fulltext.study @t Gmail

Constitutive expression of a novel isoamylase from Bacillus lentus in Pichia pastoris for starch processing

Paper ID Volume ID Publish Year Pages File Format Full-Text
34623 45037 2013 8 PDF Available
Title
Constitutive expression of a novel isoamylase from Bacillus lentus in Pichia pastoris for starch processing
Abstract

•A novel isoamylase gene was cloned.•The gene was constitutively expressed at high level.•The enzyme was purified and characterized.

Isoamylase is essential to saccharifying starch by cleavage of 1,6-glucoside linkages in starch molecules. In this study, a novel isoamylase gene from Bacillus lentus JNU3 was cloned. The open reading frame of the gene was 2412 base pairs long and encoded a polypeptide of 804 amino acids with a calculated molecular mass of 90 kDa. The deduced amino acid sequence shared less than 40% homology with that of microbial isoamylase ever reported, which indicated it was a novel isoamylase. A constitutive GAP promoter was used to express the recombinant isoamylase in the yeast Pichia pastoris by continuous high cell-density fermentation to avoid the use of methanol, which resulted in 318 U/mL extracellular isoamylase activity after 72 h in a 10 L fermenter. The recombinant enzyme was purified and characterized. It had an estimated molecular mass of 90 kDa, with its optimal activity at 70 °C, pH 6.5 and was quite stable between 30 °C and 70 °C. The recombinant isoamylase proves to be superior to pullulanase as an auxiliary enzyme in maltose production from starch. Therefore it will contribute significantly to the starch debranching process.

Keywords
Isoamylase; Bacillus lentus; Pichia pastoris; GAP promoter; Starch processing
First Page Preview
Constitutive expression of a novel isoamylase from Bacillus lentus in Pichia pastoris for starch processing
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Process Biochemistry - Volume 48, Issue 9, September 2013, Pages 1303–1310
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us