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Response Of Sedimentary Bacteria In A Louisiana Salt Marsh To Contamination By Diesel Fuel, Kevin R. Carman, Jay C. Means, Steven C. Pomarico
Response Of Sedimentary Bacteria In A Louisiana Salt Marsh To Contamination By Diesel Fuel, Kevin R. Carman, Jay C. Means, Steven C. Pomarico
Faculty Publications
In a 28 d microcosm study, we examined the effects of diesel-contaminated sediment on the sedimentary bacterial community of a Louisiana (USA) salt marsh that has been chronically exposed to petroleum hydrocarbons for decades. Diesel contaminants in microcosms as determined from polycyclic aromatic hydrocarbon (PAH) concentration ranged from 0.55 to 55 ppm (dry weight). Bacterial metabolism (incorporation of 14C-acetate and 3H-leucine) and bacterial abundance were not affected by diesel-contaminated sediment at any concentration. Bacterial degradation of 14C-phenanthrene, however, increased in direct proportion to the amount of diesel- contaminated sediment added. Ambient sediment also exhibited significant capacity to degrade PAH. The …
Urea Production And Turnover Following The Addition Of Amp, Cmp, Rna And A Protein Mixture To A Marine Sediment, Mette S. Therkildsen, Gary M. King, Bente Aa Lomstein
Urea Production And Turnover Following The Addition Of Amp, Cmp, Rna And A Protein Mixture To A Marine Sediment, Mette S. Therkildsen, Gary M. King, Bente Aa Lomstein
Faculty Publications
The potential of adenosine 5′-monophosphate (AMP), cytidine 5′-monophosphate (CMP), 16S ribosomal RNA, and a protein (bovine serum albumin) to serve as substrates for bacterial urea production was evaluated in a defaunated, anoxic marine sediment. AMP, CMP and RNA stimulated urea production and urea turnover, but CMP to a lesser degree than AMP and RNA. The increase in urea production and turnover rates took place immediately after AMP, CMP, and RNA were added to the sediment. The rapid response in urea production and turnover rates suggests that the necessary uptake mechanisms and enzymes to utilize the substrates were present constitutively. Addition …