Re: Questions about Fungi

How long does it take hyphe to grow 20cm?

The only research I was able to find on this was performed in a controlled laboratory environment. One research project compared the growth rates of several species of fungi under different conditions: http://www.springerlink.com/content/8436w34542653854/

The slowest species grew 0.44 cm/day under the best conditions; at that rate, it would take about 45 days to grow 20 cm.

The fastest species grew 1.88 cm per day under the best conditions. At those rates, it would take between 10 and 11 days to grow 20 cm.

How many times can a yeast cell bud?

Each time a yeast cell buds, a small scar is left on the cell wall where the daughter cell pinched off. Once there are too many scars on the surface of a mother cell, it can no longer bud. For the yeast Saccharomyces cerevisiae, which is the kind of yeast used to make bread, a cell can bud 20 to 30 times. This is known as the replicative lifespan.

How long can fungi survive under ground?

Many fungi can live indefinitely underground. Some form close associations with the roots of trees, from which they get much of their nutrition. In exchange, the fungi help the trees get minerals from the soil. Other underground fungi may live off of dead plant matter in the soil, such as the roots of dead plants, and others are pathogens of the trees. In Oregon, researchers found an example of one such fungus, Armillaria ostoyae, that has spread over an area of about 2200 acres. That is, a single individual that covers an area about the size of 1600 football fields! Its age, estimated based on its enormous size, is at least 2000 years.

Some underground fungi form mushrooms above ground as a means of reproduction, but aside from that, they spend their life in the soil.

Dr. Alex Brands

References:
Zervakis G, Philippoussis A, Ioannidou S, Diamantopoulou P. (2001) Mycelium growth kinetics and optimal temperature conditions for the cultivation of edible mushroom species on lignocellulosic substrates. Folia Microbiol. 46(3), 231-234.
DOI: 10.1007/BF02818539

Smith, ML; Bruhn, JN; Anderson, JB (1992). "The fungus Armillaria bulbosa is among the largest and oldest living organisms". Nature 356: 428– 431.