Metataxonomia bacteriana do leite caprino por sequenciamento do gene 16S rRNA

• Autor(a) principal: Leon, Candice Maria Cardoso Gomes de
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/14248
• topic: Caprinos; Microbiologia; Metagenômica; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL

The objective of this study was to characterize the goat milk microbiota by sequencing the 16S rRNA gene associated with different lactation periods and when goats are reared in different geographic regions. In the first chapter, we present a theoretical reference that covers a brief history about the study of microbial communities and the methods used for this and ending with a presentation of metagenomic studies with goat milk and other species based on DNA sequencing. In the second chapter, the objective was to determine the microbial community of goat milk throughout lactation in animals free of intramammary infection. Milk samples were collected from crossbred and multiparous goats on a farm located in the semiarid region of Paraiba in three lactation periods: initial (50 days), intermediate (100 days) and final (150 days). Nocardioides was the most abundant bacterial genus independent of the lactation period. Pseudomonas and Acinetobacter were statistically more abundant in the intermediate lactation period (FDR <0.05 in the differential expression analysis) and this is possibly associated with significantly higher protein content in the same lactation period. The genus Staphylococcus and Sphingomonas were more abundant at the end of lactation, suggestively, given the increase in fat content and CCS in this same period of lactation. In the third chapter, the objective was to characterize comparatively the microbiota of the milk of goats without intramammary infection created in two microregions of the state of Paraíba. Samples of goat milk (crossbred and multiparous goats) were collected from a property located in the Cariri micro region and at a property located in the Brejo da Paraíba micro region approximately 80 days after lactation. The richness of the bacterial community of goat milk was significantly different (p <0.05) among the studied regions. However, the genera Bacillus, Sphingomonas, Anoxybacillus and Escherichia-Shigella presented differential abundance for the regions evaluated (FDR <0.05 in the differential expression analysis). The data generated demonstrate that the goat milk microbiota is complex and that physiological (lactation) and geographic factors (climate and food) influence the composition and structure of this bacterial community.