Purification and Physiochemical Characterization of Melanin Pigment from Klebsiella sp. GSK

( Sajjan,Shrishailnath ),( Guruprasad Kulkarni ),( Veeranagouda Yaligara ),( Kyoung Lee ),( T. B. Karegoudar ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.11

A bacterium capable of producing melanin pigment in the presence of L-tyrosine was isolated from a crop field soil sample and identified as Klebsiella sp. GSK based on morphological, biochemical, and 16S rDNA sequencing. The polymerization of this pigment occurs outside the cell wall, which has a granular structure as melanin ghosts. Chemical characterization of the pigment particles showed then to be acid resistant, alkali soluble, and insoluble in most of the organic solvents and water. The pigment got bleached when subjected to the action of oxidants as well as reductants. This pigment was precipitated with FeCl3, ammoniacal silver nitrate, and potassium ferricynide. The pigment showed high absorbance in the UV region and decreased absorbance when shifted towards the visible region. The melanin pigment was further charecterized by FT-IR and EPR spectroscopies. A key enzyme, 4- hydroxyphenylacetic acid hydroxylase, that catalyzes the formation of melanin pigment by hydroxylation of Ltyrosine was detected in this bacterium. Inhibition studies with specific inhibitors, kojic acid and KCN, proved that melanin is synthesized by the DOPA-melanin pathway.

Properties and Functions of Melanin Pigment from Klebsiella sp. GSK

( Sajjan ),( Shrishailnath S ),( Anjaneya O ),( Guruprasad B Kulkarni ),( Anand S Nayak ),( Suresh B Mashetty ),( T B Karegoudar ) 한국미생물생명공학회(구 한국산업미생물학회) 2013 한국미생물·생명공학회지 Vol.41 No.1

Purified melanin pigment from Klebsiella sp. GSK was characterized by thermogravimetric, differential thermal, X ray diffraction and elemental analysis. This melanin pigment is structurally amorphous in nature. It is thermally stable up to 300oC and emits a strong exothermic peak at 700oC. Its carbon, hydrogen and nitrogen composition is 47.9%, 6.9% and 12.0%, respectively. It was used to scavenge metal ions and free radicals. After immobilizing the pigment and using it to adsorb copper and lead ions, the metal ion adsorption capacity was evaluated by atomic absorption spectroscopy (AAS) and the identity of melanin functional groups involved in the binding of metal ions was determined by Fourier transform infrared (FT-IR) spectroscopy. Batch adsorption studies showed that 169 mg/g of copper and 280 mg/g of lead were adsorbed onto melanin-alginate beads. The metal ion adsorption capacity of the melanin-alginate beads was relatively significant compared to alginate beads. The metal ion desorption capacity of HCl was greater (81.5% and 99% for copper and lead, respectively) than that of EDTA (80% and 71% for copper and lead, respectively). The ability of the melanin pigment to scavenge free radicals was evaluated by inhibition of the oxidation of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2`-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and was shown to be about 74% and 98%, respectively, compared with standard antioxidants.

Model tests on the moored vessel with different moonpool shapes

Sajjan, Sharanabasappa C.,Surendran, S. Techno-Press 2013 Ocean systems engineering Vol.3 No.2

Moonpools are vertical wells in a floating body used onboard many types of vessels like cable-laying vessels and offshore support vessels. Moonpool gives passage to underwater activities for different types of ships as per their mission requirements. It is observed that inside a moonpool considerable relative motions may occur, depending on shape, depth of the moonpool and on the frequency range of the waves to which the ship is exposed. The vessel responses are entirely different in zero and non-zero Froude number. Former situation is paid attention in this study as the mission requirement of the platform is to be in the particular location for long period of operation. It is well known that there are two modes of responses depending on the shape of the moonpool viz., piston mode for square shape and sloshing mode for rectangular shapes with different aspect ratios of opening like 1:1.5 and 1:2 ratios. Circular shaped moonpool is also tested for measuring the responses. The vessel moored using heavy lines are modeled and tested in the wave basin. The moored lines are provided with pre-tension and the dynamic tensions on the lines are measured. The different modes of oscillations of water column are measured using wave gauge and the vessel response at a particular situation is determined. RAOs determined for various situations provide better insight to the designer. The experiments done in the wave basin may also be compared with a software package meant for handling moored floating bodies.

Effect of Pretension on Moored Ship Response

Sajjan, Sharanabasappa C.,Surendran, S. Korean Society of Ocean Engineers 2013 International journal of ocean system engineering Vol.3 No.4

Moonpools are vertical wells in a floating body used onboard many types of vessels like Exploration and drilling vessels, Production barges, Cable-laying vessels, Rock dumping vessels, Research and offshore support vessels. Moonpool gives passage to underwater activities for different types of ships as per their mission requirements. It is observed that inside a moonpool considerable relative motions may occur, depending on shape, depth of the moonpool and on the frequency range of the waves to which the ship is exposed. The vessel responses are entirely different in zero and non-zero Froude number. Former situation is paid attention in this study as the mission requirement of the platform is to be in the particular location for long period of operation. It is well known that there are two modes of responses depending on the shape of the moonpool viz., piston mode for square shape and sloshing mode for rectangular shapes with different aspect ratios of opening like 1:1.5 and 1:2 ratios. Circular shaped moonpool is also tested for measuring the responses. The vessel moored using heavy lines are modelled and tested in the wave basin. The pretensions of the lines are varied by altering the touchdown points and the dynamic tensions on the lines are measured. The different modes of oscillations of water column are measured using wave gauge and the vessel response at a particular situation is determined. RAOs calculated for various situations provide better insight to the designer.

RNA interference mediated knockdown of juvenile hormone esterase gene in Bemisia tabaci (Gennadius): Effects on adults and their progeny

Sajjan Grover,Vikas Jindal,Geetika Banta 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.1

Juvenile hormone is responsible for regulating metamorphosis and reproduction in insects. Analysis of key elements of juvenile hormone regulation would enhance the understanding of this complex mechanism. Juvenile hormone esterase plays an important role in maintaining juvenile hormone titres in insects. In this study, effects of knockdown of juvenile hormone esterase gene (jhe) in Bemisia tabaci were studied using RNA interference (RNAi) technique. dsRNA corresponding to two conserved regions of jhe gene, substrate binding pocket site (jhe1), catalytic triad site (jhe2), green fluorescent protein gene (gfp) as control were synthesized. dsRNAs incorporated in artificial diet (20% sucrose solution) @ 2.5, 1.0, 0.5 and 0.1 μg/μl were fed to adult whiteflies for 48 h, followed by shifting whiteflies to live plants for next generation biology study. Based on qRT-PCR analyses, reduced jhe gene expression was observed in adult whiteflies after dsRNA feeding @ 2.5 and 1.0 μg/μl. jhe gene knockdown affects the survival and reproduction of whiteflies adversely in a dose-dependent manner. Moreover, oral feeding of dsRNA to adult whiteflies @ 2.5 and 1.0 μg/μl showed adverse effects on next generation of whitefly viz., lower egg hatchability and shortened egg incubation period. Minimum number of viable eggs (1.04 and 1.80 eggs/female) were observed when whiteflies were fed with highest concentration of dsjhe1 and dsjhe2 as compared to control (16.58 eggs/female). These data suggest that jhe gene acts as a major biological player in whitefly and its progeny and further indicate to be potential target for managing whitefly population.

Effect of the Presence of Corpus Luteum on Oocyte Recovery and Subsequent in vitro Maturation and Fertilization in Buffaloes

Singh, Sajjan,Dhanda, O.P.,Malik, R.K. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.12

The effect of the presence or absence of corpus luteum in the ovaries of slaughtered buffaloes was studied for the oocytes recovery and their subsequent maturation and fertilization in vitro. On an average, 0.41 and 0.67 oocytes per ovary were recovered from ovaries with and without corpus luteum, respectively. Immature oocytes were matured in TCM-199 medium. Significant difference was observed in maturation rate between good (74%) and fair (37%) oocytes. However, there was no significant difference in cleavage rate between the two types. The results of this study show that although the presence of corpus luteum in the ovary at the time of recovery significantly affected availability of total oocytes and in-vitro maturation, but fertilization and cleavage remained unaffected under in vitro conditions.

Synthesis and characterization of GTMAC grafted chitosan membranes for the dehydration of low water content isopropanol by pervaporation

Ashok M. Sajjan,H.G. Premakshi,Mahadevappa Y. Kariduraganavar,Y. Kariduraganavar 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-

Glycidyltrimethylammonium chloride (GTMAC) grafted chitosan (CS) membranes were prepared by the solution casting technique. The chemical composition and morphological characteristics of the prepared GTMAC/CS membranes were investigated by various techniques such as Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The effects of grafting and feed composition on pervaporation performance of the membranes were systematically studied. The membrane containing 40 mass% of GTMAC exhibited the highest separation selectivity of 2133 with a flux of 6.91 102 kg/m2 h at 30 8C for 10 mass% of water in the feed. The total flux and flux of water are almost overlapping each other, manifesting that these membranes could be used effectively to break the azeotropic point of water–isopropanol mixture. From the temperature dependent diffusion and permeation values, the Arrhenius activation parameters were estimated. The activation energy values obtained for water permeation (Epw) are significantly lower than those of isopropanol permeation (EpIPA), suggesting that the grafted membranes developed here have higher separation ability for water- isopropanol system. The positive heat of sorption (DHs) values was obtained for all the grafted membranes, suggesting that the Henry’s mode of sorption is predominant.

Binding affinity of amlodipine, atorvastatin and telmisartan drugs to purified bacterial melanin pigment: a kinetic study

Shrishailnath S. Sajjan,M. Santoshkumar,S. Sanjeevkumar,T. B. Karegoudar 한국약제학회 2013 Journal of Pharmaceutical Investigation Vol.43 No.4

Amlodipine, atorvastatin and telmisartan are the most commonly used pharmaceutical drugs against cardiovascular disease, management of hypertension and in the treatment of angina. They have side-effects like edema,allergic reactions, breathing problems, etc. The melanin pigment from Klebsiella sp. GSK has the ability to adsorb pharmaceutical drugs, metals ions and to scavenge free radicals. We have studied here the binding of these drugs to melanin pigment at different concentrations and temperatures. It shows that these drugs in higher concentrations form stable complexes with melanin pigment. The amount of drug bound to melanin increases with increase in initial drug concentration. The drug-binding properties of melanin pigment were investigated kinetically. Telmisartan and amlodipine bind strongly at 40 C (59 and 25.8 lg/mg,respectively) than atorvastatin (18 lg/mg). Batch adsorption,uptake kinetics, Langmuir and Freundlich equations and temperature adsorption studies were also conducted with melanin pigment.

Development of novel grafted hybrid PVA membranes using glycidyltrimethylammonium chloride for pervaporation separation of water–isopropanol mixtures

Ashok M. Sajjan,Mahadevappa Y. Kariduraganavar,B.K. Jeevan Kumar,Arjumandbanu A. Kittur 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

Tetraethylorthosilicate incorporated hybrid poly(vinyl alcohol) membranes were grafted with glycidyltrimethylammonium chloride (GTMAC) in different mass%. The resulting membranes were subjected to physico-chemical investigations using Fourier transform infrared (FTIR) spectroscopy,wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA) and scanning electron microscopy (SEM). The effects of grafting and feed composition on pervaporation performance of the membranes were systematically investigated. The membrane containing 30 mass% of GTMAC exhibited the highest separation selectivity of 1570 with a flux of 1.92 102 kg/m2 h at 30 8C for 10 mass% of water in the feed. The total flux and flux of water are almost overlapping each other, manifesting that these membranes could be used effectively to break the azeotropic point of water–isopropanol mixtures. From the temperature dependent diffusion and permeation values, the Arrhenius activation parameters were estimated. The activation energy values obtained for water permeation (Epw) are two to three times lower than those of isopropanol permeation (EpIPA), suggesting that the developed membranes have higher separation ability for water–isopropanol system. The Ep and ED values ranged between 63.73 and 33.07, and 62.78 and 32.75 kJ/mol, respectively. The positive heat of sorption (DHs) values was obtained for all the membranes, suggesting that Henry’s mode of sorption is predominant in the process.

Two dimensional quantitative structure activity relationship models for 5alpha-reductase type 2 inhibitors

Urvashi Balekundri,Shrishailnath S. Sajjan,Shivakumar B. Madagi 한국약제학회 2015 Journal of Pharmaceutical Investigation Vol.45 No.3

Prostate cancer in men is the major cause of cancer mortality and is the active area for the researchers to discover new drugs for prostate cancer. 5alpha-reductase inhibitors have been proved to inhibit the growth and development of prostate cancer, hence identifying the potential of such compounds is necessary to invent new drugs. Quantitative structure activity relationship (QSAR) modeling is a well-known in silico drug designing approach that relates the chemical structure of compounds with their biological activities. In the present work 2D QSAR models are built using machine learning techniques such as linear regression, SMO, simple logistic, decision tree j48 and random forest, from the functions available in Weka 3.7 version. The present in silico QSAR study will help to identify new bioactivities for the drug discovery of prostate cancer and also narrow down the time required for drug discovery process.