Bacterial oxidation

Gas sampler 3. Sample gas 4. Cotton filter 5. Reference reactor 6. Methane oxidizing bacterial reactor 7. Oxygen electrode ... 

Fig. 3. Absorption spectra of oxidized bacterial and plant ferredoxins.

Although the spectra of oxidized bacterial and plant ferredoxins are different, Fig. 4 shows that, when reduced, their absorption spectra are remarkably similar. In both cases, the absorbancy peaks in the visible region disappear, while there is little change in ultraviolet absorption. In Fig. 4 the ferredoxins were reduced by hydrogen gas with a bacterial hydrogenase preparation. When air was admitted into the cuvettes, both ferredoxins were auto-oxidized and showed their original absorption spectra (Fig. 3). Ferredoxins, therefore, are like cytochrome c in that reduction and oxidation is a reversible process. However, unlike the cytochromes, the ferredoxins are colored in the oxidized state and colorless when reduced. 

Table 7. Oxidation state of the iron in oxidized bacterial and plant ferredoxin in the presence and absence of p-chloromercuriphenyl sulfonic acid (PCMS)...

Gunner, M. R., Robertson, D. E., and Dutton, P. L., 1986, Kinetic Studies on the Reaction Center Protein form Rps. Sphaeroides Temperature and Free Energy Dependence of Electron Transfer between various Quinones in the QA site and Oxidized Bacteri-ochlorophyll Dimer J. Phys. Chem. 90 378333795. 

Ward, B. B., EveiUard, D., Kirshtein, J. D., Nelson, J. D., Voytek, M. A., andjackson, G. A. (2007). Ammonia-oxidizing bacterial community composition in estuarine and oceanic environments assessed using a functional gene microarray. Environ. Microbiol. 9, 2522—2538. 

Distel DL, Lane DJ, Olsen GJ, Giovannoni SJ, Pace B, Pace NR, 72. Stahl DA, Felbeck H. Sulfur-oxidizing bacterial endosymbionts ... 

Battaglia-Brunet E., Dictor M. C., Garrido F., Crouzet C., Morin D., Dekeyser K., Clarens M., and Baranger P. (2002) An arsenic(III)-oxidizing bacterial population selection, characterization, and performance in reactors. J. Appl. Microbiol. 93, 656-667. 

ORD spectra (300—600 nm) of bacterial ferredoxin and rubredoxin suggested similar asymmetric environments for both non-heme iron proteins. Spectral differences with plant ferredoxin were attributed to transitions involving the iron-sulfur chromophores (116). Subsequent CD measurements in the range 215—800 nm resolved more differences between oxidized bacterial ferredoxin and rubredoxin however, the spectra were considered to be sufficiently alike to support the existence... 

Bodelier, R L. E., Roslev, R, Henckel, T., and Frenzel, R (2000). Ammonium stimulates methane oxidation in rice soil. Nature 403, 421-424. Both, G. J., Gerards, S., and Laanbroek, H. J. (1992). Temporal and spatial variation in the nitrite-oxidizing bacterial community of a grassland soil. EEMS Microbiol. Ecol. 101, 99-112. 

Fig. 22. Resonance Raman spectra [457.9 (proteins) and 514.5 (analog) nm excitation] of 4-Fe proteins and the benzyl thiolate analog. The [Fe4S4(SCH2Ph)4] spectra are assignable on the basis of a tetrahedral structure in frozen solution but the known distortion in tetraethylammonium crystals. Assignments are indicated. The RR spectrum of oxidized bacterial ferredoxin is very similar to the analog crystals, indicating a similar Dy distortion, whereas the spectrum of reduced HiPIP (same oxidation level) is similar to the analog spectrum in solution, indicating a structure that is more tetrahedral.

Many chemicals with little or no nutritive value are added to commercially processed food (Figure 16.4). Some of these food additives serve to protect the food from being spoiled by oxidation, bacterial attack, or aging. Others add and enhance flavor or color. Still others control pH prevent caking or stabilize, thicken, emulsify, sweeten, leaven, or tenderize the food. 

There are basically two families of nanosized cellulosic particles (1) Nanofibrillar cellulose, which includes mechanically isolated microfibrils, chemically isolated microfibrils (TEMPO-oxidation), bacterial cellulose and can be considered spaghetti-like, and (2) Cellulose nanocrystals - rods of highly crystalline cellulose which are isolated by acid hydrolysis. Cellulose nanocrystals are represented in literature by synonyms like cellulose whiskers, cellulose nanowhiskers, cellulose microfibrils, micro-crystalline cellulose and nanocrystalline cellulose because they are not yet commercially available. These are needle-shaped (100 run to 200 run X 10 nm), highly crystalline, strong (E - 150 GPa) and form liquid crystal suspensions. 

Nanofibrillar cellulose which includes mechanically isolated microfibrils, chemically isolated microfibrils (TEMPO-oxidation), bacterial cellulose and can be considered as spaghetti-like ... 

Sedimentation Ck)agulation-flocculation Wet oxidation Bacterial filters... 

Sericin is recovered during the various stages of producing raw silk. Sericin is oxidation-, bacterial-, and UV-resistant, and it absorbs and releases moisture rapidly. Sericin can be cross-linked, copolymerized, and blended with other macromolecular materials, especially artificial polymers. The materials modified with sericin and sericin composites are useful as degradable biomaterials, biomedical materials, polymers, functional membranes, fibers, and fabrics [26]. 

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