Aquatic microorganisms: processes, populations, and molecular solutions to environmental problems

Abstract

Studies on aquatic ecosystems at the trophic level of bacteria include population succession and the movement of species through the water column. Factor and path analysis of environmental parameters and the bacterial profiles indicate that the bacterial populations are under the control of environmental factors. The most important environmental factors in the Canadian study reported here are temperature followed by oxygen levels, nutrient levels, and ion concentrations. A major revolution in investigative approaches has begun in aquatic bacterial population studies using technology based on molecular methods. Finger print analysis of bacterial 16S RNA (molecular phylogeny) has not only changed the classification of bacteria but also the approach to solving environmental problems. The bacterial groups have been placed into species that are more functionally and ecologically aligned. Uncultured mixed biomass can be examined by gene probes for both procaryotes and eucaryotes to identify specific nucleotide sequences. Aquatic ecosystem health is maintained by the balanced biota and the process of biodegradation is an important stage in bioremediation. Control of toxic wasters in the waters and groundwaters can be accomplished byin situ bioremediation using indigenous microorganisms as demonstrated by the field study reported by Litchfieldet al. (1990).