Biographical Memoirs Volume 81 (2002) / Chapter Skim
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Marvin P. Bryant
Marvin P. Bryant
Pages 66-99
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From page 67... ...
him towarc! Washington State College in Pullman.
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From page 68... ...
flasks, glass tubing, en cl assorted salvage. Among the things "manufactured" were a complete Warburg apparatus, micro-modification of the Newcomer-HaTciane constant pressure volumetric gas analyzer, all condensers, en cl various units required for the determination of lactate en cl volatile fatty acicis when chromatographic en c!
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From page 69... ...
His research involvecl the isolation en cl characterization of the small rumen spirochete of the genus Treponema, which conic! move through agar or particulate forage en cl compete with cellulolytic bacteria for use of the soluble sugar energy sources produced by the latter from cellulose.
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From page 70... ...
During his stay in Ithaca, Professor William Pounden of Ohio State University visited and carried word to Beltsville Agricultural Research Center that Hungate had a graduate student working in rumen microbiology. A research bacteriology position was offered by the Bureau of Dairy Industry and, alter a strong push from Hungate, Marv decided to accept.
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From page 71... ...
Marv's main goals were to taxonomically describe, with emphasis on ecologically important metabolic features, the numerous species of rumen bacteria en c! to chemically identify "unusual" growth factors present in rumen Quill but not in most organically rich growth meclia.
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From page 72... ...
A balances! mineral anaerobic solution similar to the growth medium, but with rumen Quill en cl sugar energy sources removed served as the ru-a ~ .
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From page 73... ...
Marv user! various mollifications for studying anaerobic bacteria as diverse as methanogens, photosynthetic bacteria, sulfate reducers, human GI tract anaerobes, en cl those of meclical concern.
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From page 74... ...
various amounts of propionate, acetate, lactate, en cl CO2 from many different sugars en cl starch en cl also clegraclecl a number of amino acids. The subspecies lactitytica fermented important energy sources such as lactic acid en cl glycerol.
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From page 75... ...
The studies of the flora of young calves gave Marv further insight into the diversity of anaerobic bacteria en c! the clifficulty of identifying well-stucliec!
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From page 76... ...
This organism was of interest because of its ability to produce butyrate en cl longer-chain volatile fatty acicis from one-carbon compounds such as methanol or H2-CO2. The studies of pure cultures of functional rumen bacteria clisclosecl large numbers of species that proclucecl such products as lactate en cl ethanol, which were not normal products or important extracellular intermediates in the rumen fermentation.
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From page 77... ...
. These studies were the first of a series from Marv's lab showing that many rumen bacteria, other heterotrophic bacteria, and most methanogenic anaerobic bacteria hacl a very limitecl ability to utilize organic nitrogen sources such as amino acids or peptides.
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From page 78... ...
that most functional rumen bacteria couIcl be grown in relatively simple chemically clefinecl culture meclia. Many species usecl ammonia, rather than free amino acids or pepticles, as the major en cl essential source of nitrogen, en cl all species were able to utilize ammonia as their main nitrogen source.
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From page 79... ...
ruminicola container! a lo-type cytochrome involved in electron transport for fumarate reduction to succinate by reduced pyridine nucleotide generated in glycolysis during the CO2-dependent fermentation of carbohy
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From page 80... ...
in the nutrition of rumen organisms, isolatecl the methanogen using the techniques previously developed but with hydrogen gas replacing sugars as the energy sources. They confirmed!
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From page 81... ...
the major celluTolytic en cl some other rumen fermentative bacteria in certain major nutritional features. Because of his work at Illinois en cl later efforts of several other laboratories, it is now known that all species of methanogens so far stucliecl require ammonia as the main nitrogen source en cl that acetate is often a preferrer!
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From page 82... ...
His expertise in growing methanogens on hydrogen gas en cl CO2 turned out to be crucial to many of the advances macle in the Dairy Science Microbiology Division labs in collaboration with Wolin en cl in the laboratory of Wolfe in the Department of Microbiology. After his move to Illinois, work on the unknown factor required by M
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From page 83... ...
, was founcl to be involvecI. Previous workers in Wolfe's laboratory had isolated a chemically unknown compound with a relatively low molecular weight en cl with blue-green fluorescence in ultraviolet light en cl hac!
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From page 84... ...
When Marv arrivecl at Illinois, Wolfe hacl expressect some ctoubts about the purity of the culture because slightly differing cell shapes were sometimes seen in cultures en cl he felt that these might represent two species. He suggested that Marv isolate colonies from the ethanolgrown culture by growing them in H2-CO2 agar roll tubes using techniques previously used for M
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From page 85... ...
It is considered even more important in methanogenic ecosystems where more complete anaerobic degradation occurs (e.g., where products such as volatile and longerchain fatty acids are largely converted to methane and CO2)
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From page 86... ...
be grown fairly effectively on pyruvate in pure culture. Recicly showocl that this fermentation involvecl production of acetate en c!
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From page 87... ...
further evidence that reduced pyridine nucleotide produced in glycolysis by fermentative bacteria couIcl be reoxiclizecl via H2 production if methanogens use the H2 efficiently. The efficient use of H2 allowocl the fermentative bacteria to produce larger amounts of H2 and acetate en cl smaller amounts of ethanol, lactate, succinate, propionate, en c!
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From page 88... ...
out the various oxidations of the three-carbon fatty acid, propionate, and longer-chain fatty acids, and disposed of electrons generated via CO2 reduction to methane. Although several species carrying out these reactions hac!
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From page 89... ...
or acetate and propionate (fatty acids with odd-numbered carbon atoms) in obligate syntrophy with Hz-using methanogens such as M
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From page 90... ...
In cooperation between Marv's laboratory and those of Frank Hinds and Fred Owens (Department of Animal Science) , Ronald Isaacson set up model experiments with continuous cultures of mixed rumen bacteria growing on glucose to determine the efficiency of rumen bacterial growth in relationship to the rate of passage of material through the system.
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From page 91... ...
Graduate student Mary Ann Wozny then developed a rapid assay and growth medium in which most pure cultures of fermentative anaerobes grew en cl expressec! urease activity.
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From page 92... ...
Marv, along with graduate student Dan Schaefer en cl Professor Carl Davis, proved that important rumen bacterial species hac! a great affinity for ammonia as nitrogen source en cl couIcl achieve maximum growth rates with mM or less ammonia.
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From page 93... ...
Marv hacl long suspected that some important rumen bacteria hac! a growth requirement for a fat-soluble vitamin of the vitamin K group.
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From page 94... ...
a special tone to his voice when his beloved rumen bacteria were being discussed. He was a national treasure of information on anaerobes en cl
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From page 95... ...
M A RVI N P . B RYA N T 95 his colleagues at Illinois en c!
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From page 96... ...
Volatile fatty acid growth factor for cellulolytic cocci of the bovine rumen. Science 128:47475.
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From page 97... ...
109:53945. 1973 Nutritional requirements of the predominant rumen cellulolytic bacteria.
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From page 98... ...
Efficiency of bacterial protein synthesis during anaerobic degradation of cattle waste.
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