Analysis of the Microbial Community of Wastewater Stabilization Ponds from Small Dairy Industries using Whole Genome Shotgun Sequencing

JOSÉ MATÍAS IRAZOQUI; ARIEL AMADIO

Buenos Aires

Congreso; 4th ISCB-Latin American Conference; 2016

ISCB

Stabilization ponds are a common treatment technology due to their low operation and maintenancecosts. Normally they combine anaerobic and facultative processes. The microbial communitycomposition in two stabilization ponds systems of dairy industries was analyzed using whole genomeshotgun sequencing. Samples were collected from six full-scale stabilization ponds belonging to twodairy industries (CYC and AUR). CYC treatment consisted in four serial ponds, while AUR have twoserial ponds.We carried out two different approaches to study the composition of the community. A taxonomicanalysis was made using different tools, including Centrifuge, Kraken and MetaPhlAn2. We found amajority of the reads belonging to Bacteria, mostly of phylum Proteobacteria. However, theabundances within the phylum varies depending the pond. Also, approximately 1% of the reads comefrom Archaeas and a not negligible amount come from Viruses, mainly bacteriophages. Then. a binningprocess was performed using MaxBin and MetaBAT, aiming to reconstruct complete genomes. Thequality of the binning was evaluated using CheckM, which uses sets of genes that are ubiquitous andsingle-copy within a lineage. In total, we found 39 bins corresponding to CYC ponds with a high levelof completeness (>90% of the genome) and 22 corresponding to AUR. Also, we found 43 bins in CYCwith a substantial level of completeness (>70%) and 29 using AUR reads.The knowledge about the composition of the microbial community and the reconstruction of completegenomes is key to understand how substrate are processed and to identify genes of biotechnologicalinterest.