Ethanol from rice byproduct using amylases secreted by Rhizopus microsporus var. oligosporus. Enzyme partial purification and characterization

Autor(es)

de Barros Ranke, Fabiane Fernanda ^[1] ; Shinya, Thais Yumi ^[2] ; de Figueiredo, Franciane Cristina ^[1] ; Fernandez Nunez, Eutimio Gustavo ^[3] ; Cabral, Hamilton ^[4] ; Neto, Pedro de Oliva ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Inst Pesquisa Bioenergia IPBEN, Dept Biotecnol, Lab Biotecnol Ind, Campus Assis, Ave Dom Antonio 2100, Assis 19806900, SP - Brazil

^[2] Univ Estadual Piaui, Campus Herois Jenipapo, Campo Major, PI - Brazil

^[3] Univ Sao Paulo, Escola Artes Ciencias & Humanidades EACH, Rua Arlindo Bettio 1000, Sao Paulo 03828000, SP - Brazil

^[4] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeira Preto, Lab Tecnol Enzimat, Ave Cafe S-N, Ribeirao Preto 14040903, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Environmental Management; v. 266, JUL 15 2020.
• Citações Web of Science: 0

Resumo

A three-stage bioethanol bioprocess was developed. Firstly, amylases were obtained from Rhizopus microsporus var. oligosporus using wheat bran in solid-state fermentation. Secondly, amylases hydrolyzed a rice byproduct to make a glucose-rich solution, and this sugar was finally metabolized by Saccharomyces cerevisiae to produce bioethanol. Besides, the secreted enzymes were also partially purified and characterized. The amylase activity (AA) in the crude extract was 358 U/g substrate, and the partially purified enzyme showed the best activity in the 4.0-5.5 pH range. A wide pH stability range (3.5-8.5) was confirmed. The amylase was thermostable up to 60 degrees C. The ion Mn+2 (10 mM) improved by 60% the AA. There was a 54.9% yield in the conversion of rice residues into reducing sugars in 10 h. The glucose-rich solution was undergone fermentation by S. cerevisiae and showed high ethanol efficiency, 95.8% of the theoretical value. These results suggested a promising technology for bioethanol production. (AU)

• Processo FAPESP: 14/24188-1 - Desenvolvimento de bioprocessos para a obtenção de produtos com aplicações potenciais nas indústrias de bioenergia e ração animal a partir de resíduos agroindustriais
• Beneficiário: Pedro de Oliva Neto
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Regular