title: pH-dependent effect of pectinase secretion in Penicillium griseoroseum recombinant strains.
abstract: A number of parameters, including culture medium pH, affect growth and enzyme production by microorganisms. In the present study, the production and secretion of pectin lyase (PL) and polygalacturonase (PG) by recombinant strains of Penicillium griseoroseum cultured in mineral-buffered media (MBM; initial pH 6.8) and mineral-unbuffered medium (MUM; initial pH 6.3) were evaluated. Under these culture conditions, no change in the transcriptional levels of plg1 and pgg2 was observed. However, the levels of secreted total protein ranged from 7.80 ± 1.1 to 3.25 ± 1.50 µg ml(-1) in MBM and MUM, respectively, and were evaluated by SDS-PAGE. PL and PG enzymatic activities decreased 6.4 and 3.6 times, respectively, when P. griseoroseum was cultivated under acidic pH conditions (MUM). Furthermore, differences were observed in the hypha and mycelium morphology. These findings suggest that acidic growing conditions affect PL and PG secretion, even though the transcription and translation processes are successful. The data obtained in this study will help to establish optimal culture conditions that increase production and secretion of recombinant proteins by filamentous fungi.
authors.affiliation: Department of Microbiology/BIOAGRO, Federal University of Viçosa (Universidade Federal de Viçosa), Viçosa-MG, Brazil.
authors.forename: Janaina Aparecida
authors.initials: JA
authors.lastname: Teixeira
authors.forename: Thamy Lívia Ribeiro
authors.initials: TL
authors.lastname: Corrêa
authors.forename: Marisa Vieira
authors.initials: MV
authors.lastname: de Queiroz
authors.forename: Elza Fernandes
authors.initials: EF
authors.lastname: de Araújo
mesh_terms: D005656:Fungal Proteins / Q000096:biosynthesis / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D030781:Organisms, Genetically Modified; D010407:Penicillium / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D011096:Polygalacturonase / Q000096:biosynthesis / Q000378:metabolism*; D011133:Polysaccharide-Lyases / Q000096:biosynthesis; D011462:Prostaglandins G / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D011462:Prostaglandins G; C038291:prostaglandin G2; D011096:Polygalacturonase; D011133:Polysaccharide-Lyases; C027349:pectin lyase
keywords: Mycelial morphology; Pectin lyase; Penicillium griseoroseum; Polygalacturonase; Secretion