title: Glucose and penicillin concentrations in agar medium below fungal colonies.
abstract: The growth of colonies of Rhizoctonia cerealis and Penicillium chrysogenum on solid media in plate cultures was studied. When grown on defined media containing 10-50 mM-glucose, R. cerealis did not cause a significant reduction in the glucose concentration of the medium in advance of colonization, but did cause the formation of a steep glucose concentration gradient in the substrate below the colony; the medium directly below the centre of a 7 cm diameter colony of R. cerealis was exhausted of glucose even when the fungus was grown on medium containing 50 mM-glucose. Penicillin produced by colonies of P. chrysogenum accumulated in the medium in advance of fungal colonization. For a period up to about 18 d after inoculation, the concentration of penicillin in the medium throughout the plate increased with colony development and thereafter, except at the margins of the plate, decreased.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D003470:Culture Media; D005947:Glucose / Q000378:metabolism*; D003904:Mitosporic Fungi / Q000254:growth & development*; D010406:Penicillins / Q000378:metabolism*; D010408:Penicillium chrysogenum / Q000254:growth & development; D012232:Rhizoctonia / Q000254:growth & development*
chemical_list: D003470:Culture Media; D010406:Penicillins; D000255:Adenosine Triphosphate; D005947:Glucose