BIOINFORMATIC CHARACTERIZATION OF GENES ENCODING XYLAN DEGRADING ENZYMES IN THE Paenibacillus sp. AR247 AND Cohnella sp. AR92 GENOMES.

PISA, JOSÉ HORACIO; HERO, JOHAN SEBASTIAN; HÉCTOR G ROMERO BRUNETTO; PEROTTI, NORA INÉS; MARTINEZ, MARIA ALEJANDRA

Congreso; XII Congreso Argentino de Microbiología General-SAMIGE; 2017

The increasing interest to renewable lignocellulosic materials for the production of environment-friendlychemicals and biofuels boosts the search of new carbohydrate-active enzymes (Cazymes) and microbialstrains. In this study, we analyze the draft genomes of two highly hemicellulolytic bacteria isolatedfrom industrial liquor samples from the local paper industry to unravel their xylan degrading pathways.Gene annotations were carried out using Rapid Annotations Subsystems Technology (RAST) 2.0. BlastPwas employed to find orthologous genes between the translated proteins from the predicted openreading frames of both genomes and a local database consisting on the translated proteins of the141genomes of the Paenibacillaceae family members available on NCBI database up to date. Only bidirectionalmatches were considered. To identify potential Cazymes, translated proteins were submitted tothe dbCAN database. The genome sizes were 7.1 Mb (Paenibacillus sp. AR247) and 6.0 Mb (Cohnellasp. AR92), which contained 7159 and 5439 coding sequences, respectively. 51 orthologous genes werefound by the BlastP analysis, most of which corresponded to ribosomal genes. The phylogenetic treebuilt on the basis of those concatenated gene sequences showed Cohnella genus (including the strainAR92) as a monophyletic group within the paraphyletic group of Paenibacillus spp., while the strainAR247 was found to be related to Paenibacillus sp. P1XP2, Paenibacillus piniJCM 16418, Paenibacillussp. IHBB 10380, forming a well supported clade. Both genomes displayed multiple genes encoding abroad variety of extracellular and cell-wall (SLH domians) of endo-b-1,4-xylanases (GHs 10; 11; 30 and43), some of which also showed CBM domains (mainly CBM9; 22; 6). Sequences encoding potentialintracellular exo-oligoxylanase (GH8) and b-xylosidases (GHs 39; 43; 51and 52) were identified, whichmight be responsible for processing the products released by the extracellular enzymes. Finally, theoverall assimilation could beperformed by intracellular debranching enzymes a-glucuronidase (GH67),a-arabinofuranosidase (GHs 43 and 51) and acetylxylanesterase (mainly CEs 1 and 4). The redundancyof GH genes observed in the analyzed genomes, the predicted enzyme architectures and their cellularlocalization are in agreement with other well descripted Paenibacillus species. Therefore, the strainsAR247 and AR92 might display similar strategies for the degradation of xylan.