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In this article we will discuss about the features and significance of zygomycetes.
Salient Features of Zygomycetes:
The class Zygomycetes includes those members in which the resting spore (zogospore) develops by the fusion of two gametangia. They do not have motile cells (zoospores) in any stage of their life-cycle.
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The salient features of the class are as follows:
(i) The members are saprobes or weak parasites on plants to specialized parasites on animals. A few occur on dung thus coprophilous in nature.
(ii) The thallus usually consists of well developed, branched, filamentous, and coenocytic mycelium; some members possess very much reduced septate mycelium. In some cases, the coenocytic mycelium produces rhizoids and adheres to hard surfaces with their help.
(iii) The cell wall is mainly composed of chitosan-chitin.
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(iv) The asexual reproduction takes place usually by means of non-motile sporangiospores, called aplanospores, but some also reproduce by chlamydospores or by oidia formation.
(v) The sexual reproduction takes place by means of gametangial copulation, resulting in the formation of thick-walled zygospores.
(vi) The zygospore germinates by producing a germ sporangiophore that terminally bears a germ sporangium.
Significance of Zygomycetes:
(i) Many members of Zygomycetes (especially those of order Mucorales) grow rapidly and are often the first species that participate in the decay of vegetable matter by utilizing the simplest carbohydrates (sugars) efficiently leaving complex poly-saccharides (cellulose, hemicellulose, pectin, etc.) for other microorganisms to attack. Because of this, these fungi have often aptly been referred to as the “sugar fungi”.
(ii) Various species of Rhizopus, the bread-mould fungus, are used for commercial production of lactic acid; R. stolonifer for fumaric acid and R. oryzae for alcohol. Species of Mucor and Actinomucor elegans are utilized for making ‘Sufu’ or Chinese cheese from soybeans. ‘Tempeh’, a solid food prepared with soybeans, is processed with R. oligosporus.
(iii) The phenomenon of heterothellism was discovered by A.F. Blakeslee in 1904 in Mucor mucedo and M. hiemalis.
(iv) Many Zygomycetes are involved in spoilage of food, textiles, and leather.
