N. Benbouzidrollet et al., ISOLATION OF NEW PLASMIDS FROM HYPERTHERMOPHILIC ARCHAEA OF THE ORDERTHERMOCOCCALES, Research in microbiology, 148(9), 1997, pp. 767-775
A collection of 57 strains of hyperthermophilic Archaea from the order
Thermococcales was screened for the presence of plasmids; 9 plasmids
present in six of these strains were isolated and characterized in ter
ms of size and cross-hybridization. The Notl macro-restriction pattern
s of genomic DNA of strains harbouring these plasmids were obtained. P
yrococcos abyssi strains GE27 and GE23 as well as Thermococcus sp. GE3
1 contained a single plasmid of 3.5 kb (pGN27), 16.8 kb (pGN23) and 5.
3 kb (pGNB1), respectively, whilst the three strains I559, I568 and I6
90 all contained two plasmids of 3.5 kb (pSN559, pSN560, pSN690) and 2
4 kb (pLN559, pLN560, pLN690), respectively. Plasmid pGN27 strongly cr
oss-hybridized with the previously described plasmid pGT5 from P. abys
si strain GE5, whilst plasmids pGN23 and pGN31 did not cross-hybridize
with each other, nor with any other plasmid. The three small plasmids
of strains I559, I560 and I690 cross-hybridized, as well as their thr
ee large plasmids. Macrorestriction pattern analysis and the results o
f plasmid cross-hybridization experiments indicated that these three s
trains were different but closely related, and likely belonged to the
genus Thermococcus. This study shows that plasmids are widespread in h
yperthermophilic archaea, and significantly increases the number and d
iversity of plasmids available for laboratory work.