A5082939162- Microbial Metabolic Engineering and Bioproduction
- Enzyme Catalysis and Immobilization
- Amino Acid Enzymes and Metabolism
- Biofuel production and bioconversion
- Metalloenzymes and iron-sulfur proteins
- Enzyme Structure and Function
- Microbial metabolism and enzyme function
- Metabolism and Genetic Disorders
- Biochemical Acid Research Studies
- Microbial Community Ecology and Physiology
- Anaerobic Digestion and Biogas Production
- Porphyrin Metabolism and Disorders
- Polyamine Metabolism and Applications
- Electrochemical sensors and biosensors
- Metal-Catalyzed Oxygenation Mechanisms
- Pancreatic function and diabetes
- Enzyme Production and Characterization
- Photosynthetic Processes and Mechanisms
- Bacteriophages and microbial interactions
- Redox biology and oxidative stress
- Biochemical and Molecular Research
- Genomics and Phylogenetic Studies
- Alcohol Consumption and Health Effects
- Protein Hydrolysis and Bioactive Peptides
- Microbial Fuel Cells and Bioremediation
University of Waterloo
2014-2024
University of Calcutta
2022
Regional Municipality of Waterloo
2017
Jiangsu University
2010-2016
Max Planck Society
2014
University of Georgia
1993-2005
Johns Hopkins University
1993
Philipps University of Marburg
1987-1991
University of Stuttgart
1991
Microorganisms growing near and above 100 degrees C have recently been discovered shallow deep sea hydrothermal vents. Most are obligately dependent upon the reduction of elemental sulfur (S0) to hydrogen sulfide (H2S) for optimal growth, even though S0 readily occurs abiotically at their growth temperatures. The reductase activity anaerobic archaeon Pyrococcus furiosus, which grows optimally by a metabolism that produces H2S if is present, was found in cytoplasm. It purified anaerobically...
ABSTRACT The hyperthermophilic archaeon Pyrococcus furiosus grows optimally at 100°C by the fermentation of peptides and carbohydrates. Growth organism was examined in media containing either maltose, (hydrolyzed casein), or both as carbon source(s), each with without elemental sulfur (S 0 ). rates were highest on S , maltose. did not occur peptide medium . had no effect growth maltose absence peptides. Phenylacetate production (from phenylalanine fermentation) from cells grown same,...
ABSTRACT The fermentative hyperthermophile Pyrococcus furiosus contains an NADPH-utilizing, heterotetrameric (αβγδ), cytoplasmic hydrogenase (hydrogenase I) that catalyzes both H 2 production and the reduction of elemental sulfur to S. Herein is described purification a second enzyme this type, II, from same organism. Hydrogenase II has M r 320,000 ± 20,000 four different subunits with s 52,000 (α), 39,000 (β), 30,000 (γ), 24,000 (δ). heterotetramer contained Ni (0.9 0.1 atom/mol), Fe (21...
Pyrococcus furiosus is an anaerobic archaeon that grows optimally at 100 degrees C by the fermentation of carbohydrates yielding acetate, CO2, and H2 as primary products. If elemental sulfur (S0) or polysulfide added to growth medium, H2S also produced. The cytoplasmic hydrogenase P. furiosus, which responsible for production with ferredoxin electron donor, has been shown catalyze reduction (K. Ma, R. N. Schicho, M. Kelly, W. Adams, Proc. Natl. Acad. Sci. USA 90:5341-5344, 1993). From...
The bioenergetic role of the reduction elemental sulfur (S0) in hyperthermophilic archaeon (formerly archaebacterium) Pyrococcus furiosus was investigated with chemostat cultures maltose as limiting carbon source. maximal yield coefficient 99.8 g (dry weight) cells (cdw) per mol presence S0 but only 51.3 if omitted. However, corresponding maintenance coefficients were not found to be significantly different. primary fermentation products detected H2, CO2, and acetate, together H2S, when also...
Abstract Active deep-sea hydrothermal vents harbor abundant thermophilic and hyperthermophilic microorganisms. However, microbial communities in inactive have not been well documented. Here, we investigated bacterial archaeal the two sediments (named as TVG4 TVG11) collected from Southwest India Ridge using high-throughput sequencing technology of Illumina MiSeq2500 platform. Based on V4 region 16S rRNA gene, sequence analysis showed that samples were dominated by Proteobacteria , followed...
Pyruvate ferredoxin oxidoreductase (POR) has been previously purified from the hyperthermophilic archaeon, Pyrococcus furiosus , an organism that grows optimally at 100°C by fermenting carbohydrates and peptides. The enzyme contains thiamine pyrophosphate catalyzes oxidative decarboxylation of pyruvate to acetyl-CoA CO 2 reduces P. ferredoxin. Here we show this also formation acetaldehyde in a CoA-dependent reaction. Desulfocoenzyme A substituted for CoA showing cofactor plays structural...
Pyruvate decarboxylase (PDC encoded by pdc) is a thiamine pyrophosphate (TPP)-containing enzyme responsible for the conversion of pyruvate to acetaldehyde in many mesophilic organisms. However, no pdc/PDC homolog has yet been found fully sequenced genomes and proteomes hyper/thermophiles. The only PDC activity reported hyperthermophiles was bifunctional, TPP- CoA-dependent ferredoxin oxidoreductase (POR)/PDC from hyperthermophilic archaeon Pyrococcus furiosus. Another known be involved...
Abstract HNH endonucleases in bacteriophages play a variety of roles the phage lifecycle as key components DNA packaging machines. The deep-sea thermophilic bacteriophage Geobacillus virus E2 (GVE2) encodes an endonuclease (GVE2 HNHE). Here, crystal structure GVE2 HNHE is reported. This first structural study thermostable from bacteriophage. Structural comparison reveals that possesses typical ββα-metal fold and Zn-finger motif similar to those other bacteriophages, apart containing extra...
Thermococcus litoralis is a strictly anaerobic archaeon that grows at temperatures up to 98 degrees C by fermenting peptides. Little known about the primary metabolic pathways of this organism and, in particular, role enzymes are dependent on thermolabile nicotinamide nucleotides. In paper we show cytoplasmic fraction cell extracts contained NADP-specific glutamate dehydrogenase (GDH) and alcohol (ADH) activities, neither which utilized NAD as cofactor. The GDH composed identical subunits...
The strictly anaerobic archaeon Thermococcus strain ES-1 was recently isolated from near a deep-sea hydrothermal vent. It grows at temperatures up to 91 degrees C by the fermentation of peptides and reduces elemental sulfur (S(o)) H2S. is shown here that growth rates cell yields are dependent upon concentration S(o) in medium, no observed absence S(o). activities various catabolic enzymes cells grown under conditions sufficient limiting concentrations were investigated. These included...
The archaeon Pyrococcus furiosus grows optimally at 100°C during the fermentation of peptides and carbohydrates to yield organic acids, CO2 H2. It also reduces elemental sulfur (S°) H2S. production H2 is catalyzed by a Ni-containing hydrogenase which functions as reductase [Ma et al. (1993) Proc. Natl. Acad. Sci. 90, 5341–5344]. shown here that this bifunctional enzyme, termed sulhydrogenase, uses NADPH rather than ferredoxin (or NADH) an electron donor. disposal excess reductant proposed...
The reduction of N 5 ,N 10 ‐methylenetetrahydromethanopterin (CH 2 = H 4 MPT) to ‐methyltetrahydromethanopterin 3 ‐H is an intermediate step in methanogenesis from CO and . reaction catalyzed by CH MPT reductase. enzyme Methanobacterium thermoautotrophicum (strain Marburg) was found be specific for reduced coenzyme F 420 as electron donor; neither NADH or NADPH nor viologen dyes could substitute the 5‐deazaflavin. reductase purified over 100‐fold apparent homogeneity. Sodium dodecyl...
An alcohol dehydrogenase (ADH) from hyperthermophilic archaeon Thermococcus guaymasensis was purified to homogeneity and found be a homotetramer with subunit size of 40 ± 1 kDa. The gene encoding the enzyme cloned sequenced; this had 1,095 bp, corresponding 365 amino acids, showed high sequence homology zinc-containing ADHs l-threonine dehydrogenases binding motifs catalytic zinc NADP(+). Metal analyses revealed that NADP(+)-dependent contained 0.9 0.03 g-atoms per subunit. It...
A scheme for the detoxification of superoxide in Pyrococcus furiosus has been previously proposed which reductase (SOR) reduces (rather than dismutates) to hydrogen peroxide by using electrons from reduced rubredoxin (Rd). Rd is with NAD(P)H enzyme NAD(P)H:rubredoxin oxidoreductase (NROR). The goal present work was reconstitute this pathway vitro recombinant enzymes. While forms SOR and are available, gene encoding P. NROR (PF1197) found be exceedingly toxic Escherichia coli, an active form...
Pyrococcus furiosus is a hyperthermophilic archaeon that grows optimally at 100 degreesC by the fermentation of peptides and carbohydrates to produce acetate, CO2, H2, together with minor amounts ethanol. The organism also generates H2S in presence elemental sulfur (S0). Cell extracts contained NADP-dependent alcohol dehydrogenase activity (0.2 0.5 U/mg) ethanol as substrate, specific which was comparable cells grown without S0. enzyme purified multistep column chromatography. It has subunit...
An NADH oxidase from the anaerobic hyperthermophilic bacterium Thermotoga maritima was purified. The enzyme very active in catalyzing reduction of oxygen to hydrogen peroxide with an optimal pH value 7 at 80 degrees C. V(max) 230 +/- 14 mumol/min/mg (k(cat)/K(m) = 548,000 min(-1) mM(-1)), and K(m) values for were 42 3 43 4 muM, respectively. a heterodimeric flavoprotein two subunits molecular masses 54 kDa 46 kDa. Its gene sequences identified, might represent new type anaerobes....