Pseudomonas mendocina ymp

Strain ymp was isolated as part of the Yucca Mountain Project from sediment in a surface holding pond of a drilling operation at the Nevada Test Site, NV (the proposed site of the  high-level nuclear repository). It was identified as a Pseudomonas mendocina based on 16S rRNA gene sequence analysis.  Of particular importance to these investigations is the fact that this organism cannot use Fe as a terminal electron acceptor, thus Fe dissolution is for metabolic needs and not for use in dissimilatory Fe reduction.  This fact allows investigators to study dissolution and uptake mechanisms utilized by microorganisms under aerobic conditions.  P. mendocina strain ymp was selected for being common rather than for being unique or unusual.  It is a very common soil and subsurface gram-negative bacterium.  In many ways, it typifies bacteria in these environments by being capable of metabolizing a wide variety of organic substrates and of surviving the harsh conditions that exist in soil (desiccation, starvation, etc.).  It thus serves as an excellent model organism.  It was also selected for its obligate, aerobic, respiratory metabolism, which makes it somewhat of a metabolic specialist.  Understanding the genomic controls on P. mendocina production of siderophores and reductant, and comparison with other aerobic bacteria will help to bridge the gap between field and laboratory studies in geomicrobiology.  Our ongoing research on comparative genomics will pave the way for an entirely new approach to understanding geomicrobiological processes at the field scale.  Genomic sequence analysis of Pseudomonas mendocina strain ymp will facilitate understanding of the molecular controls of other cellular functions that are related to its abilities to withstand physiological stress and to metabolize a wide range of organic compounds.  It will also facilitate evolutionary studies within Pseudomonas spp., a large genus that includes environmental isolates with a variety of lifestyles.