Authors: Bingxue Li Ning Zhang Qing Peng Tie Yin Feifei Guan Guili Wang Ying Li
Publish Date: 2009/03/31
Volume: 84, Issue: 2, Pages: 293-300
Abstract
A black yeast strain “NG” was isolated from strawberry fruit and identified as Aureobasidium pullulans Strain NG displayed yeastlike cell YL swollen cell SC septate swollen cell SSC meristematic structure MS and chlamydospore CH morphologies pH was the key factor regulating cell morphogenesis of strain NG Differentiation of YL controlled by extracellular pH had no relationship with nutrition level YL was maintained at pH 60 but was transformed into SC at pH ∼45 SC a stable cell type of A pullulans could bud septate or transform into MS or CH in response to nutrition level and low pH SC produced swollen cell blastospores SCB at pH 21 with abundant nutrition and could transform into MS at lower pH 15 SC was induced to form CH by low level nutrition and pH 3 and this transition was suppressed by adjusting pH to ∼45 Crude polysaccharides without pigment melanin were produced by SC of strain NG Pullulan content of the polysaccharides was very high 9837 Fouriertransform infrared spectroscopy confirmed that chemical structures of the polysaccharides and standard pullulan were identical Swollen cells produced 208 mg/ml nonpigmented polysaccharides at 96 h in YPD medium Controlling pH of fermentation is an effective and convenient method to harvest SC for melaninfree pullulan productionThis work was supported by the Chinese Liaoning Province Higher Educational Institution Scientific Research Program Fund Grant No 20040324 and the Research Program Fund of Key Laboratory of AgroMicrobial Resource and Application Chinese Ministry of Agriculture Grant No 200601
Keywords: