DOI: 10.1111/gbi.12075
Scopus记录号: 2-s2.0-84893736287
论文题名: Thermodynamic characterization of proton-ionizable functional groups on the cell surfaces of ammonia-oxidizing bacteria and archaea
作者: Gorman-Lewis D. ; Martens-Habbena W. ; Stahl D.A.
刊名: Geobiology
ISSN: 1472-4677
EISSN: 1472-4669
出版年: 2014
卷: 12, 期: 2 起始页码: 157
结束页码: 171
语种: 英语
Scopus关键词: ammonia
; proton
; archaeon
; article
; bacterium
; calorimetry
; chemistry
; metabolism
; oxidation reduction reaction
; potentiometry
; species difference
; theoretical model
; thermodynamics
; Ammonia
; Archaea
; Bacteria
; Calorimetry
; Models, Theoretical
; Oxidation-Reduction
; Potentiometry
; Protons
; Species Specificity
; Thermodynamics
Scopus学科分类: Earth and Planetary Sciences: General Earth and Planetary Sciences
; Environmental Science: General Environmental Science
; Agricultural and Biological Sciences: Ecology, Evolution, Behavior and Systematic
英文摘要: The ammonia-oxidizing archaeon Nitrosopumilus maritimus strain SCM1 (strain SCM1), a representative of the Thaumarchaeota archaeal phylum, can sustain high specific rates of ammonia oxidation at ammonia concentrations too low to sustain metabolism by ammonia-oxidizing bacteria (AOB). One structural and biochemical difference between N. maritimus and AOB that might be related to the oligotrophic adaptation of strain SCM1 is the cell surface. A proteinaceous surface layer (S-layer) comprises the outermost boundary of the strain SCM1 cell envelope, as opposed to the lipopolysaccharide coat of Gram-negative AOB. In this work, we compared the surface reactivities of two archaea having an S-layer (strain SCM1 and Sulfolobus acidocaldarius) with those of four representative AOB (Nitrosospira briensis, Nitrosomonas europaea, Nitrosolobus multiformis, and Nitrosococcus oceani) using potentiometric and calorimetric titrations to evaluate differences in proton-ionizable surface sites. Strain SCM1 and S. acidocaldarius have a wider range of proton buffering (approximately pH 10-3.5) than the AOB (approximately pH 10-4), under the conditions investigated. Thermodynamic parameters describing proton-ionizable sites (acidity constants, enthalpies, and entropies of protonation) are consistent with these archaea having proton-ionizable amino acid side chains containing carboxyl, imidazole, thiol, hydroxyl, and amine functional groups. Phosphorous-bearing acidic functional groups, which might also be present, could be masked by imidazole and thiol functional groups. Parameters for the AOB are consistent with surface structures containing anionic oxygen ligands (carboxyl- and phosphorous-bearing acidic functional groups), thiols, and amines. In addition, our results showed that strain SCM1 has more reactive surface sites than the AOB and a high concentration of sites consistent with aspartic and/or glutamic acid. Because these alternative boundary layers mediate interaction with the local external environment, these data provide the basis for further comparisons of the thermodynamic behavior of surface reactivity toward essential nutrients. © 2014 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/85165
Appears in Collections: 影响、适应和脆弱性
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作者单位: University of Washington, Department of Earth and Space Sciences, Seattle, WA, United States; University of Washington, Department of Civil and Environmental Engineering, Seattle, WA, United States
Recommended Citation:
Gorman-Lewis D.,Martens-Habbena W.,Stahl D.A.. Thermodynamic characterization of proton-ionizable functional groups on the cell surfaces of ammonia-oxidizing bacteria and archaea[J]. Geobiology,2014-01-01,12(2)