Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
174 results
Search Results
Item The fermentation reaction producing biosurfactant using Pseudomonas aeruginosa CFTR?6 was studied. The progress of the bioreaction was monitored in terms of biomass production, product formation and substrate consumption in shake flask experiments using different initial sugar concentrations. A logistic model for biomass growth was found to be satisfactory. Average estimates of the specific growth rate, biomass yield coefficient and maintenance coefficients were obtained. Copyright © 1991 Society of Chemical Industry(A mathematical model for the production of biosurfactants by Pseudomonas aeuginosa CFTR?6: Production of biomass) Ramana, K.V.; Charyulu, N.C.L.N.; Karanth, N.G.1991Item [No abstract available](Geochemical significance of some major and minor elements and their incidence on the environmental conditions of Godavari valley coal fields - A case study) Pavanaguru, R.; Venkat Reddy, D.1990Item Coconut pith, available in abundance, especially in tropical countries, can be an excellent new substrate for the production of cellulase enzyme by solid substrate cultivation of Trichoderma viride NCIM 1051. The effect of type of pretreatment, type and level of nutrient medium, inoculum volume, average substrate particle size, and time of fermentation on cellulase enzyme production by T. viride in coconut pith solid culture was studied. The hydrogen peroxide-pretreated coconut pith was found to be a better substrate. Reese and Mandels' mineral solution mixed with coconut pith in the ratio of 10:1 (v/w; ml g-1) supported maximum cellulase activity. The effect of inoculum volume on enzyme production was only marginal. An average substrate particle size of 375 ?m resulted in better enzyme production. The highest filter paper activity and carboxymethylcellulase activities of 4.27 and 12.05 IU g-1, respectively, were obtained in 7 days of fermentation, and the maximum cellobiase activity that could be obtained was 1.8 IU g-1 in 8 days. © 1994.(Solid substrate fermentation of coconut coir pith for cellulase production) Muniswaran, P.K.A.; Charyulu, N.C.L.N.1994Item Isolation of Thiobacillus sp from aerobic sludge of distillery and dairy effluent treatment plants and its sulfide oxidation activity at different concentrations(Triveni Enterprises, 2007) Ravichandra, P.; Mugeraya, G.; Rao, A.G.; Ramakrishna, M.; Jetty, A.In the present study two strains of Thiobacillus sp were isolated from aerobic sludge of distillery and dairy effluent treatment plant using standard methods of isolation and enrichment. Experiments were conducted using isolated cultures in batch bioreactor with initial sulfide concentration of 75 and 150 mg/l. The effect of initial sulfide concentration on the activity of isolated Thiobacillus sp was studied. Sulfide oxidizing capacity was also determined at different initial sulfide concentrations. The results from the study indicate the possible isolation of Thiobacillus cultures from native source and application in the full-scale reactor. © Triveni Enterprises.Item Synthesis and antimicrobial activities of some novel 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles and 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines carrying thioalkyl and sulphonyl phenoxy moieties(2007) Karabasanagouda, T.; Vasudeva Adhikari, A.V.; Shetty, N.S.Thirty one new 6-aryl-3-{(4-substituted phenoxy) methyl}-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles (6a-s) and 6-aryl-3-{(4-substituted phenoxy methyl}-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines (7a-l) have been synthesized from 4-thioalkyl phenols (1a-b) through a multi-step reaction sequence. Compounds 1a-b reacted with ethyl chloroacetate in presence of acetone and potassium carbonate to give ethyl [4-(thioalkyl) phenoxy] acetates (2a-b). Further, 2a was oxidized to [4-(methyl sulphonyl) phenoxy] acetate (2c) using hydrogen peroxide in acetic acid. Reactions of (2a-c) with hydrazine hydrate in alcoholic medium furnished 2-[4-thiosubstituted phenoxy] acetohydrazides (3a-b) and 2-[4-methyl sulphonyl phenoxy] acetohydrazide (3c) which on treatment with carbon disulphide and methanolic potassium hydroxide yielded corresponding potassium dithiocarbazates (4a-c). They were then converted to 4-amino-5-{(4-thioalkyl phenoxy) methyl}-4H-1,2,4-triazole-3-thiols (5a-b) and 4-amino-5-{(4-methyl sulphonyl phenoxy) methyl}-4H-1,2,4-triazole-3-thiol (5c) by refluxing them with aqueous hydrazine hydrate. The title compounds 6a-s were prepared by condensing 5a-c with various aromatic carboxylic acids in presence of phosphorus oxychloride. The intermediates 5a-c, on condensation with various substituted phenacyl bromides afforded a series of title compounds (7a-l). The structures of new compounds 2a-7l were established on the basis of their elemental analysis, IR, 1H NMR, 13C NMR and mass spectral data. All the title compounds were subjected to in vitro antibacterial testing against four pathogenic strains and antifungal screening against three fungi. Preliminary results indicate that some of them exhibited promising activities and they deserve more consideration as potential antimicrobials. © 2006 Elsevier Masson SAS. All rights reserved.Item Performance of pulsed plate bioreactor for biodegradation of phenol(2007) Shetty K, K.V.; Kalifathulla, I.; Srinikethan, G.Biodegradation of phenol was carried out using Nocardia hydrocarbonoxydans immobilised on glass beads, in a pulsed plate bioreactor. The effect of operating parameters like frequency of pulsation and amplitude of pulsation on the performance of pulsed plate bioreactor for biodegradation of phenol in a synthetic wastewater containing 500 ppm phenol was studied. Axial concentration profile measurements revealed that the pulsed plate bioreactor shows continuous stirred tank behaviour. As the amplitude was increased, percentage degradation increased, reaching 100% at amplitude of 4.7 cm and higher. Introduction of pulsation is found to increase the percentage degradation. Percentage degradation has increased with increase in frequency and 100% degradation was achieved at 0.5 s-1 and above. Biofilms developed in a non-pulsed bioreactor were thicker than those in the pulsed plate bioreactor. But biofilm thickness remained almost constant with increasing frequency. Biofilm density was found to be influenced by pulsation. The time required to reach steady state was more for pulsed reactor than the non-pulsed reactor and this start-up time had increased with increase in frequency of pulsation. The performance studies reveal that the pulsed plate bioreactor with immobilized cells has the potential to be an efficient bioreactor for wastewater treatment. © 2006 Elsevier B.V. All rights reserved.Item Efficient shape descriptors for feature extraction in 3D protein structures(2007) Ranganath, A.; Shet, K.C.; Vidyavathi, N.Structural Genomics initiatives are generating an increasing number of protein structures with very limited biochemical characterization. Characterization of a protein's function and understanding the specific nature of a protein's binding is a critical part of both protein engineering and structure-based drug discovery. The accurate detection of binding site in these protein structures can be valuable in determining its function. As shape plays a crucial role in bimolecular recognition and function, the development of shape analysis techniques is important for understanding protein structure-function relationships. This paper describes the use of the continuous wavelet transforms (CWT) for characterizing shape features of 3D protein structures. The goal is to explore the CWT as a multiscale tool to generate rotation- and translation-invariant shape features. © 2007 IOS Press. All rights reserved.Item Anti-diarrheal potential of Aegle Marmelos Corr. root bark extract in rats(2007) Vrushabendra Swamy, S.B.M.; Nataraj, K.S.; Jayaveera, K.N.; Gopkumar, P.; Nayak, S.; Kumar, G.S.; Umachigi, S.P.A study was undertaken to evaluate the effect of methanolic extract of the rootbark of Aegle marmelos Corr. (MAMC) against several experimental models of diarrhoea in rats. MAMC treated animal's showed significant inhibitory effect against castor-oil induced diarrhea and PGE2 induced enteropooling in rats. The extract also showed a significant reduction in gastrointestinal motility in the charcoal meal test in rats. The results obtained to establish the efficacy and substantiate the folkare claim as an anti-diarrhoeal agent.Item Radioprotection by copper and zinc complexes of 5-aminosalicylic acid: A preliminary study(Begell House Inc., 2008) Mantena, S.K.; Unnikrishnan, M.K.; Chandrasekharan, K.The effect of copper and zinc complexes of 5-aminosalicylic acid (hereafter referred to as Cu-5ASA and Zn-5ASA, respectively) against whole-body gamma radiation-induced cytotoxicity was studied in Swiss albino mice. Protection against lethal irradiation was evaluated from 30 day mouse survival (10 Gy) and endogenous spleen colony assay (11 Gy); and against sublethal dose (4 Gy) was assessed from gamma irradiation (RT)-induced formation of micronuclei in the mouse bone marrow 24 h postirradiation. Pretreatment with either Cu-5ASA (2.5-9 mg/kg) or Zn-5ASA (3.5-14 mg/kg) intraperitoneally (i.p.) delayed and reduced percentage mortality in mice exposed to 10 Gy RT. The doses 9 mg/kg for Cu-5ASA and 7 mg/kg for Zn-5ASA were found to be the most effective dose in preventing RT-induced weight loss and reducing percentage mortality. Both the drugs also caused an increase in the endogenous spleen colonies in mouse exposed to 11 Gy RT. At sublethal doses of RT, pretreatment with either Cu-5ASA or Zn-5ASA resulted in a significant decrease in the RT-induced micronucleated polychromatic erythrocytes and normochromatic erythrocytes (MPCEs and MNCEs) and an increase in the ratio of PCE to NCE (P/N), at 24 h postirradiation. These results show that both Cu-5ASA and Zn-5ASA are effective in protecting normal tissues against lethal and sublethal doses of RT. Further pretreatment with either Cu-5ASA or Zn-5ASA enhanced the survival of tumor-bearing mice (Ehrlich's ascites carcinoma) exposed to 7.5 Gy RT. In fact, both the complexes caused an increase in the mean and average survival times (MST and AST) when compared to the irradiated control, suggesting a synergetic effect of these drugs with radiation in causing cytotoxicity to the tumor cells. The data clearly indicate that both Cu-5ASA and Zn-5ASA significantly reduced the deleterious effect of radiation and hence could be useful agents in reducing the side effects of therapeutic radiation. © 2008 by Begell House, Inc.Item Artificial neural networks model for the prediction of steady state phenol biodegradation in a pulsed plate bioreactor(2008) Shetty K, K.V.; Nandennavar, S.; Srinikethan, G.Background: A recent innovation in fixed film bioreactors is the pulsed plate bioreactor (PPBR) with immobilized cells. The successful development of a theoretical model for this reactor relies on the knowledge of several parameters, which may vary with the process conditions. It may also be a time-consuming and costly task because of their nonlinear nature. Artificial neural networks (ANN) offer the potential of a generic approach to the modeling of nonlinear systems. Results: A feedforward ANN based model for the prediction of steady state percentage degradation of phenol in a PPBR by immobilized cells of Nocardia hydrocarbonoxydans (NCIM 2386) during continuous biodegradation has been developed to correlate the steady state percentage degradation with the flow rate, influent phenol concentration and vibrational velocity (amplitude x frequency). The model used two hidden layers and 53 parameters (weights and biases). The network model was then compared with a Multiple Regression Analysis (MRA) model, derived from the same training data. Further these two models were used to predict the percentage degradation of phenol for blind test data. Conclusions: The performance of the ANN model was superior to that of the MRA model and was found to be an efficient data-driven tool to predict the performance of a PPBR for phenol biodegradation. © 2008 Society of Chemical Industry.