Role of Thiobacillus thioparus in the biodegradation of carbon disulfide in a biofilter packed with a recycled organic pelletized material.
This study reports the biodegradation of carbon disulfide (CS2) in air biofilters packed with a pelletized mixture of composted manure and sawdust. Experiments were carried out in two lab-scale (1.2 L) biofiltration units. Biofilter B was seeded with activated sludge enriched previously on CS2-degrading biomass under batch conditions, while biofilter A was left as a negative inoculation control. This inoculum was characterized by an acidic pH and sulfate accumulation, and contained Achromobacter xylosoxidans as the main putative CS2 biodegrading bacterium. Biofilter operation start-up was unsuccessfully attempted under xerophilic conditions and significant CS2 elimination was only achieved in biofilter A upon the implementation of an intermittent irrigation regime. Sustained removal efficiencies of 90-100 % at an inlet load of up to 12 g CS2 m(-3) h(-1) were reached. The CS2 removal in this biofilter was linked to the presence of the chemolithoautotrophic bacterium Thiobacillus thioparus, known among the relatively small number of species with a reported capacity of growing on CS2 as the sole energy source. DGGE molecular profiles confirmed that this microbe had become dominant in biofilter A while it was not detected in samples from biofilter B. Conventional biofilters packed with inexpensive organic materials are suited for the treatment of low-strength CS2 polluted gases (IL <12 g CS2 m(-3) h(-1)), provided that the development of the adequate microorganisms is favored, either upon enrichment or by inoculation. The importance of applying culture-independent techniques for microbial community analysis as a diagnostic tool in the biofiltration of recalcitrant compounds has been highlighted.
GIRO Joint Research Unit IRTA-UPC, Torre Marimon, 08140, Caldes de Montbui, Barcelona, Spain.
Francesc X
FX
Prenafeta-Boldú
Naiara
N
Rojo
Gorka
G
Gallastegui
Miriam
M
Guivernau
Marc
M
Viñas
Ana
A
Elías
D001673:Biodegradation, Environmental; D002246:Carbon Disulfide / Q000378:metabolism*; D058645:Denaturing Gradient Gel Electrophoresis; D005374:Filtration / Q000295:instrumentation*; D009930:Organic Chemicals / Q000737:chemistry*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D059027:Recycling; D013855:Thiobacillus / Q000378:metabolism* / Q000648:ultrastructure; D013997:Time Factors
D009930:Organic Chemicals; D012336:RNA, Ribosomal, 16S; D002246:Carbon Disulfide