Open AccessActivity and distribution of bacterial populations in Middle Atlantic Bight shelf sands
Author(s) -
Rusch Antje,
Huettel Markus,
Reimers Clare E,
Taghon Gary L,
Fuller Charlotte M
Publication year - 2003
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.1574-6941.2003.tb01093.x
Subject(s) - benthic zone , biology , sediment , flavobacterium , environmental chemistry , total organic carbon , organic matter , dissolved organic carbon , bacteria , oceanography , ecology , chemistry , pseudomonas , paleontology , genetics , geology
Abstract Spatiotemporal variation and metabolic activity of the microbial community were studied in coarse‐grained Middle Atlantic Bight shelf sediments in relation to pools of dissolved and particulate carbon. Algal cells were present 8–>70 μm) fraction of the sediment held the major share (61–98%) of benthic bacteria. Bacterial and algal cell abundances, exoenzymatic activity, and [DOC] generally showed higher values in May/July 2001 than in August/December 2000. Carbohydrates and proteins were hydrolyzed at potential rates of 1–12 nmol cm −3 h −1 (β‐glucosidase) and 3–70 nmol cm −3 h −1 (aminopeptidase), respectively. Fluorescence in situ hybridization analyses of the benthic microbes assigned 45–56% of DAPI‐stained cells to Eubacteria and less than 2% to Eukarya. The prokaryotic community was dominated by planctomycetes and members of the Cytophaga/Flavobacterium cluster. Near the sediment surface, iodonitrotetrazolium violet reducing cells, that are considered actively respiring, amounted to 15–29% of total bacteria. Despite a low organic content (particulate organic carbon <0.03%) and relatively low bacterial abundances (<10 9 cm −3 ), the Middle Atlantic Bight shelf sediments showed organic matter turnover rates that are comparable to those found in organic‐rich finer‐grained deposits. Our findings suggest a high biocatalytic filtration activity in these coarse permeable sediments.