%0 Journal Article
%T Sucrose Secreted by the Engineered Cyanobacterium and Its Fermentability Sucrose Secreted by the Engineered Cyanobacterium and Its Fermentability
%A DUAN Yangkai
%A LUO Quan
%A LIANG Feiyan
%A LU Xuefeng
%J 中国海洋大学学报（英文版）
%D 2016
%X The unicellular cyanobacterium, Synechococcus elongatus PCC 7942(Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps(encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and csc B(encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing csc B only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation
%U http://qdhb.cbpt.cnki.net/WKD/WebPublication/paperDigest.aspx?paperID=2b7809fa-1313-45c9-b9d6-e42f7682d67f