Permanent changes in growth and physiology of Bacillus subtilis ToC46 after loss of a recombinant plasmid

Chuen-Im, S., Niven, G.W. and Lynch, H.C. (2004) Permanent changes in growth and physiology of Bacillus subtilis ToC46 after loss of a recombinant plasmid. Enzyme and Microbial Technology, 35 (5). pp. 411-416. ISSN 0141-0229 doi: 10.1016/j.enzmictec.2004.05.009

Abstract/Summary

The physiology and growth of plasmid-bearing Bacillus subtilis carrying plasmid pPFF1, the non-transformed host, and cells after loss of the plasmid (so-called plasmid-cured cells) were investigated. It was found that, following plasmid loss, cells exhibited phenotypic characteristics different from those of the non-transformed host strains. Compared to plasmid-bearing cells and non-transformed host cells, an approximate 25% increase in the maximum specific growth rate and a more rapid increase in total RNA per unit cell mass were observed in plasmid-cured cells. The total enthalpy associated with irreversible denaturation events was determined in whole cells by differential scanning calorimetry. This showed higher enthalpies for plasmid-cured cells compared with the non-transformed host, which suggests increased ribosome numbers. The result from cellular DNA hybridisation suggests that there was no direct evidence of plasmid integration into the host chromosome. (C) 2004 Elsevier Inc. All rights reserved.