Abstract:
Strict legislation and chemical composition monitoring of effluent may be
useful, but the data generated do not allow for source tracking, and enforcing
legislation remains problematic in the South African setting. These difficulties
emphasize the necessity for effluent source traceability. Denaturing gradient gel
electrophoresis (DGGE) targeting the V3 region of the 16S rRNA gene was
considered as fingerprinting technique for effluent originating from abattoirs
slaughtering different animal species. The influence of treatment to remove
excess fat from effluent prior to molecular analyses and different PCR
approaches on the detection of bacterial diversity were considered. Use of a
treatment option to remove fat and a nested PCR approach resulted in up to
51% difference in inter-sample diversity similarity. A robust approach with no
pre-treatment to remove PCR inhibitors, such as fat, and direct amplification
from genomic DNA yielded optimal/maximal bacterial diversity fingerprints.
Repeatable fingerprints were obtained for poultry abattoir effluent over a 4-
month period, but profiles for the red meat abattoir varied with maximum
similarity detected only 33 2%. Genetic material from faecal indicators
Aeromona spp and Clostridium spp were detected. Genera unique to each
effluent were present; Anoxybacillus, Patulibacter and Oleispira in poultry
abattoir effluent and Porphyromonas and Peptostreptococcus in red meat abattoir
effluent.
