Halophilicity

Fn some cases, r-allylpalladium complex formation by retention syn attack) has been observed. The reaction of the cyclic allyiic chloride 33 with Pd(0) affords the 7r-allylpalladium chlorides 34 and 35 by retention or inversion depending on the solvents and Pd species. For example, retention is observed in benzene, THF, or dichloromethane with Pd2(dba)3. However, the complex formation proceeds by inversion in these solvents with Pd(Ph3P)4, whereas in MeCN and DMSO it is always inversion[33]. The syn attack in this case may be due to coordination of Pd to chlorine in 33, because Pd is halophilic. The definite syn attack in complex formation has been observed using stereoche-mically biased substrates. The reaction of the cxoallylic diphenylphosphino-acetate 36 with phenylzinc proceeds smoothly to give 37. The reaction can be explained by complex formation by a syn mechanism[31]. However, these syn attacks are exceptional, and normally anti attack dominates. 

Halophilic or Halotolerant Bacteria which thrive in a highly salt environment, up to 25% NaCl. 

Emerson D, S Chauhan, P Oriel, JA Breznak (1994) Haloferax sp. D1227, a halophilic Archaeon capable of growth on aromatic compounds. Arch Microbiol 161 445-452. 

DeFrank 11, T-C Cheng (1991) Purification and properties of an organophosphorus acid anhydrase from a halophilic bacterial isolate. / Sacfeno/ 173 1938-1943. 

V. K. Bhupathiraju, P. K. Sharma, M. J. Mclnemey, R. M. Knapp, K. Fowler, and W. Jenkins. Isolation and characterization of novel halophilic anaerobic bacteria from oil field brines. In E. C. Donaldson, editor. Microbial enhancement of oil recovery Recent advances Proceedings of the 1990 International Conference on Microbial Enhancement of Oil Recovery, volume 31 of Developments in Petroleum Science, pages 131-143. Elsevier Science Ltd,... 

D. Gevertz, J. R. Paterek, M. E. Davey, and W. A. Wood. Isolation and characterization of anaerobic halophilic bacteria from oil reservoir brines. Number 31, pages 115-129.1991. 

Membranes of extreme halophilic (Kushwaha et al. 1975, Anwar et al. 1977, Anton et al. 2002, Lutnaes et al. 2002, Oren 2002) and thermophilic bacteria (Alfredsson et al. 1988, Yokoyama et al. 1995) contain a large concentration of polar carotenoids. Membranes of these bacteria, which live in extreme conditions, should provide a high barrier to block nonspecific permeation of polar and nonpolar molecules. Incorporation of dipolar carotenoids into these membranes at a high concentration serves this purpose well because dipolar carotenoids increase the hydrophobic barrier for polar molecules (Wisniewska and Subczynski 1998, Wisniewska et al. 2006) and increase the rigidity barrier... 

Anton, J., A. Oren, S. Benlloch, F. Rodriguez-Valera, R. Amann, and R. Rossello-Mora. 2002. Salinibacter ruber gen. nov., sp. nov., a novel, extremely halophilic member of the bacteria from saltern crystallizer ponds. Int. J. Syst. Evol. Microbiol. 52 485M91. 

Lutnaes, B. F., A. Oren, and S. Liaaen-Jensen. 2002. New C-40 carotenoid acyl glycoside as principal carotenoid in Salinibacter ruber, an extremely halophilic eubacterium. J. Nat. Products 65 1340-1343. 

Oren, A. 2002. Molecular ecology of extremely halophilic archaea and bacteria. FEMS Microbiol. Ecol. 39 1-7. 

Smithies, Gibbons, and Bayley reported a relatively high nitrogen content in the walls of several halophilic bacteria which indicated that the cell material was predominantly protein. They contained only small amounts of lipides. The cell walls were lipoprotein. 

Could it be the case that microorganisms, like the suspected fossils in the Mars meteorite ALH 84001, exist in the Martian soil This question leads to the counterquestion as to whether it has previously been possible to detect and study life (primitive life forms) under highly extreme conditions. Are there such conditions on Earth We now know quite a lot about extremophiles such as the thermophilic, halophilic and hyperthermophilic microorganisms. 

Bonnete, F. Madern, D. Zaccai, G., Stability against denaturation mechanisms in halophilic malate dehydrogenase adapt to solvent connditions, 7. Mol. Biol. 1994, 244, 436-447... 

Halophile an organism requiring at least 0.2 M salt for growth. 

Xerotolerant an organism capable of growth at low water activity. For example, an extreme halophile or endolith. 

Guo J, Zhou J, Wang D, Tian C, Wang Ping M, Uddin S (2008) A novel moderately halophilic bacterium for decolorizing azo dye under high salt condition. Biodegr 19 15-19... 

Asad S, Amoozegar MA, Pourbabaee AA et al (2007) Decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria. Bioresour Technol 98 2082-2088... 

Kargi F, Uygur A (1996) Biological treatment of saline wastewater in an aerated percolator unit utilizing halophilic bacteria. Env Technol 17 325-330... 

Karigi F, Dincer AR (1998) Saline wastewater treatment by halophile supplemented activated sludge culture in an aerated rotating biodisc contactor. Enz Microbial Technol 122 427 133... 

High salt concentrations up to 15-20% can be found in wastewater from dyestuff industries. Moreover, textile manufacturers located on coastal areas can cause pollution of seawater. The biological treatability of wastewater with a high saline concentration is limited because most of the microorganisms that are able to degrade azo dyes are not active in these conditions, in which the selection of halophilic or halotolerant bacteria capable to degrade azo dyes is necessary [79]. 

J. F. Imhoff (2001) True marine and halophilic anoxygenic phototrophic bacteria. Arch. Microbiol., 176 243-254... 

In this paper, we will describe one of examples, where artificial archaeal glycolipids are applied to the construction of nano-devices containing energy-conversion membrane proteins, by employing the phytanyl-chained glycolipid we have recently developed, i.e., l,3-di-o-phytanyl-2-o- ((3-D-maltotriosyl) glycerol (Mab (Phyt)2, Fig. 1) [16,17] and natural proton pump, bacteriorhodopsin (BR) derived from purple membranes of the extremely halophilic archaeon Halobacterium salinarium S9 [18],... 

Other anomeric-oxygen exchange reactions have been recently investigated quite extensively. Closely related to the Koenigs-Knorr method is the introduction offluorine as the leaving group (Scheme 1, path B) (6,9-13). Because of the difference in halophilicity of this element as compared with bromine and chlorine, additional promoter systems besides silver salts were found useful as activators for glycosylation reactions (14-16). However,... 

Oren A (1997). Mycosporine-like amino acids as osmotic solutes in a community of halophilic cyanobacteria. Geomicrobiol J 14 231-240... 

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