Joseph Ancy, Aikawa Shimpei, Sasaki Kengo, Tsuge Yota, Matsuda Fumio, Tanaka Tsutomu, Kondo Akihiko
Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan.
Biosci Biotechnol Biochem. 2013;77(5):966-70. doi: 10.1271/bbb.120921. Epub 2013 May 7.
Metabolic pathway engineering of cyanobacteria for the production of industrially important chemicals from atmospheric CO2 has generated interest recently. Here, we engineered Synechocystis sp. PCC 6803 to produce lactic acid using a lactate dehydrogenase (ldh) gene from various lactic acid-producing bacteria, Lactococcus lactis (ldhB and ldhX), Lactobacillus plantarum (ldhL and ldh), and Lactobacillus rhamnosus (ldhL). The lactic acid was secreted outside the cell using a transporter (lldp) gene from L. plantarum. Expression of each ldh in Synechocystis sp. PCC6803 was ascertained by reverse-transcriptase polymerase chain reaction. Five transformants led to the production of L-lactic acid. Co-expression of lldp with ldhB from L. plantarum or ldhL from L. rhamnosus led to the secretion of lactic acid into the medium at concentration of 0.17 ± 0.02 or 0.14 ± 0.02 mM after 18 d of cultivation.
利用蓝细菌的代谢途径工程从大气二氧化碳中生产具有工业重要性的化学品最近引起了人们的关注。在此，我们对聚球藻属PCC 6803进行工程改造，以利用来自各种产乳酸细菌的乳酸脱氢酶（ldh）基因生产乳酸，这些细菌包括乳酸乳球菌（ldhB和ldhX）、植物乳杆菌（ldhL和ldh）以及鼠李糖乳杆菌（ldhL）。利用来自植物乳杆菌的转运蛋白（lldp）基因将乳酸分泌到细胞外。通过逆转录聚合酶链反应确定了聚球藻属PCC6803中每个ldh的表达。五个转化体导致了L-乳酸的产生。在培养18天后，将lldp与来自植物乳杆菌的ldhB或来自鼠李糖乳杆菌的ldhL共表达，导致乳酸以0.17±0.02或0.14±0.02 mM的浓度分泌到培养基中。
