Authors: Honggui Wan Jianfeng Yuan Xianyang Shan Qiyang Wu Nan Shi
Publish Date: 2011/10/05
Volume: 16, Issue: 4, Pages: 761-
Abstract
A gray and low viscosity extracellular polysaccharide EPS composed of Nacetylglucosamine xylose and mannose was isolated from culture medium of Bacillus sp strain LBP32 by ethanol precipitation followed by dialysis and freezedrying The crude biopolymer showed an apparent molecular weight Mw of ∼ 962 × 104 Chemical and spectroscopic studies revealed that the bacterial biopolymer was composed of a β14linked backbone carrying a low content of β13linked backbone In addition the EPS demonstrated a high antioxidant activity in a concentration dependent manner The 50 inhibition concentration IC50 for quenching hydroxyl radical ·OH and superoxide radical ·O2 − were 0042 and 0165 mg/mL respectively Furthermore the EPS demonstrated a strong protective effect against lipid peroxidation and radiation such as UV radiation and ion beam irradiation These results indicate that the protective effects of the EPS were most likely due to its free radical scavenging ability
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