Open AccessCryptic plasmids of thermophilic actinomycetes isolated from composts
Author(s) -
Pidcock Kenneth A.,
Montenecourt Bland S.,
Sands Jeffrey A.
Publication year - 1988
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1988.tb02826.x
Subject(s) - plasmid , biology , thermophile , microbiology and biotechnology , nocardia , mycelium , alkaline lysis , lysis , restriction digest , restriction enzyme , dna , bacteria , genetics , botany , dna vaccination
The natural occurrence of plasmids in thermophilic actinomycetes was investigated. Actinomycetes capable of growth at 55°C were isolated, using membrane filters, from organic composts containg agricultural wastes and manure. True actinomycetes producing a white aerial mycelium, which were susceptible to one or more Thermomonospora bacteriophages, were isolated most frequently. Thermophilic actinomycetes were screened for covalently closed DNA (CCCDNA), using a neutral cleared lysate procedure followed by acidic phenol extraction for removal of chromosomal fragments. Two isolates were found to possess plasmids 8–13 kbp in length. 13 kbp plasmids found in both isolates exhibited identical fragment patterns following digestion with restriction endonucleases. Analysis of CCCDNA recovered from density gradients revealed the presence of a larger plasmid in both isolates.