Bioprocessos para produção de biomassa de levedura e enriquecimento nutricional de resíduos agroindustriais
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Data
2017-05-04
Autores
Shinya, Thaís Yumi [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O aumento da população mundial levou à busca por novas fontes de proteína e maior produção animal. Nesse sentido, a biomassa microbiana produzida em larga escala demonstra ser uma saída viável para amenizar tais problemas, e, aliada ao uso de resíduos agroindustriais como substrato, representa uma solução para entraves ambientais, sociais e econômicos. O resíduo final tem seus valores nutricionais incrementados, sendo um interessante alimento para os animais. O objetivo desse estudo foi a seleção de leveduras com capacidade de crescer em bagaço de cana e de mandioca, pré-tratados ou não, para produção de biomassa microbiana e incremento do valor nutricional dos resíduos para uso como ração. A capacidade em crescer em anaerobiose, em ausência pontual de aminoácidos e vitaminas, assimilação de alguns carboidratos e avaliação da composição centesimal das espécies foram avaliados. A pré-seleção de nove leveduras isoladas do meio ambiente ocorreu em agitador orbital em aerobiose contendo bagaço de cana sem ou pré-tratado com CaO, H2SO4 e NaOH. Quatro linhagens foram selecionadas e cultivadas em fermentador com bagaço de cana e de mandioca hidrolisado com amilases ou não, em batelada simples ou alimentada. Uma linhagem de Saccharomyces cerevisiae M26 serviu como comparativo para os testes em fermentador. O pré-tratamento do bagaço de cana não foi benéfico para o crescimento celular. As maiores atividades celulolíticas foram atingidas para o meio contendo soro de leite, variando até 0,18 FPU/mL e 0,90 U/mL (CMCase). De acordo com as maiores concentrações celulares, quatro espécies foram selecionadas e identificadas como Sporobolomyces japonicus Sia 70a, Sporidiobolus pararoseus Sia 33.1, Wickerhamomyces onychis LABI2 e Rhodotorula mucilaginosa LABI1. Todas produziram xilanases em cultivo com bagaço de cana em fermentador (0,25 U/mL para S. pararoseus Sia 33.1, 0,31 U/mL da R. mucilaginosa LABI1, 0,34 U/mL da W. onychis LABI2 Sia 70a, 0,52 U/mL da S. japonicus Sia 70a), sendo as amilases produzidas por S. japonicus Sia 70a (0,2 U/mL), S. pararoseus Sia 33.1 (0,26 U/mL) e R. mucilaginosa LABI1 (0,33 U/mL) em cultivo com bagaço de mandioca. As maiores concentrações de biomassa foram atingidas com o uso do bagaço de mandioca como substrato. O bagaço de mandioca hidrolisado resultou na produção de 5,2 g/L de S. pararoseus Sia 33.1, 8,5 g/L de R. mucilaginosa LABI1e 10,9 g/L de W. onychis LABI2, sendo muito superior ao obtido por S. cerevisiae M26 no mesmo meio (3,1 g/L). S. japonicus Sia 70a alcançou 8,1 g/L utilizando a mandioca sem tratamento, valor duas vezes maior que S. cerevisiae M26 nas mesmas condições. Após os cultivos em fermentador, ambos resíduos tiveram seu conteúdo proteico incrementado em todos tratamentos, sendo o máximo atingido de 1,8% para 8,3% (S. pararoseus Sia 33.1 em mandioca hidrolisada). As quatro cepas demonstraram capacidade em crescer em anaerobiose, produzir seus próprios aminoácidos e grande versatilidade no uso dos carboidratos testados. A biomassa unicelular obtida possui altas concentrações de carbono, nitrogênio, fósforo, com concentração proteica de 20,2% para W. onychis LABI2, 25,1% para R. mucilaginosa LABI1, 35,6% para S. japonicus Sia 70a e 43,3% para S. pararoseus Sia 33.1. Além do crescimento favorável em resíduos agroindustriais e incremento do valor nutricional desses resíduos, as leveduras possuem características desejáveis aos micro-organismos probióticos com possibilidade de uso na alimentação animal.
The increase of world population led to the search for new sources of protein and higher animal production. In this sense, microbial biomass produced on large scale demonstrate to be a viable way to soften such problems and combined with the use of agro-industrial residues represent a solution to environmental, social and economic concerns. The final residue has its nutritional values increased, being an interesting food for animals. The objective of this study was to select yeasts with growth capacity in sugarcane bagasse and cassava residue, pre-treated or not, for the production of microbial biomass as well as increase the residue nutritional value to use as feed. The ability to grow in anaerobiosis, absence of amino acids and vitamins, assimilation of some carbohydrates and evaluation of the chemical composition of the species were evaluated. The preselection of nine yeasts isolated from the environment occurred in orbital shaker incubator in aerobiosis with sugarcane bagasse with or without treatment (CaO, H2SO4 and NaOH). Four strains were selected and cultivated in bioreactor with sugarcane bagasse and cassava residue, hydrolysed with amylases or not, in single-batch or fed-batch process. An industrial strain of Saccharomyces cerevisiae M26 served as a comparison for bioreactor tests. Pretreatment of sugarcane bagasse was not beneficial for cell growth. Higher cellulolytic activities were measured in medium containing whey, ranging up to 0.18 FPU/mL and 0.90 U/mL (CMCase). According to the highest cellular concentrations, four yeasts were selected and identified as Sporobolomyces japonicus Sia 70a, Sporidiobolus pararoseus Sia 33.1, Wickerhamomyces onychis LABI2 and Rhodotorula mucilaginosa LABI1. All produced xylanase in bioreactor with sugarcane bagasse (0.25 U/mL for S. pararoseus Sia 33.1, 0.31 U/mL R. mucilaginosa LABI1, 0.34 U/mL W. onychis LABI2 and 0.52 U/mL S. japonicus Sia 70a), and amylases were produced by S. pararoseus Sia 33.1 (0.26 U/mL), R. mucilaginosa LABI1 (0.33 U/mL) and S. japonicus Sia 70a (0.2 U/mL) in cultures with cassava residue. The highest biomass concentrations were obtained using cassava residue as substrate. The hydrolyzed cassava residue produced 5.2 g/L of S. pararoseus Sia 33.1, 8.5 g/L of R. mucilaginosa LABI1 and 10.9 g/L of W. onychis LABI2, being much higher than obtained by S. cerevisiae M26 in the same medium formulated (3.1 g/L). S. japonicus Sia 70a produced 8.1 g/L after culture with cassava residue without treatment 2 times more than S. cerevisiae M26 under the same conditions. After fermentation, both residues had their protein content increased in all treatments, and the maximum reached from 1.8% to 8.3% was obtained by S. pararoseus Sia 33.1 in hydrolyzed cassava residue. The four strains demonstrated ability to grow in anaerobiosis, producing amino acids by its owns and great versatility in the use of the carbohydrates tested. The yeast biomass obtained had high concentrations of carbon, nitrogen and phosphorus, with a protein concentration of 20.3% for W. onychis LABI2, 25.1% for R. mucilaginosa LABI1, 35.6% for S. japonicus Sia 70a and 43.3% for S. pararoseus Sia 33.1. In addition to the favorable growth in agro-industrial residues and increase the the nutritional value of these residues, these yeasts have desirable characteristics as probiotic microorganisms with possible application in animal feed.
The increase of world population led to the search for new sources of protein and higher animal production. In this sense, microbial biomass produced on large scale demonstrate to be a viable way to soften such problems and combined with the use of agro-industrial residues represent a solution to environmental, social and economic concerns. The final residue has its nutritional values increased, being an interesting food for animals. The objective of this study was to select yeasts with growth capacity in sugarcane bagasse and cassava residue, pre-treated or not, for the production of microbial biomass as well as increase the residue nutritional value to use as feed. The ability to grow in anaerobiosis, absence of amino acids and vitamins, assimilation of some carbohydrates and evaluation of the chemical composition of the species were evaluated. The preselection of nine yeasts isolated from the environment occurred in orbital shaker incubator in aerobiosis with sugarcane bagasse with or without treatment (CaO, H2SO4 and NaOH). Four strains were selected and cultivated in bioreactor with sugarcane bagasse and cassava residue, hydrolysed with amylases or not, in single-batch or fed-batch process. An industrial strain of Saccharomyces cerevisiae M26 served as a comparison for bioreactor tests. Pretreatment of sugarcane bagasse was not beneficial for cell growth. Higher cellulolytic activities were measured in medium containing whey, ranging up to 0.18 FPU/mL and 0.90 U/mL (CMCase). According to the highest cellular concentrations, four yeasts were selected and identified as Sporobolomyces japonicus Sia 70a, Sporidiobolus pararoseus Sia 33.1, Wickerhamomyces onychis LABI2 and Rhodotorula mucilaginosa LABI1. All produced xylanase in bioreactor with sugarcane bagasse (0.25 U/mL for S. pararoseus Sia 33.1, 0.31 U/mL R. mucilaginosa LABI1, 0.34 U/mL W. onychis LABI2 and 0.52 U/mL S. japonicus Sia 70a), and amylases were produced by S. pararoseus Sia 33.1 (0.26 U/mL), R. mucilaginosa LABI1 (0.33 U/mL) and S. japonicus Sia 70a (0.2 U/mL) in cultures with cassava residue. The highest biomass concentrations were obtained using cassava residue as substrate. The hydrolyzed cassava residue produced 5.2 g/L of S. pararoseus Sia 33.1, 8.5 g/L of R. mucilaginosa LABI1 and 10.9 g/L of W. onychis LABI2, being much higher than obtained by S. cerevisiae M26 in the same medium formulated (3.1 g/L). S. japonicus Sia 70a produced 8.1 g/L after culture with cassava residue without treatment 2 times more than S. cerevisiae M26 under the same conditions. After fermentation, both residues had their protein content increased in all treatments, and the maximum reached from 1.8% to 8.3% was obtained by S. pararoseus Sia 33.1 in hydrolyzed cassava residue. The four strains demonstrated ability to grow in anaerobiosis, producing amino acids by its owns and great versatility in the use of the carbohydrates tested. The yeast biomass obtained had high concentrations of carbon, nitrogen and phosphorus, with a protein concentration of 20.3% for W. onychis LABI2, 25.1% for R. mucilaginosa LABI1, 35.6% for S. japonicus Sia 70a and 43.3% for S. pararoseus Sia 33.1. In addition to the favorable growth in agro-industrial residues and increase the the nutritional value of these residues, these yeasts have desirable characteristics as probiotic microorganisms with possible application in animal feed.
Descrição
Palavras-chave
Proteína unicelular, Leveduras probióticas, Enriquecimento proteico de resíduos, Biomassa microbiana, Single cell protein, Probiotic yeasts, Proteic enrichment of residues, Microbial biomass