PSII-24 Towards a better understanding of the gut microbiome functions in the swine production: extensive cultivation of the swine gut microbiome from different growth stages

Abstract

Abstract Substantial progress has been made in the culture-omics of the human gut microbiota. However, little is known about the culture-omics of the swine gut microbiota, despite recent reports of their significant roles in swine health and production. To fill this knowledge gap in research, we tested 52 bacterial cultivation methods with different media and gas combinations. Fresh fecal samples (0.2g/sample) were collected from three pigs at the end of four growth stages: lactation, nursery, growing and finishing and were mixed with a stomacher in 20 mL saline. Aliquots of 50 uL microbial suspensions were then spread onto different media plates and incubated under aerobic and anaerobic conditions at 37C for up to 5 days. An additional aliquot of each sample was subjected to direct DNA extraction as a positive control. Bacterial colonies from each plate were collected and DNA was extracted from these samples using the Powersoil DNA isolation kit and sequenced with an Illumina Miseq sequencer targeting the V4 region of the 16S rRNA gene. Sequences were analyzed with the Deblur algorithm in the QIIME2 package. A total of 378, 482, 565, and 555 bacterial features were observed from microbial solutions at the end of lactation, nursery, growing and finishing. Our culturing methods recovered 415, 675, 808, and 823 features correspondingly, representing 45.2%, 54.8%, 53.3%, and 56.4% of total features observed in microbial solutions. The top ten most easily cultured genus were Escherichia, Streptococcus, Lactobacillus, Megasphaera, Acidaminococcus, Bacillus, Mitsuokella, Enterococcus and Prevotella. Non-parametric permutational multivariate analysis of variance shows that the main factors driving the swine culture-omics included medium, age and oxygen condition. This study identifies the cultivable bacteria from fecal samples collected at different growth stages of pigs and provides a guidance to cultivate potential beneficial or pathogenic bacteria of interests and validate their functions in swine production.