Molecular, biochemical and kinetic analysis of a novel, thermostable lipase (LipSm) from Stenotrophomonas maltophilia Psi-1, the first member of a new bacterial lipase family (XVIII)

Abstract

BackgroundMicrobial lipases catalyze a broad spectrum of reactions and are enzymes of considerable biotechnological interest. The focus of this study was the isolation of new lipase genes, intending to discover novel lipases whose products bear interesting biochemical and structural features and may have a potential to act as valuable biocatalysts in industrial applications.ResultsA novel lipase gene (lipSm), from a new environmental Stenotrophomonas maltophilia strain, Psi-1, originating from a sludge sample from Psittaleia (Greece), was cloned and sequenced. lipSm was further overexpressed in E. coli BL21(DE3) and the overproduced enzyme LipSm was purified and analyzed in respect to its biochemical and kinetic properties. In silico analysis of LipSm revealed that it is taxonomically related to several uncharacterized lipases from different genera, which constitute a unique clade, markedly different from all other previously described bacterial lipase families. All members of this clade displayed identical, conserved consensus sequence motifs, i.e. the catalytic triad (S, D, H), and an unusual, amongst bacterial lipases, Y-type oxyanion hole. 3D-modeling revealed the presence of a lid domain structure, which allows LipSm to act on small ester substrates without interfacial activation. In addition, the high percentage of alanine residues along with the occurrence of the AXXXA motif nine times in LipSm suggest that it is a thermostable lipase, a feature verified experimentally, since LipSm was still active after heating at 70 °C for 30 min.ConclusionsThe phylogenetic analysis of LipSm suggests the establishment of a new bacterial lipase family (XVIII) with LipSm being its first characterized member. Furthermore, LipSm is alkaliphilic, thermostable and lacks the requirement for interfacial activation, when small substrates are used. These properties make LipSm a potential advantageous biocatalyst in industry and biotechnology.Electronic supplementary materialThe online version of this article (10.1186/s40709-018-0074-6) contains supplementary material, which is available to authorized users.

Correction to: Molecular, biochemical and kinetic analysis of a novel, thermostable lipase (LipSm) from Stenotrophomonas maltophilia Psi‑1, the first member of a new bacterial lipase family (XIX)

“…We have recently (8th February 2018) published our article entitled “Molecular, biochemical and kinetic analysis of a novel, thermostable lipase (LipSm) from Stenotrophomonas maltophilia Psi-1, the first member of a new bacterial lipase family (XVIII)” [ 1 ]. While our manuscript was going through the final stages of publication, an article by Samoylova et al [ 2 ] was published (12th January 2018) in the journal Extremophiles , entitled “Cloning, expression and characterization of the esterase estUT1 from Ureibacillus thermosphaericus which belongs to a new lipase family XVIII”.…”

Peer Review #3 of "A proposed update for the classification and description of bacterial lipolytic enzymes (v0.1)"

“…Jaeger and Eggert (2002) redefined these families by splitting family I.5 into two new families, family I.5 and family I.6, and moving the previous members of family I.6 into family I.7 (Jaeger & Eggert, 2002). In the 20 years since this bacterial lipolytic enzyme classification system was published, more than twice as many 'novel' families have been proposed (Handrick et al, 2001;Ewis, Abdelal & Lu, 2004;Lee et al, 2010Lee et al, , 2006Levisson, van der Oost & Kengen, 2007;Bender et al, 2009;Kim et al, 2009;Hu et al, 2010;Rao et al, 2011;Jeon et al, 2011;Bassegoda, Pastor & Diaz, 2012;Charbonneau & Beauregard, 2013;Zarafeta et al, 2016;Castilla et al, 2017;Parapouli et al, 2018). A recent update to this system expanded the system to include some (11 of 30) of the recently published novel lipases within 19 families and 8 true lipase sub-families, however many lipolytic proteins remain unclassified (Kovacic et al, 2019).…”

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“…Cultivation of lipase positive isolates from waste-treatment sludge, determined by Rhodamine B-olive oil plates, identified Stenotrophomonas maltophila Psi-1 and the identification of LipSm (40.7 kDa) (24). LipSm activity was tested against two pNPbound fatty acids (C4 and C12) with maximum activity against C12.…”