Biosynthesis of rare ketoses through constructing a recombination pathway in an engineered Corynebacterium glutamicum. Issue 1 (10th September 2014)

• Record Type: Journal Article
• Authors: Yang, Jiangang; Zhu, Yueming; Li, Jitao; Men, Yan; Sun, Yuanxia; Ma, Yanhe
• Is Part Of: Biotechnology and bioengineering. Volume 112:Issue 1(2015:Jan.)
• Page Start: 168
• Page End: 180
• Publication Date: 2014-09-10
• Subjects: Biotechnology -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/bit.25345
• Languages: English
• ISSNs: 0006-3592

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>ABSTRACT</title> <sec id="bit25345-sec-0001" sec-type="section"> <p>Rare sugars have various known biological functions and potential for applications in pharmaceutical, cosmetics, and food industries. Here we designed and constructed a recombination pathway in <italic>Corynebacterium glutamicum</italic>, in which dihydroxyacetone phosphate (DHAP), an intermediate of the glycolytic pathway, and a variety of aldehydes were condensed to synthesize rare ketoses sequentially by rhamnulose‐1‐phosphate aldolase (RhaD) and fructose‐1‐phosphatase (YqaB) obtained from <italic>Escherichia coli</italic>. A wild‐type strain harboring this artificial pathway had the ability to produce <sc>D</sc>‐sorbose and <sc>D</sc>‐psicose using <sc>D</sc>‐glyceraldehyde and glucose as the substrates. The <italic>tpi</italic> gene, encoding triose phosphate isomerase was further deleted, and the concentration of DHAP increased to nearly 20‐fold relative to that of the wild‐type. After additional optimization of expression levels from <italic>rhaD</italic> and <italic>yqaB</italic> genes and of the fermentation conditions, the engineered strain SY6(pVRTY) exhibited preferable performance for rare ketoses production. Its yield increased to 0.59 mol/mol <sc>D</sc>‐glyceraldehyde from 0.33 mol/mol <sc>D</sc>‐glyceraldehyde and productivity to 2.35 g/L h from 0.58 g/L h. Moreover, this strain accumulated 19.5 g/L of <sc>D</sc>‐sorbose and 13.4 g/L of <sc>D</sc>‐psicose using a fed‐batch culture mode under the optimal conditions. In addition, it was verified that the strain SY6(pVRTY) meanwhile had the ability to synthesize C4, C5, C6, and C7 rare ketoses when a range of representative achiral and homochiral aldehydes were applied as the substrates. Therefore, the platform strain exhibited the potential for microbial production of rare ketoses and deoxysugars. Biotechnol. Bioeng. 2015;112: 168–180. © 2014 Wiley Periodicals, Inc.</p> </sec> </abstract>