Details

Autor(en) / Beteiligte

• Wang, Yongze
• Li, Kunpeng
• Huang, Feng
• Wang, Jinhua
• Zhao, Jinfang
• Zhao, Xiao
• Garza, Erin
• Manow, Ryan
• Grayburn, Scott
• Zhou, Shengde

Titel

Engineering and adaptive evolution of Escherichia coli W for l-lactic acid fermentation from molasses and corn steep liquor without additional nutrients

Ist Teil von

• Bioresource technology, 2013-11, Vol.148, p.394-400

Ort / Verlag

Kidlington: Elsevier Ltd

Erscheinungsjahr

2013

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• •An Escherichia coli W derivative, WYZ-L, was engineered for production of l(+)-lactic acid.•WYZ-L produced 97gL−1l(+)-lactic acid from 100gL−1 sucrose with an optical purity of 99%.•WYZ-L effectively fermented the combined wastes of molasses and corn steep liquor into l(+)-lactic acid without other nutrients. The d-lactic acid producing strain, Escherichia coli HBUT-D, was reengineered for l(+)-lactic acid fermentation by replacing the d-lactate dehydrogenase gene (ldhA) with an l(+)-lactate dehydrogenase gene (ldhL) from Pedicoccus acidilactici, followed by adaptive evolution in sucrose. The resulting strain, WYZ-L, has enhanced expression of the sucrose operon (cscA and cscKB). In 100gL−1 of sucrose fermentation using mineral salt medium, WYZ-L produced 97gL−1 of l(+)-lactic acid, with a yield of 90%, a maximum productivity of 3.17gL−1h−1 and an optical purity of greater than 99%. In fermentations using sugarcane molasses and corn steep liquor without additional nutrients, WYZ-L produced 75gL−1 of l(+)-lactic acid, with a yield of 85%, a maximum productivity of 1.18gL−1h−1, and greater than 99% optical purity. These results demonstrated that WYZ-L has the potential to use waste molasses and corn steep liquor as a resource for l(+)-lactic acid fermentation.