Freeze-drying

Miranda K. Martin <martins [at] toad__net> writes

>David A. Tremain <david_tremain [at] pch__gc__ca> writes
>
>>last posting about freeze-drying (Conservation DistList Instance:
>>16:59 Monday, April 7, 2003).
>
>Regarding the issue of freeze-drying moldy materials, in addition to
>David's point relating to the risk that the spores may be
>reactivated, is the concern that even dormant or dead mold spores
>may cause allergenic reactions. ...

In my book "Fungal Facts" I discuss both the effect of freeze-drying
on fungal structures and the need to remove fungal structures after
any biocidal treatment because they retain their antigenic activity
after death. The freeze-drying parameters (pretreatment with
glycerol and extremely rapid temperature changes both in freezing
and thawing) that are used to allow fungi to remain viable for long
term storage are not those of the parameters used in freeze-drying
wet artifacts. Thus the fungal structures will be killed but remain
antigenic in artifact freeze-drying. It is also important to note
that its not only the spores--conidia--that are allergenic but all
fungal structures. The antigen is beta-glucans common in the cell
walls of all fungal structures.

Mary-Lou Florian


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                  Conservation DistList Instance 16:62
                 Distributed: Thursday, April 17, 2003
                       Message Id: cdl-16-62-001
                                  ***