Algae. 2004; 19(3): 271-276.
Screening of Bioactive Materials from Freshwater Microalgae
Wan-Seok Lee, Aeran Choi, Chi-Yong Ahn, Hyuncheol Oh1, Jong Seog Ahn1 and Hee-Mock Oh*
Environmental Biotechnology Laboratory and 1Laboratory of Cellular Signalling Modulator, Korea
Research Institute of Bioscience and Biotechnology, Daejeon 305-333, Korea
One hundred and fifty four micro algal strains, newly isolated from nationwide freshwaters in Korea, were screened for their anticancer, ant diabetic, and antibiotic activities. The micro algal strains were cultured with different nutritional conditions that were divided into 4 groups as follows; a normal Allen medium, nitrogen (N)-limited medium, phosphorus (P)-limited medium, and N and P-limited medium. Algal biomass was extracted with a mixture of acetone:H₂O (1:1, v:v) and the extracts were used for the screening of bioactive materials. Anticancer, ant diabetic, and antibiotic materials were screened by the methods of vaccinia Hl-related protein tyrosine phosphates (VHR DS-PTPase) inhibition, protein tyrosine phosphates 1B (PTP1B) inhibition, and paper disk. The inhibition activity of VHR DS-PTPase was observed in 18 strains, having a maximum 79% inhibition from Anabaena affinis and the inhibition activity of PTP1B was observed in 9 strains, having a maximum 97% from Sphaerocystis schroeteri. Microcystis aeruginosa incubated in an N and P-limited medium showed antibiotic activity in 8 species out of 13 pathogenic bacteria. As a whole, it seemed that the stressed condition such as N and/or P limitation increased the production of bioactive materials in micro algae.
Keywords : bioactive materials; microalgae; protein tyrosine phosphatase 1B(PTP1B); vaccinia H1-related protein tyrosine phosphatase(VHR DS-PTPase)