Characteristics and diversity of subarctic marine oligotrophic, stenoheterotrophic, and euryheterotrophic bacterial populations

Abstract

Major differences were found in the characteristics of bacterial populations isolated on media containing high and low nutrient concentrations. Bacteria isolated on low-nutrient media were physiologically more tolerant and nutritionally more versatile than bacteria isolated on high-nutrient media. It appears that euryheterotrophy, as opposed to oligotrophy, is characteristic of subarctic marine bacterial populations capable of growing at low nutrient concentrations. The bacteria examined in this study were capable of growth under a wide variety of physiological and nutritional conditions. The isolates from high-nutrient media were somewhat more specialized than those isolated from low-nutrient media. While the physiological and metabolic capabilities of the bacterial populations isolated on low-nutrient media were very heterogeneous, their taxonomic diversity was lower than bacterial populations from high-nutrient isolation media. The inclusion of petroleum in the isolation media did not alter the characteristics of the isolates obtained from either high- or low-nutrient media.