BioConcepts

microbiomeMikrobiom (ger.)

• 1) A population of microorganisms inhabiting a specific environment; a microbial community or ecosystem, now esp. that of the body. (OED 2013)
  category symbiosis

  1952

  The protozoan fauna (as a matter of fact, the whole microbiome) [of a harbour station] is poor in species and individuals, and those present are typically polysaprobes

  Mohr, J.L. (1952). Protozoa as indicators of pollution. The Scientific Monthly 74, 7-9: 7.
  

  2001

  The accompanying table […] includes Lederberg’s own recent coinage of microbiome, to signify the ecological community of commensal, symbiotic, and pathogenic microorganisms that literally share our body space and have been all but ignored as determinants of health and disease.

  Lederberg, J. & McCray, A.T. (2001). Ome sweet ‘omics: a genealogical treasury of words. Scientist 15 (Apr. 2, 2001), 8.
  

• 2) The collective genomes of all the microorganisms inhabiting a specific environment, esp. that of the body.  
  category symbiosis

  2001

  The Nobel laureate Joshua Lederberg has suggested using the term ‘microbiome’ to describe the collective genome of our indigenous microbes (microflora).

  Hooper, L.V. & Gordon, J.I. (2001). Commensal host-bacterial relationships in the gut. Science 292, 1115-1118: 1115.