Abstract:
The high organic content of abattoir-associated process water provides an alternative for
low-cost and non-invasive sample collection. This study investigated the association of microbial
diversity from an abattoir processing environment with that of chicken meat. Water samples from
scalders, defeathering, evisceration, carcass-washer, chillers, and post-chill carcass rinsate were
collected from a large-scale abattoir in Australia. DNA was extracted using theWizard® Genomic
DNA Purification Kit, and the 16S rRNA v3-v4 gene region was sequenced using Illumina MiSeq. The
results revealed that the Firmicutes decreased from scalding to evisceration (72.55%) and increased
with chilling (23.47%), with the Proteobacteria and Bacteroidota changing inversely. A diverse
bacterial community with 24 phyla and 392 genera was recovered from the post-chill chicken, with
Anoxybacillus (71.84%), Megamonas (4.18%), Gallibacterium (2.14%), Unclassified Lachnospiraceae
(1.87%), and Lactobacillus (1.80%) being the abundant genera. The alpha diversity increased from
scalding to chilling, while the beta diversity revealed a significant separation of clusters at different
processing points (p = 0.01). The alpha- and beta-diversity revealed significant contamination during
the defeathering, with a redistribution of the bacteria during the chilling. This study concluded that
the genetic diversity during the defeathering is strongly associated with the extent of the post-chill
contamination, and may be used to indicate the microbial quality of the chicken meat.
