SURVIVAL AND ACTIVITY OF LUX-MARKED PHENANTHRENE-DEGRADING PSEUDOMONAS STUTZERI P16 UNDER DIFFERENT CONDITIONS

Document Type: Regular Paper

Authors

1 Biotechnology and Tissue Engineering Research Center, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, I. R. of Iran,

2 Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK

Abstract

Viable cell concentration and luminescence activity of P. stutzeri P16 luxAB4 was measured by
plate counting and luminometery in sterile and non-sterile soil adjusted to matric potential of -1500, -750 and
-30 kPa. Results showed that matric potential had a significant effect on survival and activity of P. stutzeri
P16 luxAB4 in soil. P. stutzeri P16 luxAB4 could survive better in Hutner’s minimal medium supplemented
with 1mg l-1 phenanthrene than 1 mg ml-1. However changes in viable cell concentration and luminescence
activity of lux-marked and wild type strains of P. stutzeri P16 were significantly different in Hutner’s
medium, amended with high and low concentrations of phenanthrene. Inoculation of soil with high
concentrations of phenanthrene caused an initial decline in the viable cell concentration of P. stutzeri P16
luxAB4 that took a longer time than liquid medium. Changes in viable cell concentration were similar to
changes in luminescence indicating the advantage of Bioluminescence-marker systems for monitoring the
survival and activity of biodegradative genetically engineered microorganisms (GEMs) in polluted
environments. Our results also showed the importance of influence of environmental factors such as matric
potential and pollutant concentration on the fate of GEMs.

Keywords