Influence of carbon sources and C/N ratio on EPS production in anaerobic sequencing batch biofilm reactors for wastewater treatment.
The objective of this work was to evaluate the influence of different carbon sources and the carbon/nitrogen ratio (C/N) on the production and main composition of insoluble extracellular polymers (EPS) produced in an anaerobic sequencing batch biofilm reactor (ASBBR) with immobilized biomass in polyurethane foam. The yield of EPS was 23.6 mg/g carbon, 13.3 mg/g carbon, 9.0 mg/g carbon and 1.4 mg/g carbon when the reactor was fed with glucose, soybean oil, fat acids, and meat extract, respectively. The yield of EPS decreased from 23.6 to 2.6 mg/g carbon as the C/N ratio was decreased from 13.6 to 3.4 gC/gN, using glucose as carbon source. EPS production was not observed under strict anaerobic conditions. The results suggest that the carbon source, microaerophilic conditions and high C/N ratio favor EPS production in the ASBBR used for wastewater treatment. Cellulose was the main exopolysaccharide observed in all experimental conditions.
Laboratório de Processos Biológicos, Departamento de Hidráulica e Saneamento, Escola de Engenharia de São Carlos, Universidade de São Paulo, Engenharia Ambiental-Bloco 4-F, Av. João Dagnone, 1100-Santa Angelina, 13.563-120, São Carlos, SP, Brazil.
A P
AP
Miqueleto
C C
CC
Dolosic
E
E
Pozzi
E
E
Foresti
M
M
Zaiat
D000693:Anaerobiosis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects*; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000032:analysis* / Q000494:pharmacology*; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D010084:Oxidation-Reduction / Q000187:drug effects; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014865:Waste Disposal, Fluid; D018508:Water Purification / Q000379:methods*
D005232:Fatty Acids, Volatile; D011135:Polysaccharides, Bacterial; D002244:Carbon; D009584:Nitrogen