Dataset Information

Enhancement of pullulanase production from recombinant Bacillus subtilis by optimization of feeding strategy and fermentation conditions.

ABSTRACT: Pullulanase is an important starch-debranching enzyme mostly used in starch processing-related food industries. However, the levels of pullulanase produced from recombinant Bacillus subtilis, a Generally Recognized as Safe (GRAS) host, are generally limited. To enhance the activity of pullulanase, batch fermentation and fed-batch fermentation were systematically investigated. The overall purpose is to improve the fermentation yield by optimizing the feeding strategy in the fermentation process, thereby increasing the enzyme activity of pullulanase. Therefore, in this study, the feeding methods, the feeding ingredients, the feeding concentration, and pH values were studied in detail. The optimized fermentation conditions for pullulanase production from recombinant B. subtilis were determined as following: inoculum volume 7%, pH 6.5, the dissolved oxygen level 30%, and constant-rate feeding of 100 mL glucose solution (400 g L-1) in late logarithmic growth. The OD600 of recombinant B. subtilis and enzyme activity were 84.54 and 102.75 U mL-1, which were respectively 141% and 144% higher than that before optimization. These findings provided a prerequisite for further amplification of the fermentation system to obtain higher enzyme activity.

SUBMITTER: Zhang Y

PROVIDER: S-EPMC6969872 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Enhancement of pullulanase production from recombinant Bacillus subtilis by optimization of feeding strategy and fermentation conditions.

Zhang Yu Y Nie Yao Y Zhou Xia X Bi Jiahua J Xu Yan Y

AMB Express 20200118 1

Pullulanase is an important starch-debranching enzyme mostly used in starch processing-related food industries. However, the levels of pullulanase produced from recombinant Bacillus subtilis, a Generally Recognized as Safe (GRAS) host, are generally limited. To enhance the activity of pullulanase, batch fermentation and fed-batch fermentation were systematically investigated. The overall purpose is to improve the fermentation yield by optimizing the feeding strategy in the fermentation process, ...[more]

PMID: 31955316

Similar Datasets

Project description:The physiological functions of two amylolytic enzymes, a maltogenic amylase (MAase) encoded by yvdF and a debranching enzyme (pullulanase) encoded by amyX, in the carbohydrate metabolism of Bacillus subtilis 168 were investigated using yvdF, amyX, and yvdF amyX mutant strains. An immunolocalization study revealed that YvdF was distributed on both sides of the cytoplasmic membrane and in the periplasm during vegetative growth but in the cytoplasm of prespores. Small carbohydrates such as maltoheptaose and beta-cyclodextrin (beta-CD) taken up by wild-type B. subtilis cells via two distinct transporters, the Mdx and Cyc ABC transporters, respectively, were hydrolyzed immediately to form smaller or linear maltodextrins. On the other hand, the yvdF mutant exhibited limited degradation of the substrates, indicating that, in the wild type, maltodextrins and beta-CD were hydrolyzed by MAase while being taken up by the bacterium. With glycogen and branched beta-CDs as substrates, pullulanase showed high-level specificity for the hydrolysis of the outer side chains of glycogen with three to five glucosyl residues. To investigate the roles of MAase and pullulanase in glycogen utilization, the following glycogen-overproducing strains were constructed: a glg mutant with a wild-type background, yvdF glg and amyX glg mutants, and a glg mutant with a double mutant (DM) background. The amyX glg and glg DM strains accumulated significantly larger amounts of glycogen than the glg mutant, while the yvdF glg strain accumulated an intermediate amount. Glycogen samples from the amyX glg and glg DM strains exhibited average molecular masses two and three times larger, respectively, than that of glycogen from the glg mutant. The results suggested that glycogen breakdown may be a sequential process that involves pullulanase and MAase, whereby pullulanase hydrolyzes the alpha-1,6-glycosidic linkage at the branch point to release a linear maltooligosaccharide that is then hydrolyzed into maltose and maltotriose by MAase.

Dataset Information

Enhancement of pullulanase production from recombinant Bacillus subtilis by optimization of feeding strategy and fermentation conditions.

Publications

Enhancement of pullulanase production from recombinant Bacillus subtilis by optimization of feeding strategy and fermentation conditions.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets