Phylum Zygomycota clusters more than 1100 different species, mostlysaprotrophic soil fungi, who exploits nutrients by decomposing waste products,such as rotten fruit.
Their name, refers to their reproductive sexualmechanism, as it forms a structure called zygosporangium, arising from theconjugation between two compatible hyphae, with each hyphae stemming from a separateorganism. After conjugation, a cell wallis formed behind the fusing hyphae, which at this point are called gametangia.Next to this, the wall separating the two hyphae is broken down, leading tofusion of both hyphae’s cell components into one organism, except their nuclei,which are still separate entities. Following this, their nuclei fuse and thewalls around the zygosporangium grows even harder and thicker than before – thisconverts the sporangium to a zygospore. After a long resting period, meiosis occurs,and the fused nuclei are divided into two separate recombinant nuclei. These are then later integrated and releasedas meiospores.
Most Zygomycota are harmless to humans, although a few arepathological causing a disease called mucormycose,which arises when spores are inhaled from dusty environments. Fungi in the thirdphyla, phylum Ascomycota, are themost abundant phylum as more than 65.000 species belong here.
Their trademarkis their structural component, the ascus, which is a sac-like unit, harboringeight ascospores, in which sexual and asexual reproduction occurs. The formationof this component arises when a spore lands on a suitable substrate, afterwhich a haploid mycelium is formed. From this, asexual structures can beproduced, or sexual structures, gametangia, can be formed. The female sexualstructure is called ascogonium, while the male sexual structure is anantheridium. Fusing of sexual structuresleads to formation of one organism with two separate nuclei, this is called anascogonius hypha. Fusing of nuclei, takes place at the tip of this hyphae,creating a diploid ascus, who undergoes meiosis and thus produces 4 recombinanthaploid nuclei. Followed by a round of mitosis eight ascospores are formed,which can then be released and the cycle repeats.
Due to the sheer amount ofspecies, phylum Ascomycota, exert both a positive and negative effect on thehuman condition. Beneficial species such as Penicilliumnotatum and Saccharomyces cerevisiaecontribute to our health and or ability to produce beverages, while maligneffects are seen by species of the Aspergillus genus who can cause a respiratorydisease, decay food, synthetize carcinogenic toxins in nuts etc. TheAspergillus genus will be investigated extensively later in this paper.