کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10890955 | 1081846 | 2005 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Environmental pH as an important factor for the distribution of urease positive ammonia-oxidizing bacteria
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
بیوتکنولوژی یا زیستفناوری
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Environmental pH as an important factor for the distribution of urease positive ammonia-oxidizing bacteria Environmental pH as an important factor for the distribution of urease positive ammonia-oxidizing bacteria](/preview/png/10890955.png)
چکیده انگلیسی
The effect of pH on ureolytic activity of a number of chemolithotrophic ammonia-oxidizing bacteria (AOB) has been studied in context with distribution patterns of these species. The pH-optima for urea-based nitrification were found to differ clearly among the examined species. Pronounced optima ranged between pH 5.0 and 8.0. Urease is an intracytoplasmic enzyme and should therefore be independent of the external pH. Our first results indicated the presence of a pH-dependent uptake system for urea. Simultaneous oxidation of free ammonia, possible only at high pH values, led to a strong intensification of ureolysis. The lag-phase of growth on urea as the sole energy source was clearly prolonged compared to free ammonia. Our results point on the existence of an active, most likely energy-linked urea-uptake system in addition to a possible passive diffusion of urea. The different pH-optima of urea-uptake agree with known distribution patterns of distinct AOB. It might be a reason for the shift of dominant Nitrosospira populations along pH gradients in acid soils as observed by others in molecular analyses of natural AOB populations.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microbiological Research - Volume 160, Issue 1, 28 February 2005, Pages 27-35
Journal: Microbiological Research - Volume 160, Issue 1, 28 February 2005, Pages 27-35
نویسندگان
Andreas Pommerening-Röser, Hans-Peter Koops,