BIOACTIVITIES OF Β-GLUCAN IN SIX MARINE MICROALGAE
ZHOU Cheng-Xu;TIAN Tian;CHEN Hai-Min;YAN Xiao-Jun;LUO Qi-Jun;School of Marine Science,Ningbo University;
The biological activity of β-glucan in different organisms varies significantly. We studied the bioacitivity, in terms of cytotoxicity, antioxidation, and antimicrobe, of β-glucans extracted from mass cultures of six strains of marine diatom and haptophyte, namely, Skeletonema costatum, Phaeodactylum tricornutum, Thalassiosira pseudonana, Chaetoceros debilis, Isochrysis galbana, and Pleurochrysis sp. The results show that β-glucan from each microalgal strain showed moderate cytotoxicity on Hela cells. The most potent β-glucan was from T. pseudonana in concentration ranged 50-100 μg/ml, and Pleurochrysis sp. at 200 μg/ml. β-glucan from I. galbana and Pleurochrysis sp. show good positive concentration-cytotoxcitiy correlation. Moreover, β-glucan from all the strain was concentration-relevant in antioxidation against reactive oxygen and DPPH; for example, at 400μg/ml, β-glucan could remove 72% to 74% reactive oxygen. However, the effects on microorganism by β-glucan differed among the strains. For instances, β-glucan from marine microalga could inhibit the growth of E. coli up to 60% at the concentration of 400 μg/ml, but promote the growth of Staphylococcus aureus(best for β-glucan from S. costatum). The activities were concentration- and time- dependent. Significant difference may exist among the microalga at the same glucan concentration, calling for more works in the future.