Aerobic and Facultatively Anaerobic Bacteria

There has been a revival of interest in the role of mycobacteria in the degradation of polycyclic hydrocarbons including naphthalene (Kelley et al. 1990), phenanthrene (Guerin and Jones 1988), anthracene (van Herwijnen et al. 2003), and pyrene (Heitkamp et al. 1988 Grosser et al. 1991  

Specific Activity (pmol Bromide Produced per mg Protein per min) of Dehalogenase from Selected Species of Mycobacteria toward 1,2-dibromoethane 

Note Bi, biphenyl Nap, naphthalene Phe, phenanthrene Anth, anthracene Hu, fluoranthene Pyr, pyrene Chr, chrysene BaAnth, benz[a]anthracene BaPyr, benzo[a]pyrene BbFlu, benzo[h]fluoranthene DBaAnth, dibenz[a,/i]anthracene 3-Me-Chol, 3-methylcholanthrene. 

Considerable interest has been expressed in the chlorophenol-degrading organism Mycobacterium chlorophenolicum (R. chlorophenolicus) (Apajalahti et al. 1986), partly motivated by its potential for application to bioremediation of chlorophenol-contaminated industrial sites (Haggblom and Valo 1995). 

The pathway used by a strain of Mycobacterium sp. for the degradation of 4-nitrotoluene is initiated by reduction to the hydroxylamine and rearrangement to 3-hydroxy-4-aminotoluene before further degradation (Spiess et al. 1998). 

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At many sites, the subsurface environment will be anoxic or even anaerobic due to the activity of aerobic and facultatively anaerobic bacteria in the surface layers of the soil. It is therefore essential to take into consideration the extent to which anaerobic degradation may be expected to be significant. Reactions may take place under sulfidogenic or methanogenic conditions, and the occurrence of sulfate at sites containing building material waste and the metabolic versatility of sulfate-reducing bacteria makes them particularly attractive. 

In 1987, Vibrio alginolyticus isolated from the starfish A. polyacanthus and puffer T. snyderi contained TTX (Narita et al., 1987 Noguchi et al., 1987). In the study of Noguchi et al. (1987), 26 of 33 strains of aerobic and facultative anaerobic bacteria that were isolated from the puffer were found to belong to genera of Vibrio. By instrumental analysis, TTX was detected in all strains of V. alginolyticus. 

Aerobes and facultative anaerobes These outcompete most fermenting bacteria for electron donors. 

Many bacteria have the ability to produce ethanol, but relatively few taxa contain bacteria that produce ethanol as a major end product. Ethanol-producing species can be found among aerobic, anaerobic, and facultative anaerobic bacteria within the family Enterobacteriaceae and the genera Bacillus, Bacteroides, Bifidobacterium, Clostridium, Euhacterium, Lactobacillus, and many others (Wiegel 1980). Examples of mesophilic (O Table 3.4) and thermophilic (O Table 3.5) bacteria that can produce one or more moles of ethanol per mole of glucose metabolized have been compiled by Wiegel (Wiegel 1980,1992). 

Bacteria can grow in two main environments, aerobic and anaerobic. In aerobic treatment, aerobic and facultative bacteria use molecular oxygen as their terminal electron acceptor. The treatment occurs in the presence of a molecular oxygen supply. In anaerobic treatment, anaerobic and... 

Spore formation is limited almost entirely to two genera of rodshaped bacteria Bacillus (aerobic or facultatively anaerobic), and Clostridium (anaerobic or aerotolerant). With one possible exception, the common spherical bacteria do not sporulate. Some spore-bearing species can be made to lose their ability to produce spores. When the ability to produce spores is once lost, it is seldom regained. SporMation is not a process to increase bacterial numbers because a cell rarely produces more than one spore. 

Table 3.2 Alternative Electron Acceptors (redox couple) Used by Aerobic, Facultatively Anaerobic, and Obligately Anaerobic Bacteria at Neutral pH and the Associated Microbial Processes...

Metabolic Pathway of Facultative Anaerobic Bacteria and the Amount of NADH Produced Under Aerobic Conditions... 

Facultative anaerobic bacteria such as Enterobacteriaceae and Bacillus species produce organic acids and alcohols from pyruvate and NADH under anaerobic conditions in a way similar to anaerobic bacteria. However, the facultative anaerobes possess the pathways for aerobic metabolism, such as the TCA cycle and electron transport system (even under anaerobic condition), and quickly respond to the presence of oxygen to oxidize NADH via the by electron transport system. NADH are also produced in the TCA cycle as seen in Figure 4. In the presence of oxygen, hydrogen production stops. 

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