Effects of organic nutrients and growth factors on biostimulation of tributyltin removal by sediment microorganisms and Enterobacter cloacae.
Natural attenuation can reduce contamination of tributyltin (TBT), but persistence of the xenobiotic can cause long-term issues in the environment. Biostimulation is used to accelerate biodegradation. This study investigated the ability of individual organic nutrients and growth factors to enhance TBT biodegradation by sediment microorganisms (SED) and Enterobacter cloacae strain TISTR1971 (B3). The supplements that produced high biomass yield were selected for degradation enhancement. For TBT degradation at initial concentration of 0.1 mg/l, negative or limited degradation was observed in some selected supplements indicating that increasing the biomass did not necessarily promote degradation. Consequently, the addition of nutrients was expected to increase both dioxygenase activity and the degrader population. At different concentrations of supplements, a mixture of succinate/glycerol showed the highest removal for SED which reduced TBT by 77%, 75%, and 68% for 0.1×, 1×, and 10× supplement concentration, respectively. For B3, the addition of succinate showed degradation of 49% (0.1×), 75% (1×), and 77% (10×). Most nutrients and amino acids had an inhibitory effect at 1× or 10× levels. Excess amount of the nutrients added can inhibit the initial degradation of TBT. Therefore, TBT biostimulation requires supplements that increase the capability of TBT degraders at an appropriate amount.
David Livingstone Centre for Sustainability, Department of Civil Engineering, University of Strathclyde, Glasgow, Scotland, G1 1QE, UK. a.sakultantimetha@strath.ac.uk
Arthit
A
Sakultantimetha
Helen E
HE
Keenan
Tara K
TK
Beattie
Sornnarin
S
Bangkedphol
Olga
O
Cavoura
D000596:Amino Acids / Q000378:metabolism; D001673:Biodegradation, Environmental; D003470:Culture Media / Q000378:metabolism; D016972:Enterobacter cloacae / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism*; D019015:Geologic Sediments / Q000382:microbiology*; D019802:Succinic Acid / Q000378:metabolism; D014220:Trialkyltin Compounds / Q000378:metabolism*; D014815:Vitamins / Q000378:metabolism
D000596:Amino Acids; D003470:Culture Media; D014220:Trialkyltin Compounds; D014815:Vitamins; C011559:tributyltin; D019802:Succinic Acid