Adsorption properties of cross-linked cellulose-epichlorohydrin polymers in aqueous solution.

Cellulose was cross-linked with epichlorohydrin (EP) at variable levels (CLE-0.5, CLE-2 and CLE-4), where CLE-i denotes the cellulose to EP mole ratios. The cross-linked products were characterized by TGA and FT-IR spectroscopy, pH at the point of zero charge (pHpzc), water swelling, and dye-adsorption methods employing two types of dyes [phenolphthalein (phth) and p-nitrophenol (PNP)].

Helminths in ruffed grouse at the host's southeastern range boundary.

Carcasses of 268 ruffed grouse (Bonasa umbellus) collected in eastern Tennessee (USA) from October 1983 through February 1988 were examined between 16 January 1985 and 25 April 1988 for non-filarioid helminths. Three nematode species and one cestode species were found. The two most common parasites were the cecal worm Heterakis bonasae (81% prevalence, mean intensity +/- SD of 62 +/- 114) and the tapeworm Echinolepis carioca (27% prevalence, 30 +/- 73 mean intensity).

Mercury residues in wood ducks and wood duck foods in eastern Tennessee.

Liver, breast muscle and body fat from 50 juvenile and five adult wood ducks (Aix sponsa) collected on the Holston River, Tennessee were analyzed for total mercury content. Black fly larvae (Simulium vittatum) sago pondweed (Potamogeton pectinatus), tapegrass (Vallisneria americanus), water stargrass (Heteranthera dubia), Elodea canadensis, and river bottom sediments were also analyzed to elucidate the distribution of mercury in the wood duck's environment. Liver tissues of juveniles contained the highest mean concentration of mercury (0.

Infection of mice by aerosols of Klebsiella pneumoniae under hyperbaric conditions.

Both the physical behavior of aerosols and survival of airborne Serratia marcescens in hyperbaric chambers with a helium-air mixture at 20 atm of pressure was approximately the same as in the system at ambient pressures. Exposure of mice to aerosols of Klebsiella pneumoniae at 1-, 2-, and 17-atm (ca. 101-, 203-, and 1,722-kPa) pressures of helium-oxygen mixture showed that the number of viable organisms constituting a 50% lethal dose was not significantly affected by the hyperbaric conditions.

Evidence for more than one division of bacteria within airborne particles.

When the protocol that we had used to demonstrate a single division of bacterial cells in airborne particles was changed to one that increased the glycerol content of the atomizer fluid from 1 to 5% (vol/vol), thus producing larger particles, more than two (and nearly three) divisions of bacteria occurred within 6 h of aerosol time.

Evidence that bacteria can form new cells in airborne particles.

Serratia marcescens incubated for 8 h at 31 degrees C in a chemically defined medium contained in shake flasks was aerosolized into rotating-drum aerosol chambers at 30 degrees C and saturated humidity. Cells furnished tryptone (Difco) and glycerol just before aerosolization increased (in viable numbers and countable cells) almost twofold within 1 to 2 h after becoming airborne, whereas cells not furnished additional tryptone decreased in viable numbers at a faster rate than the number of particles removed by gravitational settling. Limited tests with a Coulter Counter showed that cell volume changes occurred in growing cells that did not occur in the nongrowing population.

Evidence for incorporation of thymidine into deoxyribonucleic acid in airborne bacterial cells.

As part of an effort to discover whether bacteria might propagate within airborne particles, we studied the incorporation of thymidine into the trichloroacetic acid-insoluble fraction of airborne cells of Serratia marcescens to seek evidence of the possible formation of new DNA. Two aerosols, one of S. marcescens and another of [3H]thymidine ([3H]dT) suspended in growth medium were caused to aggregate in air just prior to directing the aerosols into rotating-drum aerosol storage chambers.

Evidence for propagation of aerobic bacteria in particles suspended in gaseous atmospheres.

One factor involved in the possibility that airborne microbes might contaminate the Jovian atmosphere, is whether microbes have the capacity to propagate in air. Prior to these studies, the evidence was that the airborne state was lethal to microbes. By mixing an aerosol of aerobic bacteria with another containing 14C glucose, we were able to detect the presence of 14CO2, showing that the airborne cells were metabolically active.

Correlations between free radical production and viability of lyophilized bacteria.

When Serratia marcescens cultures were treated with dilute solutions of phenol or hydrogen peroxide before drying or by lyophilization at suboptimal pH, the log of the number of cells surviving lyophilization was correlated with subsequent free radical production by the dried cells. Since the rate of free radical production and rate of death were similarly affected by temperature, the log of the number of cells surviving after 6 days was inversely related to the free radical concentration at that time. Free radicals were produced in proportion to the log of oxygen pressure, and viability was inversely related to oxygen tension; again, free radical concentration appeared to be correlated with the death of organisms.

Studies on survival of bacteria: rhythmic response of microorganisms to freeze-drying additives.

Various materials were mixed with suspensions of Serratia marcescens and other organisms. Samples were removed and frozen at intervals after mixing; the number of cells that survived both freeze-drying and exposure to air varied rhythmically as a function of time between mixing and freezing. When assayed before or immediately after drying there were essentially no fluctuations.

Effect of 3 percent hydrogen peroxide on the viability of Serratia marcescens.

Campbell, Jack E. (University of California, Berkeley), and R. L.

Injury and growth of Serratia marcescens studied in a thermal gradient incubator.

An incubator capable of producing a controlled thermal gradient of 0 to 40 C is described. Serratia marcescens was incubated in small tubes held in the gradient. When turbidity in the tubes was assayed and recorded by a semiautomatic photometer, growth-temperature patterns were obtained.

RHYTHMIC RESPONSE OF SERRATIA MARCESCENS TO ELEVATED TEMPERATURE.

Dimmick, Robert L. (University of California, Berkeley). Rhythmic response of Serratia marcescens to elevated temperature.

ATTACHMENT AND GROWTH OF BACTERIA ON SURFACES OF CONTINUOUS-CULTURE VESSELS.

Don H. Larsen (Brigham Young University, Provo, Utah), and R. L.

FREE RADICAL FORMATION AND SURVIVAL OF LYOPHILIZED MICROORGANISMS.

Heckly, Robert J. (University of California, Berkeley), R. L.