Naslov
STREPTOMICETI KAO PROIZVOĐAČI LIPOLITIČKIH ENZIMA
(STREPTOMYCETES AS PRODUCERS OF LIPOLYTIC ENZYMES)

Autori
Vujaklija, Dusica ; Leščić, Ivana ; Abramic, Marija ; Kojić-Prodić, Biserka ; Pigac, Jasenka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
1st Central European Forum for Microbiology (CEFORM)

Mjesto i datum
Keszthely, Mađarska, 26.10.2005. - 28.10.2005

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
.

Sažetak
Microbial lipases are widely diversified in their enzymatic properties and substrate specificities. According to the previously published results it seemed that members of this genus are not typical lipase producers compared to other bacteria. There are five cloned and sequenced lipase genes from streptomycetes described so far: from S. exfoliatus, S. albus and S. coelicolor exhibiting more than 80 % sequence identity in spite of their taxonomic divergence, and lipases that show no similarity to those, from S. cinnamomeus and S. rimosus. Based on the bacterial lipolytic enzyme classification, S. cinnamomeus lipase belongs to family I while S. exfoliatus, S. albus and S. coelicolor A3(2) lipases are members of family III. Our results show that the novel lipase from S. rimosus belongs to GDS(L) or family II of the lipolytic enzymes as well as the S. coelicolor putative hydrolases that were found by data base search, thus representing a third lipase family previously unrecognized in Streptomyces. Out of eight examined streptomycetes, the presence of this rare type of bacterial lipase gene was detected in two belonging to the S. rimosus taxonomic cluster, and in one unrelated species. To our knowledge, there is only characterized from Photorabdus luminescens that belongs to the same family of lipolytic enzymes. S. rimosus lipase gene has been located on the AseI B fragment approximately 2 Mb far from the left end of the S. rimosus linear chromosome, similar to the position of the putative S. coelicolor lipase gene indicating non-essential functions of these genes. Biochemical properties of this rare type of bacterial lipase might have significant biotechnological potential due to its relatively high working temperature, pronounced stability as well as an unchanged activity over a broad pH range. Comparison of the peptide mass fingerprints from the reduced and non-reduced overexpressed enzyme unequivocally revealed three intramolecular disufide bonds. A chemical modification approach combined with MALDI mass spectrometry identified the serine at the position 10 in the Gly-Asp-Ser-(Leu)-like consensus motif as the nucleophilic amino acid residue. Thus, this experimental evidence supports clasiffication of these novel bacterial enzymes. References D. Vujaklija, W. Schroeder, M. Abramic, P. Zou, I. Lescic, P. Franke, J. Pigac, 2002. Arch. Microbiol. 178 : 124-130. M. Zehl, I. Lescic, M. Abramic, A. Rizzi, B. Kojic-Prodic, and G. Allmaier, 2004. J. Mass Spectrom. 39: 1474-1483.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija

POVEZANOST RADA