High-pressure adaptation by salt stress in a moderately halophilic bacterium obtained from open seawater

• Published in: Applied microbiology and biotechnology Vol. 57; no. 1-2; pp. 200 - 204
• Main Authors: TANAKA, T, BURGESS, J. G, WRIGHT, P. C
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.10.2001; Springer Nature B.V
• Subjects: Action of physical and chemical agents on bacteria; Adaptation; Adaptation, Physiological; Adaptations; Bacteria; Bacteriology; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; Chemical analysis; Fundamental and applied biological sciences. Psychology; High pressure; Microbiology; Micrococcus - physiology; Micrococcus roseus; Miscellaneous; Mission oriented research; Osmotic Pressure; piezotolerance; Pressure; Seawater; Sodium chloride; Water analysis; Actinomycetales; Kocuria rosea; Halophily; Microorganism culture; Bacteria; Actinomycetes; Stress; Adaptation; Seawater; High pressure; Sodium Chlorides
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s002530100759

High-pressure adaptation was examined using a moderately halophilic bacterium (Micrococcus roseus), which was isolated from open seawater and capable of growing in 15% w/v NaCl (optimum NaCl concentration: 3% w/v). After treatment at 207 MPa, colony-forming units (CFUs) significantly decreased; however, the loss of integral cells after pressure was only 30% when direct cell count was performed microscopically. In order to investigate the piezotolerance of M. roseus under high pressure without morphological change, the survival of cells was examined under pressure at 138 MPa for 2 h. M. roseus in 3% NaCl was still sensitive to pressure at 138 MPa. However, the cells in the third generations showed remarkably increased pressure resistance, and no significant loss of viability was confirmed. Furthermore, when M. roseus was cultured in 1, 3, 5, 10 and 15% NaCl, the survival ratio proportionally increased at increased NaCl concentration. M. roseus cultured in 15% NaCl was remarkably resistant (94.7% viability) to pressure at 138 MPa, even when suspended in lower concentration of NaCl. This suggests that NaCl concentrations in growth culture affect the piezotolerance of M. roseus and that this species has an ability to adapt to high pressure.