Influence of volumetric oxygen transfer coefficient (k_La) on xylanases batch production by Aspergillus niger van Tieghem in stirred tank and internal-loop airlift bioreactors

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• 作者：Michele Michelin ; Andr茅 Manuel de Oliveira Mota ; Maria de Lourdes Teixeira de Moraes Polizeli ; Daniel Pereira da Silva ; Ant贸nio Augusto Vicente ; Jos茅 Ant贸nio Teixeira
• 关键词：Bioreactors ; kLa ; Xylanase ; 尾-Xylosidase ; Corncob ; Aspergillus
• 刊名：Biochemical Engineering Journal
• 出版年：15 November, 2013
• 年：2013
• 卷：80
• 期：Complete
• 页码：19-26
• 全文大小：1159 K

文摘

Oxygenation is an important parameter involved in the design and operation of mixing-sparging bioreactors and it can be analyzed by means of the oxygen mass transfer coefficient (k_La). In this study, batch fermentations in stirred tank bioreactor (STB) and airlift bioreactor (ALB) were operated under a range of k_La values, in attempts to optimize and compare the activities of extracellular xylanase and 尾-xylosidase synthesized by the fungus Aspergillus niger van Tieghem, using corncob as inducer source. The higher xylanase levels were observed on STB (9000 U l^鈭?; k_La = 30 h^鈭?), while the 尾-xylosidase production was similar in both bioreactors. However, when the enzymatic activity was compared for the same k_La value (12 h^鈭?) in STB and ALB, the xylanase and 尾-xylosidase productions were higher in ALB (7000 U l^鈭? xylanase; 2100 U l^鈭? 尾-xylosidase) than STB (4500 U l^鈭? xylanase; 1800 U l^鈭? 尾-xylosidase).