title: Effect of pH, temperature and culture medium composition on the production of an extracellular cysteine proteinase by Micrococcus sp. INIA 528.
abstract: Growth and proteinase production by Micrococcus sp. INIA 528 in a batch-operated laboratory fermentor were investigated, with trypticase soy broth as the basal medium for studies on optimum temperature, pH and medium composition. Maximum growth was recorded at 34 degrees C and pH 7.5, whereas optimum temperature and pH for proteinase production were 31 degrees C and pH 6.25. Maximum rate of enzyme production occurred during the late log and early stationary phases of growth. Addition of 5.0 g l-1 yeast extract, 1.0 g l-1 glucose, 1.0 g l-1 MgSO4 or 1.0 g l-1 K2HPO4 to basal medium resulted in a lower enzyme yield, but supplementation of basal medium with 2.5 g l-1 (NH4)2SO4 increased enzyme production by 45%. A high initial biomass added to fresh both supplemented with 2.5 g l-1 (NH4)2SO4 only increased enzyme activity by 19%, compared to the maximum enzyme activity achieved with the standard inoculum.
authors.affiliation: Departamento de Tecnología de Alimentos, CIT-INIA, Madrid, Spain.
authors.forename: A F
authors.initials: AF
authors.lastname: Mohedano
authors.forename: J
authors.initials: J
authors.lastname: Fernández
authors.forename: P
authors.initials: P
authors.lastname: Gaya
authors.forename: M
authors.initials: M
authors.lastname: Medina
authors.forename: M
authors.initials: M
authors.lastname: Nuñez
mesh_terms: D001431:Bacteriological Techniques; D003470:Culture Media / Q000494:pharmacology; D003546:Cysteine Endopeptidases / Q000096:biosynthesis* / Q000378:metabolism; D005285:Fermentation / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D008837:Micrococcus / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development*; D013696:Temperature
chemical_list: D003470:Culture Media; D003546:Cysteine Endopeptidases