Bacteria and organic matter dynamics during a bioremediation treatment of organic-rich harbour sediments.
We studied the dynamics of bacteria and organic matter in the Ancient Port of Genoa (Italy) during a bioremediation treatment of sediment (during summer-autumn 1998) in an area characterised by continuous sewage discharge. A strong increase in total benthic bacterial density (TBN) was recorded at the end of the study, from 14 x 10(8) to 58-172 x 10(8) cell g(-1) in different parts of the treated area. The TBN increase was linked to organic matter depletion, from more than 40 to less than 20 mg x g(-1). In order to highlight the main ecological mechanisms involved in bioremediation, a laboratory experiment based on both water and sediment from the basin studied was carried out. We observed an increase in TBN during the first 20 days and a decrease in sediment organic matter (up to about 20%). Increases of organic matter (about 2-fold) and TBN (from 21 to 33 x 10(9) cell l(-1)) occurred in the overlying water, suggesting a strong association between the sediments and water column processes. Hydrolytic activities, which double in the sediment and increase up to a 300-fold in the water, are consistent with the decrease in sediment organic matter and with the water fraction dynamics.
Fabiano
Mauro
M
Dipartimento per lo Studio del Territorio e delle sue Risorse (Dip Te Ris), Università di Genova, C so Europa 26, 16132 Genova, Italy. fabianom@unige.it
Marrale
Daniela
D
Misic
Cristina
C
D001419:Bacteria; D001673:Biodegradation, Environmental; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D007558:Italy; D011157:Population Dynamics; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology*; D014871:Water Microbiology; D014872:Water Movements
D012722:Sewage