Coexistence of two d-lactate-utilizing systems in Pseudomonas putida KT2440.
It is advantageous for rhizosphere-dwelling microorganisms to utilize organic acids such as lactate. Pseudomonas putida KT2440 is one of the most widely studied rhizosphere-dwelling model organisms. The P. putida KT2440 genome contains an NAD-dependent d-lactate dehydrogenase encoding gene, but mutation of this gene does not play a role in d-lactate utilization. Instead, it was found that d-lactate utilization in P. putida KT2440 proceeds via a multidomain NAD-independent d-lactate dehydrogenase with a C-terminal domain containing several Fe-S cluster-binding motifs (Fe-S d-iLDH) and glycolate oxidase, which is widely distributed in various microorganisms. Both Fe-S d-iLDH and glycolate oxidase were identified to be membrane-bound proteins. Neither Fe-S d-iLDH nor glycolate oxidase is constitutively expressed but both of them can be induced by either enantiomer of lactate in P. putida KT2440. This study shows a case in which an environmental microbe contains two types of enzymes specific for d-lactate utilization.
State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.
Yingxin
Y
Zhang
State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.|School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, People's Republic of China.
Tianyi
T
Jiang
State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.
Binbin
B
Sheng
State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.
Yangdanyu
Y
Long
State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.
Chao
C
Gao
State Key Laboratory of Microbial Technology and School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.
Cuiqing
C
Ma
State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
Ping
P
Xu