Microorganisms anaerobic

Formate dehydrogenases are a diverse group of enzymes found in both prokaryotes and eukaryotes, capable of converting formate to CO2. Formate dehydrogenases from anaerobic microorganisms are, in most cases, Mo- or W- containing iron-sulfur proteins and additionally flavin or hemes. Selenium cysteine is a Mo- ligand. 

Under anaerobic conditions, p,p -DDT is converted to p,p -DDD by reductive dechlorination, a biotransfonnation that occurs postmortem in vertebrate tissues such as liver and muscle and in certain anaerobic microorganisms (Walker and Jefferies 1978). Reductive dechlorination is carried out by reduced iron porphyrins. It is carried out by cytochrome P450 of vertebrate liver microsomes when supplied with NADPH in the absence of oxygen (Walker 1969 Walker and Jefferies 1978). Reductive dechlorination by hepatic microsomal cytochrome P450 can account for the relatively rapid conversion of p,p -DDT to p,p -DDD in avian liver immediately after death, and mirrors the reductive dechlorination of other organochlorine substrates (e.g., CCI4 and halothane) under anaerobic conditions. It is uncertain to what extent, if at all, the reductive dechlorination of DDT occurs in vivo in vertebrates (Walker 1974). 

Studies on 4-hydroxybenzoate decarboxylase and 3,4-hydroxybenzoate decarboxylase have been restricted to obligate anaerobic bacteria, C. hydroxy-benzoicum Aside from the obligate anaerobic microorganism, C. hydroxy-benzoicum, very recently facultative anaerobic bacteria, Enterobacter cloacae strains exhibiting high 4-hydroxybenzoate decarboxylase or... 

Morris PJ, JF Quensen III, JM Tiedje, SA Boyd (1992) Reductive debromination of the commercial polybro-minated biphenyl mixture Firemaster BP6 by anaerobic microorganisms from sediments. Appl Environ Microbiol 58 3249-3256. 

Bedard DL, HM van Dort (1998) Complete reductive dehalogenation of brominated biphenyls by anaerobic microorganisms in sediment. Appl Environ Microbiol 64 940-947. 

Mikesell MD, S A Boyd (1986) Complete reductive dechlorination and mineralization of pentachlorophenol by anaerobic microorganisms. Appl Environ Microbiol 52 861-865. 

Many contaminants contain nitrogen, phosphorus, or sulfur, and degradative organisms may utilize one or more of these leaving the major part of the substrate intact. This is particularly important for munitions-related compounds with a high N/C ratio, when the addition of carbon sources may lead to the favorable development of anaerobic or facultatively anaerobic microorganisms. 

The most critical issue to be investigated during the initial biofeasibility study is the determination of which metabolic mode—aerobic or anaerobic—is more appropriate for the specific contaminants. As shown in Table 14.5, the redox potential is closely related to the metabolic mode, and careful control of this parameter is required to maintain the optimum metabolic mode during bioremediation. A general rule is that the redox potential should be above 50 mV to maintain the activity of aerobic and facultative anaerobic microorganisms and below that value for strictly anaerobic m icroorganisms.12... 

A wide variety of aerobic and anaerobic microorganisms are able to express the enzyme urease (urea amidohydrolase), which catalyses the hydrolysis of urea to ammonia and carbon dioxide.27 So far,... 

Some kraft mills use basins without mechanical aerators. Known as stabilization basins, this is the simplest form of aerobic treatment. This process uses shallow basins that cover very large areas and relies on natural diffusion of air into the wastewater and algae to create aerobic conditions. At depths greater than 1.2 m (4 ft), anaerobic microorganisms will become active in lower depths thus, stabilization basins are shallow. Typically, the basin is earthen although some are lined with compacted clay. Wastewater retention time may last up to 30 d to achieve up to 90% BOD5 removal. 

Chang BV, Yu CH, Yuan SY (2004) Degradation of nonylphenol by anaerobic microorganisms from river sediment. Chemosphere 55 493-500... 

Penta-BDE and octa-BDE mixtures degradation studies in solid media in anaerobic conditions are very scarce. In the case of penta-BDE mixture, Vonderheide et al. [2] inoculated a culture with different anaerobic microorganisms in a contaminated soil by this mixture. After a short time, the major compound in the mixture, BDE-99, was almost completely degraded, as well as other PBDEs present in lower proportion (hexa-BDEs and penta-BDEs). Moreover, for the same time, it was observed an increase of the amount of BDE-47, which corresponds to the second major compound in the mixture. The authors argue that BDE-47 amount increase could be caused by the fact that it is a degradation product of other higher brominated PBDEs such as BDE-99. In fact, it was demonstrated later that BDE-47 is formed from BDE-99 degradation in anaerobic conditions [37]. 

Oxygen-sensitive samples such as enzymes from strictly anaerobic microorganisms which have been previously prepared anaerobically (e.g., in a glove box) can be transferred from their container (e.g., a capped septum bottle) to an empty EPR tube that has been made anaerobic on the manifold. The transfer can be done with an injection needle that has been made anaerobic in an empty septum bottle on the manifold. Note that after the transfer the connecting rubber has a hole, so any addition to this sample can only be made after it has been frozen and subsequently made anaerobic with a new, intact connecting rubber on the manifold. 

Gu J-D, Fan Y, Shi H (2002) Relationship between structures of substituted in-dolic compounds and their degradation by marine anaerobic microorganisms. Mar Poll Bull 45 379-384... 

Infections caused by these injuries are most often caused by the normal oral flora, which includes both aerobic and anaerobic microorganisms. The most frequent aerobic organisms are Streptococcus spp., Staphylococcus spp., and Eikenella corrodens. The most common anaerobic organisms are Fusobacterium, Prevotella, Porphyromonas, and Peptostreptococcus spp. 

In some anaerobic microorganisms, production of hydrogen serves as a mechanism to get rid of excess reducing potential, while in many others hydrogen consumption is coupled... 

Kuhn EP, Suflita JM. 1989. Dehalogenation of pesticides by anaerobic microorganisms in soils and groundwater-a review. In Reactions and movement of organic chemicals in soils. Soil Science Society of America Special Publication 22 111 -180. 

Williams PP. 1977. Metabolism of synthetic organic pesticides by anaerobic microorganisms. Residue Rev 66 63-135. 

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