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Pseudomonas putida Δ9‐fatty acid desaturase: Gene cloning, expression, and function in the cationic surfactants stress
Author(s) -
Heredia Romina M.,
Lucchesi Gloria I.
Publication year - 2019
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201800595
Subject(s) - pseudomonas putida , biochemistry , palmitoleic acid , fatty acid , escherichia coli , palmitic acid , chemistry , membrane fluidity , biology , gene expression , gene , membrane
Pseudomonas putida counteract the fluidizing effect of cationic surfactants decreasing the content of membrane unsaturated fatty acid (UFA). A Δ9‐fatty acid desaturase gene ( desA) from P. putida was isolated, cloned, and successfully expressed in Escherichia coli , a Δ9 desaturase deficient organism. desA consists of 1185 bp and codes for 394 amino acids. The deduced amino acid sequence reveals three histidine clusters and a hydropathy profile, typical of membrane‐bound desaturases. Validating desA expression in E. coli cells, the amount of palmitoleic acid increased from 2.05 to 7.36%, with the concomitant increase in membrane fluidity (fluorescence polarization value decrease from 0.13 ± 0.03 to 0.09 ± 0.02). Also, when DesA activity was assayed in vivo , the percentage of UFA obtained from exogenous palmitic acid [1‐ 14 C] increased 10‐fold. In contrast, when cells expressing desA were exposed 15 min at sublethal concentration of cationic surfactants, the amount of UFA was 82% lower than that detected in cells non‐exposed. Thus, the decrease in UFA content to counteract the fluidizing effect of cationic surfactants can be correlated with reduction of DesA activity.