Lipase Biocatalyst Immobilization from Solid State Fermentation of Palm Oil Empty Fruit Bunches, Bagasse, and Palm Oil Sludge with Adsorption-Cross Linking Method in Anion Macroporous Resin

Enzymes are used to make a production of biomass based process more efficient and more selective. Lipase is a biocatalyst in the breakdown of fat reaction that is widely used in the industry, including the industry in Indonesia. Lipase production can be carried out by bacterial solid state fermentation by using agro-industry waste substrate containing carbon and nitrogen. The developments of various industrial sectors are demanding the use and application of lipase commercially in industrial processes as biocatalysts chosen by its ability to work in a friendly environment and have high specificity. Fermentation of Aspergillus niger are able to produce enzyme lipase that can be done by using solid-state fermentation method. In this study palm oil empty fruit bunches (POEFB), bagasse, and palm oil sludge are used as fermentation substrates and will be treated variations of inducer concentration and fermentation time. The results of solid state fermentation of solid substrates POEFB with inducer concentration of 8% for 7 days showed the highest activity value of 2.2 U/mL and 8.2 U/mL in the form of dry extract lipase. The result of the dry lipase enzyme immobilized so that enzyme was stable in repetitive use with cross linking adsorption method using macroporous resin as a support. Experiments showed that empty fruit bunches of oil palm fermentation substrate could produce lipase enzyme with enzyme loading of 56.6% wt. Enzyme activity test carried out in the synthesis of biodiesel through interesterification reaction mole ratio of reactants palm oil and metal acetate 1:12 at 40°C operating temperature conditions for 50 hours in 4 reaction cycles. Biodiesel synthesis results were analyzed using High Perfomance Liquid Chromatography (HPLC) showed biodiesel yield values of 48.6% and the enzyme was able to move up to 68.60% initial yield of 4 cycles of biodiesel synthesis.

Cloning and expression of two genes coding endo-β-1,4-glucanases from Trichoderma asperellum PQ34 in Pichia pastoris

Two genes coding endo-β-1,4-glucanases were cloned from Trichoderma asperellum PQ34 which was isolated from Thua Thien Hue province, Vietnam. The expression of these genes in Pichia pastoris produced two enzymes with molecular masses of approximately 46 kDa (about 42 kDa of enzymes and 4 kDa of signal peptide). The effects of induction time and temperature, inducer concentration, and culture medium on the endo-β-1,4-glucanase activity were investigated. The results showed that the highest total activities of two endo-β-1,4-glucanases were approximately 4.7 × 10

Effects Exerted by Transcriptional Regulator PcaU from Acinetobacter sp. Strain ADP1

ABSTRACT Protocatechuate degradation is accomplished in a multistep inducible catabolic pathway in Acinetobacter sp. strain ADP1. The induction is brought about by the transcriptional regulator PcaU in concert with the inducer protocatechuate. PcaU, a member of the new IclR family of transcriptional regulators, was shown to play a role in the activation of transcription at the promoter for the structuralpca genes, leaving open the participation of additional activators. In this work we show that there is no PcaU-independent transcriptional activation at the pca gene promoter. The minimal inducer concentration leading to an induction response is 10−5 M protocatechuate. The extent of expression of thepca genes was observed to depend on the nature of the inducing carbon source, and this is assumed to be caused by different internal levels of protocatechuate in the cells. The basal level of expression was shown to be comparatively high and to vary depending on the noninducing carbon source independent of PcaU. In addition to the activating function, in vivo results suggest a repressing function for PcaU at the pca gene promoter in the absence of an elevated inducer concentration. Expression at the pcaU gene promoter is independent of the growth condition but is subject to strong negative autoregulation. We propose a model in which PcaU exerts a repressor function both at its own promoter and at the structural gene promoter and in addition functions as an activator of transcription at the structural gene promoter at elevated inducer concentration.

Corticosterone 6 beta-hydroxylase in A6 epithelia: a steroid-inducible cytochrome P-450

We found microsomal corticosterone 6 beta-hydroxylase (6 beta-OHase) from cultured A6 kidney epithelial cells to be a cytochrome P-450 enzyme with both similarities to and differences from the rat liver steroid 6 beta-OHase P-450p. Enzyme activity was inhibited by CO, alpha-naphthoflavone, metyrapone, and clotrimazole, well-known inhibitors of P-450 enzymes, and increased by known inducers of P-450 enzymes, including dilantin, phenobarbital sodium, and corticosteroids. Moreover, some additional, relatively specific inducers of P-450p (troleandomycin and pregnenolone-16 alpha-carbonitrile) also induced the A6 6 beta-OHase, whereas inducers of other forms of P-450 (aroclor, spironolactone, and isosafrole) appeared to repress the A6 enzyme. The time course of increase in enzyme activity and increased cellular cytochrome P-450 content were consistent with increased levels of enzyme protein. Induction of 6 beta-OHase by the substrate (corticosterone), the metabolite (6 beta-OH-corticosterone), dexamethasone, and aldosterone was biphasic as a function of inducer concentration, with approximate 50% effective concentration (EC50) values of 10(-8)-10(-9) M and 10(-5)-10(-6) M for the respective components of induction. Cortisol also induced the enzyme at 10(-8)-10(-6) M; however, its metabolite 6 beta-OH-cortisol was ineffective or decreased activity at higher concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

The primary alkylsulfatase of Pseudomonas aeruginosa: inducer specificity and induction kinetics

The ability of primary alkylsulfate esters and alkanesulfonates to induce alkylsulfatase formation in Pseudomonas aeruginosa was compared on the basis of maximum enzyme levels, induction rate, and levels of induction as a function of inducer concentration. Apparent Kinducer values for these effectors were calculated from linear relationships between reciprocals of induction rate and inducer concentration. Maximum enzyme levels estimated from linear progress relationships for each effector indicated that little major distinction could be made between effectors. Excepting carbon chain lengths of C8 which induced about the same level of enzyme, sulfate esters were generally better inducers than sulfonates with little or no apparent induction occurring with effectors of chain length ≤ C6. These observations also held true when rates were compared, except that the rate for the C8 ester was approximately ninefold greater than that for the analogous sulfonate. Apparent Kinducer constants decreased with increasing alkyl chain length for the esters (C6–C12) and the sulfonates (C8–C14). Values for the esters were approximately sixfold greater than those for sulfonates of equivalent chain length. Plots of log apparent Kinducer values against carbon chain length for each series of esters and sulfonates yielded straight-line relationships characteristic of an homologous series in each instance.