J.P. Bhatt

Synthesis, antimicrobial, and antitumor activity of a series of palladium(II) mixed ligand complexes

Mixed ligand complexes of cisdichloromethioninepalladium(II) with 2-mercaptopyrimidine and 2-aminopyrimidine were synthesized and characterized by elemental analysis, conductivity data, infrared, and 1H NMR and 13C NMR spectra. In these mixed ligand complexes methionine coordinates to palladium through amino nitrogen and sulphur, thus leaving a free carboxylic acid group. The pyrimidine ligand coordinates to metal ion through N3. Mixed ligand complexes of cisdichloroethioninepalladium(II) with cytosine and guanosine were synthesized and characterized earlier. All the above mixed ligand complexes were screened for antimicrobial activity against Vibrio parahaemolyticus, Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, Shigella flexnerri, Salmonella typhii, Klebsella pneumoniae, and Vibrio cholerae. It was found that complexes [Pd(meth)Cl2]: [Pd(meth)(2merpy)Cl]Cl; [Pd(meth)(2ampy)Cl]Cl; [Pd(ethio)Cl2]; [Pd(ethio)(cyt)Cl]Cl; and [Pd(ethio)(guo)Cl]Cl showed broad spectrum antimicrobial activity against all the human pathogens tested, however [Pd(meth)(2merpy)Cl]Cl eliminated plasmid with 100% frequency. These complexes have also been screened in vitro for antitumor activity against Hela (Epidermoid Carcinoma Cervix) and CHO cell lines. An excellent correlation between the antitumor activity of Pd(II) complexes and their ability to cure plasmids exists.

Light dependent hydrogen production by Halobacterium halobium coupled to Escherichia coli

Observations on the rate of hydrogen production by twenty-two different strains of Halobacterium halobium isolated from the salt farm of the CSMCRI are reported.

Photosensitized production of hydrogen by halobacterium halobium MMT22 coupled to Escherichia coli : use of immobilization for enhancement of hydrogen production

Abstract Immobilization of Halobacterium halobium MMT22 coupled to Escherichia coli both stabilizes and enhances hydrogen production. The ultimate yield of hydrogen produced was over five times as large for immobilized cells as compared to the free cells.

Photoelectrochemical studies on Halobacterium halobium for continuous production of hydrogen

Continuous hydrogen evolution was obtained photoelectrochemically using Halobacterium halobium as catalyst at −2 V vs SCE. Deacedite FF resin was used to control the pH of the system.

Large scale photobiological solar hydrogen generation using Halobacterium halobium MMT22 and silicon cell

Abstract This biophotoelectrochemical system produces about twice the amount of H 2 compared with that of a solar photovoltaic hydrogen system due to the low requirement of reduction potential of ≥ − 0.41 V. Halobacterium halobium MMT 22 covered on 1 m 2 area produces about 11.36 1 h −1 under solar insolation of 70–80 mW cm −2 .

Photosensitized production of hydrogen by halobacterium halobium MMT22 coupled to Escherichia coli in reversed micelles of sodium lauryl sulfate in organic solvents

Observations on the enhanced production of hydrogen by Halobacterium halobium MMT 22 coupled to Escherichia coli entrapped inside the reversed micelles formed by sodium lauryl sulfate in various organic solvents, namely benzene, carbon tetrachloride, toluene, n-heptane, nitrobenzene, chlorobenzene, are reported. In the present system, a hundred fold increase in activity as compared to the activity in the usual aqueous medium was observed.

Polyethylene glycol mediated fusion of Halobacterium halobium MMT22 and Escherichia coli for enhancement of hydrogen production

Abstract A simplified system with enhanced rates of hydrogen production was obtained by polyethylene glycol mediated fusion of Halobacterium halobium MMT22 and Escherichia coli. A continuous evolution of hydrogen was observed at the rate of 60.2 μmol mg−1 cells min−1 for about 2 weeks by fusion product 1.

Photosensitized continuous production of hydrogen by Halobacterium halobium MMT22 coupled to Escherichia coli

Abstract Continuous evolution of hydrogen was obtained for 12 weeks in a specially designed “chemostat” by Halobacterium halobium MMT22 coupled to Escherichia coli.

Photofixation of carbon dioxide in semiconductor particulate and microbial systems

Photocatalytic reduction of CO2 to HCOOH and HCHO was carried out in a Pt/CdS/RuO2 semiconductor particulate system using [RuIII(EDTA-H)H2O] complex as catalyst. Upon illumination at 505 nm (band gap energy of CdS), the system produced HCOOH and HCHO at rates equal to 3.05 × l0−2 Mh−1 and 2.0 × 10−2 M h−1, respectively. Trace amounts of CH2OH, CH4 and CO were also detected in the reaction vessel. Photobiological conversion of CO2 to formic acid was achieved by usingHalobacterium halobium MMT22 in aqueous solution at a rate equal to 0.45 M h−1. A one-and-half-fold increase in the rate of formation of formic acid was observed when the photobiological reduction of CO2 was performed in the presence of L-ascorbic acid as electron-donating agent and [RuIII(bipy)3]2+ as photosensitizer.

Photogeneration of hydrogen by Halobacterium halobium MMT22 coupled with silicon PN junction semiconductor without external bias potential — II

Abstract Hydrogen generation by the biophotoelectrochemical cell using Halobacterium halobium MMT 22 for photoproton pumping and platinum coated silicon for photoelectron generation requires 1–2 h of illumination or 15–20 min of external potential of 0.6-0.9 V for the development of required hydrogen reduction potential. The evolution of H 2 continues as long as illumination is provided to the surfaces. The rate of generation of H 2 is about 5.45 I h −1 from 1 m 2 of H. halobium surface.