Open AccessThe engineering potential of natural benthic bacterial assemblages in terms of the erosion resistance of sediments
Author(s) -
Gerbersdorf Sabine Ulrike,
Manz Werner,
Paterson David M.
Publication year - 2008
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2008.00586.x
Subject(s) - biology , bacteria , benthic zone , extracellular polymeric substance , sediment , abiotic component , biofilm , nutrient , environmental chemistry , bacterial growth , ecology , microbiology and biotechnology , chemistry , paleontology , genetics
The secretion of extracellular polymeric substances (EPS) by bacteria has been recognized as important across a wide range of scientific disciplines, but in natural sediments, EPS production by microalgae as a mechanism of sediment stabilization has received much more attention than bacterial products. In the present study, the stabilization potential of a natural benthic bacterial assemblage was tested in cultures growing on noncohesive glass beads. The surface erosion resistance as determined by a cohesive strength meter was significantly enhanced over time compared with controls. Nutrient enrichment of the bacterial assemblages by a general broth (bacteria+) resulted in enhanced stabilization (× 3.6) compared with nutrient‐depleted (bacteria) assemblages (× 1.8). This correlated with higher bacterial biomass and EPS concentrations in enriched cultures. Substratum stability was closely related to bacterial cell numbers ( R 2 =0.75/0.78) and EPS protein concentrations ( R 2 =0.96/0.53) (for bacteria/bacteria+ treatments, respectively), but not to EPS carbohydrates. This study implies a greater significance of extracellular proteins in substratum cohesion within the EPS complex than recognized previously. The data show both the importance of bacterial assemblages for microbial sediment stabilization and that a change in abiotic conditions can significantly affect sediment stabilization.