The benthic microalgae of sediments of the two tidal flats in
Yaquina Bay, Oregon were investigated to determine the environmental
factors limiting the abundance and the horizontal and vertical distribution
of these organisms. The Southbeach tidal flat which is under the
marine realm of deposition consists of fine to medium...
The purpose of this study was to determine what insect species
occurred in waste water facilities at Corvallis, Oregon, and to
correlate these species with the chemical, physical, and biological
features common to these facilities. Data collected on a routine
basis included dissolved oxygen, temperature, algal density, and
insect population...
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,...
The ecological and silvicultural importance of snowbrush,
Ceanothus velutinus, in the areas west of the summit of the Oregon
Cascades was studied. Particular attention has been given its nitrogen-
fixing ability under both field and greenhouse conditions.
On west slopes of the Oregon Cascades snowbrush occurs above
2, 500 feet...
This thesis reports a portion of a general ecological study of
a stream under conditions of controlled flow and low levels of organic
enrichment. It is concerned with the effects of experimental variations
of light intensity and concentration of soluble organic enrichment
imposed on seasonal variations of temperature and total...
Chemical and microbial analyses were made at four seasonal intervals on soil horizons under red alder, conifers, and mixed
alder-conifers at the Cascade Head Experimental Forest, established in 1937 by the U. S. Forest Service near Otis, Oregon.
Microbial analyses showed that although plate counts of molds and bacteria fluctuated...
Studies were conducted from 1962 to 1966 to investigate the
effectiveness of several practices in manipulating medusahead
(Taeniatherum asperum (Sim. ) Nevski) infested and/or dominated
ecosystems by releasing competition in favor of perennial grasses.
Several herbicide treatments were evaluated for selective
control of medusahead and cheatgrass (Bromus tectorum L. )...
Studies were conducted to determine the competitive ability of
medusahead, Taeniatherum asperum (Sim.), for nitrogen when grown in
association with perennial range grass species. The method used to
determine this competitive ability was to compare the dry weight,
percent nitrogen, and total nitrogen of medusahead and perennial
wheatgrass species growing...
A method was devised and tested for rapid and quantitative
identification of microbial flora in fresh seafoods. The rapid
identification of large numbers of isolates was made possible by
(1) a simplified identification scheme established by reference
culture studies and from the known reactions of microorganisms
reported in the literature,...
Bdellovibrio bacteriovorus is a small parasitic bacterium present
in soil, mud, and aquatic habitats. Due to its lysis of Gramnegative
bacteria, an important role in soil ecology has been suggested
for this organism. A study of effects of herbicides upon
Bdellovibrio might consequently be of considerable value.
In this study...
The storage life at 43°F of ground dover sole fillets (Microstomas pacificus) was determined microbiologically after treatment with
ionizing radiation and antimicrobial agents. Sodium benzoate, potassium
sorbate and the sodium salts of the methyl and propyl esters
of parahydroxybenzoic acid (MPB and PPB) all approximately doubled
the refrigerated storage life...
Most studies of bacteria in water have concerned public health; little attention has been given to organisms which are indigenous to
the aquatic environment. Myxobacteria are known to occur in soil,
in the marine environment, and several have been studied in relation
to diseases of salmonid fishes. However, little information...
Certain species of the orders Myxobacterales and Pseudo-monadales are well-known antagonists. Pseudomonas fluorescens
and Pseudomonas putida have been reported to produce bacteriostatic
and bactericidal substances. Among the myxobacteria there
are various species which are known for their ability to produce
lytic enzymes and antibiotics. Organisms from both of these groups...
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...
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...
Comparatively little work has been done to determine the ecology
of Clostridium botulinum type E since its initial isolation in the
nineteen-thirties. This spore forming, anaerobic microorganism is
relatively heat labile and has been missed in ecological surveys in
which heat was used to selectively screen for spore formers. Use...
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...
Humus is one of the important factors controlling the soil
formation process. The nutrients released from it during the decomposition
process also affect the growth and reproduction of the
forest. The type of humus formed is influenced by the nature of the
forest litter and the environment in which it...
To study the association between Fusarium root-rot resistance
(Fusarium solani f. sp. phaseoli) and economically inportant characteristics
of beans, 2259 lines each consisting of 30 plants were used.
The lines were randomly selected for root-rot reaction, but were
selected for differences in vigor and differences in plant and seed
pigments,...
Cells of an obligately psychrophilic marine bacterium, Vibrio
marinus, strain MP-1, were grown at 4 C and 15 C and studied for
possible physiological differences. No differences were noted in
sugar fermentation or temperature-shift growth studies; in both cases
adequate nutrients were available. Some differences were noted in
viability retention...
Raw and biologically stabilized Kraft mill effluents were introduced
into laboratory artificial streams at a ratio of 15 ml per liter
of water over a two year period. Effluent from the stabilization pond
of a second mill was introduced at concentrations of from 5 to 40 ml
per liter of...
Optimum growth of Marine Psychrophile 41 (MP-41) an obligately
psychrophilic marine vibrio, occurred at 18 C and pH 8.0
to pH 8.3.
Twenty eight-fold purification of gelatinase from this organism
was effected by ammonium sulfate fractionation and column chromatography
on Sephadex G-200 gel.
The effects of temperature, pH, pressure, and...
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...
Subterranean clover was grown in nutrient solution and S
deficient Steiwer soil in the greenhouse. Plants were harvested at
15, 30, 45 and 60 days after emergence.
When subterranean clover was grown in nutrient solution significant
yield response to each increment of added sulfate (SO₄-S)
occurred in 15, 30, 45...
Gamma irradiation inactivation kinetics were studied using
fifteen organisms naturally contaminating seafoods. Survival curves
for seven Salmonella, three Shigella, two Streptococcus species and
a Staphylococcus, Escherichia and Proteus species were determined
using Hartsell's broth and fresh oysters. Also, the Shigella species
and one species of Streptococcus, Escherichia and Proteus were...
Abundant conidial and sclerotial production occurs on iris
plants infected with Botrytis convoluta Whetzel and Drayton during
the cool moist months of the year. Experiments were designed to
study the survival and inoculum potential of conidia and sclerotia.
Basic nutritional requirements of the fungus in culture were also
studied.
Results...
This study was conducted to investigate the differences of the
profile distribution of free iron and free manganese and the reduction-oxidation changes in soils of the Willamette drainage sequence.
Based on the results of the chemical analyses, free iron and
free manganese distributions in these soils were governed to a...
Two separate investigations were carried out. The first experiment
on subterranean clover (Mr. Barker) was conducted in the field
and greenhouse on the Steiwer soil. The second experiment on alfalfa
(DuPuits) was conducted in the greenhouse on selected eastern Oregon
soils.
The purposes of the first experiment were to determine...
The incitant of Verticillium wilt of peppermint (Verticillium
dahliae Kleb.) causes disease symptoms only in the genera Mentha
(the mints) and Monarda. This fungus is unable to grow saprophytically
through natural soil. V. dahliae survives in soil by colonizing
and forming microsclerotia in susceptible plants, living root tissue
of many...