A. Yayanos | University of California, San Diego (original) (raw)

Papers by A. Yayanos

The Journal of Physical Chemistry, 1972

The volume of aqueous solutions of glycine and of its uncharged isomer! glycolamide, of D,L-a-ala... more The volume of aqueous solutions of glycine and of its uncharged isomer! glycolamide, of D,L-a-alanine and of its uncharged isomer, lactamide, and of glycylglycine has been determined a t 25' and a t pressures to 1000 atm. The apparent molal volume of the dipolar amino acids increases, whereas that of the uncharged isomers decreases with pressure. The rate of change with pressure is concentration and pressure dependent. The electrostriction decreases with increasing pressure and appears dependent on the dipole moment of the amino acid. The Fuoss-Kirkwood theory of the solvation of amino acids does not appear to be adequate to explain the magnitude of the pressure effect on the electrostriction. The PV isotherms approximately fit a Mietype equation of state from which an estimate of their tensile strength was made. The tensile strengthincreased with concentration and was higher in the case of the amino acid solutions than in that of corresponding uncharged isomers.

Comparative Biochemistry and Physiology Part A: Physiology, 1981

Amphipods were recovered cold and undecompressed (at 601 bars) from a 5900 m depth. The animals a... more Amphipods were recovered cold and undecompressed (at 601 bars) from a 5900 m depth. The animals at 2°C were decompressed from 601 bars to atmospheric pressure at a controlled rate with the loss of locomotor activity at 215 bars. 2. The animals were left at atmospheric pressure for 4min. Locomotor activity was immediately regained foliowing recompression. 3. Vertical migrations of more than 3000 m appear ~hysjo~ogj~~iy possible even if perhaps never done by the benthic amphjp~s studied. 4. Brief man~polatjons of deep-sea amphipods outside of pressure vessels appear feasible.

Advances in High Pressure Bioscience and Biotechnology, 1999

Bacteria inhabit virtually all of Earth’s high pressure oceanic environments. The deep oceanic ha... more Bacteria inhabit virtually all of Earth’s high pressure oceanic environments. The deep oceanic habitats are at pressures as high as ~109 MPa and at temperatures between -0.5 and ~113°C. The study of bacteria from these environments gives an idea of how pressure, p, and temperature, T, as coordinate variables affect bacterial adaptation and evolution. The comparison of the growth kinetics of bacteria from the cold deep sea (2°C), from the abyssal Sulu Sea (9.8 °c), and from the abyssal Mediterranean Sea (13.5 °c) shows the interplay of habitat temperature and pressure to set the response of an organism. The traditional definition of barophily is profitably replaced with one of piezophily which is operationally defined with the aid of a plot of the growth rate constant, k, as a function of T and p. Such a plot, called a pTk diagram, also provides quantitative relationships between growth characteristics of an organism and its habitat. The relationships, furthermore, allow for an otherwise difficult comparison of organisms from different pT habitats. These diagrams may also help in the selection of bacteria with properties appropriate for particular biotechnological applications.

Science, 1978

Amphipods were collected from an ocean depth of 5700 meters in a windowed pressure-retaining trap... more Amphipods were collected from an ocean depth of 5700 meters in a windowed pressure-retaining trap, kept alive in the trap for as long as 9 days aboard ship, and transported to a land laboratory. Observations suggest that the animals can easily tolerate decompressions of 29 percent and briefly of 70 percent of the value of 580 bars, the pressure of their natural habitat. The average pleopod beat frequency was 106 beats per minute. Evidence suggests that food (fish bait) can have at least a 4-day residence time in the gut of these animals.

Review of Scientific Instruments, 1969

Biophysical Journal, 1969

AssrRAcr In cultures of Escherichia coli 15 (thymine-, leucine-) which were incubated at high hyd... more AssrRAcr In cultures of Escherichia coli 15 (thymine-, leucine-) which were incubated at high hydrostatic pressures, cell division occurred only at pressures below 430 atm but in a somewhat synchronous fashion at around 250 atm. The rate of leucine-14C incorporation into a macromolecular fraction of the cells diminished to a zero value at about 580 atm and that of uracil-l4C incorporation to a zero value at about 770 atm. The rate of thymine-"4C incorporation at pressures around 330 atm was that to be expected with a culture in which DNA synthesis is somewhat synchronous. At pressures above 500 atm, thymine-l4C was incorporated only over the initial part of the pressure incubation and further incorporation under pressure was not observed no matter how long the duration of the incubation. We present evidence along several lines that the thymine incorporation kinetics reflect an effect of pressure on a locus at the origin (or termination) of a replication of the bacterial chromosome. The recovery of cell division and of the incorporation rates upon release of pressure were found to depend on the magnitude of the pressure and the duration of the pressure incubation.

Analytical Biochemistry, 1985

A spectrofluorometric technique for bacterial DNA base composition has been developed. This fast ... more A spectrofluorometric technique for bacterial DNA base composition has been developed. This fast and simple technique requires two fluorescent dyes and a few inexpensive reagents. The data from this assay indicate that the guanine-cytosine content obtained was within acceptable statistical limits in comparison to commonly cited literature values. The spectrofluorometric technique is reliable and reproducible.

Deep Sea Research, 1978

The density of a lipid mlxture composed of nearly 85 ~ wax esters and isolated from the copepod C... more The density of a lipid mlxture composed of nearly 85 ~ wax esters and isolated from the copepod Calanus plumchrus was determined at 5 13, 14 49, and 23 65°C and at pressures up to 783 bars_ At atmospheric pressure, the density was determined at temperatures between 1 6, and 15.54°C The experimental isotherms and isobars were fitted to several equations of state and these were used to calculate coefficients of thermal expansion and compressibility The wax ester mixture visibly melted as a function of temperature at atmospheric pressure. The high pressure isotherms show a volume discontinuity as a function of pressure that suggests a first-order hquid-solid phase transition The coefficient of thermal expansion at atmospheric pressure is quite large (up to ten times that of water) and is apparently due in part to the phase change and its concolmtant volume change The coefficient of compressibility at atmosphenc pressure is larger for the more solid form of the wax ester mixture than for the more liquid form The contlabution of wax esters to the buoyant properties of organisms is discussed. The buoyant force on the wax ester in seawater changes more as a function of temperature than as a function of pressure The data also have imphcatlons to understanding sound scattering by wax ester-contaimng organisms At depths defined by the pressure-temperature curve for the phase change, the wax ester mixture is on the verge of either melting or freezing This results In a large coefficient of compressibility and may result in distinctive sound scattering by organisms containing wax esters and swimming at such depths Furthermore, sound scattenng should be different in organisms with solid wax ester mixtures than in those with liquid mixtures

Deep Sea Research and Oceanographic Abstracts, 1976

A method is described for determining pressure-volume isotherms of liquids at high pressures. A v... more A method is described for determining pressure-volume isotherms of liquids at high pressures. A volumometer without a ground glass joint i s used. The pressure-volume-temperature (PVT) surface of lsopar-M has been determined, and shows that this hydrocarbon liquid is suitable for floats to 1100 bars at 0°C. The so-called Tait equation has been used as the equation of state for the PVT values.

Applied and environmental microbiology, 1983

The colony-forming ability and the rate of reproduction of Bacillus stearothermophilus were deter... more The colony-forming ability and the rate of reproduction of Bacillus stearothermophilus were determined as a function of temperature and pressure. Colonies were formed between 39 and 70 degrees C at atmospheric pressure and between 54 and 67 degrees C at 45 MPa. Colonies did not form at 55.9 MPa. The rate of reproduction in broth cultures decreased with increasing pressure at all temperatures. The rate of reproduction diminished rapidly with pressure above 10.4 MPa. Therefore, increased hydrostatic pressure was not sufficient to enable B. stearothermophilus to function beyond the temperature limiting growth and reproduction at atmospheric pressure, and B. stearothermophilus should grow in naturally or artificially warmed regions of the deep sea, where the pressure is less than approximately 50 MPa, although growth rates would be low above 10 MPa.

Applied and environmental microbiology, 1982

The barophilic deep-sea bacterium, isolate CNPT-3, was inactivated by exposures to temperatures b... more The barophilic deep-sea bacterium, isolate CNPT-3, was inactivated by exposures to temperatures between 10 and 32 degrees C at atmospheric pressure. Inactivation in samples from warmed cell suspensions was measured as the loss of colonyforming ability (CFA) at 10 degrees C and 587 bars. At atmospheric pressure, there was a slow loss of CFA even at 10 degrees C. The loss of CFA was rapid above 20 degrees C and only slightly affected by high pressures. The first-order rate constants for thermal inactivation fit the Arrhenius equation with an activation energy of 43 kcal (ca. 179.9 kJ)/mol. Light microscopy and scanning transmission electron microscopy revealed morphological changes due to warming of the cells. The changes ensued the loss of CFA. The results supported the hypothesis from an earlier work that indigenous (autochthonous) deep-sea bacteria from cold deep seas are both barophilic and psychrophilic. If ultimately sustained, these characteristics may be useful in designing ex...

Applied and environmental microbiology, 1986

The fatty acid composition of the membrane lipids in 11 deep-sea bacterial isolates was determine... more The fatty acid composition of the membrane lipids in 11 deep-sea bacterial isolates was determined. The fatty acids observed were typical of marine vibrios except for the presence of large amounts of long-chain polyunsaturated fatty acids (PUFAs). These long-chain PUFAs were previously thought to be absent in procaryotes, with the notable exception of a single marine Flexibacter sp. In three barophilic strains tested at 2 degrees C, there was a general increase in the relative amount of PUFAs as pressure was increased from a low growth pressure towards the optimal growth pressure. In Vibrio marinus MP-1, a psychrophilic strain, PUFAs were found to increase as a function of decreasing temperature at constant atmospheric pressure. These results suggest the involvement of PUFAs in the maintenance of optimal membrane fluidity and function over environmentally relevant temperatures and pressures. Furthermore, since these lipids are essential nutrients for higher taxa and are found in lar...

Applied and environmental microbiology, 1984

A pressurized temperature gradient instrument allowed a synoptic determination of the effects of ... more A pressurized temperature gradient instrument allowed a synoptic determination of the effects of temperature and pressure on the reproduction of bacteria. The instrument consisted of eight pressure vessels housed parallel to each other in an insulated aluminum block in which a linear temperature gradient was supported. For a given experiment, eight pressures between 1 and 1,100 bars were chosen; the linear temperature gradient was established over an interval within -20 to 100 degrees C. Pure cultures and natural populations were studied in liquid or solid medium either in short (ca. 2-cm) culture tubes or in long (76.2-cm) glass capillaries. In the case of a pure culture, experiments with the pressurized temperature gradient instrument determined values of temperature and pressure that bounded its growth. Feasibility experiments with mixed populations of bacteria from water samples from a shallow depth of the sea showed that the instrument may be useful in identifying the extent to...

Applied and environmental microbiology, 1976

The intestinal microflora of deep-sea amphipods, in enrichment culture employing starch, urea, an... more The intestinal microflora of deep-sea amphipods, in enrichment culture employing starch, urea, and N-acetyl-d-glucosamine and when examined under simulated in situ conditions, exhibited growth rates and substrate conversion approximately equal to, or greater than, atmospheric controls during short-term incubation. These observations are significant since these microorganisms may play an important role in biodegradation in the deep sea.

Oceans '02 MTS/IEEE, 2002

Recent developments in the manufacture of borosilicate glass housings offer scientific investigat... more Recent developments in the manufacture of borosilicate glass housings offer scientific investigators and ocean engineers the opportunity to go "deep and cheap." The 17-inch OD spheres, manufactured By Schott Glasswerks in Jena, Germany, provide ample interior space and positive buoyancy. The clarity of the glass and manufacturing tolerance control make the housings useful for photographic imaging. Other sensors suites may

This presentation addresses the rationale, history, strategy, and management techniques used in t... more This presentation addresses the rationale, history, strategy, and management techniques used in the development of the US Subseabed Disposal Program (SDP) for both high level waste and spent fuel. The three subsections will summarize first, the US Department of Energy (DOE) high level waste and spent fuel waste disposal strategy and the position that the SDP occupies within that strategy;