A new alkaliphilic cold-active esterase from the psychrophilic marine bacterium Rhodococcus sp.: functional and structural studies and biotechnological potential.
The special features of cold-adapted lipolytic biocatalysts have made their use possible in several industrial applications. In fact, cold-active enzymes are known to be able to catalyze reactions at low temperatures, avoiding side reactions taking place at higher temperatures and preserving the integrity of products. A lipolytic gene was isolated from the Arctic marine bacterium Rhodococcus sp. AW25M09 and expressed in Escherichia coli as inclusion bodies. The recombinant enzyme (hereafter called RhLip) showed interesting cold-active esterase activity. The refolded purified enzyme displayed optimal activity at 30 °C and was cold-active with retention of 50% activity at 10 °C. It is worth noting that the optimal pH was 11, and the low relative activity below pH 10 revealed that RhLip was an alkaliphilic esterase. The enzyme was active toward short-chain p-nitrophenyl esters (C2-C6), displaying optimal activity with the butyrate (C4) ester. In addition, the enzyme revealed a good organic solvent and salt tolerance. These features make this an interesting enzyme for exploitation in some industrial applications.
Institute of Protein Biochemistry, National Research Council, Via P. Castellino, 111, 80131, Naples, Italy.
Concetta
C
De Santi
Pietro
P
Tedesco
Luca
L
Ambrosino
Bjørn
B
Altermark
Nils-Peder
NP
Willassen
Donatella
D
de Pascale
D000595:Amino Acid Sequence; D059001:Aquatic Organisms; D001110:Arctic Regions; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003080:Cold Temperature; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D002479:Inclusion Bodies / Q000737:chemistry; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D058849:Protein Refolding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012240:Rhodococcus / Q000737:chemistry* / Q000201:enzymology; D055049:Salt Tolerance; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D008049:Lipase