title: GH53 Endo-Beta-1,4-Galactanase from a Newly Isolated Bacillus licheniformis CBMAI 1609 as an Enzymatic Cocktail Supplement for Biomass Saccharification.
abstract: Galactanases (endo-β-1,4-galactanases-EC 3.2.1.89) catalyze the hydrolysis of β-1,4 galactosidic bonds in arabinogalactan and galactan side chains found in type I rhamnogalacturan. The aim of this work was to understand the catalytic function, biophysical properties, and use of a recombinant GH53 endo-beta-1,4-galactanase for commercial cocktail supplementation. The nucleotide sequence of the endo-β-1,4-galactanase from Bacillus licheniformis CBMAI 1609 (Bl1609Gal) was cloned and expressed in Escherichia coli, and the biochemical and biophysical properties of the enzyme were characterized. The optimum pH range and temperature of Bl1609Gal activity were 6.5-8 and 40 °C, respectively. Furthermore, Bl1609Gal showed remarkable pH stability, retaining more than 75 % activity even after 24 h of incubation at pH 4-10. The enzyme was thermostable, retaining nearly 100 % activity after 1-h incubation at pH 7.0 at 25-45 °C. The enzymatic efficiency (K cat /K m ) against potato galactan under optimum conditions was 241.2 s(-1) mg(-1) mL. Capillary zone electrophoresis demonstrated that the pattern of galactan hydrolysis by Bl1609Gal was consistent with that of endogalactanases. Supplementation of the commercial cocktail ACCELLERASE(®)1500 with recombinant Bl1609Gal increased hydrolysis of pretreated sugarcane bagasse by 25 %.
authors.affiliation: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, CEP 13083-970, Campinas, São Paulo, Brazil.|Faculdade de Engenharia de Alimentos, Universidade Estadual de Campinas, Campinas, Brazil.
authors.forename: Evandro Antonio
authors.initials: EA
authors.lastname: de Lima
authors.affiliation: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, CEP 13083-970, Campinas, São Paulo, Brazil.
authors.forename: Carla Botelho
authors.initials: CB
authors.lastname: Machado
authors.affiliation: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, CEP 13083-970, Campinas, São Paulo, Brazil.
authors.forename: Letícia Maria
authors.initials: LM
authors.lastname: Zanphorlin
authors.affiliation: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, CEP 13083-970, Campinas, São Paulo, Brazil.|Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Richard John
authors.initials: RJ
authors.lastname: Ward
authors.affiliation: Faculdade de Engenharia de Alimentos, Universidade Estadual de Campinas, Campinas, Brazil.
authors.forename: Hélia Harumi
authors.initials: HH
authors.lastname: Sato
authors.affiliation: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Caixa Postal 6192, CEP 13083-970, Campinas, São Paulo, Brazil. robruller@gmail.com.
authors.forename: Roberto
authors.initials: R
authors.lastname: Ruller
mesh_terms: D000069976:Bacillus licheniformis / Q000201:enzymology* / Q000235:genetics; D018533:Biomass; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005685:Galactans / Q000737:chemistry*; D005690:Galactose / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D006868:Hydrolysis; D031786:Saccharum / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: D005685:Galactans; D006026:Glycoside Hydrolases; C094192:arabinogalactan endo-1,4-beta-galactosidase; C005653:arabinogalactan; D005690:Galactose
keywords: Bacillus licheniformis; Bioenergy; Biomass saccharification; Cocktail supplementation; Galactanases; Heterologous expression; Pectinases