208 • Technologies To Maintain Biological Diversity 



and described or identified (25). Therefore, any 

 changes that occur cannot be determined as 

 temporary or permanent. 



For example, the composition of microbial 

 populations within environments can be dra- 

 matically altered by pollutants (18,19,32). 

 Studies of microbial populations at a pharma- 

 ceutical dump site in the Atlantic Ocean indi- 

 cate that the survival and growth of certain 

 marine micro-organisms over others in the pop- 

 ulation occur as a result of pollution (27). Al- 

 though it is clear that pollution or environ- 

 mental disturbance can produce quantitative 

 changes, definitive evidence of extinction of 

 micro-organisms, as is seen in plants and ani- 

 mals, is rare. But it would seem likely that where 

 micro-organisms are highly adapted to a spe- 

 cific environment, loss of that environment 

 could result in extinction of the micro-orga- 

 nisms (10). 



One group of micro-organisms for which the 

 potential for loss has been a particular concern 

 is the macrofungi— more specifically, the edi- 

 ble wild mushrooms. Morels, chanterelles, and 

 other mushrooms have long been collected by 

 fanciers, particularly in the Northwest United 

 States (33). However, increased collection to 

 serve a growing commercial demand for wild 

 mushrooms has raised fears that the most 

 sought-after species could become rare or ex- 

 tinct (1,33). Scientists currently disagree about 

 whether this is possible, for it is not even known 



if wild mushrooms can be overharvested (33). 

 In the absence of information, some efforts have 

 been made to limit collection (33). Research on 

 the biology and ecology of these mushrooms 

 and their distribution is needed. 



Microbial Diversity Offsite 



The principal repositories for those few 

 micro-organisms that have been isolated are off- 

 site collections. Offsite collections of micro- 

 organisms provide easier and quicker access 

 to specific strains than repeatedly returning to 

 onsite sources to obtain them. In addition, it 

 may not always be possible to obtain the same 

 micro-organism from the same place. The 

 fungus from which penicillin was derived, for 

 example, could not again be isolated from air 

 or dust samples in the laboratory where it was 

 first found as a culture contaminant. Offsite col- 

 lections also are used as reference standards for 

 taxonomic and comparative studies. In micro- 

 biology, a "type" strain of a micro-organism 

 is maintained for use as a reference and as a 

 source for subsequent studies (17). It would be 

 impossible to isolate type-strains from natural 

 environments each time comparative studies 

 were initiated (19,21). 



Current offsite collections of micro-orga- 

 nisms are actively used as resources by indus- 

 try and by the scientific community. Yet such 

 collections are rarely established or maintained 

 for preserving microbial diversity (26). 



MAINTENANCE TECHNOLOGIES 



Onsite maintenance is the only feasible long- 

 term method for maintaining the major portion 

 of microbial diversity, because most of the 

 micro-organisms in any single environment 

 have yet to be identified (19). But existing pro- 

 grams to maintain animal and plant diversity 

 will likely cover all but a few specialized envi- 

 ronments (e.g., deep-sea steam vents), so estab- 

 lishing reserves specifically for maintaining 

 micro-organisms should not be necessary. 



The most cost-effective approach to provid- 

 ing ready access to the many economically. 



medically, agriculturally, or scientifically im- 

 portant micro-organisms today is to preserve 

 them in offsite collections (19). The following 

 sections assess the techniques required to main- 

 tain micro-organisms offsite. 



Isolation and Sampling 



Isolation of micro-organisms and their incor- 

 poration into a collection generally reflects a 

 particular set of goals. Laboratory applications, 

 such as those involved in genetic engineering, 

 require specific strains of micro-organisms that, 



