An ecological study of a microorganism similar to that isolated
in 1956 and designated as Micrococcus radiodurans indicated
that the organism could be isolated from several different environments.
By taking advantage of its radio-resistivity, high levels of
gamma radiation were used in the isolation procedures to inactivate
most of the...
The dairy industry relies primarily on consistent acid production
by the lactic streptococci for the manufacture of certain cheeses
and fermented dairy products. Variation in these cultures due to
genetic exchange has not been thoroughly investigated. This study
was undertaken to determine if genetic homology exists within the lactic
group,...
The terminal reactions in the biosynthetic pathway of methionine
in Saccharomyces cerevisiae were investigated in this study. Analyses
of a number of methionine auxotrophs for biochemical deficiences
established four mutant groups. It was observed from qualitative feeding
experiments that some auxotrophs were able to utilize S-adenosylmethionine
(AM) and S-adenosyl-homocysteine (AH)...
When nitrate is used in a biological electron transport
system as the final acceptor of hydrogen to form water,
the system is characterized as "Nitrate Respiration." However,
the quantitative expression of the over-all participation
of NO₃⁻(0) in the oxidation of glucose by denitrifiers
such as Pseudomonas stutzeri deserves clarification.
In...
The public health and economic significance of rapid acid production
by lactic streptococci in controlled dairy fermentations is well
known. However, the fast acid-producing characteristic of these organisms
is not stable, and cultures of fast organisms have been shown
to contain slow cells. These studies were carried out to characterize...
Comparisons were made of the abilities of Streptococcus lactis,
Streptococcus cremoris and Streptococcus diacetilactis bacteriophages
to endure various laboratory isolation and storage treatments.
Neutralization of Cottage cheese whey containing phages offered no
survival advantage over unneutralized samples, refrigeration of
neutral and acid whey samples increased the survival of only the...
The mechanism of transsulfuration and the role of cystathionine
in the biosynthesis of methionine in yeast were investigated.
Saccharomyces were shown to accumulate cystathionine by use
of the ³⁵S labeled compound.
Cell-free extracts of the wildtype clone as well as methionine
auxotrophs were shown to cleave cystathionine. The enzymatically
produced...
Prevailing concepts relating to the non-enzymatic gaseous
loss of nitrite from soil are thought to be inadequate as regards
to the mechanisms involved. The conventional explanation for
nitric oxide formation i.e., the acid decomposition of nitrite,
is held to be insufficient in substrates of only mild or slight
acidity. A...
Studies were carried out to elucidate the mechanism of enzymatic
control of methionine biosynthesis in Saccharomyces cerevisiae.
Enzymatic studies demonstrated that, in addition to the methionine
activating enzyme, the S-adenosylmethionine:homocysteine
transmethylase enzyme was induced during cultivation in the presence
of excess methionine. A similar, though reduced effect was
observed when...
An enzyme system was prepared from Saccharomyces cerevisiae,
strain MCC, which carries out the transfer of the methyl group from
S-adenosylmethionine or methionine to the side chain of yeast sterols.
The cell-free system has been shown to be incapable of synthesizing
ergosterol but carries out the synthesis of two as...
The enzymes and pathways involved in the catabolism of
glucose by several strains of Streptococcus diacetilactis, Streptococcus
cremoris, and Streptococcus lactis, commonly called the
lactic streptococci, were studied. The presence of aldolase,
triosephosphate isomerase and alcohol dehydrogenase in these
organisms provided evidence for the operation of the Embden-Meyerhof-Parnas (EMP) pathway...
Characterization of a virus requires that its physical, biochemical
and biological properties be determined. In this study the
Oregon sockeye salmon virus was characterized. It was isolated
in the fall of 1958 from juvenile sockeye salmon, Oncorhynchus
nerka, being reared at the Oregon Fish Commission's Willamette
River Hatchery.
When inoculated...
Experiments were carried out to purify and characterize the
galactosidase of the Streptococcus lactis 7962. Purification was
accomplished using standard procedures; however the lability of
the enzyme to numerous treatments limited the techniques that could
be used and the amount of active enzyme recovered. Gel filtration
revealed that the enzyme...
Some enzymes of the citric acid cycle and glycolytic pathway
in cell-free extracts of Vibrio marinus MP-1 were compared for
thermal lability. After one hour of moderate temperature exposure,
enzymes of both pathways rapidly lost catalytic activity. For all
but one enzyme, 50 percent remaining activity occurred near an
averaged...
The regulation of ergosterol biosynthesis in yeast has been
studied. The system has been examined for the presence of an end-product inhibition. Both anaerobically and aerobically grown cells
have been examined for this effect. A feedback inhibition of sterol
synthesis has been shown, but it appears to be a secondary...
The association of other materials with DNA has been studied
extensively in higher organisms and more recently in bacteria.
However, investigation of these complexes in bacteria have for the
most part been restricted to the study of a specific function this association
may serve, or a specific kind of association....
The mycorrhizal rootlets of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco.) and red alder (Alnus rubra Bong.) were extensively investigated. A jet-black mycorrhiza was found to be dominant on Douglas-fir rootlets. The fungal symbiont was identified as Cenococcum graniforme (Sow.) Ferd. and Winge. Two forms of mycorrhizae predominated on root systems of...
The effect of Endothal (3, 6-endoxyhexahydrophthalic acid),
sodium pentachlorophenate (Na-PCP) and TD-47 (di-N, N-dimethylcocoamine
salt of Endothal) on the microbial populations, ammonification,
nitrification and respiration in six different soils was investigated.
It was found that Endothal at 20 and 200 ppm had no adverse
effect on the microbial population, ammonification,...
Pseudomonas aeruginosa cells were selected for their ability
to grow in the presence of 750 ppm alkyldimethylethylbenzyl
ammonium chloride (QAC). These cells were found to retain their
resistance to the germicide throughout tri-weekly transfers for 7
months in tryptone glucose yeast extract (TGY) broth containing no
QAC. Comparisons of the...
Denitrification is classically defined as the microbial reduction
of nitrate and nitrite with the liberation of molecular nitrogen
and, in some instances, nitrous oxide. The sequence of reactions
in which nitrogen is evolved as an end-product is essentially a
respiratory mechanism in which nitrate and/or nitrite replaces
molecular oxygen. The...
A water-soluble complex containing ergosterol together with
a component of yeast has been isolated. The complex can be isolated
from commercial yeast extract to which ergosterol has been
added or directly from whole yeast cells. The complexing agent
from yeast extract is also capable of solubilizing cholesterol and
a long...
The marine psychrophilic bacterium Vibrio marinus MP-4
possessed a maximum temperature and hydrostatic pressure of
20 C and 425 atm for growth. The effects of temperatures of 21 and
25 C and hydrostatic pressures of 200, 400, 500, and 1,000 atm on
protein, RNA and DNA synthesis by V. marinus...
The purpose of this investigation was to purify and characterize
the autolytic enzyme from cell walls of Bacillus subtilis 168. The
crude enzyme was obtained by autolysis of purified cell walls in
buffer at 37° C. Two purification methods were developed. The first
involved fractional precipitation with ammonium sulfate. The...
A cell-free system for assessing the role of S-adenosyl-methionine
in the methylation of homocysteine deriving the methyl
group from serine has been developed. No role for S-adenosyl-methionine
could be shown in the in vitro reaction
The enzyme serine transhydroxymethylase has been studied in
crude and partially purified cell extracts. Evidence...
Disc gel electrophoresis of the vegatative cell -free extracts ofstrains of Clostridium botulinum types A, B, C, E, and F and therelated nontoxic group showed limited value as a means for identifyingthese closely related microorganisms, since separation,though not consistent in all cases, could only be based on the numberof protein...
Glucose metabolism of phage-infected Streptomyces griseus
was examined by using the specific radioactivities of the amino
acids from the extracted protein of the host and phage as an index
of the catabolic pathways of glucose metabolism. Conventional
methods for the study of phage-infected bacteria did not suit the
host-actinophage system...
From a population of cells of Pseudomonas aeruginosa sensitive 33 parts per million (ppm) and 0.1 mg per ml of quaternary
ammonium (QAC) and chloramphenicol respectively, pure strains
resistant to 750 ppm and 50 mg per ml of these antibiotics were isolated.
Lipids from the sensitive and resistant cells grown...
The genome of the nuclear polyhedrosis virus which infects the
larvae of the tussock moth, the lepidopteran, Hemerocampa
pseudotsugata, was isolated, identified as deoxyribonucleic acid, and
characterized in terms of its physical and biological properties. An
isolation procedure for the viral DNA was established which consisted
of the following steps:...
The ability of Streptococcus diacetilactis to inhibit a variety of
food-borne pathogens and spoilage organisms in milk and broth cultures
was demonstrated. Test organisms inhibited included Pseudomonas
and Alcaligenes species, Eschericia coli, Salmonella, Staphylococcus
aureus, Clostridium perfringens and Vibrio parahaemolyticus.
In general, approximately 99.0% and 99.9% inhibition was
observed in...
The vitamin B₁₂ concentrations in both the water and sediments
of Klamath Lake were found to vary significantly during a
one-year period. The patterns of B₁₂ distribution were remarkably
similar among the three main sites. In all cases there was an extremely
sharp gradation in concentration in relation to depth...
The effects of various physical parameters on the binding, uptake,
and catabolism of glucose in the marine psychrophilic bacterium,
Vibrio marinus, were studied. It was shown that shortly after
the cell was exposed to labeled glucose, the radioactive label became
rapidly associated with the cell fraction. It was also shown...
Since the isolation of the Oregon sockeye salmon virus (OSV) in
1958, extensive investigations have been undertaken to characterize
the properties of this virus. The results of these investigations
have indicated that OSV is a single-stranded RNA virus which contains
essential lipids and has a density of 1.16 gm/cm³ in...
Synthesis of total RNA, DNA, and protein was followed in a
haploid yeast auxotroph during starvation for required amino acids
and uracil, and during shift-up and shift-down conditions.
During amino acid starvation, synthesis of macromolecular
constituents was not immediately affected, reflecting the presence
of large intracellular amino acid pools. Under...
The Oregon sockeye salmon virus (OSV) was isolated from
diseased sockeye salmon (Oncorhynchus nerka) fingerlings in 1958
by J. L. Fryer. Experimentation performed prior to the research
reported herein indicated that the OSV contained essential lipids, was
100 to 300 mμ in size, and possessed RNA (presumptively identified
by 5-bromodeoxyuridine...
Phosphorylation of free galactose by lactic streptococci was
mediated by an adenosine triphosphate (ATP) dependent kinase which
was repressed by glucose. The phosphoenolypyruvate (PEP) phosphotransferase
system (PTS) was not involved in transport of galactose,
The conversion of free galactose to glucose was also demonstrated.
A key Leloir pathway enzyme, uridine...
The purpose of this study was to develop means to facilitate
the detection of staphylococcal enterotoxin and to elucidate factors
that influence enterotoxin formation. It was found that semipurification
flat-gel electrophoresis in a water-cooled apparatus
was more efficient than CM-cellulose and Sephadex column chromatography
currently used to separate toxin from...
Saccharomyces cerevisiae strain XS-380, a. heteroallelic
diploid strain, carries six genetically analyzed loci on the left arm of
chromosome VII. Nitrosoguanidine (NMG) at low concentrations was
observed to cause allelic recombination (either mitotic recombination
or gene conversion) of the heteroallelic loci with low lethality.
The NMG-inducible heteroallelic system was used...
A selective, differential plating medium for the enumeration of
coagulase-positive staphylococci was developed. The ingredients of
this medium were analysed for their effect on normal, heat treated
and frozen staphylococcal cells. The nutrient base consisted of 10 gm
Tryptone, 5 gm Beef Extract, 1 gm Yeast Extract and 17 gm...
The research presented in this thesis is concerned
with the
characterization of two salmonid cell lines, CSE 119 derived
from
embryos of coho salmon (Oncorhynchus kisutch) and
STE 137 derived
from embryos of steelhead trout (Salmo gairdneri).
The rates of
glucose utilization and lactic acid production during the most
active...
The species composition of soil microfungal populations in-adjacent
stands of red alder, conifers, and mixed alder conifer correlated
strongly with the dominant vascular vegetation. A total of 92
species were isolated: 55 from the alder stand; 45 from the conifers;
and 46 from the mixed alder-conifer, with few species (16,...