Recommendations for quick identification of luminous bacteria
Among the luminous bacteria isolated from various natural sources, the most
frequently found are the following: Photobacterium phosphoreum, Photobacterium
leiognathi, Vibrio fischeri and Vibrio harveyi.
Due to their ability to emit visible light luminous bacteria colonies on solid
medium can be easily differentiated from other bacterial colonies in darkness.
Bacteria V. fischeri form yellow pigment and can be easily differentiated by
the colony colour. V.harveyi produce into the medium brown pigment, their colonies
have respective colouring in case of long cultivation or storage on solid medium.
The genus of luminous bacteria can be determined by examining the form of growth
in semi-liquid agar (compact, usually consisting of microcolonies - for Photobacterium;
dissipated, homogeneous - for Vibrio) [Medvedeva et al., 1993], and by estimating
the luminescence reaction kinetics [Vorobyova et al., 1982, Sandalova, Tyulkova,
1992]. The specific dependence of the luminescence reaction kinetics on the
length of the aldehyde used makes it possible to assign luminous bacteria to
certain species [Vorobyova et al., 1982].
Taxonomically close species, P.phosphoreum and P.leiognathi, have different
temperature characteristics of growth. P.phosphoreum strains grow at 4oC, however
most of them terminate their growth at a temperature of 25°C and have optimal
temperatures of growth between 18 and 20°C. P.leiognathi strains grow well
at temperatures between 30 and 35°C, don't grow at 4°C and above 40°C.