Faculty Publications
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Item Continuous phenol removal using Nocardia hydrocarbonoxydans in spouted bed contactor: Shock load study(2009) Dabhade, M.A.; Saidutta, M.B.; Murthy, D.V.R.Shock load studies are essential to investigate the suitability of biocontactors in degradation of pollutants. In the present work, the degradation of phenol by immobilized Nocardia hydrocarbonoxydans in a spouted bed contactor was conducted. Granular activated carbon (GAC) and polymer beads were tested for the immobilization of cells of N. hydrocarbonoxydans-NCIM 2386. Initially, batch immobilization study was conducted to know the quantity of immobilized microorganisms per gram of solids and then the immobilized solids were used in the spouted bed contactor for phenol degradation. Also, the shock loading of phenol and hydraulic shock load test was performed to check the stability of operation. The immobilized Nocardia cells sustained the shock load and hydraulic load of phenol. Increase of influent phenol concentration and dilution rates increased the steady state effluent phenol concentration. Almost 95% degradation at maximum phenol loading of 0.73 gL-1h-1 was achieved. GAC has more attached biomass weight compared to polymer beads. © 2009 Academic Journals.Item New manufacturing process of carbon-carbon composites and their mechanical properties(2011) Naik, P.S.; SurendranathanThis paper presents the synthesizing of carbon-carbon (CC) composites by preformed yarn (PY) method, by varying the percentage of carbon fiber volume. The PY used is carbon fiber bundle surrounded by coke and pitch which is enclosed in nylon-6. Three types of samples with fiber weight fractions of 30%, 40% and 50% respectively, are fabricated and tested. In each case, the PY is chopped and filled into a die of required shape and hot pressed at 600°C to get the carbonized composite. To obtain the graphitic structure, the specimen is heat treated at 1800°C followed by soaking for two hours. Further, one cycle pitch impregnation is done by hot isostatic pressing, to eliminate the voids. The characteristics such as hardness, compressive strength and creep, are studied. It is observed that, as the carbon fiber percentage increases the properties also improved, provided sintering is done at fairly higher temperatures. The superiority of the new class of CC composites made by the proposed PY technique over those obtained by the conventional methods is also demonstrated. © 2011 CAFET-INNOVA TECHNICAL SOCIETY.Item Synthesis and evaluation of antioxidant, antimicrobial activities of new 2,4-disubstituted thiazoles(2012) Malladi, S.; Isloor, A.M.; Peethambar, S.K.; Shivananda, K.N.A new series of 2,4-disubstituted thiazole derivatives were synthesized by the reaction of various 3-aryl-1H-pyrazole-4- carbaldehyde thiosemicarbazones (2a-e) and phenacyl bromides. The compounds (3a-n) were characterized by IR, NMR, mass spectra and C, H, N analyses. All the synthesized compounds were screened for their antioxidant and antimicrobial activities. Antioxidant studies revealed that, compounds 3b, 3j and 3n showed significant scavenging activity whereas compounds 3e and 3n exhibited significant antimicrobial activity. The acute oral toxicity study for the compound 3e and 3n have revealed good safety profile till the uppermost dose (2000 mg/kg).Item Production of Naringinase by a new soil isolate of Serratia Sp.: Effect of different carbon and nitrogen sources(2013) Pavithra, M.; Belur, P.D.; Saidutta, M.B.Four strains of Naringin degrading bacteria were isolated and tested for naringinase activity. All the four isolates showed extracellular naringinase activity. The one which showed consistently good activity in three different media was selected (2 U/L) and was identified by phenotypic characterization as Serratia Sp. In shake-flask trials, effect of various carbon and nitrogen sources was studied. Among all the carbon sources, glucose enhanced the naringinase production. Peptone supplemented with ammonium nitrate was found to be favourable. Maximum of 9.2 U/L naringinase activity was achieved in the medium comprising naringin, glucose, peptone, ammonium nitrate and salts.Item Methodological and parametric studies of machinability of carbon and alloy steels(2013) Lalbondre, R.; Krishna, P.; Mohan Kumar, G.C.The carbon and alloy steels form an increasingly diverse variety and range of steels in manufacturing industries. The assessment of the machinability of an engineering material becomes a matter of prime activity to improve productivity. The machinability of carbon and alloy steels is affected by many factors, such as the composition, microstructure, and strength level of the steel; the feeds, speeds, and depth of cut; and the choice of cutting fluid, cutting tool material and its geometry. Thus the machinability is an intrinsic technological property which is complex to understand and difficult to determine. This paper discusses different methodology of determining the machinability and its rating/index. One of the methodologies, the face turning method in particular, shall be used to determine the machinability of carbon and alloy steel. Further it deals with identifying the appropriate cutting parameters to test the machinability in an effective, simple and easy way. The research work findings here provide useful economic machining solution of knowing, in advance, the machinability of steels to gain and maintain a competitive advantage. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.Item Production of naringinase from a new soil isolate, Bacillus methylotrophicus: Isolation, optimization and scale-up studies(2014) Mukund, P.; Belur, P.D.; Saidutta, M.B.Five strains of naringin-degrading bacteria were isolated and found to be positive for extracellular naringinase activity. The one that showed highest activity in the selective medium was identified by 16S rRNA analysis as Bacillus methylotrophicus. The best combination of carbon-nitrogen source was determined by employing two-level full factorial analyses, comprising 24 experiments in shake flasks. Sucrose-yeast extract showed significant increase in naringinase activity (7.46 U/L) compared to the basal medium. Naringinase production was found to be inducible and naringin was found to be the best inducer among naringin, naringenin, hesperidin, and L-rhamnose. Inoculum size of 2% (v/v) and age of 48 hr favored naringinase and biomass production. Highest naringinase activity of 8 U/L was observed at the initial medium pH of 6. Response surface modeling was applied based on central composite design to determine the effects of three independent variables (sucrose, yeast extract, and naringin) and their mutual interactions. In total, 20 experiments were conducted and a statistical model was developed, which predicted naringinase production of 10.61 U/L. Subsequently, verification experiments were conducted and validity of the model was verified. Bioreactor studies conducted with the optimized medium showed an enzyme production of 12.05 U/L within 34 hr of fermentation. Copyright © Taylor & Francis Group, LLC.Item The combined effects of carbon/nitrogen ratio, suspended biomass, hydraulic retention time and dissolved oxygen on nutrient removal in a laboratory-scale anaerobic–anoxic–oxic activated sludge biofilm reactor(IWA Publishing, 2018) Manu, D.S.; Thalla, A.K.The current trend in sustainable development deals mainly with environmental management. There is a need for economically affordable, advanced treatment methods for the proper treatment and management of domestic wastewater containing excess nutrients (such as nitrogen and phosphorus) which can cause eutrophication. The reduction of the excess nutrient content of wastewater by appropriate technology is of much concern to the environmentalist. In the current study, a novel integrated anaerobic–anoxic–oxic activated sludge biofilm (A2O-AS-biofilm) reactor was designed and operated to improve the biological nutrient removal by varying reactor operating conditions such as carbon to nitrogen (C/N) ratio, suspended biomass, hydraulic retention time (HRT) and dissolved oxygen (DO). Based on various trials, it was seen that the A2O-AS-biofilm reactor achieved good removal efficiencies with regard to chemical oxygen demand (95.5%), total phosphorus (93.1%), ammonia nitrogen concentration (NH4þ-N) (98%) and total nitrogen (80%) when the reactor was maintained at C/N ratio of 4, suspended biomass of 3 to 3.5 g/L, HRT of 10 h, and DO of 1.5 to 2.5 mg/L. Scanning electron microscopy (SEM) of suspended and attached biofilm showed a dense structure of coccus and bacillus bacteria with the diameter ranging from 0.3 to 1.2 ?m. The Fourier transform infrared (FTIR) spectroscopy results indicated phosphorylated macromolecules and carbohydrates mix or bind with extracellular proteins in exopolysaccharides. © IWA Publishing 2018.Item Production of oxalate oxidase from endophytic Ochrobactrum intermedium CL6(Journal of Pure and Applied Microbiology micro_drkhan@yahoo.com 54, Near Post Office, Thana Street, Shahjahanabad Bhopal 462 001, 2018) Kumar, K.; Belur, P.D.Four oxalate degrading endophytic bacteria were isolated from oxalate rich Colocasia esculenta tubers. Based upon the oxalate oxidase (EC 1.2.3.4) activity produced in nutrient medium, one bacterium was selected and identified as Ochrobactrum intermedium by 16S rDNA sequencing. Studies on effect of nutritional and non-nutritional parameters showed that oxalate oxidase production is inducible, requires Manganese ions in the medium, and very low fill-up volume is beneficial. Shake flask fermentation carried out with medium comprising Sucrose, Ammonium chloride, Sodium oxalate along with basal salts gave 0.5 UmL-1 oxalate oxidase activity and 0.454 Umg-1specific activity after 65h of fermentation. © 2018 The Author(s).Item Synthesis of hybrid polycycles containing fused hydroxy benzofuran and 1H-indazoles via a domino cyclization reaction(Royal Society of Chemistry, 2019) Janardhanan, J.C.; James, K.; Puthuvakkal, A.; Bhaskaran, R.P.; Suresh, C.H.; Praveen, V.K.; Manoj, N.; Babu, B.P.A stoichiometry controlled domino cyclization reaction of hydrazone and p-benzoquinone to an angularly fused 3H-benzofuro[3,2-e]indazole core with an embedded oxygenated dibenzofuran framework under mild reaction conditions is disclosed. The reaction involves palladium catalyzed 5-hydroxy-1H-indazole formation followed by TFA mediated [3+2] annulation between the in situ formed 5-hydroxy-1H-indazole and p-benzoquinone. The developed method is attractive because of the concomitant formation of two heterocyclic rings with consecutive multiple bond forming events that include two C-C, one C-N and one C-O bonds. Spectroscopic and theoretical studies of the blue emissive benzofuroindazole derivatives have also been described. © 2019 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.Item Expression of Bacillus licheniformis chitin deacetylase in E. coli pLysS: Sustainable production, purification and characterisation(Elsevier B.V., 2019) Bhat, P.; Pawaskar, G.-M.; Raval, R.; Cord-Landwehr, S.; Moerschbacher, B.; Raval, K.Chitosan obtained by enzymatic deacetylation of chitin using chitin deacetylase (CDA) holds promise primarily due to the possibility to yield chitosan with non-random patterns of acetylation and more environmentally friendly process compared to chemical deacetylation. In the present study, a sustainable bioprocess is reported for over-expression of a bacterial CDA in E. coli pLysS cells. A Bacillus licheniformis CDA gene is identified in the genome of the bacterium, cloned, and expressed, yielding enzymatically active recombinant protein. For enzyme production, a growth medium is formulated using carbon and nitrogen sources, which do not compete with the human food chain. The maximum enzyme activity of 320 ± 20 U/mL is achieved under optimized conditions. The CDA productivity is improved by about 23 times in shake flask culture by optimizing operating conditions and medium components. The CDA is purified and the enzyme kinetic values i.e. Km, Vmax and Kcat are reported. Also the effect of cofactors, temperature, and pH on the enzyme activity is reported. Further, economic yield is proposed for production of CDA through this bioprocess. © 2019 Elsevier B.V.