Microaerophilic conditions

Their activities in desulfurization lead to a hybrid process, protected under the title of Method for electrobiologically desulfurizing petroleum [143], awarded to the Marine Biotechnology Institute by the Japanese Patent Office [143], This method is based on contacting anaerobic sulfur-oxidizing bacteria with petroleum under anaerobic condition or microaerophilic conditions. The bacteria used belonged to Proteobacteria or Thiomicrospira bacteria. 

Shewanella decolorationis S12 Fast Acid Red GR After 4 h incubation, more than 90% of the color was removed under anaerobic conditions while 12.8 and 33.7% decolorizing rates were observed under aerobic and microaerophilic conditions [84]... 

Xu M, Guo J, Sun G (2007) Biodegradation of textile azo dye by Shewanella decolorationis S12 under microaerophilic conditions. Appl Microbiol Biotechnol 76 719-726... 

The NREL Pichia strain NPw9 was equivalent to the D5A yeast in ethanol production however, it did not utilize xylose under the anaerobic conditions used in the screening experiments (data not shown). However, the Pichia strain NPw9 has been shown to ferment xylose in toxic pretreated softwood hydrolysates under microaerophilic conditions (23). 

After incubation under microaerophilic conditions at 37°C for 72 h the culture is centrifuged for 20 min at 8000 g in a Sorvall GSA rotor to obtain the culture supernatant. 

Oxygen Aerobic, anaerobic, facultative anaerobic, microaerophilic conditions depending... 

For example, E. coli has three genes for fiimarate hydratase (fnmarase). The constitutively expressed FumA is the major fnmarase under anaerobic and microaerophilic conditions. FumB provides minor activity under anaerobic conditions. Both enzymes lose activity at high O2 levels due to oxidation of their iron—sulfur clusters. FumC, which lacks an iron-sulfur cluster, is the major fnmarase under aerobic conditions. " The availability of three isozymes means that fnmarase activity can be maintained regardless of the concentration of O2. 

In a recent study, it was found that a high initial cell concentration increased the rate of xylose utilization and ethanol formation in P. stipitis [20]. Results from our previous work [20] and this work suggest that there are two options available for using P. stipitis for biomass fermentation. The first option is to operate at suboptimal conditions of low aeration where adaptation or a high initial cell concentration improves the speed of the fermentation. The second option is to operate at optimal fermentation conditions where microaerophilic conditions need to be maintained. Choosing between these two options under industrial conditions will require cost benefit analysis to determine the most viable option. 

The required quantity of P. falciparum parasites maintained in a complete medium (RPMI-1640, 25-mM HEPES, 25-mM NaHCOs, and 10% pooled human serum, with uninfected human red blood cells at 2.5% haematocrit) is introduced into flat-bottomed 96-well plates. The cell suspension (1% parasitaemia) is added to the plates (0.2mL/well), which contains test compound in triplicate alongside untreated controls. The plates are shaken vigorously using a microculture plate shaker, and they are incubated at 37°C for 18 h under microaerophilic conditions [124]. To each well, tritiating hypoxanthine with a specific activity of 14.1Ci/mmol is added (0.5pCi/well) and incubated at 37°C for another 24h. The contents of the well are frozen at -30°C, unfrozen at 50°C, filtrated, and washed several times with water. The disks are dried and added to toluene scintillator in vials, and the radioactivity incorporated into parasites is estimated. 

They have very fastidious requirements for the B group of vitamins and may be sub-divided on their nutritional requirements. They may be grown and counted on the commercially available MRS medium, preferably under microaerophilic conditions. These nutritional requirements may be utilised for the bioassay of certain vitamins such as cyanocobalamin (see Chapter 11). 

Like brewers yeast, it readily adapts to microaerophilic conditions and terminal oxidation is repressed [72],... 

Another feature of the enterobacteria is their ability to use nitrate under anaerobic or microaerophilic conditions as a hydrogen acceptor instead of oxygen. The consequence is that if a brewery fermentation is conducted in the presence of enterobacterial contaminants and nitrate is present, an unacceptable level of nitrite may be produced [73],... 

RCs were purified using a DEAE chromatography method developed for Rb. capsulatus (10). Bacteria were grown under microaerophilic conditions (nonphotosynthetic) to avoid selection of undesirable revertants. Optical spectra were recorded with a Perkin-Elmer Lambda diode array model 3840 spectrophotometer interfaced to a model 7300 workstation. RC pigment content was determined (6) through the absorbance of near-infrared pigment bands after extraction of RCs with acetone/methanol, 7 2 (voLvol). 

Pkormidium laminosum is a filamentous thermophilic cyanobacterium, non-heterocystous, that can fix nitrogen under microaerophilic conditions. Anabaena azollae is a species of nitrogen Hxing, heterocystous cyanobacterium which is usually found as a symbiont of aquatic ferns Azolla. 

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