Thursday, 20 August 2015
Alexander Fleming’s discovery
Species of Penicillium are recognized by their dense brush-like spore-bearing structures called penicilli (sing.: penicillus). The conidiophores are simple or branched and are terminated by clusters of flask-shaped phialides. The spores (conidia) are produced in dry chains from the tips of the phialides, with the youngest spore at the base of the chain, and are nearly always green. Branching is an important feature for identifying Penicillium species. Penicillium is a large and difficult genus encountered almost everywhere, and usually the most abundant genus of fungi in soils.
Penicillium chrysogenum is a widely studied species of Penicillium. It plays a significant role in the medical community as an antibiotic because it can create penicillin which inhibits the biosynthesis of bacterial cell walls affecting lysis of the cell.
Penicillium was originally discovered by Alexander Fleming. Fleming observed that staphylococcus cultures which had been left on the lab bench and allowed to grow, had begun to lyze and that the active factor could be extracted by filtration of the mold. He described Penicillium as a fungal colony that begins as a “white fluffy mass” that later turns green then black. A yellow colour appears after several days that will diffuse throughout the medium.