Six serotypes of calicivirus (San Miguel Sea Lion Virus types 4,6,7
and 13, Mink Calicivirus and Reptile Calicivirus) were plaque purified,
and two-dimensional gel electrophoresis fingerprints, of the ³²P-labeled
Ribonuclease T1 digested viral RNA, were performed for each serotype.
Fingerprints revealed several oligonucleotides with similar mobilities,
and therefore, possibly similar...
Antigen presentation is a mechanism used by cells to present peptides on the cell surface. Peptides, derived from both viral or self-proteins are presented on the cell surface by MHC Class I molecules to be recognized and detected by cytotoxic T cells. T cells comprise the defense system to protect...
Bdellovibrio bacteriovorus 100 and B. stolpii UKi-2 each produce
two extracellular proteases which attack Azocoll (collagen)
while B. starrii A3.12 produces at least four such proteolytic
enzymes. Under standard growth and assay conditions each Bdellovibrio
species produces a unique amount of proteolytic activity. The
decreasing order of enzyme units was...
Pseudomonas aeruginosa is a ubiquitous environmental microbe, opportunistic pathogen, and a highly social organism. P. aeruginosa utilizes a wide array of cooperative behaviors to adapt to the environmental conditions around it. These behaviors include quorum sensing (QS), a form a cell-to-cell signaling that coordinates the expression of secreted products in...
Mycobacterium avium subspecies hominissuis (MAH) is an opportunistic pathogen that is ubiquitous in the environment and often isolated from faucets and showerheads. MAH mostly infects humans with an underlying disease, such as chronic pulmonary disorder (COPD), cystic fibrosis (CF), or are immunocompromised, though infections in patients without concurrent disease are...
The myxozoan parasite Ceratonova shasta threatens both juvenile and adult salmonid populations in the Pacific Northwest region of the United States, causing intestine necrosis and hemorrhaging, along with high mortality in some fish strains. It induces an inflammatory tissue response in susceptible strains of fish; understanding the interactions between C....
Two experimental approaches have been used to investigate the interaction of sterols with respiration in yeast. Cells were tested with an antifungal sterol, azasterol, and a mutant was obtained with an altered sterol composition. Polarographic measurements were done on mitochondria for both experiments. The effects of azasterol on mitochondrial respiration...
Limnology is undergoing a transition to high-throughput -omic analysis of freshwater
bacterial communities. An important first step in making the transition is to
characterize several genomes that can be used as references to guide metagenome
assembly and analysis. Here I characterize four new freshwater cyanobacterial
genomes, a pair of lake...
To examine the macrophage response to M. avium, I compared inflammasome and cytosolic sensor expression and activation. My result demonstrated that virulent strains of M. avium (A5 and 104) suppress IL-1β production and induce IFN-β production in macrophages. M. avium mutants deficient at DNA export in the biofilm exhibited reduced...
A Lactobacillus species of human intestinal origin (strain
MLC) used in swine feeding experiments was characterized using
biochemical, genetic and serological techniques and found to be
Lactobacillus lactis. Bottle feeding of the MLC strain in concentrate
form (> 10⁹ cfu/ml) resulted in a reduction in both fecal coliforms
and the...
The serological detection of staphylococcal enterotoxin A by the
quantitative technique of Laurell electroimmunodiffusion is described
as well as the application of the technique to the detection of small
quantities of enterotoxin A in foods.
High dilutions of type-specific rabbit antiserum were used in 1%
agarose gels, 1 mm thick,...
Several biochemical tests were studied to determine their
correlation with coagulase activity. The lysozyme test was in perfect
agreement with the coagulase test for the strains studied.
Mannitol fermentation and egg yolk lipase tests were in agreement
with the coagulase test for 96% of the coagulase positive strains.
Sheep red...
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 objectives for this study were to determine the causes of
slime formation in activated sludge treatment and to recommend
possible control measures. The primary problem was a seasonal
filamentous bulking which was caused by the mold, Geotrichum
candidum. During the winter, mycelial fibers appeared and formed a
free floating...
Coreplication experiments have revealed that replication of
turnip yellow mosaic virus (TYMV) RNA in turnip protoplasts is cis-preferential.
Genomes encoding mutant p141 or p66, proteins
essential for virus replication, were inefficiently rescued by a
helper genome. One model for the cis-preferential replication of
TYMV is that p66 and p141 form...
The generation of the methyl group of methionine, and is also involved in thymidylic acid and purine biosynthesis. The understanding of the mechanisms and controls involved in one-carbon metabolism is incomplete, and is complicated by the existence of conjugated folate cofactors containing up to seven glutamic acid residues. The information...
Plant viruses have been instrumental in our understanding of the biophysical properties pertaining to non-enveloped icosahedral virus particles. A substantial amount of research has been performed over five decades on Turnip yellow mosaic virus (TYMV), arguably one of the most extensively studied icosahedral plant viruses and the type-member of the...
Routine studies of bacterial fatty acid and lipid composition,
made possible by recently developed techniques, have brought about
an increasing interest in the physiological significance of these
compounds. The purpose of this study was to characterize the fatty
acids of the vegetative cells of Clostridium botulinum 33A, as the
first...
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)...
A laboratory-prepared hot-water extract of yeast is required
for vigorous growth of San Francisco sourdough bacteria (Lactobacillus
sanfrancisco) in pure culture. This requirement was examined
with the goal of determining what is unique about fresh yeast extractives
(commercial extractives exhibit much lower growth promoting
activity), and which components of fresh...
Annual ryegrass (Lolium multiflorum) is a major seed crop
in the Willamette Valley of Oregon. Persistent crop diseases have
necessitated annual field burning to protect future crops. This practice,
while very effective for disease eradication, produces large
quantities of air polluting smoke in the valley and a general wastage
of...
The ability of mercury to inhibit β - galactosidase activity from
cell-free extracts of Streptococcus lactis, Escherichia colt and
intestinal homogenates of hogs, female rats, and humans was studied. Mercuric acetate was added in vitro to all sources of β - galactosidase except for the rats, which were placed on...
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...
Freshwater cyanobacterial blooms are a nuisance and health threat in the Pacific Northwest. The accepted methods of characterizing these blooms by microscopic cell counts cannot differentiate between toxic and non-toxic strains of the cyanobacterium Microcystis. Also, there is limited understanding of freshwater cyanophage that may control bloom dynamics. In order...
Roles of lactic acid bacteria in flour pre-ferment and white
bread were investigated. Volatile compounds produced by the
organisms were identified using gas-liquid chromatography (GLC).
Lactic acid bacteria were isolated from domestic commercial
compressed yeast and active dry yeast. Numbers per gram of
sample were 10⁸ to 10⁹ in compressed...
The primary purpose of this investigation was to characterize
the lipids of the spores and vegetative cells of Cl. botulinum. A
second purpose was to explore the possibility that lipids might serve
as a means of differentiating the chiefly proteolytic Cl. botulinum
type B from the nonproteolytic Cl. botulinum types...
A report in the literature suggesting that the use of cottage
cheese dressing cultured with S. diacetilactis would afford enhanced
flavor and shelf life in the finished product prompted this study to
examine reasons for its effectiveness. The method used involved
addition of a culture of S. diacetilactis 18-16 to...
Core samples from five sites in the Yaquina and Coos Estuary
were assayed for vertical distribution of total sulfides, percent
volatile solids, redox potential, particle size, total aerobic and
sulfate reducing bacteria. Higher total sulfide levels were found at
sites having more than four percent volatile solids, redox potential
below...
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...
Nutritional shift-up experiments have revealed many important
macromolecular interactions in bacteria. It has been shown that RNA
synthesis can be dissociated from protein and DNA synthesis. The
rates of protein synthesis were found to be, at a given temperature,
strictly dependent on the numbers of mature ribosomes present.
DNA synthesis...
Some positive-strand RNA plant viruses possess a transfer RNA-like structure (TLS) at the 3'-terminus of their genomic RNAs. The closest mimicry to tRNA is exhibited by the valylatable TLSs from tymoviruses and furo-like viruses, which are able to interact with key cellular tRNA enzymes: [CTP, ATP]:tRNA nucleotidyltransferase (CCA NTase), valyl-tRNA...
The characteristics of an inhibitor of infectious pancreatic necrosis virus (IPNV)
found in normal rainbow trout serum (RTS) were studied. The serum inhibitor had a
molecular weight of approximately 150 kDa and was dependent on divalent cations,
either Ca²⁺ or Mg²⁺. It was stable at temperatures up to 50°C and...
A chitinase producing bacterium was isolated from soil and identified
as a species of Arthrobacter. The organism grew well at temperatures
between 27 and 33.5 C, and the chitinase production was highest
at 25.5 C. As the temperature increased above the optimum point, the
level of enzyme production rapidly decreased,...
Three closely related isolates belonging to the A₁ serotype of infectious pancreatic
necrosis virus (IPNV) were selected for comparison, to provide insight into the nature of
variation in the virulence of IPN viruses. Brook trout fry (Salvelinus fontinalis) were
experimentally infected with the three isolates by immersion. Cumulative mortalities over...
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...
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...
Phytophthora cactorum lacks sterol synthesis capability. Nevertheless,
it exhibits vegetative growth in the total absence of sterol.
Supplementation of the growth medium with sterol, however, resulted in
a three-fold increase in cell yield. This increase was shown by whole
cell and cell free experiments to be the consequence of altered...
Comparatively little work has been done on bacterial lipids.
There are profound differences between bacterial lipids in general
and lipids of the higher forms of life in such respects as the absence
of sterols, phospholipids low in nitrogen but high in inositol
and carbohydrate, the presence of large proportions of...
The difficulties encountered in working with micro-quantities
of lipids have been overcome by the advent of new and improved
procedures in chromatography which have made possible better
fractionation and identification. Bacterial lipids because of their
different lipid pattern from other life forms have stimulated much
interest. Studies have been made...
Trypticase-Soy Broth (TSB) was inoculated with Streptococcus
diacetilactis, incubated at 21C for 24 hours and centrifuged to remove
the cells. When the spent TSB was inoculated with Staphylococcus
aureus, it allowed 99.8% less growth than fresh TSB. If the spent
TSB were supplemented with 0.08 μg/ml of niacinamide, this inhibition...
In an attempt to determine the natural habitat of Streptococcus
lactis, Streptococcus cremoris, and Streptococcus diacetilactis 27
different species of vegetables, 18 species of fruits and many individual
cow raw milk samples were examined.
S. lactis was found to occur on potatoes, corn, cucumbers,
peas, beans, and cantaloupe. In each...
Investigations into the phylogeny, genome size, and karyotype of microsporidian Nadeispora canceri were initiated to further characterize the organism. Isolates of N. canceri spores were obtained from both Dungeness (Cancer magisrer) and red rock crabs (Cancer productus). Analysis of the ssu rDNA sequence from spore isolates of the two crab...
Plasma membranes isolated from a yeast sterol auxotroph (RD5-R)
grown on 1,5, and 15 pg m1⁻¹ exogenous concentrations of sterol showed
no discontinuity in plots of steady-state fluorescence anisotropy.
Liposomes constructed from phospholipid and sterol extracted from RD5-R
grown on different sterols indicated exogenously supplied sterol
modulated cellular phospholipids such...
The advent of improved DNA sequencing technologies has allowed the analysis of various microbial communities. Bloom-forming freshwater cyanobacteria can produce toxins and taste-and-odor compounds that can negatively affect drinking water supplies. Here, I have employed second- and third-generation sequencing technologies to characterize bloom-forming freshwater cyanobacterial genomes and their associated heterotrophic...