Production of lipase from Aspergillus niger USM E15 using palm kernel cake as substrate and the enzyme application in terpene ester synthesis
Loading...
Date
2009
Authors
Kumar, Subbalaxmi Pandian
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The objective of the study is to produce lipase from an indigenous isolate on solid state fermentation for terpene ester synthesis. From the total 100 isolates screened, isolate USM E15 which was identified as Aspergillus niger was selected as a potential producer of lipase. Optimizations of physical and chemical parameters were carried out in Erlenmeyer flask and tray system to enhance the maximum growth and lipase production. The optimum conditions for 250 ml flask system were 10 g of 0.5 mm palm kernel cake, 70% of (v/w) moisture content, (0.5%) w/w of olive oil, (0.5%) w/w of molasses, (0.5%) w/w of peptone, 1 ml inoculum with spore size 1x106 spore/ml, was cultivated for 72 hr at room temperature (28 ± 3)oC. The maximum lipase activity achieved was 44.5 ± 1.95 U/g substrate with the growth of 1.66 ± 0.09 mg glucosamine/g substrate. The cultivation of Aspergillus niger USM E15 was also carried out in tray system of size 297 mm x 200 mm x 60 mm containing 100 g of substrate (Palm kernel cake), 70% of moisture content, 0.5% (w/w) of olive oil, 1% (w/w) of molasses, 0.5% (w/w) of peptone and inoculum with spore size 1x107 spores/ml cultivated at room temperature (28 ± 3)oC for 72 hr. The maximum lipase activity obtained was 39.75 ± 0.27 U/g substrate and growth of 1.32 ± 0.01 mg glucosamine/g substrate. Characterization of the enzyme shows that the optimum pH was 5.5. The lipase from Aspergillus niger USM E15 is stable at pH range from pH 4.5 to 8.0 respectively. The optimum temperature was 37oC. The lipase was stable at temperature up to 40oC. The presence of metal ions does not show any effect. At the final concentration of 1 mM EDTA, the lipase was inhibited by 16%. The lipase also exhibited specificity towards the C-18:1 fatty acids and triolein was the best substrate. Surfactants such as Tween 20, Tween 40, Tween 60 and Triton X-100 also inhibited the lipase activity. The lipase is a 1, 3 positional specific.
The SSF material was used for the synthesis of terpene esters. The optimum conditions for geranyl butyrate synthesis were geraniol (500 mM) butyric acid (250 mM) at the ratio of 1:0.5, SSF material 0.75 g, molecular sieve pellets 0.75 g in 10 ml n-hexane as solvent. The maximum degree of esterification after optimization obtained was 91.5 ± 1.5%.The objective of the study is to produce lipase from an indigenous isolate on solid state fermentation for terpene ester synthesis. From the total 100 isolates screened, isolate USM E15 which was identified as Aspergillus niger was selected as a potential producer of lipase. Optimizations of physical and chemical parameters were carried out in Erlenmeyer flask and tray system to enhance the maximum growth and lipase production. The optimum conditions for 250 ml flask system were 10 g of 0.5 mm palm kernel cake, 70% of (v/w) moisture content, (0.5%) w/w of olive oil, (0.5%) w/w of molasses, (0.5%) w/w of peptone, 1 ml inoculum with spore size 1x106 spore/ml, was cultivated for 72 hr at room temperature (28 ± 3)oC. The maximum lipase activity achieved was 44.5 ± 1.95 U/g substrate with the growth of 1.66 ± 0.09 mg glucosamine/g substrate. The cultivation of Aspergillus niger USM E15 was also carried out in tray system of size 297 mm x 200 mm x 60 mm containing 100 g of substrate (Palm kernel cake), 70% of moisture content, 0.5% (w/w) of olive oil, 1% (w/w) of molasses, 0.5% (w/w) of peptone and inoculum with spore size 1x107 spores/ml cultivated at room temperature (28 ± 3)oC for 72 hr. The maximum lipase activity obtained was 39.75 ± 0.27 U/g substrate and growth of 1.32 ± 0.01 mg glucosamine/g substrate. Characterization of the enzyme shows that the optimum pH was 5.5. The lipase from Aspergillus niger USM E15 is stable at pH range from pH 4.5 to 8.0 respectively. The optimum temperature was 37oC. The lipase was stable at temperature up to 40oC. The presence of metal ions does not show any effect. At the final concentration of 1 mM EDTA, the lipase was inhibited by 16%. The
xx
lipase also exhibited specificity towards the C-18:1 fatty acids and triolein was the best substrate. Surfactants such as Tween 20, Tween 40, Tween 60 and Triton X-100 also inhibited the lipase activity. The lipase is a 1, 3 positional specific.
The SSF material was used for the synthesis of terpene esters. The optimum conditions for geranyl butyrate synthesis were geraniol (500 mM) butyric acid (250 mM) at the ratio of 1:0.5, SSF material 0.75 g, molecular sieve pellets 0.75 g in 10 ml n-hexane as solvent. The maximum degree of esterification after optimization obtained was 91.5 ± 1.5%.
Description
Master
Keywords
Biological Science , Palm kernel cake , Lipase , Terpene ester synthesis