Obligate autotrophy in the ammonia oxidizing bacterium Nitrosomonas europaea.

PDF Version Also Available for Download.

Description

Closing report for project DOE-FG02-03ER15436. The project studied obligate autotrophy in the ammonia oxidizing bacterium Nitrosomonas europaea. Nitrosomonas europaea can obtain all of its energy and reductant for growth from the oxidation of ammonia to nitrite and is, therefore, classified as a chemolithotroph. This bacterium is also an autotroph, which can derive all cellular carbon from carbon dioxide. N. europaea seems incapable of growth with other carbon or energy sources. This restricted capability is surprising given that ammonia is a poor energy source. The main goal of the project was to examine the basis of autotrophy in N. europaea or, ... continued below

Creation Information

Arp, Daniel James & Sayavedra-Soto, Luis Alberto January 1, 2006.

Context

This text is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 112 times . More information about this text can be viewed below.

Who

People and organizations associated with either the creation of this text or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this text. Follow the links below to find similar items on the Digital Library.

Description

Closing report for project DOE-FG02-03ER15436. The project studied obligate autotrophy in the ammonia oxidizing bacterium Nitrosomonas europaea. Nitrosomonas europaea can obtain all of its energy and reductant for growth from the oxidation of ammonia to nitrite and is, therefore, classified as a chemolithotroph. This bacterium is also an autotroph, which can derive all cellular carbon from carbon dioxide. N. europaea seems incapable of growth with other carbon or energy sources. This restricted capability is surprising given that ammonia is a poor energy source. The main goal of the project was to examine the basis of autotrophy in N. europaea or, thought of another way, to determine the barriers to heterotrophy. The approach was enabled by the N. europaea genome sequence, stimulating new ways of thinking about this physiological paradox—an insistence on a single, albeit poor, energy source. Objective 1 was to examine the expression and regulation of the genes coding for alpha-ketoglutarate dehydrogenase, determine if the enzyme’s activity is present, and determine whether alteration of the expression levels influences autotrophic growth. Although Nitrosomonas europaea lacks measurable alpha-ketoglutarate dehydrogenase activity, the genome sequence revealed the presence of the genes encoding the enzyme. A knockout mutation was created in the sucA gene encoding the E1 subunit. Compared to wild-type cells, the mutant strain showed an accelerated loss of ammonia monooxygenase and hydroxylamine oxidoreductase activities upon entering stationary phase. In addition, unlike wild-type cells, the mutant strain showed a marked lag in the ability to resume growth in response to pH adjustments in late stationary phase. The results were published in Hommes N.G., Kurth E. G., Sayavedra-Soto L.A., and Arp D.J. (2006) Disruption of sucA, which encodes a subunit of alpha-ketoglutarate dehydrogenase, affects the survival of Nitrosomonas europaea in stationary phase. Journal of Bacteriology 188:343-347. Objective 2 was to determine the basis of fructose stimulation of growth on ammonia, examine fructose metabolism, and determine the impact of other compounds on growth on ammonia. Previous studies showed that N. europaea can utilize limited amounts of certain organic compounds, including amino acids, pyruvate, and acetate, although no organic compound has been reported to support the growth of N. europaea. The genomic sequence of N. europaea revealed a potential permease for fructose. N. europaea utilized fructose and other compounds as carbon sources to support growth. Cultures were incubated in the presence of fructose or other organic compounds in sealed bottles purged of CO(2). In these cultures, addition of either fructose or pyruvate as the sole carbon source resulted in a two- to threefold increase in optical density and protein content in 3 to 4 days. Studies with [(14)C]fructose showed that >90% of the carbon incorporated by the cells during growth was derived from fructose. Cultures containing mannose, glucose, glycerol, mannitol, citrate, or acetate showed little or no growth. N. europaea was not able to grow with fructose as an energy source, although the presence of fructose did provide an energy benefit to the cells. These results show that N. europaea can be grown in carbon dioxide free medium by using fructose and pyruvate as carbon sources and may now be considered a facultative chemolithoorganotroph. The results were published in Hommes N.G., Sayavedra-Soto L.A. and Arp. D.J. (2003). Chemolithotrophic growth of Nitrosomonas europaea on fructose. Journal of Bacteriology. 185:6809-2773. Objective 3 attempted to grow N. europaea heterotrophically through pathways predicted by the genome. Experiments with mutant strains and complementation studies were performed to test whether N. europaea can utilize other carbon sources. N. europaea was not able to grow heterotrophically in the conditions tested in this objective.

Language

Item Type

Identifier

Unique identifying numbers for this text in the Digital Library or other systems.

  • Report No.: DOE-ER15436
  • Grant Number: FG02-03ER15436
  • Office of Scientific & Technical Information Report Number: 944067
  • Archival Resource Key: ark:/67531/metadc902119

Collections

This text is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this text?

When

Dates and time periods associated with this text.

Creation Date

  • January 1, 2006

Added to The UNT Digital Library

  • Sept. 27, 2016, 1:39 a.m.

Description Last Updated

  • Nov. 7, 2016, 3:31 p.m.

Usage Statistics

When was this text last used?

Yesterday: 0
Past 30 days: 3
Total Uses: 112

Interact With This Text

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Arp, Daniel James & Sayavedra-Soto, Luis Alberto. Obligate autotrophy in the ammonia oxidizing bacterium Nitrosomonas europaea., text, January 1, 2006; United States. (digital.library.unt.edu/ark:/67531/metadc902119/: accessed April 21, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.