Journal of Microbiology

Research Support, Non-U.S. Gov'ts

NOTE] Biosynthetic Pathway for Poly(3-Hydroxypropionate) in Recombinant Escherichia coli: Qi Wang , Changshui Liu , Mo Xian , Yongguang Zhang , Guang Zhao; J. Microbiol. 2012;50(4):693-697. Published online August 25, 2012; DOI: https://doi.org/10.1007/s12275-012-2234-y

Abstract: Poly(3-hydroxypropionate) (P3HP) is a biodegradable and biocompatible thermoplastic. In this study, we engineered a P3HP biosynthetic pathway in recombinant Escherichia coli. The genes for malonyl-CoA reductase (mcr, from Chloroflexus aurantiacus), propionyl-CoA synthetase (prpE, from E. coli), and polyhydroxyalkanoate synthase (phaC1, from Ralstonia eutropha) were cloned and expressed in E. coli. The E. coli genes accABCD encoding acetyl-CoA carboxylase were used to channel the carbon into the P3HP pathway. Using glucose as a sole carbon source, the cell yield and P3HP content were 1.32 g/L and 0.98% (wt/wt [cell dry weight]), respectively. Although the yield is relatively low, our study shows the feasibility of engineering a P3HP biosynthetic pathway using a structurally unrelated carbon source in bacteria.

NOTE] Development of a High-Throughput Screening Method for Recombinant Escherichia coli with Intracellular Dextransucrase Activity: So-Ra Lee , Ah-Rum Yi , Hong-Gyun Lee , Myoung-Uoon Jang , Jung-Mi Park , Nam Soo Han , Tae-Jip Kim; J. Microbiol. 2011;49(2):320-323. Published online May 3, 2011; DOI: https://doi.org/10.1007/s12275-011-1078-1

Abstract: To efficiently engineer intracellular dextransucrase (DSase) expression in Escherichia coli, a high-throughput screening method was developed based on the polymer-forming activity of the enzyme. Recombinant E. coli containing the Leuconostoc citreum DSase (LcDS) gene was grown on Luria-Bertani agar plates, containing 2% sucrose, at 37°C for 8 h. The plates were then evenly overlaid with 0.6% soft agar, containing 1.2 mg/ml D-cycloserine, and incubated at 30°C to allow gradual cell disruption until a dextran polymer grew through the overlaid layer. A significant correlation between dextran size and enzyme activity was established and applied for screening truncated mutants with LcDS activity.

Search