A Bacillus sp. isolated from sediments of the Sarno River mouth, Gulf of Naples (Italy) produces a biofilm biosorbing Pb(II).
A Pb-resistant bacterial strain (named hereinafter Pb15) has been isolated from highly polluted marine sediments at the Sarno River mouth, Italy, using an enrichment culture to which Pb(II) 0.48mmoll(-1) were added. 16S rRNA gene sequencing (Sanger) allowed assignment of the isolate to the genus Bacillus, with Bacillus pumilus as the closest species. The isolate is resistant to Pb(II) with a minimum inhibitory concentration (MIC) of 4.8mmoll(-1) and is also resistant to Cd(II) and Mn(II) with MIC of 2.22mmoll(-1) and 18.20mmoll(-1), respectively. Inductively coupled plasma atomic emission spectrometry (ICP-AES) showed that Pb inoculated in the growth medium is absorbed by the bacterial cells at removal efficiencies of 31.02% and 28.21% in the presence of 0.48mmoll(-1) or 1.20mmoll(-1) Pb(II), respectively. Strain Pb15 forms a brown and compact biofilm when grown in presence of Pb(II). Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS) confirm that the biofilm contains Pb, suggesting an active biosorption of this metal by the bacterial cells, sequestering 14% of inoculated Pb as evidenced by microscopic analyses. Altogether, these observations support evidence that strain Pb15 has potentials for being used in bioremediation of its native polluted sediments, with engineering solutions to be found in order to eliminate the adsorbed Pb before replacement of sediments in situ.
Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
Milva
M
Pepi
Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
Marco
M
Borra
Consiglio Nazionale delle Ricerche, Istituto per l'Ambiente Marino Costiero UOS Capo Granitola, Palermo, Italy.
Stella
S
Tamburrino
Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
Maria
M
Saggiomo
Università di Catania, Corso Italia 57, I-95129 Catania, Italy.
Alfio
A
Viola
Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
Elio
E
Biffali
Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
Cecilia
C
Balestra
Consiglio Nazionale delle Ricerche, Istituto per l'Ambiente Marino Costiero UOS Capo Granitola, Palermo, Italy.
Mario
M
Sprovieri
Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy. Electronic address: raffaella.casotti@szn.it.
Raffaella
R
Casotti
D000327:Adsorption; D001407:Bacillus / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria; D001673:Biodegradation, Environmental; D018441:Biofilms; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D007558:Italy; D007854:Lead / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D012336:RNA, Ribosomal, 16S; D045483:Rivers / Q000737:chemistry / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; D007854:Lead
16S rRNA gene; Biosorption; ICP-AES; Lead; SEM-EDS; Sarno River