Bacterial Community and Spoilage Profiles Shift in Response to Packaging in Yellow-Feather Broiler, a Highly Popular Meat in Asia

Abstract

The consumption of yellow-feathered broiler has been advocated for purchasing with chilled meat rather than live broilers in Asia due to the outbreaks of animal influenza. Here, the microbial community of chilled yellow-feathered broiler response to modified-air packaging (MAP, 80% CO₂/20% N₂) and penetrated-air packaging (PAP, air-filling) during storage was revealed by a combination of whole-metagenome shotgun sequencing and traditional isolation methods, and the volatile organic compounds and proteolytic activity of representative dominant isolates were also accessed. The results revealed that MAP prolonged shelf life from 4 to 8 days compared to PAP, when the numbers of total viable counts and lactic acid bacteria reached more than 7 log CFU/g. Aeromonas, Acinetobacter, Escherichia, and Streptococcus occupied the bacteria communities in initial broiler carcasses. MAP dramatically increased the bacteria diversity during storage compared to PAP. Clear shifts of the dominant bacteria species were obviously observed, with the top genera of Aeromonas, Lactococcus, Serratia, and Shewanella in MAP, whereas the microbial communities in PAP were largely dominated by Pseudomonas. The isolates of Pseudomonas from PAP carcasses and Aeromonas from MAP carcasses displayed strong proteolytic activities. Meanwhile, the principal component analysis based on the volatile organic compounds indicated that the metabolic profiles greatly varied between each treatment, and no link between the natural odor of spoilage meat in situ and the volatile odor of the dominant isolates incubated in standard culture was found. These data could lead to new insights into the bacteria communities of yellow-feathered broiler meat during storage and would benefit the development of novel preservative approaches.

Keywords: bacteria diversity; metagenomics; packaging; spoilage; yellow-feathered broiler.

FIGURE 1

The whole research proposal of this working.

FIGURE 2

Numbers of bacteria (obtained from plate counting method) of broiler carcass. Error bars represent standard deviations of the mean (n = 4). Different lowercase letters at the same indicators and different capital letters at the same treatment are statistically different (p < 0.05).

FIGURE 3

The heat map of relative abundance within each sample of the top 35 bacterial in family (A) level and genus (B) level.

FIGURE 4

Clustering tree based on the Bray–Curtis distance obtained from the relative abundance in family (A) and species (B) levels of all samples.

FIGURE 5

Principal component analysis (PCA) based on the bacteria diversity in family (A) and species (B) levels of all samples.

FIGURE 6

Top 10 bacteria obtained from the relative abundance in genus (A) and species (B) levels.

FIGURE 7

Principal component analysis based on the volatile organic compounds analysis of spoilage meat in situ (A) and a combination of spoilage meat in situ and the supernatant of isolates incubated in standard culture (B).

FIGURE 8

The decomposition zone diameters of identified isolates incubated on raw-chicken juice agar (RJA) plate. Error bars represent standard deviations of the mean (n = 4), mean values in column with different lower-case letters are statistically different (p < 0.05).