Effect of Pretreatment with Patoran and Diuron on Growth and Nitrogen Metabolism of Cunninghamella echinulata PDF

Keywords

spore, germination, herbicides

Abstract

Fungal felts, produced by spore germination on patoran or diuron, seemed to be adapted to the continuous supply of large doses of the herbicides (up to 160 micro g/ml). A higher biomass yield followed continuous culturing of the mats of Cunninghamella echinulata on fresh herbicide-containing media, though this was smaller than in control samples. The effect was more substantial after patoran treatment as compared with diuron. Patoran induced a consistent inhibition of respiratory carbon dioxide output even after the pretreated mycelia were transferred to a plain nutritive medium. Continuous supply of the herbicide was highly toxic. However, C. echinulata seemed more adapted to diuron. The deleterious effects of pretreatment with the herbicides was more apparent on nitrogen metabolism; secretion of nitrogen from the mycelium increased with both treatments, particularly with the continuous supply of the herbicides. Recovery, after an initial herbicide treatment, seemed to induce better nitrogen accumulation than continuous supply of the herbicides. The lower residual nitrogen content of mycelia continuously supplied with the herbicides, as compared with their respective 'recovering' samples, indicates lesser tolerance of the former samples to the herbicides with prolonged exposure to the large doses.