Robert A. Uphaus

CULTIVATION OF MICROORGANISMS IN HEAVY WATER

Data are presented on the culture of a variety of algae and other microorganisms in highly deuterated systems. Growth rates for the unicellular green algae Scenedesmus obliquss and Chlorella ralgaris in 99.6% D/sub 2/O were improved so that they approach one-half the rates in H/sub 2/O nutrient media. S. obliquus was also successfully mass cultured in 5-liter units. The blue-green alga Plectonema calothricoides was grown on a continuous laboratory scale in 99.6% D/sub 2/O. A number of other green, blue-green, and red algae and diatoms have been cultured at D/sub 2/O levels from 75 to 99.6%. The bacterium Escherichia coli, the yeast Tonalopsis utilis, and the mold fungus Asperallus niger were grown in fully deuterated media. Protozoa have been cultured at somewhat lower D/sub 2/O concentrationsi Paramecium caudatum routinely in 60% D/ sub 2/O lettuce infusion and Paramecium bursaria in 50% lettuce infusion. In general, algae are best adapted to D/sub 2/O by serial subculyure, 0 to75 to 99 to 99.6% D/sub 2/O, but Chlorella, E. coli, T. utilis, and A. niger can be grown by direct transfer from H/sub 2/O to 99.6% D/sub 2/O nutrient media. (auth)

Triplet states in photosynthesis

Abstract A comparison of zero field splitting (ZFS) and spin polarization of triplet spectra of bacteriochlorophyll a in vitro and in vivo provides support for the special pair model of photoreactive chlorophyll in photosynthetic bacteria. Spin polarization of the triplet spectra is a new and unique probe of primary events in the light conversion act in photosynthesis.

ESR of triplet states of chlorophylls a, b, c1, c2 and bacteriochlorophyll a. Applications of ZFS and electron spin polarization to photosynthesis☆

Abstract ZFS parameters for the title chlorophylls in both ordinary and fully deuterated form have been determined under experimental conditions that allow the aggregation state of the chlorophylls to be specified. The triplet state spectra are polarized. The electron spin polarization (ESP) can be analyzed by a simple scheme, and is found to be sensitive to the aggregation state of the chlorophyll. Comparison of in vivo and in vitro bacteriochlorophyll spectra supports the chlorophyll special pair proposal for the structure of in vivo photo-reactive chlorophyll.

Electron spin resonance in 13C-labeled chlorophyll and 13C-labeled algae

Abstract ESR signals have been recorded from algae and chlorophyll a highly enriched in 13C. A theoretical treatment of the effects on line shape to be expected from 13C substitution has been developed. The 13C isotope effect in the line shape of ESR photosignal I in 13C-labeled algae is shown to be consistent with delocalization of the spin over a special pair of chlorophyll molecules. The anisotropy of 13C ESR signals allows the conclusion to be drawn that reaction center chlorophyll in photosynthesizing algae is held in a rigid matrix.

A living organism of unusual isotopic composition sequential and cumulative replacement of stable isotopes in Chlorella vulgaris

Abstract Replacement of the biologically important isotopes by the corresponding heavier stable isotopes results in marked cytological changes in the alga Chlorella vulgaris. The isotopes used were those of hydrogen, carbon, oxygen and nitrogen. Progressive isotopic substitution results in increasingly greater deviations from normal cell size, the more highly substituted cells being much larger than ordinary cells. Isotopic substitution also changes the quantity and distribution of such cellular components as nucleic acids, carbohydrates and proteins, as evidenced by staining techniques.

Fluorescence of Tryptophan Derivatives in Trifluoroacetic Acid

Solutions of tryptophan-containing proteins in trifluoroacetic acid (TFA) develop green fluorescence. Studies have been made of the effect of TFA on tryptophan and tryptophan derivatives, and a dihydro-β-carboline has been identified among the fluorescent products.

Isotope biology of 13C extensive incorporation of highly enriched 13C in the alga Chlorella vulgaris

Abstract In contribution of previous work on the consequences of isotopic replacement in living organisms1, the green alga Chlorella vulgaris has been grown on 13CO2 (95% 13C) in 1H2O and 2H2O media. Cell size distribution was determined and the organisms subjected to cytochemical investigation for nucleic acids, carbohydrates, amino acids, and proteins. Some of the abnormalities noted in 13C2H organisms are diminished in 13C2H algae, indicating that the consequences of multiple isotope replacement in living organisms do not necessarily follow a simple additive relationship.

Effect of heavy water on the germination of a number of species of seeds

SummaryThe effect of deuteriation on the germination rate of seeds is studied as a possible screening technique prior to the cultivation of a plant in high concentrations of D2O. There appears to be a simple relationship between size of the seed and germination capacity in high deuterium concentrations. Larger seeds may be more successful in germinating because of greater hydrogen-containg food reserves.

Deuterium Isotope Effect on Carbon Isotope Fractionation in Photosynthesis

Plants grown in D2O show a decreased tendency to fractionate carbon-13 during photosynthetic incorporation of carbon dioxide. The isotopic ratio C13/C12 of the tissues of deuterated plants appears to be proportional to the deuterium content of the tissue. This effect was found in specimens of the partially deuterated vascular plant Nicotiana tabacum as well as in cultures of the fully deuterated alga Chlorella vulgaris.

FAST NEUTRON INDUCED LUMINESCENCE IN VITREOUS SILICA AND QUARTZ

A reddish luminescence mouch more intense than the scattered light was observed in excited fast neutron irradiated vitreous silica and quartz. The cause of this luminescence was investigated. It is probably necessary to observe the detailed behavior of the absorption bands during lumoinescence in order to identify the luminescence centers; however, this work does not identify the excitation centers as being those with which the tail of the ultraviolet absorption is associated. (J.R.D.)