Xanthan production from olive-mill wastewaters

Olive mill wastewaters (OMW) are a by-product from olive oil manufacture that cause environmental pollution. These wastes have been used as substrate for the production of the extracellular polysaccharide xanthan by Xanthomonas campestris NRRL B1459-S4L41. Growth and xanthan production on dilute OMW as a sole source of nutrients were obtained at OMW concentrations below 60%, yielding a maximal xanthan production of 4.4gl⁻¹ at 30–40% OMW concentration. Addition of nitrogen and/or salts led to significantly increased xanthan yields with a maximum of 7.7gl⁻¹. The N/salts supplements also allowed an increase in the optimal OMW concentration. Inocula pre-grown on OMW can be used. Results suggest that an improved xanthan yield could be obtained with adequate balance between waste concentration and nitrogen or salt supplementation. OMW is proposed as a low-cost substrate for xanthan production with the additional environmental benefit of this use.     

Effects of epidermal growth factor on deoxyribonucleic acid synthesis and stomach weight in hypophysectomized adult mice

Epidermal growth factor (EGF) or saline was administered intraperitonally to hypophysectomized adult male CD2F₁ mice or intact controls at 0700 hr. Subgroups of mice were killed at 4, 8, or 12 hr after injection. EGF was shown to stimulate [³H]TdR incorporation into DNA into several organs as previously reported. The response to EGF was found to be enhanced in both hypophysectomized and fasted mice. Differences in [³H]TdR incorporation into DNA, corneal epithelium mitotic index, RNA in pancreas and kidney of hypophysectomized and intact mice are reported. EGF was shown to result in stomach enlargement due to increased luminal contents in both hypophysectomized and intact mice.     

Cell-mediated immune responses in recurrent herpesvirus infections. I. Lymphocyte proliferation assay.

Studies in immunosuppressed and immunodeficient patients indicate that the cell-mediated immune response appears to be responsible for controlling reactivated herpesvirus infections. In this study, the various parameters of a herpesvirus (types 1 and 2) antigen specific lymphocyte proliferation assay were optimized and used to evaluate individuals with clinical, recurrent HSV-1 and HSV-2 infections. Normal individuals with neutralizing antibody to HSV-1 or HSV-2 responded to virus antigen in culture as well as individuals with recurrent disease. Normal individuals without neutralizing antibody responded with a significantly lower response. Specificity of the lymphocyte proliferation assay was observed most strikingly in normal individuals with a rare HSV-1 infection during the vesicular eruption. Specificity was also observed by determining the ratio of the response to HSV-1 as compared to the response to HSV-2. Evaluated in this manner, individuals with recurrent HSV-1 infections had significantly higher ratios than individuals with HSV-2 infections and vice versa. Data from individuals with recurrent disease was compared to that of normal individuals to determine whether the former demonstrated a specific alteration in this response. Individuals with recurrent disease were found to have higher neutralizing antibody titers than normals. The neutralizing antibody titers in normal individuals correlated well with the lymphocyte proliferation assay results, whereas a similar evaluation in individuals with recurrent disease gave a negative correlation. The ratio of HSV-1 response/HSV-2 response also demonstrated a suppressed response in recurrent infections to the homologous virus during active disease, which disappeared when the individual was convalescent. These studies indicate that individuals with recurrent HSV infections have virus antigen specific alterations of their cell-mediated immune response, which can be associated with their disease.     

Choline-containing bacteriophage receptors in Streptococcus pneumoniae.

Choline-containing teichoic acid seems to be essential for the adsorption of bacteriophage Dp-1 to pneumococci. This conclusion is based on the following observations: In contrast to pneumococci grown in choline-containing medium, cells grown in medium containing ethanolamine or other submethylated aminoalcohols instead of choline were found to be resistant to infection by Dp-1. Live choline-grown bacteria and heat- or UV-inactivated cells and purified cell walls prepared from these cells were capable of adsorbing phage Dp-1; ethanolamine-grown pneumococci or cell wall preparations were unable to do so. Adsorption of Dp-1 to choline-containing cell walls was competitively inhibited by phosphorylcholine and by several choline-containing soluble cell surface components, such as the Forssman antigen and the teichoic acid-glycan complexes formed by autolytic cell wall degradation. Cell walls prepared from pneumococci grown in ethanolamine or phosphorylethanolamine were inactive. Electron microscopic studies with pneumococci that had segments of choline-containing cell wall material amid ethanolamine-containing regions indicated that the Dp-1 phage particles adsorbed exclusively to the choline-containing surface areas. We suggest that the choline residues of the pneumococcal teichoic acid are essential components of the Dp-1 phage receptors in this bacterium.     

Creatine kinase elevations in marathon runners: relationship to training and competition.

Elevation of creatine kinase (CK) in serum after exertion is a reliable marker of skeletal muscle injury. Limited data exist on CK levels in conditioned athletes after endurance training and competition. Serum CK was measured by a kinetic UV method (normal < 100 U/L) in 15 long distance runners before (pre-race), 24 hours after (post-race) and four weeks following (post-race) the 1979 Boston Marathon. CK levels were elevated throughout the study. Mean values for all runners and for those finishing before and after three hours and 30 minutes are as follows: Post-race CK was significantly elevated among the ten faster as compared to the five slower runners (p = 0.025). Elevations of creatine kinase drawn 24 hours post-marathon are inversely related to finishing times among the runners tested.     

The effect of secretin and cholecystokinin-pancreozymin on the secretion of bile in the anaesthetized rabbit.

Effects of secretin and Cholecystokinin-Pancreozymin (CCK-PZ) on the secretion of bile in anaesthetized rabbits have been studied. Single injections of secretin (5.0 u.kg(-1) significantly increased the flow of bile irrespectively of whether the cystic duct was free or had been tied. A sustained increase in bile flow could be obtained by the continuous infusion of secretin. Cholecystokinin-Pancreozymin was effective in increasing the bile flow in doses of 1.0 u.kg(-1). Much of the effect could be attributed to contraction of the gallbladder but a significant increase in flow could still be elicited after ligation of the cystic duct. Our findings strongly suggest that the biliary secretion in rabbits is not as different from the general pattern as has previously been suggested.     

The effect of grazing by the detritivore Orchestia grillus on Spartina litter and its associated microbial community

Summary Orchestia grillus efficiently feeds upon microorganisms attached to ingested Spartina alterniflora litter, but does not digest litter itself. Microorganisms respond to Orchestia grazing with increased metabolic activity, reflected in accelerated decomposition of the nitrogen fraction of litter and increased microbial biomass. Increased microbial activity may be partly a function of ammonia excretion and higher diffusion rate due to animal movement, but mainly it is a direct response to grazing. Microbial biomass increases with grazing because the pool of available nitrogen becomes larger. A model postulating interactions between Orchestria, Spartina litter and attached microorganisms is presented.This is contribution no. 180 from the Program in Ecology and Evolution at the State University of New York at Stony Brook     

Defluorination of fluoroacetate in the rat

Rats given 5 ppm F as FAc (equivalent to 26 ppm of NaFac) in the drinking water for approximately four months deposited as much fluoride in the skeletal system as did rats receiving 5 ppm F as NaF in the water. Little evidence could be found for the presence of organically bound fluoride in bone after ingesting FAc, though an appreciable proportion of skeletal fluoride deposited when NaF was ingested was shown not to respond to the fluoride ion electrode. The daily urinary excretion of total fluoride after FAc was somewhat greater than after NaF; about two thirds of this fluoride responded to the electrode, whereas more than 90 percent of the total fluoride after NaF was ionic in nature. The data are interpreted as showing that the rat is capable of splitting the C-F bond in FAc and/or in its fluoride-containing metabolites, with subsequent skeletal storage and renal excretion of the released fluoride ion. The chronic administration of this low level of FAc caused an early but temporary retardation of growth. The Krebs cycle was interfered with, as evidenced by increased concentrations of citrate in the kidney and urine. At termination of the experiment, histological examination of the testes showed that the FAc had induced severe damage characterized by massive disorganization of the tubules, nearly total loss of functional cells, absence of sperm, and damage to the Sertoli cells.     

Effects of membrane composition and lipid structure on the photopolymerization of lipid diacetylenes in bilayer membranes

Molecules analogous to biological and synthetic lipids have been prepared with conjugated diacetylene moieties in the long alkyl chain. These lipid diacetylenes form bilayer structures when suspended in aqueous buffers. Ultraviolet light (254 nm) exposure initiates the polymerization of the diacetylenes in the lipid bilayer to give a fully conjugated, highly colored product. The reaction is topotactic, and its efficiency depends on the correct alignment of the monomeric units. Thus, the lipid diacetylenes are photopolymerizable if the hydrocarbon chains are in a regular lattice found at temperatures below the lipid transition temperature; polymerization is inhibited above this transition. The photopolymerization of a diacetylenic glycerophosphocholine in lipid bilayer membranes was observed in two-component mixtures with a nonpolymerizable lipid, either dioleoylphosphatidylcholine or distearoylphosphatidylcholine. The photochemical and thermochemical characteristics suggest that the diacetylenic glycerophosphocholine exists largely in separate domains in the mixed bilayers. Lipid diacetylenes analogous to a dialkyldimethylammonium salt and to a dialkyl phosphate have a plane of symmetry, which suggests that both chains penetrate equally into the bilayer. The photopolymerization of these symmetrical synthetic species is more than 10³-times more efficient than that of the diacetylenic glycerophosphocholine. These differences are interpretable in terms of the expected conformational preference of the lipid molecules.