ARTHROBACTER AS BIOFACTORY OF THERAPEUTIC ENZYMES

Therapeutic enzymes are proteins which can be used to treat rare and deadly diseases. They represent a small but profitable market. Therapeutic enzymes are superior to non-enzymatic drugs owing to their high specificity toward the target and also their ability to multiple substrate conversion. They are essential for speeding up all the metabolic processes and many a life-supporting chemical inter-conversions. Actinomycetes including Arthrobacter form an enormous reservoir of secondary metabolites and enzymes. The characterization of L-asparaginase, β-glucosidase, urate oxidase, methionine γ-lyase, acetyl cholinesterase, and arginase activities from actinomycetes Arthrobacter clearly demonstrate the potential of Arthrobacter as potent producer of therapeutic enzymes. These metabolic enzymes can be used either separately or in combination with other therapies for the treatment of several diseases such as leukemia, gout, asthma, and neurological disorders. The objective of this review is to compile the information on the application of therapeutic enzymes produced by Arthrobacter and their future prospects as drugs

Enzymatic Synthesis of Isopropyl Acetate by Immobilized Bacillus cereus Lipase in Organic Medium

Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM), concentration of biocatalyst (25–125 mg/mL), reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55°C in n-heptane under continuous shaking (160 rpm) using bound lipase (25 mg). Addition of molecular sieves (3 Å × 1.5 mm) resulted in a marked increase in ester synthesis (73.0 mM). Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse

Microbial L-Asparaginase: A Potent Antitumour Enzyme

184-194L-asparaginase (LA) can be effectively used for the treatment of acute lymphoblastic leukemia and tumour cells. Interest in this enzyme arose few decades ago when it was discovered that the antilymphoma activity of the guinea pig serum was due to LA. For pharmacological and clinical tests, microbial sources are best for the bulk production of LA. Initially this drug failed to fall in antineoplastic category due to the immunogenic reactions caused by the foreign protein. With the development of protein engineering, modifications carried out in purified LA either reduced or completely eliminated the immunogenicity of LA in test model. The improved therapeutic activity and decreased immunogenicity of LA can be of immense use as an antineoplastic agent

Production of β-carotene from deproteinized waste whey filtrate using Mucor azygosporus MTCC 414 in submerged fermentation

The cheese whey, a by-product of dairy industry proved to be an attractive substrate for production of β-carotene. The β-carotene production from Mucor azygosporus MTCC 414 by using deproteinized waste whey filtrate under submerged fermentation was investigated. Various fermentation variables, such as lactose content in whey, initial pH, production temperature, incubation time, and carbon and nitrogen sources played significant role on β-carotene production. Maximum β-carotene production (385 μg/g dcw) was obtained with the whey (pH 5.5) containing 3.5% (w/v) lactose supplemented with soluble starch at (1.0%, w/v) at 30°C after a 5 days incubation. Moreover, unlike other microorganisms which utilize pre-hydrolyzed lactose, this Mucor azygosporus MTCC 414 was found to be capable of utilizing unhydrolyzed lactose present in the whey

Paraffin as oxygen vector modulates tyrosine phenol lyase production by Citrobacter freundii MTCC 2424

The efficiency of three oxygen-vectors liquid paraffin, silicone oil and n-dodecane in the production of tyrosine phenol lyase (TPL) by Citrobacter freundii MTCC 2424 was evaluated at 4% (v/v) concentration. The liquid paraffin as oxygenvectors was found to exhibit a stimulatory effect on TPL synthesis. The liquid paraffin at 6% (v/v) resulted in 34% increase in the TPL synthesis accompanied by a 13% increase in the production of cell mass at a 10 L scale. This improvement in TPL and cell mass production in the presence of liquid paraffin can be related to the fact that liquid paraffin was capable of maintaining dissolved O2 concentration above 28% throughout the course of the fermentation. Maintenance of the dissolved O2 concentration above 28% could be viewed in terms of an adequate oxygen supply to the rapidly dividing cells of the bacterium, which in turn resulted in enhanced synthesis of TPL and cell mass

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Selective production of fragrance fatty acid ester from isopropanol and acetic acid has been achieved using silica-immobilized lipase of Bacillus cereus MTCC 8372. A purified thermoalkalophilic extracellular lipase was immobilized by adsorption onto the silica. The effects of various parameters like molar ratio of substrates (isopropanol and acetic acid; 25 to 100 mM), concentration of biocatalyst (25-125 mg/mL), reaction time, reaction temperature, organic solvents, molecular sieves, and initial water activity were studied for optimal ester synthesis. Under optimized conditions, 66.0 mM of isopropyl acetate was produced when isopropanol and acetic acid were used at 100 mM: 75 mM in 9 h at 55 • C in n-heptane under continuous shaking (160 rpm) using bound lipase (25 mg). Addition of molecular sieves (3Å × 1.5 mm) resulted in a marked increase in ester synthesis (73.0 mM). Ester synthesis was enhanced by water activity associated with pre-equilibrated saturated salt solution of LiCl. The immobilized lipase retained more than 50% of its activity after the 6th cycle of reuse