Metabolic and exercise endurance effects of coffee and caffeine ingestion

Caffeine (Caf) ingestion increases plasmaepinephrine (Epi) and exercise endurance; these results are frequentlytransferred to coffee (Cof) consumption. We examined theimpact of ingestion of the same dose of Caf in Cof or in water. Ninehealthy, fit, young adults performed five trials after ingesting(double blind) either a capsule (Caf or placebo) with water or Cof(decaffeinated Cof, decaffeinated with Caf added, or regularCof). In all three Caf trials, the Caf dose was 4.45 mg/kgbody wt and the volume of liquid was 7.15 ml/kg. After 1 h of rest, thesubject ran at 85% of maximal O₂consumption until voluntary exhaustion (~32 min in the placebo anddecaffeinated Cof tests). In the three Caf trials, the plasma Caf andparaxanthine concentrations were very similar. After 1 h of rest, theplasma Epi was increased (P < 0.05)by Caf ingestion, but the increase was greater(P < 0.05) with Caf capsules thanwith Cof. During the exercise there were no differences in Epi amongthe three Caf trials, and the Epi values were all greater(P < 0.05) than in the othertests. Endurance was only increased(P < 0.05) in the Caf capsule trial; there were no differences among the other four tests. One cannot extrapolate the effects of Caf to Cof; there must be a component(s) ofCof that moderates the actions of Caf.

     

Bioremediation of HMX-Contaminated Soil Using Soil Slurry Reactors

Soil in some parts of the Iowa Army Ammunition Plant in Burlington, Iowa, was contaminated with cyclotetramethyleneter-anitramine, commonly known as high melting explosive (HMX). A laboratory treat-ability study was conducted to find out the ability of the native soil bacteria present in the contaminated site to degrade HMX. The results indicated that the HMX can be removed effectively from soil by native soil bacteria through a co-metabolic process. Molasses, identified as an effective co-substrate, is inexpensive, and this factor makes the treatment system cost-effective. The successful operation of aerobic-anoxic soil slurry reactors in batch mode with HMX-contaminated soil showed that the technology can be scaled up for field demonstration. The HMX concentration in the contaminated soil was decreased by 97% in 4 months of reactor operation. The advantage of the slurry reactor is its simplicity of operation. The method needs only mixing and the addition of molasses as co-substrate.     

Transformation of nitroaromatic compounds by a methanogenic bacterium,Methanococcus sp. (strain B)

The transformation of several nitroaromatic compounds by a newly isolated methanogenic bacterium, Methanococcus sp. (strain B) was studied. The presence of nitroaromatic compounds (0.5 mM) viz., nitrobenzene, 2,4-dinitrobenzene, 2,4,6-trinitrobenzene, 2,4-dinitrophenol, 2,4-dinitrobenzene, and 2,6-dinitrotoluene in the culture medium did not inhibit growth of the isolate. The bacteria grew rapidly and reached stationary phase within seven days of incubation. All the nitroaromatic compounds tested were 80 to 100% transformed by the bacterium to amino compounds by a reduction process. The isolate did not use the nitroaromatic compounds as the sole source of carbon or nitrogen. The transformation of nitroaromatic compounds by this isolate was compared to that of other methanogenic bacteria. Out of five methanogens studied, only Methanococcus deltae and Methanococcus thermolithotrophicus could transform the nitroaromatic compounds; however, the transformation rates were significantly less than that of the new isolate Methanococcus sp. (strain B). The nitroaromatic compounds were not transformed by Methanosarcina barkeri, Methanobacterium thermoautotrophicum, and Methanobrevibacter ruminantium.Abbreviations NB Nitrobenzene - DNB 2,4-Dinitrobenzene - TNB 2,4,6-Trinitrobenzene - DNP 2,4-Dinitrophenol - 2,4-DNT 2,4-Dinitrotoluene - 2,6-DNT 2,6-Dinitrotoluene