This research was carried out to improve the utilization of agar by evaluating the effect of agarooligosaccharides on the intestinal microflora. Medium containing 0.2% agarooligosaccharides remarkably enhanced the growth of Bifidobacterium infantis; however, agarooligosaccharides did not influence the growth of Clostridium perJlingens. Agarooligosaccharides affected intestinal microflora to different extent by various pH and NaCl concentration. The growth of B. infantis enhancad over pH 4.5. Within 1 % NaCl concentration, addition of agarooligosaccharides enhanced the growth of B. infantis. In contract, NaCl did not affect the growth of Cl. perflingens at all concentrations tested. Therefore, agarooligosacchariedes improved the benevolent intestinal microflora and depressed to the level of bacteria causing putrefaction and food poisoning.

Agarooligosaccharides were produced by β-agarase from Bacillus cereus ASK 202. LD_(50) of Agarooligosaccharides was determined to be 1359 mg/kg which corresponded to GRAS material. Agarooligosaccharides at 5% level exhibited 88.3% inhibition on TA98 and 54% on TA100, indicating agarooligosaccharides to be potent antimutagenic substance. Immunologic activity of agarooligosaccharides was also confirmed by mouse spleen cell culture. Agarooligosaccharides addition of 200 ㎕/ml stabilized spleen cells (2.5 × 10^6 cells/ml) as compared to control (6.4 × 10⁴ cells/ml).

Agar, one of the most abundant marine products has not been utilized extensively because of low level of processing technology in Korea. This research was carried out to improve the utilization of agar and consequent increase in profit. Antibacterial activity of agarooligosaccharides were evaluated against bacteria causing putrefaction and food poisoning. Addition of 0.4% agarooligosaccharides showed antibacterial activity toward Staphylococcus aureus and Escherichia coli O157:H7; furthermore, autoclave treatment of agarooligosaccharides solution enhanced the antibacterial activity. Agarooligosaccharides showed high stability against the pH change. Addition of amino acid(alanine, lysine, glycine, phenylalanine) in agarooligosaccharides solution enhanced antibacterial activity in E. coli O157:H7, Streptococcus mutans and Staphylococcus aureus.