Identificação de microrganismos com potencial probiótico a partir do leite e colostro humanos

• Ano de defesa: 2020
• Autor(a) principal: Netzel, Vinícius Augusto
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Positivo; Brasil; Pós-Graduação; Programa de Pós-Graduação em Biotecnologia Industrial; UP
• Palavras-chave em Português: Biotecnologia industrial; Cianobactérias; Enterococcus faecalis; Streptococcus salivarius; Separação celular; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: https://repositorio.cruzeirodosul.edu.br/handle/123456789/2291

When there is an imbalance in the intestinal microbiota, supplementation with probiotics can provide a therapeutic alternative for diseases associated with this imbalance. Probiotic microorganisms can be isolated from several sources, with colostrum and human milk being potential sources for the identification of these microorganisms. This dissertation addresses these themes in two chapters. Chapter 1 presents a literature review that investigates the main genera and species with probiotic potential present in human colostrum and milk and the application of bacterial strains with regard to the probiotic potential they offer. Chapter 2 presents an experimental article that aims to evaluate the microbial diversity in milk and colostrum in relation to the frequency of abundance of potential probiotic genera and to isolate strains that are candidates for probiotics from these sources. For this, for each volunteer, about 2 mL of colostrum and breast milk samples were collected. A total of 7 colostrum samples and 10 human milk samples were obtained. The identification of the microbial diversity of the samples was carried out by new generation sequencing of two pool of samples, collected for colostrum and breast milk, separately. The isolation of strains of microorganisms from the samples collected was performed in Petri dishes containing MRS medium supplemented with L-cysteine, incubated at 37 ° C under anaerobic conditions for 48 hours or more. After incubation, the isolated colonies had the DNA extracted for further amplification of the 16S rRNA gene through PCR (Polymerase Chain Reaction) and sanger sequencing. The sequences obtained were compared with the international bank NCBI (National Center for Biotechnology Information) using the BLAST tool (Basic Local Alignment Search Tool) for molecular identification of isolated microorganisms. The following microorganisms were identified: Staphylococcus epidermidis, Candida parapsilosis, Propionibacterium acnes, Enterococcus faecalis and Streptococcus salivarius, of which the last two have potential probiotic effects. The new generation sequencing showed a greater microbial diversity presence in breast milk pool in relation to colostrum one, both at the phylum and genus level. In the colostrum pool, the phylum Firmicutes represented more than 90% of the total pool, whereas in breast milk there was a distribution of the phyla Cyanobacteria, Firmicutes and Proteobacteria. Streptococcus was the most abundant genus followed by Staphylococcus in both pools, Lactobacillus and Bifidobacterium were found in such low frequency that it did not allow their isolation. Thus, it is concluded in this dissertation that breast milk is the most suitable for the isolation of microorganisms due to its greater microbial diversity and the isolation of possible probiotic strains, however some specific genera that are better known for their probiotic properties such as: Lactobacillus, Bifidobacterium, Lactococcus and Pediococcus could not be isolated due to their low frequency in both samples. However, strains belonging to other genera that were isolated from breast milk samples showed that they could be possible candidates for probiotic properties to be used in the future with the purpose of being part of a food supplement, after the characterization of these strains.