ECOLOGICAL AND LABORATORY STUDIES ON THE ROLE OF LUMINOUS BACTERIA AND THEIR LUMINESCENCE IN COASTAL POLLUTION SURVEILLANCE

This study was aimed at finding out how bacterial bioluminescence, a t rait very sensitive to toxicants, is affected in coastal environs whic h receive various types of effluents. For this, observations on occurr ence and distribution of visibly luminous bacteria from both polluted and nonpolluted environments were documented during a 7 vr period. Whi le luminous colonies were abundant, often contributing over 10% of the total colony-forming units in the pollutant free areas, none of over 200 water, sediment, fish, shellfish and plankton samples from the pol luted localities yielded any visibly luminous colony. On analysing sev eral bacterial strains originating from the latter environment, it was evident that there were many dark (nonvisibly luminous) strains of th e usually luminescent Photobacterium leiognathi. Laboratory studies on the effect of various chemicals on light emission by different lumino us species suggested a strong depression (and/or irreversible loss) of luminescence in them. Results of this study suggest that in addition to several advantages known with these bacteria, they are useful as bi omarkers in the assessment of environmental health.