Preparation of free heat-resistant ascospores from Byssochlamys asci

When Byssochlamys is grown for production of ascospores, some of the asci break up into their constituent ascospores, whereas others do not. For heat resistance studies, it is desirable to prepare a uniform suspension of free ascospores. This was accomplished with the aid of a pressure cell, from which a suspension of asci under high pressure was released to atmospheric pressure through a small orifice. Spores so treated had about the same heat resistance as untreated spores.