SE179:/MS03

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Sample Set Information

ID	TSE1337
Title	Genetic manipulation of a metabolic enzyme and a transcriptional regulator increasing succinate excretion from unicellular cyanobacterium.
Description	Succinate is a building block compound that the U.S. Department of Energy (DOE) has declared as important in biorefineries, and it is widely used as a commodity chemical. Here, we identified the two genes increasing succinate production of the unicellular cyanobacterium Synechocystis sp. PCC 6803. Succinate was excreted under dark, anaerobic conditions, and its production level increased by knocking out ackA, which encodes an acetate kinase, and by overexpressing sigE, which encodes an RNA polymerase sigma factor. Glycogen catabolism and organic acid biosynthesis were enhanced in the mutant lacking ackA and overexpressing sigE, leading to an increase in succinate production reaching five times of the wild-type levels. Our genetic and metabolomic analyses thus demonstrated the effect of genetic manipulation of a metabolic enzyme and a transcriptional regulator on succinate excretion from this cyanobacterium with the data based on metabolomic technique.
Authors	Osanai, T., Shirai, T., Iijima, H., Nakaya, Y., Okamoto, M., Kondo, A. and Hirai, M.Y.
Reference	Front Microbiol. 2015 Oct 6;6:1064. doi: 10.3389/fmicb.2015.01064.
Comment

ID	MS03
Title	Measurement of organic acids by high-performance liquid chromatography (HPLC)
Instrument	LC-2000Plus Systems (JASCO, Tokyo, Japan)
Instrument Type
Ionization
Ion Mode
Description	Freeze-dried supernatants were resolved in 100 μL of filtered 3 mM perchloric acid. The resolved samples were analyzed by HPLC using a LC-2000Plus Systems (JASCO, Tokyo, Japan) with a photodiode array detector and two RSpak KC-811 columns (Showa Denko, Tokyo, Japan). Organic acids were quantified with 0.2 mM bromothymol blue in 15 mM sodium phosphate buffer; peaks were detected at 445 nm. The column temperature was 60°C, and the flow rates of 3 mM perchloric acid and 0.2 mM bromothymol blue solutions were 1.0 and 1.5 mL/min, respectively.
Comment_of_details