Macrophage-stimulating activity of exo-biopolymer from cultured rice bran with Monascus pilosus.
To find a new use of rice bran, five fungi were examined for the production of exo-biopolymer with macrophage-stimulating activity from rice bran. Among the exo-biopolymers produced from the cultures, Monascus pilosus had the most potent macrophage stimulating activity in a liquid culture rather than in a solid culture. In order to improve the yield of exo-biopolymer with macrophage-stimulating activity, a suitable medium for exo-biopolymer was tested in submerged culture of M. pilosus. The highest amount of exo-biopolymer (13.9 mg/mL) was obtained in a medium containing rice bran as an only carbon source followed by media with additional maltose and sucrose (13.8 and 13.7 mg/mL, respectively). The addition of peptone resulted in the production of high amount of exo-biopolymer (15.1 mg/mL), meanwhile the addition of ammonium chloride resulted in 264.0 microg/mL of glucosamine content. Among eight different kinds of inorganic salts tested, potassium phosphate (0.1%) was the most effective inorganic salt for the mycelial growth and exo-biopolymer production. Therefore the optimal medium composition was as follows (g/L): 20 g of rice bran, 5 g of peptone, and 1 g of KH2PO4. The optimal culture pH and time for mycelial growth and exo-biopolymer production was pH 5.0 and 25 degrees C, respectively. The maximum exo-biopolymer (20.1 mg/mL) was observed at the fourth day of cultivation. Exo-biopolymer, a crude polysaccharide fraction, mainly contained neutral sugar (81.8%) with considerable amounts of uronic acid (18.2%). Component sugar analysis showed that the active fraction consisted mainly of arabinose, galactose, glucose, which was digested from starch of rice bran during cultivation, and uronic acid (molar ratio; 0.8:1.0:0.7:0.8).
Yu
K W
KW
Department of Kimchi and Food Science, Chongju National College of Science and Technology, Jeungpyeong 368-701, Korea.
Kim
Y S
YS
Shin
K S
KS
Kim
J M
JM
Suh
H J
HJ
D000818:Animals; D001704:Biopolymers / Q000096:biosynthesis* / Q000494:pharmacology*; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D032741:Monascus / Q000378:metabolism*; D012275:Oryza / Q000382:microbiology*; D012639:Seeds / Q000382:microbiology*
D001704:Biopolymers