SAWA Yoshihiro Shimane Univ., Dept. of Agricul., Associated Professor., 農学部, 助教授 (70127489)
SHIBATA Hitoshi Shimane Univ., Dept. of Agricul., Professor., 農学部, 教授 (40032601)
|Budget Amount *help
¥2,600,000 (Direct Cost : ¥2,600,000)
Fiscal Year 1991 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 1990 : ¥1,300,000 (Direct Cost : ¥1,300,000)
A strain of thermophilic cyanobacteria, Phormidium lapideum, has been shown to be useful species from viewpoints of "photo-bioreactor". However, P. lapideum has no plasmids DNA. Thus, we isolated a small plasmid, pPF1, from Phormidium foveolarum, and constructed a recombinant DNA, pPFI-pBR322, to use it as a possible shuttle vector between P. lapideum and E. coli. Taking advantage of electroporation technique, we succeeded in the transformation of P. lapideum. This success is the very first case of transformation of filamentous and thermophilic cyanobacteria. It should be noted that pPFI is requisite for the transformation of Phormidium species.
Sequencing of pPFI was performed through the conventional methods. pPF1 has 1509 base pairs (A : 461, C : 316, G, 394, T : 338 ; GC content, 47.1%). Suprisingly, pPF1 showed 97.8% homology to a small plasmid of Plectonema boryanum. This fact strongly suggests that pPFI could be useful as a broad range vector for PP group which include Lyngbya, Plectonema and Phormidium genera. pPF1 might be a versatile plasmid in the LPP group which include Lyngbya, Plectonema and Phormidium genera. pPF1 might be a versatile plasmid in the LPP ground species in nature. pPFI has possibility to make a very unique and big hair pin structure along the base sequences. The hair pin is composed of 137 base pairs and contains a part of "proto-oncogene" (19 base pairs with perfect coincidence) of house mouse. Moreover, pPFI is found to have possible ORFs. Studies on the pPF1 functions are now in progress.