Search PubMed⌕ Search

Biomedical subjects

B F Taylor

Publications and source records attributed to B F Taylor.

At least 37 records · Page 2Linked to original sources
PubMed1979

Assessment of microbial fouling in an ocean thermal energy conversion experiment.

A project to investigate biofouling, under conditions relevant to ocean thermal energy conversion heat exchangers, was conducted during July through September 1977 at a site about 13 km north of St. Croix (U.S. Virgin Islands). Seawater was drawn from a depth of 20 m, within the surface mixed layer, through aluminum pipes (2.6 m long, 2.5-cm internal diameter) at flow velocities of about 0.9 and 1.8 m/s. The temperature of the seawater entering the mock heat exchanger units was between 27.8 and 28.6 degrees C. After about 10 weeks of exposure to seawater, when their thermal conductivity was reported to be significantly impaired, the pipes were assayed for the accumulation of biological material on their inner surfaces. The extent of biofouling was very low and independent of flow velocity. Bacterial populations, determined from plate counts, were about 10 cells per cm. The ranges of mean areal densities for other biological components were: organic carbon, 18 to 27 mug/cm; organic nitrogen, 1.5 to 3.0 mug/cm; adenosine 5'-triphosphate, 4 to 28 ng/cm; carbohydrate (as glucose in the phenol assay), 3.8 to 7.0 mug/cm; chlorophyll a, 0.2 to 0.8 ng/cm. It was estimated from the adenosine 5'-triphosphate and nitrogen contents that the layer of live bacteria present after 10 weeks was only of the order of 1mum thick. The C/N ratio of the biological material suggested the presence of extracellular polysaccharidic material. Such compounds, because of their water-retaining capacities, could account for the related increase in thermal resistance associated with the pipes. This possibility merits further investigation, but the current results emphasize the minor degree of biofouling which is likely to be permissible in ocean thermal energy conversion heat exchangers.

Journal Article↗
PubMed1977

(14C)acetate assimilation by a type I obligate methylotroph, Methylococcus capsulatus.

Methanol and formate oxidation supported the assimilation of [14C]acetate by cell suspensions of Methylococcus capsulatus; oxidation of other primary alcohols, except ethanol, did not. The extent of [1-14C]acetate assimilation supported by methanol oxidation was decreased in the presence of primary alcohols, except ethanol. Potassium cyanide (0.33 mM) completely inhibited the oxidation of formate and its stimulation of [1-14C]acetate assimilation. The amount of [1-14C]acetate assimilation supported by methanol oxidation was significantly inhibited by cyanide.

Acetates↗
PubMed1976

N(2) Fixation Associated with Decaying Leaves of the Red Mangrove (Rhizophora mangle).

N(2) (C(2)H(2)) fixation was associated with decaying leaves of Rhizophora mangle. The process was predominantly anaerobic, with about two-thirds of the nitrogenase activity being light dependent. Average N(2) fixation rates in the light were 11 mug of N per g (dry weight) per h for leaves that had decayed for 2 to 3 weeks. This nitrogen input is probably significant in the estuarine, detrital food chains linked to R. mangle.

Journal Article↗
PubMed1970

Anaerobic degradation of the benzene nucleus by a facultatively anaerobic microorganism.

A bacterium was isolated by elective culture with p-hydroxybenzoate as substrate and nitrate as electron acceptor. It grew either aerobically or anaerobically, by nitrate respiration, on a range of aromatic compounds. The organism was identified as a pseudomonad and was given the trivial name Pseudomonas PN-1. Benzoate and p-hydroxybenzoate were metabolized aerobically via protocatechuate, followed by meta cleavage catalyzed by protocatechuic acid-4,5-oxygenase, to yield alpha-hydroxy-gamma-carboxymuconic semialdehyde. Pseudomonas PN-1 grew rapidly on p-hydroxybenzoate under strictly anaerobic conditions, provided nitrate was present, even though protocatechuic acid-4,5-oxygenase was repressed. Suspensions of cells grown anaerobically on p-hydroxybenzoate oxidized benzoate with nitrate and produced 4 to 5 mumoles of CO(2) per mumole of benzoate added; these cells did not oxidize benzoate aerobically. The patterns of the oxidation of aromatic substrates with oxygen or nitrate by cells grown aerobically or anaerobically on different aromatic compounds indicated that benzoate rather than protocatechuate was a key intermediate in the early stages of anaerobic metabolism. It was concluded that the pathway for the anaerobic breakdown of the aromatic ring is different and quite distinct from the aerobic pathway. Mechanisms for the anaerobic degradation of the benzene nucleus by Pseudomonas PN-1 are discussed.

Benzene↗
PubMed1969

New facultative Thiobacillus and a reevaluation of the heterotrophic potential of Thiobacillus novellus.

A new facultatively autotrophic Thiobacillus has been isolated in pure culture. The general physiological characteristics of the organism are described together with a redescription of Thiobacillus novellus. The new isolate differs from T. novellus in its ability to grow heterotrophically at faster rates and on a greater range of organic compounds. It can be transferred readily between autotrophic and heterotrophic conditions. It can grow anaerobically by nitrate respiration on a number of organic compounds, but not on thiosulfate. Some problems in the nomenclature and taxonomy of the thiobacilli are discussed with reference to the new isolate.

Cell-Free System↗