Production of citric acid by Aspergillus niger using acid hydrolysates of sugarcane bagasse

• Main Authors: Po-yun Wu, 吳柏昀
• Other Authors: Chin-hang Shu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/50775011104143866927

碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 97 === Biorefinery, which is one of the renewable technologies, has been developed for few years. And the use of lignocellulosic materials available in agricultural wastes as a source of raw material for citric acid is interest because of their renewable nature and abundance. The present study discusses the hydrolysate of sugar cane bagasse as carbon source for the production of citric acid by Aspergillus niger . First, we use sugar cane bagasse in medium directly, but the results show that it was not a good method. Then we use dilute acid method for sugar cane bagasse pretreatment, which is one of the few technologies to break down the protective structure of lignin and hemicellulose, but during pretreatment process, several compounds like acetic acid and 5-hydromethylfurfural and furfural were toxic to microorganisms. However, there need some methods to detoxify the acid hydrolysates. In this study toxic compounds were removal from hydrolysate by activated charcoal, so that the hydrolysate could be used by A. niger .After detoxic process, the maximum growth rate (μmax) and citric acid concentration of A.niger fermentation were closed to those of the control medium.