OPTIMASI KONDISI PURIFIKASI PARSIAL LIPASE Aspergillus niger 65I6 SOLID STATE FERMENTATION (SSF) PADA MEDIUM BUNGKIL JARAK SEBAGAI SUMBER BELAJAR PENGANTAR MIKROBIOLOGI

Extracellular lipase is an enzyme that catalyzes the hydrolysis reaction of triglycerides into free fatty acids and glycerol and synthesis reaction of esters. Lipase can be produced by microbes include bacteria, fungi and yeasts. Lipase by Aspergillus niger 65I6 produced in the medium of Jatropha cake using solid-state fermentation has a different character of the lipase produced by other microorganisms. The aims of this research were to determine the optimum condition partially purified lipase by Aspergillus niger 65I6. The methods of this research were conducted in 2 steps: (1) production of lipase, (2) partial purification using ion exchange chromatography, (3) SDS-PAGE. The results of this research showed that partial purification lipase by Aspergillus niger 65I6 using anion exchange chromatography esterification activity of 45.58 U/ml with specific activity of 421.97 U/mg adsorbed at pH 8 and 0.5 M NaCl elution. Partially purified lipase by Aspergillus niger 65I6 was 86.11% yield and purification factor 12,12 and a molecular mass of Lipase by Aspergillus niger at 19 kDa estimated by SDS-PAGE. Found of this research can be explained for the development study of microbiology concept and practical contribution about procedure research simple design. Students understand about technique and condition of partial purification.  Kata kunci:         Lipase, Aspergillus niger, Solid-State Fermentation, Purifikasi, SDS-PAG

Characterization of Aspergillus Niger 65i6 lipase from solid-state fermentation using Jatropha seed cake medium

Jatropha curcas seed cake contains a high amount of protein, and consequently has very high potentialas a medium for lipase production. The objective of this research was to characterize lipase from Aspergillusniger 6516, which was produced by solid-state fermentation on Jatropha curcas seed cake as the medium. The effects of pH and temperature on enzyme activity were evaluated, along with substrate specifcity and enzyme stability. Fermentation was performed at a water concentration of 63% and temperature of 30 °C for 7 days. The results showed that the optimum pH and temperature for Aspergillus niger 6516 lipase activities were 8.0 and 40 °C, respectively. The lipase had the substrate specifcity to hydrolyze long-chain fatty acids and was stable in polar organic solvents. The lipase had a molecular weight, Km and vmax about 19 kDa, 0.27 µmol/ml, and 52.63 µmol/ml/min, respectively. The results also suggested that the produced lipase from Aspergillus niger 6516 was an alkaline lipase. Based on these results, we conclude that Jatropha seed cake is a suitable medium for lipase production

OPTIMASI KONDISI PURIFIKASI PARSIAL, KARAKTERISASI DAN KINETIKA ESTERIFIKASI LIPASE Aspergillus niger 65I6 DARI SOLID STATE FERMENTATION PADA MEDIUM BUNGKIL JARAK

Extracellular lipase is an enzyme that catalyzes the hydrolysis reaction of triglycerides into free fatty acids and glycerol and synthesis reaction of esters. Lipase can be produced by microbes include bacteria, fungi and yeasts. Lipase by Aspergillus niger 65I6 produced in the medium of Jatropha cake using solid-state fermentation has a different character of the lipase produced by other microorganisms. The aims of this research was to determine the optimum condition partially purified lipase by Aspergillus niger 65I6 for characteristics. The methods of this research were conducted in 3 steps: (1) production of lipase, (2) partial purification using ion exchange chromatography, (3) characterization of lipases, including: pH, incubation time and temperature for optimum enzyme activity of lipase, stability temperature of lipase, organic solvents , molecular weight, lipase kinetics parameters (Km and Vmak). The results of this research showed that partial purification lipase by Aspergillus niger 65I6 using anion exchange chromatography esterification activity of 45.58 U/ml with specific activity of 421.97 U/mg adsorbed at pH 8 and 0.5 M NaCl elution.The enzyme gave the highest lipase activity when methanol used as a substrate. The optimum pH range for activity of lipase was alkaline pH ranges, about pH 8.0. The optimum temperature for activity of lipase was 40°C. The optimum incubation time for activity of lipase was 30 minutes. The enzyme was stable between at temperature range of 30-40°C. Partially purified lipase by Aspergillus niger 65I6 was 86.11% yield and purification factor 12,12. Km value of 0.27 mol/ml and vmax value of 52.63 mol/min/ml and a molecular mass of Lipase by Aspergillus niger at 19 kDa estimated by SDS-PAGE