Bioremediation in the vadose zone is unpredictable because of poor understanding of factors influencing microbial growth in this environment. A lab-scale experimental system was developed to examine, noninvasively, interactions between microbial growth, water flow, and solute transport in unsaturated porous media. Measurements of microbial colonization, and its impact on hydrology,...
Nodulation success by two indigenous Rhizobium
trifolii serogroups, 6 and 36, on subterranean clover
(Trifolium subterraneum L.) was affected by the addition
of phosphate to Abiqua soil (Ultic Haploxeroll). To
understand the impact of phosphorus nutrition on the
survival and nodulation characteristics of the two
serogroups, studies were carried out...
Although the biology of Bradyrhizobium has been studied for almost
one hundred years, virtually nothing is known about the ecology and genetic
variation in natural soil populations of this genus. The majority of
information has been obtained from studies of one species, Bradyrhizobium
japonicum, and the diversity within soil populations...
The regulation of monooxygenase enzymes has been demonstrated in bacteria that grow on methane and long chain-length alkanes (>C10). Less is known about monooxygenase regulation in short chain alkane oxidizing bacteria that grow on intermediate chain-length alkanes C2-C10. This dissertation focuses on the regulation of butane monooxygenase (BMO) expression and...
The chemolithoautotrophic nitrite oxidizing bacteria (NOB) participate in the
biogeochemical cycling of nitrogen by catalyzing and conserving energy from the
oxidation of nitrite (NO₂-) to nitrate (NO₃-) via a nitrite oxidoreductase (NXR). The
main objective of this work was to comparatively annotate and analyze the genome
sequences of Nitrobacter winogradskyi...
In recent years considerable interest has been shown in the diversity of ammonia-oxidizing bacteria in soil communities. The majority of the research has been carried out in Northern Europe where soils have received high atmospheric inputs of nitrogen over the past two centuries. In contrast, although much work has been...
Although much has been learned about the comparative
nodulating behavior of simple mixtures of rhizobial strains
under non-soil situations, it is unclear how these findings
relate to the factors influencing nodulation success by the
complex mixtures of strains found within soil-borne
rhizobial populations. Information on the structure and
physiological behavior...