BACTERIAL-POPULATIONS AND THEIR ROLES IN A PHARMACEUTICAL-WASTE ANAEROBIC FILTER

The bacterial populations, their roles and distribution in an anaerobi c filter treating a simulated pharmaceutical effluent containing a bra nched-chain fatty acid (BCFA) were studied. The BCFA degradation pathw ay and mechanisms were also investigated. The biofilm from the filter was enriched in serum bottle cultures using different BCFAs and fatty acids as the sole carbon source. The anaerobic biofilm was a consortiu m of (1) BCFA-degrading Syntrophomonas spp, which produced ethanoic ac id and H-2, (2) H-2-utilizing Methanococcus spp, and (3) ethanoate-uti lizing Methanothrix spp. Beta-oxidation was proposed as the acidogenic mechanism. The bacterial consortium could degrade BCFAs with tertiary carbon but not those with quaternary carbon. Branching at the alpha o r beta position along the carbon chain interfered with the beta-oxidat ion mechanisms. Bacterial distribution in the filter was uneven, which was attributed to incomplete mixing. Copyright (C) 1996 Elsevier Scie nce Ltd