@article { ISI:000250792200005, title = {Immobilization of mushroom polyphenol oxidase on poly(allyl glycidyl ether-co-ethylene glycol dimethacrylate) macroporous beaded copolymers}, journal = {Reactive \& Functional Polymers}, volume = {67}, number = {10}, year = {2007}, month = {OCT}, pages = {905-915}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Functional, macroporous, beaded copolymers containing epoxy groups were synthesized for immobilization of polyphenol oxidase (PPO) from edible mushroom (Agaricus bisporus). The effect of incorporation of two different sets of monomers such as glycidyl methacrylate (GMA) and allyl glycidyl ether (AGE) and the effect of cross-linking agent ethylene glycol dimethacrylate (EGDM) with varying cross-link densities on binding and expression of mushroom PPO activity were studied. The effect of porogen viz. cyclohexanol and hexanol on PPO immobilization was studied. AGE copolymers with hexanol as a porogen were found to give higher binding and expression of PPO activity than GE polymers. Crosslinking of amino groups of enzyme with 5\% glutaraldehyde for 6 h gave a stable binding of PPO on AGE-75(Hex) polymer with storage half-life of approximately 25 days. Under optimum conditions, AGE-75(Hex) polymer gave 70.3\% of activity yield while percent retention of PPO activity was found to be 83.5\%. Immobilized PPO showed a broader pH, higher temperature and excellent storage stability. (c) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {cross-linking agent, Enzyme immobilization, Epoxy-activated support, mushroom PPO}, issn = {1381-5148}, doi = {10.1016/j.reactfunetpolym.2007.05.015}, author = {Vaidya, Bhalchandra K. and Karale, Abhijeet J. and Suthar, Hitesh K. and Ingavle, Ganesh C. and Pathak, Tara Sankar and Ponrathnam, S. and Nene, Sanjay} } @article { ISI:000254479300039, title = {Immobilization of Candida rugosa lipase on poly(allyl glycidyl ether-co-thylene glycol dimethacrylate) macroporous polymer particles}, journal = {Bioresource Technology}, volume = {99}, number = {9}, year = {2008}, month = {JUN}, pages = {3623-3629}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

Macroporous polymer particles containing surface epoxy groups were synthesized for immobilization of Candida rugosa lipase (CRL). The effect of incorporation of two different sets of monomers [allyl glycidyl ether (AGE) and glycidyl methacrylate (GMA)] and the effect of crosslinking density on immobilization of lipase were studied. AGE-co-EGDM polymers gave higher binding and expression of lipase than GMA-co-EGDM polymers. Optimization of immobilization parameters was done with respect to immobilization time and enzyme loading. Amongst AGE-co-EGDM polymer series, AGE-150 polymer found to give maximum lipase activity yield and therefore evaluated for temperature, pH and storage stability. Under optimum conditions, AGE-150 polymer gave 78.40\% of activity yield. Immobilized lipase on AGE-150 showed a broader pH, higher temperature and excellent storage stability. (C) 2007 Published by Elsevier Ltd.

}, keywords = {Candida rugosa lipase, Enzyme immobilization, Epoxy-activated support}, issn = {0960-8524}, doi = {10.1016/j.biortech.2007.07-035}, author = {Vaidya, Bhalchandra K. and Ingavle, Ganesh C. and Ponrathnam, S. and Kulkarni, B. D. and Nene, Sanjay N.} } @article { ISI:000257381600004, title = {Sulfur nanoparticles synthesis and characterization from H2S gas, using novel biodegradable iron chelates in w/o microemulsion}, journal = {Nanoscale Research Letters}, volume = {3}, number = {6}, year = {2008}, month = {JUN}, pages = {221-229}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Sulfur nanoparticles were synthesized from hazardous H2S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe3+-malic acid chelate (0.05 M aqueous solution) was studied in w/o microemulsion containing cyclohexane, Triton X-100 and n-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of alpha-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm) and narrow particle size distribution (in range of 5-15 nm) as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (\> 99\%). Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi) than that of colloidal sulfur.

}, keywords = {Antimicrobial activity, H2S gas, iron chelates, sulfur nanoparticles, w/o microemulsion}, issn = {1931-7573}, doi = {10.1007/s11671-008-9140-6}, author = {Deshpande, Aniruddha S. and Khomane, Ramdas B. and Vaidya, Bhalchandra K. and Joshi, Renuka M. and Harle, Arti S. and Kulkarni, Bhaskar D.} } @article { ISI:000257971900057, title = {Use of response surface optimization for the production of biosurfactant from rhodococcus spp. MTCC 2574}, journal = {Bioresource Technology}, volume = {99}, number = {16}, year = {2008}, month = {NOV}, pages = {7875-7880}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

The production of biosurfactant from Rhodococcus spp. MTCC 2574 was effectively enhanced by response surface methodology (RSM). Rhodococcus spp. MTCC 2574 was selected through screening of seven different Rhodococcus strains. The preliminary screening experiments (one-factor at a time) suggested that carbon source: mannitol, nitrogen source: yeast extract and meat peptone and inducer: n-hexadecane are the critical medium components. The concentrations of these four media components were optimized by using central composite rotatable design (CCRD) of RSM. The adequately high R-2 value (0.947) and F score 19.11 indicated the statistical significance of the model. The optimum medium composition for biosurfactant production was found to contain mannitol (1.6 g/L), yeast extract (6.92 g/L), meat peptone (19.65 g/L), n-hexadecane (63.8 g/L). The crude biosurfactant was obtained from methyl tert-butyl ether extraction. The yield of biosurfactant before and after optimization was 3.2 g/L of and 10.9 g/L, respectively. Thus, RSM has increased the yield of biosurfactant to 3.4-fold. The crude biosurfactant decreased the surface tension of water from 72 mN/m to 30.8 mN/m (at 120 mg L-1) and achieved a critical, micelle concentration (CMC) value of 120 mg L-1. (C) 2008 Published by Elsevier Ltd.

}, keywords = {Biosurfactant, Medium optimization, Response surface methodology, Rhodococcus spp.}, issn = {0960-8524}, doi = {10.1016/j.biortech.2008.02.027}, author = {Mutalik, Snehal R. and Vaidya, Bhalchandra K. and Joshi, Renuka M. and Desai, Kiran M. and Nene, Sanjay N.} } @article { ISI:000265398300007, title = {Enhanced production of amidase from Rhodococcus erythropolis MTCC 1526 by medium optimisation using a statistical experimental design}, journal = {Journal of Industrial Microbiology \& Biotechnology}, volume = {36}, number = {5}, year = {2009}, month = {MAY}, pages = {671-678}, publisher = {SPRINGER HEIDELBERG}, address = {TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY}, abstract = {

In the present work, statistical experimental methodology was used to enhance the production of amidase from Rhodococcus erythropolis MTCC 1526. R. erythropolis MTCC 1526 was selected through screening of seven strains of Rhodococcus species. The Placket-Burman screening experiments suggested that sorbitol as carbon source, yeast extract and meat peptone as nitrogen sources, and acetamide as amidase inducer are the most influential media components. The concentrations of these four media components were optimised using a face-centred design of response surface methodology (RSM). The optimum medium composition for amidase production was found to contain sorbitol (5 g/L), yeast extract (4 g/L), meat peptone (2.5 g/L), and acetamide (12.25 mM). Amidase activities before and after optimisation were 157.85 units/g dry cells and 1,086.57 units/g dry cells, respectively. Thus, use of RSM increased production of amidase from R. erythropolis MTCC 1526 by 6.88-fold.

}, keywords = {Amidase, Medium optimisation, Plackett-Burman screening, Response surface methodology, Rhodococcus erythropolis}, issn = {1367-5435}, doi = {10.1007/s10295-009-0536-9}, author = {Vaidya, Bhalchandra K. and Mutalik, Snehal R. and Joshi, Renuka M. and Nene, Sanjay N. and Kulkarni, Bhaskar D.} } @article { ISI:000265398300016, title = {Media optimization for biosurfactant production by rhodococcus erythropolis MTCC 2794: artificial intelligence versus a statistical approach}, journal = {Journal of Industrial Microbiology \& Biotechnology}, volume = {36}, number = {5}, year = {2009}, month = {MAY}, pages = {747-756}, publisher = {SPRINGER HEIDELBERG}, address = {TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY}, abstract = {

This paper entails a comprehensive study on production of a biosurfactant from Rhodococcus erythropolis MTCC 2794. Two optimization techniques-(1) artificial neural network (ANN) coupled with genetic algorithm (GA) and (2) response surface methodology (RSM)-were used for media optimization in order to enhance the biosurfactant yield by Rhodococcus erythropolis MTCC 2794. ANN and RSM models were developed, incorporating the quantity of four medium components (sucrose, yeast extract, meat peptone, and toluene) as independent input variables and biosurfactant yield [calculated in terms of percent emulsification index (\% EI24)] as output variable. ANN-GA and RSM were compared for their predictive and generalization ability using a separate data set of 16 experiments, for which the average quadratic errors were similar to 3 and similar to 6\%, respectively. ANN-GA was found to be more accurate and consistent in predicting optimized conditions and maximum yield than RSM. For the ANN-GA model, the values of correlation coefficient and average quadratic error were similar to 0.99 and similar to 3\%, respectively. It was also shown that ANN-based models could be used accurately for sensitivity analysis. ANN-GA-optimized media gave about a 3.5-fold enhancement in biosurfactant yield.

}, keywords = {Artificial neural network, Biosurfactant, Genetic algorithm, Media optimization, Response surface methodology, Rhodococcus}, issn = {1367-5435}, doi = {10.1007/s10295-009-0547-6}, author = {Pal, Moumita P. and Vaidya, Bhalchandra K. and Desai, Kiran M. and Joshi, Renuka M. and Nene, Sanjay N. and Kulkarni, Bhaskar D.} } @article { ISI:000291903100003, title = {Strain improvement and statistical media optimization for enhanced erythritol production with minimal by-products from candida magnoliae mutant R23}, journal = {Biochemical Engineering Journal}, volume = {55}, number = {2}, year = {2011}, month = {JUL}, pages = {92-100}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Mutants of Candida magnoliae NCIM 3470 were generated by ultra-violet and chemical mutagenesis to enhance erythritol production. The mutants were screened for higher reductase activity on agar plates containing high concentration of glucose and 2,3,5-triphenyl tetrazolium chloride (TTC). One of the mutants named as R23 gave maximum erythritol production, 60.3 g L(-1), compared to 14 g L(-1) of the parent strain. Glucose and yeast extract were identified as critical medium components which decide the ratio of polyols produced, mainly erythritol, mannitol and glycerol. In order to enhance the production of erythritol and to minimize the production of mannitol and glycerol, a four component-five level-three response central-composite-rotatable-design (CCRD) of response surface methodology (RSM) model was used. The optimum medium composition for erythritol production was found to contain (g L(-1)) glucose 238, yeast extract 9.2, KH(2)PO(4), 5.16 and MgSO(4) 0.23. Moreover, erythritol production was studied in a 10 L fermentor in batch and fed-batch mode using RSM optimized medium. In fed-batch fermentation, 87.8 g L(-1) erythritol was produced with 31.1\% yield, without formation of any other polyols. Thus present study involving strain improvement followed by media and process optimization resulted in 6.2-fold increase in erythritol production and 3.4-fold increase in the yield. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {Candida magnoliae, Erythritol, Fermentation, Metabolite over-production, Modelling, Optimization}, issn = {1369-703X}, doi = {10.1016/j.bej.2011.03.009}, author = {Savergave, Laxman S. and Gadre, Ramchandra V. and Vaidya, Bhalchandra K. and Narayanan, Karthik} } @article { ISI:000309096400004, title = {Poly(allyl glycidyl ether-co-ethylene glycol dimethacrylate) copolymer beads as support for covalent immobilization of L-aminoacylase}, journal = {Reactive \& Functional Polymers}, volume = {72}, number = {10}, year = {2012}, month = {OCT}, pages = {687-694}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Porous epoxy-activated copolymer beads were synthesized as support for the covalent immobilization of Aspergillus melleus L-aminoacylase. Here, a series of copolymer bead were synthesized using either glycidyl methacrylate (GMA) or ally] glycidyl ether (AGE) as monomer units and ethylene glycol dimethacrylate (EGDM) as cross-linking agent. The effect of monomer used and the effect of amount of cross-linking agent on covalent immobilization of aminoacylase were studied. Furthermore, the effect of porogen on immobilization of aminoacylase was also evaluated. AGE-co-EGDM copolymer beads gave higher binding of aminoacylase than GMA-co-EGDM copolymer beads. AGE-co-EGDM copolymer beads synthesized with lauryl alcohol as porogen and having 150\% cross-linked density (i.e. AGE-(L)-150) gave maximum enzyme binding. Under optimum conditions, AGE-(L)-150 copolymer beads gave about 130 U/g of aminoacylase activity which corresponds to 72.24\% of activity yield. Immobilized aminoacylase showed a broader pH, higher temperature and extended storage stability. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Enzyme immobilization, Epoxy-activated support, L-Aminoacylase}, issn = {1381-5148}, doi = {10.1016/j.reactfunctpolym.2012.06.012}, author = {Vaidya, Bhalchandra K. and Ingavle, Ganesh C. and Ponrathnam, S. and Nene, Sanjay N.} } @article { ISI:000300036000006, title = {Preparation of cross-linked enzyme aggregates of L-aminoacylase via co-aggregation with polyethyleneimine}, journal = {Journal of Molecular Catalysis B-Enzymatic}, volume = {74}, number = {3-4}, year = {2012}, month = {FEB}, pages = {184-191}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

L-Aminoacylase from Aspergillus melleus was co-aggregated with polyethyleneimine and subsequently cross-linked with glutaraldehyde to obtain aminoacylase-polyethyleneimine cross-linked enzyme aggregates (termed as AP-CLEA). Under the optimum conditions, AP-CLEA expressed 74.9\% activity recovery and 81.2\% aggregation yield. The said method of co-aggregation and cross-linking significantly improved the catalytic stability of L-aminoacylase with respect to temperature and storage. AP-CLEA were employed for enantioselective synthesis of three unnatural amino acids (namely: phenylglycine, homophenylalanine and 2-naphthylalanine) via chiral resolution of their ester-. amide- and N-acetyl derivatives. The enantioselectivity of AP-CLEA was the highest for hydrolysis of amino acid amides; was moderate for hydrolysis of N-acetyl amino acids and was the least for hydrolysis of amino acid esters. Furthermore, AP-CLEA were found to retain more than 92\% of the initial activity after five consecutive batches of (RS)-homophenylalanine hydrolysis suggesting an adequate operational stability of the biocatalyst. (C) 2011 Elsevier B.V. All rights reserved.

}, keywords = {chiral resolution, Cross-linked enzyme aggregates, L-Aminoacylase, Polyethyleneimine, Unnatural amino acids}, issn = {1381-1177}, doi = {10.1016/j.molcatb.2011.10.003}, author = {Vaidya, Bhalchandra K. and Kuwar, Suyog S. and Golegaonkar, Sandeep B. and Nene, Sanjay N.} } @article {PACHFULE, title = {Two-stage fermentation process for enhanced mannitol production using Candida magnoliae mutant R9}, journal = {Bioprocess and Biosystems Engineering}, volume = {36}, number = {2}, year = {2013}, month = {FEB}, pages = {193-203}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Mutants of Candida magnoliae NCIM 3470 were generated by treatment of ultra-violet radiations, ethyl methyl sulphonate and N-methyl-N{\textquoteright}-nitro-N-nitrosoguanidine. Mutants with higher reductase activity were screened by means of 2,3,5-triphenyl tetrazolium chloride agar plate assay. Among the screened mutants, the mutant R9 produced maximum mannitol (i.e. 46 g l(-1)) in liquid fermentation medium containing 250 g l(-1) glucose and hence was selected for further experiments. Preliminary optimization studies were carried out on shake-flask level which increased the mannitol production to 60 g l(-1) in liquid fermentation medium containing 300 g l(-1) glucose. A two-stage fermentation process comprising of growth phase and production phase was employed. During the growth phase, glucose was supplemented and aerobic conditions were maintained. Thereafter, the production phase was initiated by supplementing fructose and switching to anaerobic conditions by discontinuing aeration and decreasing the speed of agitation. The strategy of two-stage fermentation significantly enhanced the production of mannitol up to 240 g l(-1), which is the highest among all fermentative production processes and corresponds to 81 \% yield and 4 g l(-1) h(-1) productivity without formation of any by-product.

}, keywords = {Candida magnoliae, D-Mannitol, Mutagenesis, Strain improvement, Two-stage fermentation}, issn = {1615-7591}, doi = {10.1007/s00449-012-0775-4}, author = {Savergave, Laxman S. and Gadre, Ramchandra V. and Vaidya, Bhalchandra K. and Jogdand, Vitthal V.} }