title: Extracellular proteases of Halobacillus blutaparonensis strain M9, a new moderately halophilic bacterium.
abstract: Halophilic microorganisms are source of potential hydrolytic enzymes to be used in industrial and/or biotechnological processes. In the present study, we have investigated the ability of the moderately halophilic bacterium Halobacillus blutaparonensis (strain M9), a novel species described by our group, to release proteolytic enzymes. This bacterial strain abundantly proliferated in Luria-Bertani broth supplemented with 2.5% NaCl as well as secreted proteases to the extracellular environment. The production of proteases occurred in bacterial cells grown under different concentration of salt, ranging from 0.5% to 10% NaCl, in a similar way. The proteases secreted by H. blutaparonensis presented the following properties: (i) molecular masses ranging from 30 to 80 kDa, (ii) better hydrolytic activities under neutral-alkaline pH range, (iii) expression modulated according to the culture age, (iv) susceptibility to phenylmethylsulphonyl fluoride, classifying them as serine-type proteases, (v) specific cleavage over the chymotrypsin substrate, and (vi) enzymatic stability in the presence of salt (up to 20% NaCl) and organic solvents (e.g., ether, isooctane and cyclohexane). The proteases described herein are promising for industrial practices due to its haloalkaline properties.
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. ; Programa de Pós-Graduação em Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Anderson F
authors.initials: AF
authors.lastname: Santos
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Roberta S
authors.initials: RS
authors.lastname: Valle
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. ; Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Clarissa A
authors.initials: CA
authors.lastname: Pacheco
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Alvarez
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Lucy
authors.initials: L
authors.lastname: Seldin
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. ; Programa de Pós-Graduação em Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: André L S
authors.initials: AL
authors.lastname: Santos
mesh_terms: D003470:Culture Media / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000378:metabolism; D004795:Enzyme Stability; D058678:Halobacillus / Q000201:enzymology* / Q000254:growth & development; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010664:Phenylmethylsulfonyl Fluoride / Q000378:metabolism; D059748:Proteolysis; D057057:Serine Proteases / Q000032:analysis* / Q000737:chemistry; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: D003470:Culture Media; D004791:Enzyme Inhibitors; D012965:Sodium Chloride; D010664:Phenylmethylsulfonyl Fluoride; D057057:Serine Proteases
keywords: Halobacillus blutaparonensis; halophilic bacterium; serine proteases