SCREENING FOR RESTRICTION ENDONUCLEASES IN AEROBIC, THERMOPHILIC EUBACTERIA

A total of 216 Icelandic aerobic, heterotrophic, thermophiles belongin g to three different genera were screened for type LI restriction endo nucleases. The frequency of positive strains was 44% for both Thermus and Bacillus but 63% for Rhodothermus. Approximately half of the enzym es from each group were characterised and a total of 14 different rest riction enzymes were found. In all cases they were isoschizomers of kn own enzymes. Thermus contained 9 different types, Bacillus 6 and Rhodo thermus had 3. This is the first time that isoschizomers of BspEI, Bgl I, EagI and EcoRV ape found in Thermus and BstBI and EcoRV are found i n Rhodothermus.