Isolation and molecular characterization of extracellular lipase and pectinase producing bacteria from olive oil mills

Abstract

Lipases and pectinases are industrially important enzymes. These enzymes are produced by a variety of microorganisms. However there are few studies on the production of these enzymes by thermoacidophilic Bacillus species. The aim of this research was the isolation of extracellular lipase and pectinase producing thermoacidophilic Bacillus from olive oil mills and their identification by phenotypic tests, 16S-ITS rDNA RFLP and DNA sequencing. Eighty-six thermoacidophilic strains were isolated from olive, olive husk and soil contaminated with alpechin collected within different olive oil mills in Ayvalık. The strains were screened for the presence of 5 extracellular enzyme activities. These were lipase, pectinase, amylase, xylanase and cellulase. In total, 69 lipase (Tween 20 as subtrate), 32 pectinase and 68 amylase activities were detected. None of the isolates were able to produce xylanase or cellulase enzyme. All of the isolates were Gram(+) endospore forming rods, thus they were identified as Bacillus sp. Taq I was used for 16S-ITS rDNA based RFLP. The isolated strains were clustered into four groups by Taq I restriction profiles of 16S-ITS rDNA. One representative isolate among the members of each of the 16S-RFLP homology groups was chosen and used for 16S rRNA gene partial sequence analysis. Sequencing results were submitted to GenBank. So far the indicated accession numbers were obtained: AY601903 (isolate H 22 of G-3, 679 nucleotides), AY606276 (isolate S1 of G1, 330 nucleotides)