In this paper, the shape and size of glucose oxidase (GO) adsorbed on a gold electrode was determined by. ellipsometry. It was concluded that GO is a prolate ellipsoid molecule with a major axis of 140A and a minor axis of 50A. Two orientations of the molecule on the surface were observed: the major axis can be perpendicular to the surface (standing position) or parallel to the surface (lying position). Above a certain coverage, enzymes in the standing position are not stable and undergo a transition to the lying position due to increasing intermolecular interaction. In the lying position, the enzyme-and-substrate contact area is large, and gradual unfolding occurs, leading to a significant change in the structure of the protein. It was possible to detect direct electron transfer between a gold electrode and glucose oxidase. After a short contact time, two almost overlapping electron transfer processes were distinguished, but were gradually transformed to a single response that was characteristic for adsorbed FAD, thus showing that significant changes in the protein structure occur, leading the deactivation of the enzyme.

Previous studies have demonstrated that a novel source of ozone gas (O3) maybe used to chemically degrade numerous mycotoxins, including aflatoxin (AF) B1. Subsequent in vitro analyses demonstrated detoxification of AFB1, suggesting a potential method of remediate AF-contaminated grain. The objective of this study was to evaluate the capability of electrochemically produced ozone to degrade AFB1 in naturally contaminated whole kernel corn and confirm detoxification in turkey poults. Corn was procured from the southern coastal areas of Texas and HPLC revealed 1,220 +/- 73.3 ppb AFB1. Control and contaminated corn were treated for 92 h with O3 at 200 mg/min in 30 kg batches; greater than 95% reduction of AFB1 in contaminated corn was achieved. One-day-old female turkey poults were fed 1) control corn, 2) control corn + O3, 3) AFB1 corn, or 4) AFB1 corn + O3 mixed in rations (46% by wt.) and consumed ad libitum for 3 wk. When compared with controls, turkeys fed AFB1 corn had reduced body weight gain and relative liver weight, whereas turkeys fed control corn + O3 or AFB1 corn + O3 did not differ from controls. Furthermore, alterations in the majority of relative organ weight, liver discoloration, serum enzyme activity, hematological parameters, and blood chemistry caused by AFB1 were eliminated (no difference from controls) by treatment with O3. These data demonstrate that treatment of contaminated corn with electrochemically produced O3 provided protection against AFB1 in young turkey poults. It is important to note that treatment of control corn with O3 did not alter the performance of the turkey poults.

No abstract

1. The principle of the double-inhibitor titration method for assessing competing models of electron transport phosphorylation is expounded. 2. This principle is applied to photophosphorylation by chromatophores from Rhodopseudomonas capsulata N22. 3. It is found that, in contrast to the predictions of the chemiosmotic coupling model, free energy transfer is confined to individual electron transport chain and ATP synthase complexes. 4. This conclusion is not weakened by arguments concerning, the degree of uncoupling in the native chromatophore preparation or the relative number of electron transport chain and ATP synthase complexes present. 5. Photophosphorylation is completely inhibited by the uncoupler SF 6847 at a concentration corresponding to 0.31 molecules per electron transport chain. 6. The apparent paradox is solved by the proposal, consistent with the available evidence on the mode of action of uncouplers, that uncoupler binding causes a co-operative conformation transition in the chromatophore membrane, which leads to uncoupling and which is not present in the absence of uncoupler.

Waste biomass oxidation was carried out on platinum and lead dioxide anodes using a 12M H2SO4 electrolyte. Total organic carbon in the electrolyte was reduced by 95%. The use of ultrasound and the addition of the Ce3+/Ce4+ redox couple to the electrolyte enhanced the rates of waste oxidation. Urine‐waste biomass mixtures were electrolyzed indirectly through the anodic generation of OCl−; Cl2 constituted only 0.1% of the evolved gases. These oxidation treatments offer a means of human waste disposal without producing undesirable chemicals such as CO , NO , NO2 , CH4 , and NH3 in the effluent gas.