Título:	Bioprospecção e caracterização de bactérias anaeróbicas como fonte de enzimas industriais
Autor(es):	Ticona, Alonso Roberto Poma
Orientador(es):	Noronha, Eliane Ferreira
Assunto:	Biomassa vegetal Enzimas industriais Bactérias ruminais Bioprospecção
Data de publicação:	1-Fev-2024
Data de defesa:	31-Jul-2019
Referência:	TICONA, Alonso Roberto Poma. Bioprospecção e caracterização de bactérias anaeróbicas como fonte de enzimas industriais. 2019. 162 f., il. Tese (Doutorado em Biologia Microbiana) — Universidade de Brasília, Brasília, 2019.
Abstract:	The market for industrial enzymes has a major impact on the world economy. Microorganisms (bacteria, yeasts, and fungi) are the main source of enzymes for application in different industrial processes. Different microbiomes can be exploited as a source of microorganisms aiming biotechnological exploration, especially those naturally enriched for a given function such as the rumen, a naturally enriched microbiome capable of hydrolyzing plant biomass such as lignocellulose, and starch. This work aimed at the prospection and characterization of anaerobic bacteria isolated from bovine rumen as a source of enzymes for industrial application. Samples from bovine ruminal content were inoculated in liquid medium containing cellulose or starch as a carbon source under anaerobic atmosphere and subsequently used for isolation by culturing at 37, 50 or 60 °C on solid medium containing carboxymethylcellulose (CMC), cellulose or starch as carbon sources. A total of 46 bacterial isolates were obtained and seven of these isolates displayed highest activity of endo-1,4-β-glucanase and endo-1,4-β-xylanase, and four presented α-amylase activity. Isolate A1_50L2 identified as P. barengoltzii by the 16S rDNA sequence was selected for characterization and production of holocellulases and α-amylase. P. barengoltzii A1_50L2 was grown in liquid medium containing cellulose, wheat bran, sugarcane bagasse, and secreted cellulases, xylanases, mannanases and pectinases. Zymogram analysis revealed three endo-1,4-β-glucanase isoforms (42, 45 and 63 kDa), six endo-1,4-β-xylanase isoforms (21, 23, 43, 60, 85 and 105 kDa) and one band of 62 kDa with mannanase activity. The secretome of P. barengoltzii A1_50L2 obtained by growth on wheat bran (PbEC) presented optimum activity of endo-1,4-β-glucanase, exo-1,4-β-glucanase, β-glucosidase, endo-1,4-β-xylanase and mannanase in a range of pH 4 to 7 and optimum temperature at 50 °C. PbEC was tolerant to phenolic compounds such as gallic acid, ferulic acid, cinnamic acid, and coumaric acid, maintaining residual activity above 70%, and 60% after 5 days of incubation. PbEC showed synergism with commercial Viscozyme, increasing by 72% the release of the reducing sugar on lignocellulosic residues including sugarcane bagasse, wheat bran, banana stem, corncob, corn stover, and soya husk. Additionally, P. barengoltzii A1_50L2 α-amylase obtained by starch growth culture showed activity at pH 6 to 10 and optimum temperature at 60 °C. Zymogram analysis revealed 1 band of 66 kDa with α-amylase activity, and this activity was maintained above 60% at 50 °C up to 96 hours. In conclusion, the results of this work demonstrated that 46 bacterial isolates obtained from bovine rumen present enzymatic activities that indicate their application in industrial plant biomass processes, especially amylases and holocellulases from Paenibacillus barengoltzii A1_50L2 on hydrolysis of starch and lignocellulosic biomass. This information can be used to develop inexpensive enzymatic mixtures for application in biorefinery processes.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB) Departamento de Biologia Celular (IB CEL)
Informações adicionais:	Tese (doutorado) — Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, Programa de Pós-Graduação em Biologia Microbiana, 2019.
Programa de pós-graduação:	Programa de Pós-Graduação em Biologia Microbiana
Agência financiadora:	Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

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