title: Microbial diversity in various types of paper mill sludge: identification of enzyme activities with potential industrial applications.
abstract: This study is the first comprehensive investigation of enzyme-producing bacteria isolated from four sludge samples (primary, secondary, press and machine) collected in a Kraft paper mill. Overall, 41 strains encompassing 11 different genera were identified by 16S rRNA gene analysis and biochemical testing. Both biodiversity and enzymatic activities were correlated with sludge composition. Press sludge hosted the largest variety of bacterial strains and enzymatic activities, which included hydrolytic enzymes and ligninolytic enzymes. In contrast, strains isolated from secondary sludge were devoid of several enzymatic activities. Most strains were found to metabolize Kraft liquor at its alkaline pH and to decolorize industrial lignin-mimicking dyes. Resistance to lignin or the ability to metabolize this substrate is a prerequisite to survival in any paper mill sludge type. We demonstrate here that the bacterial strains found in a typical Kraft paper mill represent a source of potential novel enzymes for both industrial applications and bioremediation.
authors.affiliation: CRML, Centre de Recherche sur les Matériaux Lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, QC G9A 5H7 Canada ; PROTEO, Université Laval, Quebec, QC G1V 4G2 Canada.
authors.forename: Manel
authors.initials: M
authors.lastname: Ghribi
authors.affiliation: CRML, Centre de Recherche sur les Matériaux Lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, QC G9A 5H7 Canada ; PROTEO, Université Laval, Quebec, QC G1V 4G2 Canada.
authors.forename: Fatma
authors.initials: F
authors.lastname: Meddeb-Mouelhi
authors.affiliation: CRML, Centre de Recherche sur les Matériaux Lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, QC G9A 5H7 Canada ; PROTEO, Université Laval, Quebec, QC G1V 4G2 Canada.
authors.forename: Marc
authors.identifier: 0000-0002-4848-728X
authors.initials: M
authors.lastname: Beauregard
keywords: Bacteria; Bioplastic; Dyes; Enzymes; Pulping liquors