PEMURNIAN PARSIAL DAN KRISTALISASI PAPAIN DARI GETAH Carica papaya

This research has done partial purification by fractionation and optimization crystallization of papain from Carica papaya latex with the addition of ammonium sulphate. The enhancement of purification factor was determined by its specific activity. The fractionation results show that papain fraction of Carica papaya can be obtained by adding 40-80% saturated ammonium sulphate, with the highest specific activity, i.e. 2,0819 U/µg and the factor purification increase of 6,27 fold than papain extract. Meanwhile, the highest total activity, i.e. 10,7780 U of papain crystals can be obtained by presipitant agent addition of ammonium sulphate in the level / concentration 80% saturated at 15 °C. Microscopycally papain crystals profile in this condition have cube and tetragonal shape.Key words: crystallization, fractionation, ammonium sulphate, papain

CHARACTERIZATION OF CELLULASE PREPARATION OF BACILLUS SP.G4 ISOLATED FROM THE TERMITES GUT

The Bacillus sp. strain G4 isolated from termites gut can produce cellulase with high activity in rice bran medium after 72 h of incubation at 37 °C. The crude enzymewas collected by centrifugation at 6,000 rpmfor 15 minutes. The precipitation of cellulasewith ammonium sulfate 60 – 90 % saturation and acetone at the concentration 60 % – 90 % was studied. Results showed that ammonium sulfate 90 % saturation gave cellulase with highest purification factor 8.87 but the yield was only 59.9 %, whereas acetone at 90 % concentration gave highest yield 83.57 % with purification factor 4.38. CMCase activity of cellulasepreparation obtained by acetone precipitation at 90 % was optimum at pH 7 and 60 °C. Furthermore, CMCase was stable at pH 6.0 - 7.0 and at temperature lower than 50 °C. The CMCase was activated by ion Ca2+ but inhibited by Co2+, Zn2+, Cu2+, Fe2+, and was not affected by Mg2+ and Ba2+. The CMCase was inhibited by high concentration of SDS while EDTA and Tween 80 played activated role.

Synthesis of Fatty Acid Methyl Esters from Jatropha curcas Oil and Its Purification Using Solvent Fractionation

Fatty acid methyl esters (FAME) are produced by transesterification. The problem in the product of transesterification is the presence of impurities such as mono-, di-, triglycerides, and free fatty acids. So that, the purification using solvent fractionation is needed to separate them from FAME. The objective of this research were to determine the effects of crude fatty acid methyl esters-to-acetone (CFAME/acetone) ratio on yield, purity, purification factor, and recovery of FAME after fractionation and to evaluate the impurities which were separated in each step of fractionation. FAME were produced from Jatropha curcas oil using Berchmans’s and Tiwari’s methods. The impurities were separated by solvent fractionation using acetone. CFAME/acetone ratios were 1, 2, 3, 4, and 5. Fractionation was done stepwise namely 21°C, 16°C, 12°C, and 5°C. The results showed that the conversion of FAME using Tiwari’s method was 1.7-fold higher than Berchmans’s method. Purification of FAME using solvent fractionation resulted that the best CFAME/acetone ratio was 1. Yield decreased 1.6-fold at CFAME/acetone ratio 4. Purity decreased 8.74% with an increase in CFAME/acetone ratio 1 to 5. Purification factor decreased 2-fold at CFAME/acetone 1 to 3. Recovery decreased 1.3-fold at CFAME/acetone ratio 1 to 4. The impurities which were separated from FAME were mono-, di-, triglycerides, and free fatty acids and the major component of impurities was triglycerides (>59%). The results indicated that solvent fractionation could be used as an alternative method for purifying FAME and further study to optimize this method was needed.

Neural modeling of bromelain extraction by reversed micelles

A pulsed-cap microcolumn was used for bromelain extraction from pineapple juice by reversed micelles. The cationic micellar solution used BDBAC as the surfactant, isooctane as the solvent and hexanol as the co-solvent. In order to capture the dynamic behavior and the nonlinearities of the column, the operating conditions were modified in accordance with the central composite design for the experiment, using the ratio between the light phase flow rate and the total flow rate, and the time interval between pulses. The effects on the purification factor and on total protein yield were modeled via neural networks. The best topology was defined as 16-9-2, and the input layer was a moving window of the independent variables. The neural model successfully predicted both the purification factor and the total protein yield from historical data. At the optimal operating point, a purification factor of 4.96 and a productivity of 1.29 mL/min were obtained.

Batch and continuous extraction of bromelain enzyme by reversed micelles

The main aim of this study was to optimize the conditions for bromelain extraction by reversed micelles from pineapple juice (Ananas comosus). The purification was carried out in batch extraction and a micro-column with pulsed caps for continuous extraction. The cationic micellar solution was made of BDBAC as a surfactant, isooctane as a solvent and hexanol as a co-solvent. For the batch process, a purification factor of 3 times at the best values of surfactant agent, co-solvent and salt concentrations, pH of the back and forward extractions were, 100 mM, 10% v/v, 1 M, 3.5 and 8, respectively. For the continuous operation, independent variables optimal point was determined: ratio between light phase flow rate and total flow rate equal to 0.67 and 1 second for the time interval between the pulses. This optimal point led to a productivity of 1.29 mL/min and a purification factor of 4.96.

The influence of molecular weight of polyethylene glycol on separation and purification of pectinases from Penicillium cyclopium in aqueous two-phase system

In this study the possibility of the partitioning and purification of pectinases from Penicillium cyclopium by their partitioning in polymer/polymer and polymer/salt aqueous two-phase systems was investigated. In the system with 10% (w/w) polyethylene glycol 1500/5% (w/w) dextran 500 000/85% (w/w) crude enzyme, the highest values for partitioning parameters were achieved - the partition coefficient was 2.11, followed by the top phase yield of 85.68% and purification factor 1.28 for the endo-pectinase activity. The partition coefficient, yield in the top phase and purification factor for the exo-pectinase activity in the same system were 1.89, 84.28% and 3.82, respectively. In the system with 10% (w/w) polyethylene glycol 6000/15% (w/w) (NH4)2SO4/75% (w/w) crude enzyme purification factor 37.85 for exo-pectinase, and 19.52 for endo-pectinase in the bottom phase were obtained.

α-Foetoprotein: Purification on Sepharose-linked Concanavalin-A

Using serum obtained from human cord blood α-foetoprotein was purified by batch fractionation on DEAE-Sephadex A-50 followed by a single passage through a Sepharose-linked Concanavalin-A column. A 360-fold purification factor was obtained by this two step procedure.