aureobasidium Pullulans [abstract]. Society Of Industrial Microbiology. P. 72.

Technical Abstract: Several black yeasts were isolated from habitats in Thailand, and all were positively identified as Aureobasidium pullulans var. pullulans. Their exopolysaccharides (EPSs) were produced by cultivating the yeast cells in liquid culture with various carbon and nitrogen sources. The maximal EPS yield was obtained from A. pullulans NRM2 (0.53 g.g**-1) using sucrose and peptone at day 7. The hexose content of the EPSs was in the range of 97-99%. Analysis with IR and NMR suggested that the EPSs were composed of pullulan, the spectra illustrating the alpha-configuration and with the anomeric carbon of alpha-1,4 and alpha-1,6 (1,4:1,6) in a 2:1 ratio. However, the degree of pullulanase sensitivity varied among the EPSs ranging from 56% to 97%. The molecular weights (and viscosities) of these EPSs decreased late in culture from the range of 547,000-2,270,000 Da on day 3 to 16,000-160,000 Da on day 7. Amylase activities increased up to 0.11 U/ml in the culture fluid during the 7-day period.