engleski

GDS(L) lipases from streptomycetes

Streptomycetes represent a group of industrially important microorganisms since they produce numerous bioactive compounds and enzymes. However, only a few streptomycete lipases have been analyzed so far. Among them, lipase from Streptomyces rimosus (SrL), represented the firs example of the true bacterial GDSL lipase. This enzyme family, owing to their multifunctional properties, such as broad substrate specificity, high working temperature, stability and activity in organic solvents etc, has great potential for use in biotechnology. For comparison purpose, we have cloned two GDS(L) lipases from Streptomyces coelicolor. They were found in the genome of Streptomyces coelicolor based on the similarity to S. rimosus lipase: sc1 (SCO1725 ; 66% similarity) and sc2 (SCO7513 ; 33% similarity). Each gene was PCR amplified with corresponding RBS, convenient restriction sites and with or without His tag codons at 3’ terminus. Amplified DNA fragments were ligated into E. coli vector (pET-15b or pGEM-T), resequenced, and subsequently ligated into the Streptomyces expression plasmid pANT849. Heterologous, lipase deficient host Streptomyces lividans was used for production of enzymes in the liquid medium. Up to now, His-tagged sc1 protein was successfully purified and extensively biochemically characterized. Cloning of other three enzymes (sc1, sc2, His-tagged sc2) is underway. We will present here biochemical data of His-tagged sc1. The enzyme shows preference for substrates with longer acyl-chain lengths (C14), also hydrolyzes a wide variety of substrates: p-nitrophenyl alkanoates, α - and ß-naphthyl alkanoates, oils, triacylglycerols, and Tween detergents. Further, it was stable over a wide range of pH, and active up to 60°C. Moreover, similarly to S. rimosus lipase, the enzyme showed stability in four tested organic solvents while tree solvents increased its activity, dioxane up to four times. These properties shows high biotechnological potential of this lipase.

GDS(L) lipases; streptomycetes

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