title: Screening of microbial lipases and evalutaion of their potential to produce glycerides with high gamma linolenic acid concentration.
abstract: Gamma linolenic acid (GLA, 18:3, cis- 6,9,12- octadecatrienoic acid), an important compound in n- 6 eicosanoid family biosynthesis, occurs in the lipids of a few plant and microbial sources. This study focused on the screening of microbial strains with suitable lipase activity for enrichment of GLA by selective hydrolysis of the borage oil (21.6 % of GLA/total fatty acids). Firstly, 352 microrganisms were tested for their lipolytic capacity using screening techniques on agar plates containing borage oil, strains were then selected and screened for their activity (U/mg) using both submerged fermentation (SmF) and solid state fermentation (SSF). The rate of hydrolysis and the selective preference of these hydrolytic enzymes towards fatty acids, with a special focus on enrichment of GLA were studied and compared with those obtained by two commercially-available lipases. Only one of the lipases tested during this study displayed selectivity, discriminating the GLA during the hydrolysis reaction. Using the enzymatic extract from Geotrichum candidum as a biocatalyst of the reaction, it was possible to obtain a percentage of 41.7% of GLA in acylglycerols fraction when the borage oil was treated in a fixed-bed reactor for 24 hours at 30ºC.
authors.affiliation: Universidade Estadual de Campinas, Faculdade de Engenharia Química, Departamento de Processos Químicos , Campinas, SP , Brasil.
authors.forename: Patricia B L
authors.initials: PB
authors.lastname: Fregolente
authors.forename: Leonardo V
authors.initials: LV
authors.lastname: Fregolente
authors.forename: Maria R W
authors.initials: MR
authors.lastname: Maciel
authors.forename: Patricia O
authors.initials: PO
authors.lastname: Carvalho
keywords: Geotrichum candidum; borage oil; gamma linolenic acid; lipase
references.citation: J Am Board Fam Med. 2006 May-Jun;19(3):310-6
references.pmid: 16672684
references.citation: Prostaglandins Leukot Essent Fatty Acids. 1999 Jan;60(1):21-9
references.pmid: 10319914
references.citation: J Food Sci. 2008 Apr;73(3):C146-50
references.pmid: 18387091
references.citation: Biosci Biotechnol Biochem. 1992 Jan;56(4):660-4
references.pmid: 27280667
references.citation: Am J Cardiol. 2004 Apr 15;93(8):1041-3
references.pmid: 15081453
references.citation: Eur J Biochem. 1991 Dec 5;202(2):485-91
references.pmid: 1761048
references.citation: Lipids. 1983 Sep;18(9):650-7
references.pmid: 6633171
references.citation: Biosci Biotechnol Biochem. 1995 Sep;59(9):1771-2
references.pmid: 8520121
references.citation: Control Clin Trials. 1996 Feb;17(1):60-8
references.pmid: 8721802
references.citation: Protein Eng. 1994 Apr;7(4):585-8
references.pmid: 8029216
references.citation: J Dermatolog Treat. 2006;17(2):82-5
references.pmid: 16766331