Naphthalene Acetic Acid Potassium Salt (NAA-K) Affects Conidial Germination, Sporulation, Mycelial Growth, Cell Surface Morphology, and Viability of Fusarium oxysporum f. sp. radici-lycopersici and F. oxysporum f. sp. cubense in Vitro.

The response to exogenous addition of naphthalene acetic acid potassium salt (NAA-K) to Fusarium oxysporum f. sp radici-lycopersici ATCC 60095 and F. oxysporum f.

effect of recombinant amaranth cystatin (AhCPI) on spore germination, mycelial growth, stress response and cellular integrity of and .

The inhibitory effect of recombinant amaranth cystatin (AhCPI) on the spore germination and growth of the mycotoxigenic fungus and was investigated. AhCPI showed a concentration-dependent antifungal activity against both fungi. Differential effects were observed when fungi were treated with cystatin in two developmental stages.

Reduction of aflatoxin B1 during tortilla production and identification of degradation by-products by direct-injection electrospray mass spectrometry (DIESI-MS).

Objective: To determine the effect of pH, and exposure time over the inactivation of aflatoxin B1 (AFB1) during the tortilla making process as well as the degradative molecules generated.

Materials And Methods: Inactivation of AFB1 in maize-dough with alkaline pH and in alkaline methanolic solutions was determined by HPLC. Kinetics of time exposure of AFB1 in methanolic solution and the degradative products were analyzed by direct injection electrospray mass spectometry (DIESI-MS).

Life without putrescine: disruption of the gene-encoding polyamine oxidase in Ustilago maydis odc mutants.

In previous communications the essential role of spermidine in Ustilago maydis was demonstrated by means of the disruption of the genes encoding ornithine decarboxylase (ODC) and spermidine synthase (SPE). However, the assignation of specific roles to each polyamine in different cellular functions was not possible because the spermidine added to satisfy the auxotrophic requirement of odc/spe double mutants is partly back converted into putrescine. In this study, we have approached this problem through the disruption of the gene-encoding polyamine oxidase (PAO), required for the conversion of spermidine into putrescine, and the construction of odc/pao double mutants that were unable to synthesize putrescine by either ornithine decarboxylation or retroconversion from spermidine.

Mechanism of Sterigmatocystin Biosynthesis Regulation by pH in Aspergillus nidulans.

External pH constitutes one of the most important environmental factors that control growth, metabolism and differentiation in microorganisms, including fungi. We have analyzed the effect of external pH on sterigmatocystin biosynthesis in Aspergillus nidulans. It was observed in repeated experiments that alkaline pH, in opposition to acid pH, increased sterigmatocystin production and the transcript levels of aflR, the master gene that regulates expression of the sterigmatocystin cluster in A.