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Production of l-phenylalanine from trans-cinnamic acids by high-level expression of phenylalanine ammonia lyase gene from Rhodosporidium toruloides in Escherichia coli

Paper ID Volume ID Publish Year Pages File Format Full-Text
4325 221 2008 5 PDF Available
Title
Production of l-phenylalanine from trans-cinnamic acids by high-level expression of phenylalanine ammonia lyase gene from Rhodosporidium toruloides in Escherichia coli
Abstract

A combined promoter expression vector pBV–PAL for high-level expression of phenylalanine ammonia lyase gene of Rhodosporidium toruloides was constructed. Pal gene was cloned and inserted into the region between SalI and PstI restriction sites of expression vector pBV220 (containing PLPR promoter) to obtain recombinant expression vector pBV220–PAL. The tac promoter obtained from the plasmid pKtac was inserted into the expression vector pBV220–PAL to construct expression vector pBV–PAL. The recombinant plasmid pBV220–PAL and pBV–PAL were introduced into Escherichia coli JM109 by transformation. The result showed that the transformant E. coli JM109 (pBV–PAL) gave a much higher PAL activity than that transformant E. coli JM109 (pBV220–PAL). Recombinant PAL expression level of the transformant JM109 (pBV–PAL) was about 9.6% of total cellular protein, specific enzyme activity was 2.3-fold higher than that of the transformant JM109 (pBV220–PAL), reached 35 U/g (dry cells weight, DCW). PAL specific activity of 123 U/g (DCW) could be achieved in a 5-l fermentor. 80.5% conversion rate of trans-cinnamic acid to l-phenylalanine and 5.12 g/l l-phenylalanine were obtained after 3 h bioconversion using the transformant JM109 (pBV–PAL). The recombinant strain JM109 containing the combined promoter expression vector pBV–PAL was shown to be effective and practical to product l-phenylalanine.

Keywords
Phenylalanine ammonia-lyase; Recombinant DNA; Combine promoter; Enzyme activity; Fermentation; Bioconversion
First Page Preview
Production of l-phenylalanine from trans-cinnamic acids by high-level expression of phenylalanine ammonia lyase gene from Rhodosporidium toruloides in Escherichia coli
Publisher
Database: Elsevier - ScienceDirect
Journal: Biochemical Engineering Journal - Volume 42, Issue 3, 1 December 2008, Pages 193–197
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering