Storage and translocation

Fungi are thus able to store large amounts of the main nutrients locally either for later use but also as a source for translocation to other parts of the mycelium. Storage of compounds cannot be done as monomers in the cytoplasm. This would create osmotic problems. Thus storage compounds have to be either as polymers or in hydrophobic compounds. Carbon is mostly stored as fats in lipid bodies. Phosphorus is stored as oligophosphates in vacuoles. There is however no known general compound known to be used as storage for proteins. In one case a specific storage protein have been demonstrated (Fig 16).

Fig 16. Percent AOL (storage protein) of all proteins in a Arthrobotrus oligospora and total amount of soluble proteins (top) and mycelium dry weight and medium glucose concentration (bottom) at different times from the start of the experiment. From day 0 until time I the medium had C/N-ratio 5. At time I the medium was exchanged to C/N-ratio 1000. This was repeated at times II-IV. At time V the medium was changed back to C/N-ratio 5 again. Glucose was rapidly finished from the medium after e few days. When glucose was becoming limited there was nitrogen in excess and the content of AOL increased. When C were added at time I AOL started to be broken down. The fungus was able to continue growth by using the stored nitrogen in AOL and completely remove the glucose until the medium change at time III. Then there was a small surplus glucose present in the medium since the fungus was not able to take it up. When shifted to the high nitrogen content medium again at time V the accumulation of AOL started again and glucose was depleted. .

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