Effects of growth medium, inoculum size, and incubation time on culturability and isolation of soil bacteria.

ABSTRACT: Soils are inhabited by many bacteria from phylogenetic groups that are poorly studied because representatives are rarely isolated in cultivation studies. Part of the reason for the failure to cultivate these bacteria is the low frequency with which bacterial cells in soil form visible colonies when inoculated onto standard microbiological media, resulting in low viable counts. We investigated the effects of three factors on viable counts, assessed as numbers of CFU on solid media, and on the phylogenetic groups to which the isolated colony-forming bacteria belong. These factors were inoculum size, growth medium, and incubation time. Decreasing the inoculum size resulted in significant increases in the viable count but did not appear to affect colony formation by members of rarely isolated

SUBMITTER: Davis KE 

PROVIDER: S-EPMC546801 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature