Prethodno priopćenje
Factors Affecting the Growth and Production of Milk-Clotting Enzyme by Amylomyces rouxii in Rice Liquid Medium
Pei-Jing Yu
; Graduate Institute of Food Science and Technology, National Taiwan University, 59, Lane 144, Keelung Rd., Sec. 4, Taipei, Taiwan
Cheng-Chun Chou
; Graduate Institute of Food Science and Technology, National Taiwan University, 59, Lane 144, Keelung Rd., Sec. 4, Taipei, Taiwan
Sažetak
Amylomyces rouxii is one of the main fungi usually coexisting with yeasts in Chinese yeast ball, the starter of chiu-niang, a traditional Chinese fermented product from rice. In the present study, growth and production of milk-clotting enzyme (MCE) in gelatinous rice liquid culture of A. rouxii as influenced by waxy (gelatinous) rice content in the medium (5–20 %), temperature (25–40 °C), cultivation time (1–6 days), shaking speeds (0–150 rpm) and metal ions (Na+, K+, Zn2+, Mg2+, Mn2+, Cu2+, Ca2+, Fe3+ and Al3+) were investigated. Results revealed that rice content in the medium, shaking speed, temperature and cultivation time all affected the mycelial propagation and the production of milk-clotting enzyme by A. rouxii in the rice liquid culture. The maximum milk-clotting enzyme activity of ca. 1.22 unit/mL of medium was observed in the 3-day static culture of test organism grown at 30 °C in the medium containing 20 % of gelatinous rice, while mycelial propagation increased with the increase of cultivation time and shaking speed. Furthermore, a significant increase (p<0.05) in the milk-clotting enzyme activity of ca. 1.90 unit/mL of medium, which was about 1.55-fold of the control, was observed when Al3+ was added to the rice liquid medium.
Ključne riječi
Amylomyces rouxii; milk-clotting enzyme; rice liquid culture
Hrčak ID:
110548
URI
Datum izdavanja:
15.9.2005.
Posjeta: 1.908 *