Isolation of plasmids from thermophilic clostridia and construction of shuttle vectors in Escherichia coli and cellulolytic clostridia

Abstract Four small plasmids (1.5–7.2 kb) were found in three strains of thermophilic clostridia. Two shuttle vectors, pCL1 and pCS1, used in Escherichia coli and some strains of Clostridium were constructed from plasmid pTA688L or pTA688S and the E. coli plasmid pBR328. The transformation system examined in strains of thermophilic Clostridium , which have cellulolytic activities, yielded about 1–7 × 10 2 transformants per microgram of pCS1 DNA. The DNA from these transformants was of the same size as that of pCS1. Thus, the host-vector system could be useful for the study of genes involved in the cellulolytic enzymes of species of Clostridium .