Isolation, identification and bioactive potential of bacterial endophytes from Coleus

Coleus (Lamiaceae) is a large and widespread genus comprising of species with diverse ethnobotanical uses. In the present study, bacterial endophytes were isolated from Coleus forskohlii and Coleus aromaticus. Endophytes are the microorganisms which reside within the plants without showing any harmful effect on its host. Diverse types of endophytes live symbiotically within almost all plants and in turn help the plant in a number of ways such as imparting resistance against biotic and abiotic stresses, producing compounds involved in attraction of pollinators, inducing the plant defense mechanisms, etc. The bacterial endophytes isolated in this study, were characterized by microscopic examination (using gram staining) and molecularly identified by sequencing the 16S rRNA. Extracts were prepared from endophytic biomass using solvents of different polarities (methanol, ethyl acetate and butanol) and were screened for their bioactive potential (in vitro cytotoxicity anti-microbial, and anti-oxidant activity). Scale-up of endophytes showing promising results is under process, which will help in isolation of pure compounds

Isolation and Identification of L-asparaginase Producing Bacteria from Soils of Different Agroclimatic Zones of Jammu (J&K), India

A milestone was set in the field of medicine with the discovery of L-asparaginase present in the serum of guinea pig responsible for action against the acute lymphoblastic leukemia. Since then, the use of L-asparaginase as a potential anti-cancer drug has been a great success in the field of modern oncology. Despite its varied sources, new sources are continuously being explored to obtain a high therapeutic index drug. The study aims to isolate potential L-asparaginase producing microorganisms from environmental niches of Northwestern Himalayas. The climatic conditions of the region and ancient agricultural practices which are still being followed in these areas, add up to the diverse microbial repository and a potential habitat which can be explored to obtain a potent asparaginase producing microbial source. In the study, soil samples from different regions of Jammu were collected aseptically. From the isolation studies, a total of 44 bacterial isolates were obtained. Pure cultures were then screened for asparaginase activity both qualitatively as well as quantitatively using agar plate and nesselerization method. Screening studies resulted in the isolation of a potent L-asparaginase producer isolated from black gram soil sample of Rajouri, Jammu showing an enzyme activity of 9.14 U/ml. Based on biochemical and molecular approaches, the isolate was identified as Enterobacter aesburiae strain R16C1 / No. MT93543. The study resulted in the isolation of a pure bacterial culture from the soils of Northwestern Himalayas possessing anti-cancer asparaginase activity. Further, optimization studies can help in considerably increasing the enzyme activity which can be tested against different human cancer lines for its anti-cancer efficacy

Prospects of conducting polymers in biosensors

pplications of conducting polymers to biosensors have recently aroused much interest. This is because these molecular electronic materials offer control of different parameters such as polymer layer thickness, electrical properties and bio-reagent loading, etc. Moreover, conducting polymer based biosensors are likely to cater to the pressing requirements such as biocompatibility, possibility of in vivo sensing, continuous monitoring of drugs or metabolites, multi-parametric assays, miniaturization and high information density. This paper deals with the emerging trends in conducting polymer based biosensors during the last about 5 years

Prospects of conducting polymers in biosensors

pplications of conducting polymers to biosensors have recently aroused much interest. This is because these molecular electronic materials offer control of different parameters such as polymer layer thickness, electrical properties and bio-reagent loading, etc. Moreover, conducting polymer based biosensors are likely to cater to the pressing requirements such as biocompatibility, possibility of in vivo sensing, continuous monitoring of drugs or metabolites, multi-parametric assays, miniaturization and high information density. This paper deals with the emerging trends in conducting polymer based biosensors during the last about 5 years

Arthrobacter sp. lipase immobilization on magnetic sol 13gel composite supports for enantioselectivity improvement

A bacterial lipase from Arthrobacter sp. (ABL: IIIM Jammu, India strain, MTCC No. 5125) has been immobilized on non-magnetic (Type A) and magnetic (Type B) supports derived from copolymerization of 3-aminopropyltriethoxysilane and tetraethylorthosilicate.Immobilized ABLpresented 21 1334 mg/g protein binding providing 30 1375 units/g activity in Type A non-magnetic composites and 24 1345 mg/g protein binding providing 35 1390 units/g activity with Type B supports containing magnetic particles. Immobilized ABL preparations have shownenhanced stability at pH5 139 and temperature up to 70 8C whereas free ABL is unstable under these conditions. Improved hydrolytic conversion as well as enantioselectivity were observedwith acylfluoxetine intermediate (ethyl3-hydroxy-3-phenylpropanoate alkyl acylates) andchiral auxiliaryacyl 1-phenyl ethanol usingimmobilized ABL derivatives (ee�99%; 3 134-fold increase in E-values) as compared to ABL enzyme/cells (ee 93 1398%). Introduction of magnetic particles in these supports has led to easier separation process with high product recovery yields

Arthrobacter sp. lipase immobilization for improvement in stability and enantioselectivity

Arthrobacter sp. lipase (ABL, MTCC no. 5125)is being recognized as an efficient enzyme for the resolution of drugs and their intermediates. The immobilization of ABL on various matrices for its enantioselectivity,stability, and reusability has been studied. Immobilization by covalent bonding on sepharose and silica afforded a maximum of 380 and 40 IU/g activity, respectively,whereas sol 13gel entrapment provided a maximum of 150 IU/g activity in dry powder. The immobilized enzyme displayed excellent stability in the pH range of 4 1310 and even at higher temperature, i.e., 50 136

Enantioselectivity modulation through immobilization of Arthrobacter sp. lipase: Kinetic resolution of fluoxetine intermediate

Arthrobacter sp. lipase (ABL, MTCC no. 5125) has been identified for its excellent performance in kinetic resolution of a number of drug intermediates. ABL free enzyme provided product II and V (ee < 95%) from racemic fluoxetine intermediate (I and IV) compared to its cell biomass in naturally immobilized state (ee < 98%). To overcome this problem and obtaining high enantioselectivity (R isomer ee 99%), ABL enzyme was modulated by immobilization using various methods vis-`a-vis substrate modification (Scheme 2). Immobilized enzyme obtained by hydrophobic binding provided 6710–7720 U/g, covalent binding 200 U/g, and sol–gel entrapment 65–110 U/g activity. Substantial improvement in enantioselectivity was obtained using acylates of ethyl 3-hydroxy 3-phenylpropanoate a fluoxetine drug intermediate (R isomer ee from 93 to 99% and E from 43 to 127–473) at 29–45% conversion in fixed time period of 21 h, indicating thereby some change in conformation of ABL immobilized enzyme. The ABL immobilized by covalent binding and sol–gel entrapment has demonstrated reasonable superiority over the free ABL in enantioselectivity as well as over all rate of hydrolysis. Immobilized enzymes prepared by covalent and entrapment methods have shown excellent operational stability and used for 10 cycles without loss in activity and the technique can be upscaled for process development

Enantiomerically pure α-methoxyaryl acetaldehydes as versatile precursors: a facile chemo-enzymatic methodology for their preparation

A facile and efficient synthesis of optically active a-methoxyaryl acetic acids (up to 95% ee), a-methoxyaryl ethanols (up to 93% ee) and a-methoxyaryl acetonitriles (up to 93% ee) was achieved via Arthrobacter sp. lipase-catalyzed kinetic resolution of masked aldehydes as the key synthons, that is, a-hydroxyaryl acetaldehyde acetals

Arthrobacter sp. lipase immobilization for preparation of enantiopure masked β-amino alcohols

Recent reports on immobilization of lipase from Arthrobacter sp. (ABL, MTCC 5125; IIIM isolate) on insoluble polymers have shown altered properties including stability and enantioselectivity. Present work demonstrates a facile method for the preparation of enantiopure b-amino alcohols by modulation of ABL enzyme properties via immobilization on insoluble as well as soluble supports using entrapment/ covalent binding techniques. Efficacies of immobilized ABL on insoluble supports prepared from tetraethylorthosilicate/ aminopropyltriethoxy silane and soluble supports derived from copolymerization of Nvinyl pyrrolidone-allylglycidyl ether (ANP type)/N-vinyl pyrrolidone-glycidyl methacrylate (GNP type) for kinetic resolution of masked b-amino alcohols have been studied vis-à-vis free ABL enzyme/wet cell biomass. The immobilized lipase on different insoluble/soluble supports has shown 21–110 mg/g protein binding and 30–700 U/g activity for hydrolyzing tributyrin substrate. The findings have shown a significant enhancement in enantioselectivity (ee 99%) vis-à-vis wet cell biomass providing ee 70–90% for resolution of b-amino alcohols