Chitinase Inhibitor Allosamidin Is a Signal Molecule for Chitinase Production in Its Producing Streptomyces I.Analysis of the Chitinase Whose Production Is Promoted by Allosamidin and Growth Accelerating Activity of Allosamidin

摘要

Allosamidin,a typical secondary metabolite of Streptomyces,has been known as a chitinase inhibitor.We found that allosamidin can dramatically promote chitinase production and growth of its producer,Streptomyces sp.AJ9463,in a chitin medium at a few hundred nM.Allosamidin promoted production of the main chitinase detected in the culture filtrate and the chitin-hydrolytic activity of the chitinase was not inhibited by allosamidin at the concentration.The gene encoding the chitinase showed that it is a family 18 chitinase and it was revealed that two genes encoding proteins constructing two-component regulatory system were present at 5'-upstream region of the chitinase gene.Allosamidin is located in the microbial mycelia cultured in a medium without chitin,but it was released from the mycelia by responding to chitin.These results show that allosamidin acts as a key signal molecule for chitinase production in its producing strain,which may be useful for its growth in chitin-rich environment.