Induction of submerged conidiation of the biocontrol agent Penicillium oxalicum

Induction of submerged conidiation of Penicillium oxalicum has been examined using a range of synthetic and complex media and complex media supplemented with by-products of the brewing industry. Only one method (Morton's method), consisting of growth in a glucose/salts-based medium (CN ratio 62.5, medium A) for 24 h and then transference to the same medium without a nitrogen source (medium B), induced conidiation. Levels of sporulation were significantly (P = 0.05) increased by addition of calcium or poly(ethylene glycol) 6000 to medium B. The optimum age for transference of the mycelium was 24 h and the optimum pH was 6. Calcium was an induction factor when added to medium a (CN ratio 62.5) of Morton's method. It was concluded that nitrogen depletion and calcium addition to a medium with high CN ratio are the factors inducing conidiation of P. oxalicum. Maximum levels of conidiation (35 x 106 spores ml-1) were obtained when the nitrogen level in medium A of Morton's method was further reduced (CN ratio 142.9) and calcium (20 mM) was added. These results are the essential starting point to investigate liquid fermentation systems for the biocontrol agent P. oxalicum.

Bibliographic Details

Main Authors:	Pascual, S., Melgarejo, P., Magan, N.
Format:	journal article biblioteca
Language:	eng
Published:	1997
Online Access:	http://hdl.handle.net/20.500.12792/3345
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