EFFECT OF BACTERIAL HETEROGENEITY ON ADHESION TO UNIFORM COLLECTORS BY MONOCLONAL POPULATIONS

Transport of bacteria over significant distances through aquifer sedim ents occurs primarily among bacteria with low affinity for sediment ma terials. Bacterial affinity for a uniform collector surface has been r epresented quantitatively by a collision efficiency (alpha), defined a s the fraction of colliding cells that adhere to the collector surface . Using a new method for estimating alpha during advective transport o f monoclonal bacterial populations through a uniform bed of 40-mu m bo rosilicate glass spheres, we found that alpha decreased 10-fold over a bed depth of only 1 cm. Depth-dependent differences in alpha were not related to variation in bacterial size or intra-strain genetic variat ion. Intra-population heterogeneity in biocolloid-collector affinity m ay be an important determinant of subsurface bacterial transport chara cteristics, with critical implications for pathogen transport and disp ersal of bacteria for the remediation of hazardous waste.