Reclassification of a cyclodextrin glycosyltransferase-producing bacterium of industrial application

CAMINATA LANDRIEL SOLEDAD; CASTILLO JULIETA DE LAS MERCEDES; CANTERO MARÍA JOSÉ; RODRÍGUEZ GASTÓN JORGELINA ANDREA; TABOGA OSCAR ; FERRAROTTI SUSANA ALICIA; COSTA HERNÁN

Mar del Plata

Congreso; LI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología molecular; 2015

CyclodextrinGlycosyltransferase (CGTase), a glycosidehydrolase, catalyzes starchconversion into cyclodextrins and other industrial products such as maltooligosaccharides.We have isolated a CGTase froma soil bacterium which had been classified as Bacillus circulans based on its phenotypic profile. The 16S rRNAgene is widely used for phylogenetic studies; however, its use is limited dueto intragenomic heterogeneity and low discriminative power at relatedgenus. In addition, housekeeping genes are used. Theaim of this work was to identify this CGTase-producing bacterium by molecularphylogenetic analysis of the 16S rRNA gene and the housekeeping genes dnaK, gyrB, recA, rpoB and tufA. All genes were amplified by PCR and sequenced. Thesubstitution model was inferred with jModeltest.Phylogenetic trees were reconstructed by Maximum Likelihood (ML) and BayesianAnalysis methods using PAUP* and Mr. Bayes, respectively. For ML, therobustness was estimated by 500 replicates of non-parametric bootstrap. Accordingto the results, the strain of Bacilluscirculans was grouped within the genus Paenibacillus.In addition, Paenibacillus molecularsignatures in the 16S rRNA and rpoBgenes were found in the respective sequences of Bacillus circulans. We conclude that thebacterium under study must be reclassified within the Paenibacillus genus, with subsequent definition of specie.