Growth in multicellular microorganisms

If uninterrupted, growth in fungi proceeds radially outwards from the initiating spore, allowing the fungal colony to colonise new regions potentially rich in nutrients. Actual growth occurs solely at the hyphal tip; as this happens, the terminal cell grows longer, until eventually a new cross wall or septum is formed. Cells away from the tip do not become any longer during hyphal extension, however hyphae in this region may develop into aerial reproductive structures. Older hyphae at some distance from the tip may become completely empty of cytoplasm.

Cell counts and turbidometric measurements are not appropriate to estimate growth of fungi; however total mycelial mass can be measured and its change plotted against time. A fungal growth cycle shows roughly the same phases of growth as described above for bacteria.