Membrane process for biological treatment of contaminated gas streams.

A hollow fiber membrane bioreactor was investigated for control of air emissions of biodegradable volatile organic compounds (VOCs). In the membrane bioreactor, gases containing VOCs pass through the lumen of microporous hydrophobic hollow fiber membranes. Soluble compounds diffuse through the membrane pores and partition into a VOC degrading biofilm. The hollow fiber membranes serve as a support for the microbial population and provide a large surface area for VOC and oxygen mass transfer. Experiments were performed to investigate the effects of toluene loading rate, gas residence time, and liquid phase turbulence on toluene removal in a laboratory-scale membrane bioreactor. Initial acclimation of the microbial culture to toluene occurred over a period of nine days, after which a 70% removal efficiency was achieved at an inlet toluene concentration of 200 ppm and a gas residence time of 1.8 s (elimination capacity of 20 g m-3 min-1). At higher toluene loading rates, a maximum elimination capacity of 42 g m-3 min-1 was observed. In the absence of a biofilm (abiotic operation), mass transfer rates were found to increase with increasing liquid recirculation rates. Abiotic mass transfer coefficients could be estimated using a correlation of dimensionless parameters developed for heat transfer. Liquid phase recirculation rate had no effect on toluene removal when the biofilm was present, however. Three models of the reactor were created: a numeric model, a first-order flat sheet model, and a zero-order flat sheet model. Only the numeric model fit the data well, although removal predicted as a function of gas residence time disagreed slightly with that observed. A modification in the model to account for membrane phase resistance resulted in an underprediction of removal. Sensitivity analysis of the numeric model indicated that removal was a strong function of the liquid phase biomass density and biofilm diffusion coefficient, with diffusion rates below 10(-9) m2 s-1 resulting in decreased removal rates.

Embryo transfer from goats seropositive for caprine arthritis-encephalitis virus.

Twelve attempts were made to isolate caprine arthritis-encephalitis virus (CAEV) from the uterine flushings of serologically positive superovulated does mated to serologically positive bucks. Embryos were transferred to eight serologically negative estrus-synchronized recipient does and the recipients were monitored serologically following embryo transfer. Virus isolation was attempted from colostrum and placental tissues from does that kidded following embryo transfers and the surviving kid was monitored serologically until four months of age. The CAEV was not isolated from any of the uterine flushings, colostrum or placental tissues. All recipients and the kid remained seronegative throughout the trial.

Evidence for the presence of proteinase inhibitor I in vacuolar protein bodies of plant cells.

Protein bodies induced in tomato leaf cells by wounding were shown to contain proteinase Inhibitor I by using ferritin-labelled antibodies, fluorescein-labelled antibodies, and cytochrome C-labelled antibody fragments. Both pre-embedding and postembedding techniques were used. Nonspecific binding was least when p-formaldehyde was used as the initial fixative followed by treatment with cytochrome c-labelled antibody fragments.

Cell surface protein of Pseudomonas (Hydrogenomonas) facilis.

Intact cells of Pseudomonas facilis contain one major molecular weight class of protein that is exposed at the cell surface as revealed by lactoperoxidase-catalyzed iodination with (125)I. All molecular weight classes of protein in derived cell envelope preparations are apparently saturated by iodination by lactoperoxidase after prolonged sonic treatment. The molecular weight of the predominantly exposed protein in intact cells is approximately 16,000, which is the minimal molecular weight of a cell envelope protein that precipitates as a complex with phospholipid from extracts of P. facilis. The isolation of labeled phospholipoprotein (PLP) after labeling intact cells with (125)I corroborates previous experiments which suggested a surface location for the protein portion of the phospholipoprotein (P(PLP)). Solvent extraction of cells and immunological evidence, including studies with ferritin-coupled antibodies, indicate that P(PLP) is located at the cell surface and may also be within the cell envelope. These experiments suggest that P(PLP) is the major cell surface protein in P. facilis.

Effect of growth conditions on morphology of Hydrogenomonas facilis and on yield of a phospholipoprotein.

Hydrogenomonas facilis grown heterotrophically on fructose with very low aeration eventually ceased to divide and produced elongated forms. Short forms were obtained from fructose-grown long forms by increasing the availability of oxygen to the organisms. A phospholipoprotein, the protein moiety of which is known to be present in the cell envelope, precipitated upon lowering the ionic strength of extracts from cells in the earlier stages of elongation (i.e., in the middle and late log phase of growth). The maximal yield of the protein moiety of the phospholipoprotein precipitate (i.e., grams of protein/grams of soluble protein x 100) was 2%. Poly-beta-hydroxybutyric acid accumulated as growth on fructose progressed, the accumulation being more marked with lower aeration.

Vacuolar protein in apical and flower-petal cells.

Vegetative apices, floral apices and flower petals of five Solanaceae (potato, tomato, tobacco, petunia and nightshade) and of corn and Nigella were examined with an electron microscope for the presence of protein bodies in the cell vacuoles. Electron-dense bodies were found in vacuoles of all plants investigated but not in every tissue examined. The bodies observed in the apices are similar to the protein bodies previously found in tomato leaves where they appear to be related to the presence of chymotrypsin inhibitor I protein (Shumway et al., 1970). The bodies appeared in very young cells in small vacuoles, disappearing as the cell matured. They are apparently related to the growth and development of the new cells. The results suggest that plants may regulate specific proteins within the apical region through selective synthesis and degradation of proteins accompanied by compartmentalization in the vacuole.

Vacuolar protein bodies in tomato leaf cells and their relationship to storage of chymotrypsin inhibitor I protein.

Electron microscopy of leaves of tomato has shown that tissue containing chymotrypsin inhibitor I protein has protein in the cell vacuoles. The vacuolar protein was found either as many small bodies or as few large bodies. The data indicate that the vacuole is a temporary storage site for protein which may play an important role in growth and development of the plant. This strongly suggests that the plant-cell vacuole is something more than a site for terminal deposition of waste products. The system offers an unusual opportunity to study the biochemistry and ultrastructure of synthesis, vacuolar deposition, and recall of a well-characterized plant protein.

The facile isolation of a structural phospholipoprotein from hydrogenomon as facilis and Neurospora crassa.

The paper describes a new and gentle procedure for isolating "structural" phospholipoproteins from organisms and the first such isolation from a procaryotic microbe, Hydrogenomonas facilis. The amino acid composition of its protein moiety resembles that of "structural protein" from other sources. Although disc gel electrophoresis has shown the protein to be heterogeneous, this is attributed to aggregation.

Crystalline structures in vicia faba chloroplasts.

Chloroplast stroma crystals similar to those reported by PERNER (1962, 1963) but different from those described by other workers were demonstrat ed in Vicia faba chloroplasts. They were absent in chloroplasts isolated in no sucrose, 0.3 M sucrose or in situ material either fixed in the absence of sucrose of fixed in the presence of 0.3 M sucrose. They were present in chloroplasts isolated in 0.5 M sucrose and in situ chloroplasts fixed in the presence of 0.7 M sucrose.