A5058470649- Genomics and Phylogenetic Studies
- RNA and protein synthesis mechanisms
- Photosynthetic Processes and Mechanisms
- Platelet Disorders and Treatments
- Algal biology and biofuel production
- Bacterial Genetics and Biotechnology
- Blood groups and transfusion
- Blood properties and coagulation
- Wastewater Treatment and Nitrogen Removal
- Amino Acid Enzymes and Metabolism
- Polyamine Metabolism and Applications
- Coral and Marine Ecosystems Studies
- Electrochemical sensors and biosensors
- Advanced oxidation water treatment
- Aquaculture disease management and microbiota
- Carcinogens and Genotoxicity Assessment
- Microbial Metabolic Engineering and Bioproduction
- Enzyme Structure and Function
- Pharmaceutical and Antibiotic Environmental Impacts
- Marine Sponges and Natural Products
- Cassava research and cyanide
- Antimicrobial agents and applications
- Microbial Fuel Cells and Bioremediation
- Bacteriophages and microbial interactions
- Legume Nitrogen Fixing Symbiosis
Universiti Putra Malaysia
2024
University of Memphis
2010-2020
McGill University
1988-1996
National Center for Toxicological Research
1994
Pratt Institute
1986-1987
Johns Hopkins University
1985-1987
Johns Hopkins Medicine
1986
University of Houston
1981-1984
While the antibacterial properties of silver nanoparticles (AgNPs) have been demonstrated across a spectrum bacterial pathogens, effects AgNPs on beneficial bacteria are less clear. To address this issue, we compared activity against two lactobacilli ( Lactobacillus delbrueckii subsp. bulgaricus and casei) common opportunistic pathogens Escherichia coli Staphylococcus aureus). Our results demonstrate that those highly susceptible to AgNPs, while not. Acidic environment caused by is...
Dynamic and quantitative studies of the binding fibrinogen (Fg) to its receptor, GPIIb–IIIa, on activated platelets, leading platelet aggregation, are best studied with fluorescently‐labelled Fg by flow cytometry. Due conflicting reports functionality FITC‐labelled Fg, we have developed a reproducible ‘mild’ labelling FITC‐celite at pH 7.4–8.5 for direct dynamic specific platelets evaluated native platelet‐rich plasma, washed activated, fixed platelets. We demonstrated equivalence unlabelled...
Azotobacter vinelandii OP was grown to stationary phase in defined medium. The cell-free culture medium analyzed for cytokinin content by XAD-2 and Sephadex LH-20 chromatography, thin-layer tobacco callus bioassay, enzyme immunoassay. Three cytokinin-active fractions were detected tentatively identified as trans -zeatin, isopentenyladenosine, isopentenyladenine. total activity equivalent 0.75 μg of kinetin per liter.
The Ames Salmonella/microsome assay was employed to test the mutagenicity of benzidine and its analogs using strains TA98 TA100 in presence absence Aroclor 1254-induced rat S9 mix. 3,3'-Dichlorobenzidine-2HCl 4,4'-dinitro-2-biphenylamine were directly mutagenic TA98, while both 2-Aminobiphenyl, 3-aminobiphenyl, 3,3'-5,5'-tetramethylbenzidine not either or S9. In mix, 4-aminobiphenyl, benzidine, 3, 3'-dichlorobenzidine-2HCl, 3,3'-dimethoxybenzidine, 3,3'-4, 4'-tetraaminobiphenyl, o-tolidine,...
Metabolism of chloral hydrate (CH) by male B6C3F1 mouse liver microsomes (control-microsomes) generated free radical intermediates that resulted in endogenous lipid peroxidation, forming malondialdehyde (MDA), formaldehyde (FA), acetaldehyde (ACT), acetone, and propionaldehyde. Because MDA, FA, ACT are tumorigens, formation peroxidation products via a mechanism may be responsible for hepatocellular tumorigenicity CH to the mice. Trichloroacetic acid (TCA) trichloroethanol (TCE), primary...
Morphological features, genomic DNA base composition and 16S rDNA sequence similarities, as well a distinct phospholipid pattern, whole-cell fatty acid distribution the occurrence of lipoquinone 'lipid F', indicate that Clostridium quercicolum belongs to Sporomusa-Pectinatus-Selenomonas phyletic group possesses only remote relationship members genus sensu stricto. On basis these results, new combination Dendrosporobacter quercicolus gen. nov., comb. nov. are proposed.
Azotobacter vinelandii can grow with a variety of organic carbon sources and fix N2 without the need for added H2. However, due to an active H2-oxidizing system, H2-dependent mixotrophic growth in N-free medium was demonstrated when mannose provided as source. There no appreciable either H2 or alone. Both rate cell yield were dependent on concentrations both substrates, mannose. Cultures growing mixotrophically consumed approximately 4.8 mmol O2 produced 4.6 CO2 per consumed. In absence H2,...
Membranes from N2-fixing Azotobacter vinelandii were isolated to identify electron transport components involved in H2 oxidation. We found direct evidence for the involvement of cytochromes b, c, and d oxidation by use H2-reduced minus O2-oxidized absorption difference spectra. Carbon monoxide spectra showed that reduced cytochrome but not o. Inhibition cyanide was monophasic with a high Ki (135 microM); this attributed d. Cyanide inhibition malate presence an additional, low (0.1 microM...
An improved method based on HPLC-TOF/MS was developed to catalog the antioxidants in five species of Chaenomeles (Mugua). Forty-four fractions from Mugua extracts show appreciable levels antioxidative activity scavenging stable free-radical 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radicals. Twelve major antioxidant's chemical structures are identified. Antioxidant activities differ between species, but intra-species level antioxidants, regardless their ripeness, similar. C. sinensis has...
Azotobacter vinelandii cell extracts reduced NAD + and oxidized d -galactose to galactonate that subsequently was converted 2-keto-3-deoxy-galactonate. Further metabolism of 2-keto-3-deoxy-galactonate required the presence ATP resulted in formation pyruvate glyceraldehyde 3-P. Radiorespirometry indicated a preferential release CO 2 at first carbon position molecule. This suggested metabolizes via DeLey-Doudoroff pathway. The enzyme this pathway, dehydrogenase, partially characterized. It has...
Summary Deinococcus radiodurans is highly resistant to radiation and mutagenic chemicals. Mutants defective in the putative glucose‐6‐phosphate dehydrogenase gene ( zwf – ) aldolase fda were generated by homologous recombination. These mutants used test cells’ resistance agents that cause dimer formation DNA strand breaks. The more sensitive induce excision repair, such as UV irradiation H 2 O , but break‐causing methylmethanesulphonic acid (MMS) mitomycin C (MMC) wild‐type cells. Analysis...
Statistical models were used to predict the effects of tryptone, glucose, yeast extract (TGY) and Mn on biomass formation highly radioresistant bacterium Deinococcus radiodurans. Results suggested that glucose had marginal effect buildup, but was a significant factor for formation. also facilitated interactions with other nutrient components. These predictions verified by in vivo vitro experiments. TGY-grown cells metabolized solely pentose phosphate pathway (PPP). Although only fraction...
Abstract Benzamines are the major aromatic amines used in industry and can also be released from azo dyes, which widely textile, paper-making, food industries. The toxicity of 10 benzamines was tested by well diffusion assay technique against 18 common bacterial species including nitrogen-fixing bacterium Azotobacter vinelandii. p-Phenylenediamine found to inhibitory growth Aeromonas hydrophila Pseudomonas fluorescens. o-Phenylenediamine Escherichia coli, Klebsiella pnemoniae, Salmonella...
The effect of shear rate and fibrinogen concentration on adenosine diphosphate-induced aggregation suspensions washed human platelets in Poiseuille flow at 23 degrees C was studied using a previously described double infusion technique resistive particle counter size analysis. Using multiple-centrifuged -washed cells Tyrodes-albumin [3 x 10(5) microliters-1; (17)] with [fibrinogen] from 0 to 1.2 microM, the extent 0.7 microM ADP were measured over range mean transit times 0.2 43 s, tube...
ABSTRACT When the stop codons TGA, TAA, and TAG are found in second third reading frames of a protein-encoding gene, they considered premature (PSC). Deinococcus radiodurans disproportionately favored TGA more than other two triplets as PSC. The triplet was also often noncoding regions codon, though bias less pronounced. We investigated this phenomenon 72 bacterial species with widely differing chromosomal GC contents. Although were compositionally similar, we great variation use but very...