title: Characterization of bacterial pectinolytic strains involved in the water retting process.
abstract: Pectinolytic microorganisms involved in the water retting process were characterized. Cultivable mesophilic anaerobic and aerobic bacteria were isolated from unretted and water-retted material. A total of 104 anaerobic and 23 aerobic pectinolytic strains were identified. Polygalacturonase activity was measured in the supernatant of cell cultures; 24 anaerobic and nine aerobic isolates showed an enzymatic activity higher than the reference strains Clostridium felsineum and Bacillus subtilis respectively. We performed the first genotypic characterization of the retting microflora by a 16S amplified ribosomal DNA restriction analysis (ARDRA). Anaerobic isolates were divided into five different groups, and the aerobic isolates were clustered into three groups. 84.6% of the anaerobic and 82.6% of the aerobic isolates consisted of two main haplotypes. Partial 16S rRNA gene sequences were determined for 12 strains, representative of each haplotype. All anaerobic strains were assigned to the Clostridium genus, whereas the aerobic isolates were assigned to either the Bacillus or the Paenibacillus genus. Anaerobic isolates with high polygalacturonase (PG) activity belong to two clearly distinct phylogenetic clusters related to C. acetobutylicum-C. felsineum and C. saccharobutylicum species. Aerobic isolates with high PG activity belong to two clearly distinct phylogenetic clusters related to B. subtilisT and B. pumilusT.
authors.affiliation: Dipartimento di Biologia Sperimentale, Sezione di Microbiologia, University of Cagliari, Cittadella universitaria, 09042 Monserrato, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Tamburini
authors.forename: Alicia Gordillo
authors.initials: AG
authors.lastname: León
authors.forename: Brunella
authors.initials: B
authors.lastname: Perito
authors.forename: Giorgio
authors.initials: G
authors.lastname: Mastromei
mesh_terms: D001407:Bacillus / Q000302:isolation & purification / Q000378:metabolism; D001420:Bacteria, Aerobic / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification*; D001421:Bacteria, Anaerobic / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification*; D002188:Cannabis / Q000378:metabolism / Q000382:microbiology; D003013:Clostridium / Q000302:isolation & purification / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D019597:Flax / Q000378:metabolism / Q000382:microbiology; D006239:Haplotypes; D010368:Pectins / Q000378:metabolism; D010802:Phylogeny; D011096:Polygalacturonase / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D021521:Ribotyping; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D010368:Pectins; D011096:Polygalacturonase