Influence of different carbon source on mycelium growth and exopolysaccharide in submerged culture of Antrodia camphorata

• Main Author: 陳雯賢
• Other Authors: 龍明有
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/08585104049238317911

碩士 === 明新科技大學 === 化學工程研究所 === 94 === Antrodia camphorata (also known as Zang-Zhi), it is the peculiar fungi in Taiwan, and it was also one of the most expensive fungi medical mushroom with effect of remedy of anticancer, antitumour and protecting the liver. The fruiting body of A. camphorata grows slow; it is still unable to be successful by a large amount of artificial culture with present technology. In addition, to avoid Cinnamomum micranthum stolen to culture A. camphorata causing its extinction, it is need to culture mycelium of A. camphorata by using the most economy and environmental protection methods, solid and liquid fermentation. Nowadays, the submerged culture of Antrodia camphorata to produce the valuable metabolites has aroused an extensive attention of researches in Taiwan. Thus, the main purpose of this research was to investigate the influence of different carbon sources on the production of mycelium and exopolysaccharide in submerged culture of Antrodia camphorata, to understand the metabolic pathway of exopolysaccharide, and to increase production of exopolysaccharide by regulation of different carbon sources. The effect of the different carbon sources including glucose, sucrose, fructose, ribose, xylose, maltose, mannose and galactose on production of biomass and EPS are conducted in this study. The result exhibited that maltose and fructose will stimulate biomass and EPS production, respectively, comparing with control 10 g/L of glucose. In addition, the effect of various concentration of fructose (i.e. 10, 20, 30, 40, 50, 60 g/L) on biomass and EPS production of A. camphorata is conducted in shake flask cultures, indicating that biomass production increased with fructose concentration ranging from 10 to 60 g/L. The biomass concentration reaches to 6.11 g/L as fructose concentration is at 60 g/L. EPS production rose when fructose concentration increased until 50 g/L. Too high level of fructose as 60 g/L will inhibit EPS production. The optimal EPS production (125.99 g/L) is found in 50 g/L of fructose. The fermentation kinetic results showed that effect of the different concentration fructose in air-lift fermentor culture on specific growth rate (μ) has a optimal value (0.32 d-1) at 3% fructose. Production of both biomass and EPS increases with fructose concentrations, giving maximum value in 5.02 g/L and 164.87 mg/L for biomass and EPS, respectively. At 6% fructose, productivity for biomass has optimal value of 0.3349 g L-1 d-1 and productivity for EPS has optimal value of 10.9912 mg L-1 d-1. Increasing fructose concentration will favor production of both biomass and EPS; the kinetic model of EPS production belongs to growth-associated products. Fed-batch culture is conducted in this study to improve production of both biomass and EPS. The result exhibited that both biomass and EPS were enhanced by 36.7% and 44.6%, respectively, due to 3% fructose fed-batch culture comparing with 3% fructose batch culture. Besides, both biomass and EPS by 3% fructose fed-batch culture were enhanced by 18.5% and 16.7%, respectively, comparing with 6% fructose batch culture. The effect of EPS (200 ppm) produced from different carbon sources in flask cultures on both antioxidant activity and 2,2-diphenyl-1-picrylhydrazyl(DPPH) scavenging effect is examined. The result indicated that EPS (200 ppm) obtained from sucrose have largely effect on antioxidant activity (63%) and DPPH scavenging activity (76%). Besides, the effect of EPS (200 ppm) produced from different concentration fructose in flask cultures on antioxidant activity is also investigated and found that fructose at 10 g/L has an optimal antioxidant activity (56.5%) and 60 g/L for DPPH scavenging activity (65%). In air-lift fermentor cultures, the effect of EPS (200 ppm) produced from different concentration fructose on antioxidant activity and DPPH scavenging activity exhibited that an optimal antioxidant activity (56.6%) and a maximum DPPH scavenging activity (76%) are is at 1% fructose. The effect of EPS produced from different carbon sources in flask cultures on molecular weight (Mw) is examined. The result indicated that Mw of EPS from all carbon sources tested range from 1.82×106 to 9.70×106 Da. EPS produced from maltose has a maximum Mw (9.70×106 Da). In EPS from different carbon sources tested, the maximum Mw of EPS is 7.1×106 Da at 6% fructose. In air-lift fermentor cultures, EPS produced from 3% fructose has higher Mw of 3.09×106 Da. The result of carbohydrate composition analysis revealed that composition of EPS produced different carbon sources in flask culture consists of galactose and fructose; however, composition of EPS produced different concentration fructose in flask culture composes of fructose, xylose and mannose. Composition of EPS produced different concentration fructose in air-lift fermentor cultures consists of glucose, sucrose, maltose and galactose.