Actinomycetales from corn

Mesophilic Actinomycetales were isolated from whole corn, brewers grits, and break flour received from three different mills. In addition, strains were isolated from high-moisture (27 per cent) field corn; high-moisture, silo-stored corn (untreated); and high-moisture corn treated with ammonia, ammonium isobutyrate, or propionic-acetic acid. According to standard techniques, 139 strains were extensively characterized and 207 additional strains were partially characterized. On the basis of these characterizations, the streptomycete strains were identified by both the systems of Pridham et al. and Hütter because these systems are rapid and accurate. In general, only Streptomyces griseus (Krainsky) Waksman and Henrici was isolated from high-moisture whole corn (treated or untreated) except from grain exposed to ammonium isobutyrate. Strains isolated from high-moisture corn subjected to that treatment represented both S. griseus and S. albus (Rossi Doria) Waksman and Henrici. The strains isolated from corn and corn products from the three mills were identified with a number of streptomycete species. Of all Actinomycetales isolated, only three were not streptomycetes--two from brewer's grits and one from break flour.