PubMed Health⌕ Search

Biomedical subjects

J J Perry

Publications and source records attributed to J J Perry.

At least 55 records · Page 3Linked to original sources
PubMed1983

Incorporation of chlorinated alkanes into fatty acids of hydrocarbon-utilizing mycobacteria.

The cellular fatty acid composition of Mycobacterium vaccae JOB5 and Mycobacterium convolutum R22 was examined after growth on n-alkanes and compared with the fatty acids of the organisms after growth on 1-chlorohexadecane and 1-chlorooctadecane. Growth on n-alkanes resulted in normal fatty acid profiles. Mass spectral analyses indicated that, after growth on the terminally chlorinated n-alkanes, 75 to 86% of the fatty acids in M. convolutum and ca. 55% of the fatty acids in M. vaccae contained chlorine. Neither organism could utilize chloroacetate or 3-chloropropionate as sole source of carbon and energy. When these compounds were added to a growth medium with n-hexadecane as substrate, there was no evidence that chlorinated fatty acids were produced. Terminally chlorinated n-alkanes can be added to the list of n-alkanes, alkenes, and cyclohexylalkane derivatives that can be directly incorporated into cellular fatty acids of hydrocarbon-utilizing organisms.

Acetates↗
PubMed1980

Phospholipid composition and heat sensitivity in a thermophilic bacterium.

A Gram-negative thermophilic bacterium designated strain LEH-1, survived under non-growth conditions, temperatures 5 degrees C above its maximum for growth when acetate or n-heptadecane served as carbon source, whereas cells grown with glucose or glycerol were markedly more sensitive to elevated temperatures. The total extractable lipids from strain LEH-1 and the concentrations of phosphatidylethanolamine and phosphatidic acid in the cytoplasmic membranes was altered by the growth substrate. Growth with acetate of n-heptadecane as carbon source yielded cells containing more phosphatidic acid than phosphatidylethanolamine. Conversely, more phosphatidylethanolamine was present in cells following growth with glucose or glycerol as carbon source. The relative amount of specific fatty acids and distribution in major phospholipid moieties was also affected by the growth substrate. These differences in composition may reflect an alteration in the physical properties of the cellular membrane and account for the divergence in heat sensitivity.

Acetates↗
PubMed1980

Intergeneric evolutionary homology revealed by the study of protocatechuate 3,4-dioxygenase from Azotobacter vinelandii.

Protocatechuate 3,4-dioxygenase (EC 1.13.1.3) was purified to homogeneity from extracts of Azotobacter vinelandii. The molecular weight of the oligomeric protein was estimated to be 510 000 by gel filtration and 480 000 by ultracentrifugation. The oligomer appears to be formed by association of equal amounts of nonidentical subunits which were estimated by sodium dodecyl sulfate gel electrophoresis to have respective molecular weights of 23 300 and 25 250. Ten gram-atoms of iron was associated with each mol of oligomer. Therefore, the enzyme appears to be a decamer with the structure 10(alpha beta Fe). T-HE AMINO ACID COMPOSITION OF Azotobacter protocatechuate oxygenase closely resembles the amino acid compositions of protocatechuate 3,4-dioxygenases from Pseudomonas aeruginosa and Thiobacillus sp. These proteins from P. aeruginosa and P. putida are known to be formed by association of nonidentical subunits of a physical size similar to the subunits of the Azotobacter enzyme. Furthermore, antisera prepared against the Azotobacter oxygenase cross-reacted strongly with the isofunctional enzymes from the two fluorescent Pseudomonas species. A weak immunological cross-reaction was observed when the antisera were tested against protocatechuate 3,4-dioxygenase from Acinetobacter calcoaceticus. The results favor the conclusion that the bacterial protocatechuate 3,4-dioxygenases were derived from a common ancestral protein.

Amino Acids↗
PubMed1980

The atypical cell wall composition of Thermomicrobium roseum.

The cell wall of Thermomicrobium roseum, a Gram-negative, obligately thermophilic bacterium, has a composition unlike other Gram-negative thermophilic organisms. The purified cell wall was composed predominantly of a protein with a monomeric molecular weight of 75 000. The amino acid composition of this protein revealed high concentrations of proline, glutamic acid, glycine, and alanine.

Amino Acids↗
PubMed1978

Purification and characterization of a heme-containing amine dehydrogenase from Pseudomonas putida.

The primary amine dehydrogenase of Pseudomonas putida NP was purified to homogeneity as judged by polyacrylamide gel electrophoresis. Cytochrome c or an artificial electron acceptor was required for amine dehydrogenase activity. The enzyme was nonspecific, readily oxidizing primary monoamines, benzylamine, and tyramine; little or no measurable activity was detected with isoamines, L-ornithine, L-lysine, and certain diamines or polyamines. The pH optima for n-butylamine, benzylamine, and n-propylamine were 7.0, 6.5, and 7.0, respectively. The molecular weight of the enzyme was 112,000 as determined by gel filtration and 95,300 as analyzed by sedimentation equilibrium. Subunit analysis by sodium dodecyl sulfate gel electrophoresis suggested that the enzyme was composed of two nonidentical subunits with molecular weights of 58,000 and 42,000. The absorption spectrum of the purified enzyme was indicative of a hemoprotein, exhibiting absorption maxima at 277, 355, and 408 nm. Reduction with sodium dithionite or amine substrates resulted in absorption maxima at 523 and 552 nm and a shift in the Soret peak to 416 nm. These results suggested that the enzyme is a hemoprotein of the type c cytochrome. There was no evidence that flavins were present.

Cell-Free System↗
PubMed1978

Amine dehydrogenase of Pseudomonas putida: properties of the heme-prosthetic group.

There was approximately five times more hemoprotein (amine dehydrogenase) in crude extracts obtained from Pseudomonas putida grown on benzylamine than present in extracts from succinate-grown cells. The difference (reduced minus oxidized) spectrum of the purified enzyme possessed alpha,beta, and gamma bands at 550, 523, and 416 nm, respectively. The difference spectrum of the pyridine hemochrome derivative had absorption maxima at 416, 520, and 550 nm. These results, together with the fact that the heme group was covalently bound to the enzyme, indicated that the amine dehydrogenase from P. putida was a hemoprotein which contained heme c. The heme content was calculated at 2.01 mol/mol of enzyme. The enzyme was composed of two nonidentical subunits, but heme was present solely in the heavier unit. Carbon monoxide did not inhibit enzymatic activity, nor would it combine with the reduced or oxidized form of the enzyme. Amine dehydrogenase activity was inhibited by carbonyl agents with semicarbazide and cuprizone acting noncompetitively, whereas KCN and isoniazid inhibited by competitive and uncompetitive mechanisms, respectively. Spectral observations suggested that inhibition by these reagents was not due to an interaction with the heme moiety.

Binding, Competitive↗
PubMed1977

Effect of growth substrate on thermal death of thermophilic bacteria.

The heat sensitivity of gram-negative, hydrocarbon-utilizing thermophilic bacteria was altered by a change in growth substrate. Thermophilic strains CC-6, BI-1, and LEH-1, grown with acetate or n-heptadecane as the carbon source, had a higher survival rate when incubated 5 degrees C above their maximum growth temperature than cells of the same organism after growth on glucose or glycerol. There was a correlation between the growth substrated, heat resistance, and the ratios of cellular n-hexadecanoic acid/branched hexadecanoic acid and n-heptadecanoic acid/branched heptadecanoic acid. The bacterial cells that were more heat resistant had ratios of straight-chain/branched-chain fatty acids above 1.0, whereas the heat-sensitive cells had ratios below 0.6.

Acetates↗
PubMed1976

Microbial oxidation and assimilation of propylene.

Hydrocarbon-utilizing microorganisms in our culture collection oxidized propylene but could not utilize it as the sole source of carbon and energy. When propane-grown cells of Mycobacterium convulutum were placed on propylene, acrylate, the terminally oxidized, three-carbon unsaturated acid, accumulated. A mixed culture and an axenic culture (strain PL-1) that utilized propylene as the sole source of carbon and energy were isolated from soil. Respiration rates, enzyme assays, fatty acid profiles, and 14CO2 incorporation experiments suggest that both the mixed culture and strain PL-1 oxidize propylene via attack at the double bond, resulting in a C2+C1 cleavage of the molecule.

Acetates↗
PubMed1975

Metabolism of n-propylamine, isopropylamine, and 1,3-propane diamine by Mycobacterium convolutum.

Mycobacterium convolutum strain NPA-1 can utilize n-propylamine (NPA), isopropylamine (IPA), and 1,3-propane diamine (PD) as sole source of carbon, nitrogen, and energy. Enzyme assays, fatty acid profiles, and 14CO2 incorporation experiments indicate that NPA is deaminated to propionate and further metabolized via the methylmalonyl succinate pathway, and IPA and PD were metabolized (after deamination) through a C2 + C1 cleavage. An inducible amine dehydrogenase was present in cell extracts after growth on the three amines. Polyacrylamide gel electrophoresis of cell extracts from NPA- and IPA-grown cells yielded one major band of amine dehydrogenase activity. When extracts of NPA-grown cells were assayed with NPA, IPA, or PD as substrate, the relative position of the major band on gel electrophoresis was equivalent. Similar results were obtained with extracts prepared from IPA-grown cells. Sephadex G-100 chromatography also indicated one major peak of activity. This suggests that one enzyme of broad specificity is involved in deamination of IPA, NPA, and PD. IPA-grown cells utilized NPA readily, whereas NPA-grown cells could not utilize IPA without lag. Since amine dehydrogenase activity was present in extracts of cells after growth on either substrate, this lag was probably due to the inability to transport IPA without an induction period. The molecular weight of the amine dehydrogenase was approximately 38,500 as determined by gel filtration.

1-Propanol↗
PubMed1975

The origin of fatty acids in the hydrocarbon-utilizing microorganism Mycobacterium vaccae.

The fatty acid pattern in Mycobacterium vaccae strain JOB5 was examined after growth on n-alkanes (C14-C18), 1-alkenes (C14-C18), 2- or 3-methyl octadecane, and 8-heptadecene. It was evident that monoterminal oxidation of n-alkanes was followed by beta-oxidation and that both parent fatty acid and products of beta-oxidation were incorporated into cellular lipids. Radioactive experiments demonstrated that there was desaturation of long-chain fatty acids. There was no evidence of chain elongation. Growth on 1-alkenes resulted in the incorporation of fatty acids that were products of two primary modes of oxidation: (1) methyl group attack resulting in omega-unsaturated fatty acids and (2) double-bond attack resulting in the removal of one carbon from the substrate. Cells of strain JOB5 grown on 2- and 3-methyl octadecane contained the corresponding iso- or anteiso-fatty acids in significant quantity. Cells cultured on 8-heptadecene contained 8- and 9-heptadecenoic acids, 6- and 7-pentadecenoic acids, 9- and 10-methyl heptadecanoic acids, and 7- and 8-methyl pentadecanoic acids. Fatty acid composition (C13 to C19) was affected by substrate chain length and was additionally modified by cellular control mechanisms.

Acetates↗
PubMed1975

Characterization of branched and unsaturated fatty acids in Mycobacterium vaccae strain JOB5.

After growth of Mycobacterium vaccae strain JOB5 on acetate or propane, the cellular fatty acids were isolated and identified by a combination of gas-chromatographic, mass-spectral, and chemical means. The fatty acids ranged from C12 to C19 and were a mixture of saturated, monounsaturated, and methyl-branched components. The double bond was in the delta9 position in the C15 to C18 unsaturated acids. The single methyl branch was located on the C10 position of Br-C17, Br-C18, and Br-C19 fatty acids. Branched-chain synthesis occurs at the expense of an unsaturated precursor fatty acid; the double bond serves as the site of methylation. Results suggest that S-adenosylmethionine is the methyl donor involved.

Acetates↗
PubMed1974

Microbial degradation and assimilation of n-alkyl-substituted cycloparaffins.

Studies were conducted on the oxidation and assimilation of n-alkyl-substituted cycloalkane substrates by several hydrocarbon-utilizing microorganisms. These microorganisms utilized heptadecylcyclohexane and dodecylcyclohexane as the sole source of carbon and energy. Neither methylcyclohexane nor ethylcyclohexane was utilized as a growth substrate by any organisms tested. Gas-liquid chromatographic analyses of fatty acids present in cells after growth on dodecylcyclohexane confirm direct incorporation of both alpha- and beta-oxidation products. Growth patterns of these organisms on n-alkyl-substituted cyclohexane fatty acids of varying chain lengths suggest a greater probability of ring cleavage when the side chain contains an odd number of carbons.

Biodegradation, Environmental↗
PubMed1974

Effect of substrate on the fatty acid composition of hydrocarbon-utilizing filamentous fungi.

The fatty acid pattern in hydrocarbon-utilizing filamentous fungi was determined after growth on acetate, propionate, n-alkanes (C(13) to C(15)), and alk-1-enes (C(14) to C(18)). The fatty acid profile of Cunninghamella elegans and Penicillium zonatum after growth on acetate shows a predominance of even-carbon fatty acids (C(16), C(18:1), C(18:2)), whereas cells grown on propionate showed significantly higher levels of odd-carbon fatty acids (C(15), C(17), C(17:1)). Growth on n-alkanes resulted in the incorporation of fatty acids homologous to the growth substrate. Cunninghamella elegans grown on the alk-1-enes from C(14) to C(18) incorporated the unsaturated substrate into cellular fatty acid after oxidation at the saturated end of the molecule. Regardless of substrate these fungi contain, predominantly, fatty acids 18 carbons in length.

Acetates↗