Study the effect of Microwaves radiation in the growth of Some isolates fungi

Abstract

Abstract Explained this study the effect of microwaves radiation with a frequency waves (a 2,450 MHz) on five fungal isolates (Aspergillus flavus, Aspergillus niger, Aspergillus fumigates, Penicillium chrysogenum, and alternaria alternate) .Fungal isolates that cultivated on the Sabouraud dextrose agar (SDA ) , at a rate of three frequency for each isolate fungi were exposed to the radiation of microwave oven with four time periods (0 second( control), 5 , 10 , 15 seconds). where the results showed highly growth of colonies of each fungal isolates used in the study that exposed to microwaves of time periods (5 seconds, 10 seconds). While killed all fungal colonies exposed to microwaves for the time period (15 seconds). This study proved the ability of the waves and microwaves period of time (15 seconds) and above to kill the fungal colonies and do not allow for the growth of fungal spores, meaning that the rate of growth of fungal colonies is inversely proportional to the length of time of exposure to radiation of microwaves. Key words: microwave oven, Aspergillus , Penicillium , alternaria alternate.Introduction:- 1- Microwaves are non-ionizing electromagnetic waves with frequencies between 0.3 and 300 GHz(i.e.,with wave lengths from 1 meter to 1 millimetre ,respectively) [ 1 ,2 ]. Mechanism of microwaves action on living organisms, when irradiating living organisms ,microwaves produce two types of effects :thermal and non thermal . Thermal effects are the consequence of absorption of microwave energy by cell molecules causing then vibrate much faster and producing general heating of the cell . The concept of non-thermal effects of microwaves came from experiments in which bacterial cultures were to a large extent destroyed by microwave induced heating than by other heating methods producing the same working temperature and from studies showing an increase in the growth of bacteria induced by microwaves[ 3].