Session: Session 4

Metaproteomics study of the gut microbiome of Greater rhea (Rhea americana) and Blue-and-yellow macaw (Ara ararauna)

The gut microbiome in birds mediates many biological functions. The health of the host is influenced by the complex interactions and the diversity of the microbiome. Feces samples give access to hindgut microbiome and potential anti-microbial molecules. Studying the gut micriobiome diversity of bird species will enable to assess health and physiological conditions.  In this context, feces samples from two species (Greater rhea Rhea americana and  Blue and yellow macaw Ara ararauna) were analysed using metaproteomics approach.

 

Methods:

Fresh feces samples were collected from two greater rheas and two blue-and-yellow macaws at Museum National Histoire Naturelle (Paris) and were stored at -80°C. The samples were purified by centrifugation and the pellet obtaiend from the surnagent was rinsed with PBS . Proteins were extracted using 100 % TFA or urea buffer. Proteins were reduced, alkylated and digested with trypsin. Peptides were separated and analyzed using nanoLC- Orbitrap.

 

Results:

In greater rheas, 92 proteins groups were identified using TFA protocol and 68 with urea. Similarly in parrots 88 and 67 protein groups were identified with TFA and urea, respectively. Many de novo peptides could not be matched to database sequences (2014 for greater rheas, 800 for parrots). The microbial diversity  was higher in greater rheas (29 genus) compared to parrots (12 genus). Proteins with similar functional roles are produced by different species. Lactobacillus and Streptococcus are two major genera in parrots and not in nandu. Clostridium is the major genus in greater rheas.



Conclusion: 

This exploratory study implies that proteomic content could be species specific and the expression of proteins with the same functional traits by distinct microbial communities denotes functional redundancy. Deep metaproteomic sequencing with large sample cohorts will enable to decode and  the role of microbiotes and anti-microbial molecules in the context of animal conservation efforts.