Biology

There are several microorganisms in the environments which have established their secure places their respective ecological niches as determined by evolutionary strategic fitnesses in the environment. They coexist among themselves as well with all other macroorganisms. Each organism whatever the size also demonstrates a genetically bestowed innate capacity to out-survive others in many relationships such as being obligate or facultative parasites (on any other organism of any group), commensals, symbionts and so on.

Among the many microorganisms, two fungal organisms of one each of beneficial and pathogenic groups are discussed for their similarities and differences. Beneficial organisms are the species of the genus Trichoderma viride. The harmful pathogenic organisms are several species belonging to Aspergillus such as A. flavus.

Similarities
Fungi of both the groups are micropscopic and grow to a cottony off white irregular mass (some inches longwode) consisting of many microscopically visible numerous intertwined filamentous structures called (2-10 microns in diameter) hyphaemycelia.  These are septate (compartmented) with clear partitions between segments, or coenocytic (multinucleate, mostly with no compartments), and also hollowempty showing freely randomly distributed nuclei in the cytoplasm generally at the growing apices of these hyphae. They all contain all the usual subcellular organelles necessary for the other metabolic phenomena such as synthesis of proteins, cell wall material, and respiration. Generally they are aerobic.

They are all heterotrophic because they lack chlorophyll may live in dry or moist soil, decaying organic matter or on other organisms such as barks, stems, roots, leaves or of trees.  The fungi are widely distributed in all the kinds of environments. They produce numerous spores asexually or sexually fertilized zygote which are dispersed in air, or by sticking to surfaces of motile other organisms.

They are generally recognized by staining with dyes for coloring the hyphae which are a product of general or specific for each organism specific metabolism

Differences
Species of Trichoderma produce enzymes called chitinases or cellulases which Therefore they are very useful as antagonistic microorganisms or even to produces these enzymes under controlled in vitro conditions.

The pathogenic species of aspergillus  Aspergillus such as A. flavus survives by colonizing on many nutritionally important fruits and seeds such peanuts and many other species during maturity and post harvest storage.. It sucks nutrients and carbohydrates from the seedsfruits thus depriving the seeds and fruits developing into mature useful seeds. They are thus big loss to farmers.

Aspergillus flavus is notorious for promoting the production of a deadly carcinogenic toxin in the seeds called the aflatoxins. Even at low concentrations such parts per billion can be very potentially carcinogenic. Peanuts are used for consumptions in various ways and also as oils and butter for confectionary purposes. The persons consuming any of these infected products are high dangers of developing many kinds of cancers which are still not curable. There is a strict ban on importing and exporting seeds of these crops.