night fungal flora

Night fungal flora

In our everyday life, we are perhaps least aware of the presence of microorganism unless we happen to suffer from an allergy of spores of molds or actinomycetes. They form an important vehicle for spread of many microorganism and the contamination of food.

Some of the important molds produce large no. of small unwettable spores which are resistant to desiccation and light damage. They become air borne as fine dry powder or dust particle by physical disturbance and wind. Spores of Penicillium and Aspergilus seem to get everywhere and are responsible for food spoilage.

Fungi like Fusarium produce easily wettable spores which are dispersed into the atmosphere in tiny droplets of water and may get distributed in field crops during wet weather.

As relative humidity of atmosphere decreases with change from night to day, the sporophores of fungi such as Cladosporium react by twisting and collapsing, throwing the spores into the atmosphere. At the some times of year, especially during middle of the day spore of Cladosporium may be the most common spores in air spora.

Many fungi have evolved mechanism for actively firing their spores into atmosphere, a process requiring high relatively humidity. Thus, spores of yeast, which are a part of microbial flora of leaf surface of plants, are present in highest no. in middle of night when relative humidity is at highest. The friuting bodies in mushrooms have produced structure that provides its own microclimate of high relative humidity so that these fungi can fire their spores into air even in middle of day.

Optimum rate of relative humidity for survival of most microorganism is between 40- 80 % low and high relative humidity cause the death of most micro organism