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

PISA JH; HERO JS; ROMERO BRUNETTO H; PEROTTI NI; MARTÍNEZ MA

SAN MIGUEL DE TUCUMÁN

Congreso; XII CONGRESO DE MICROBIOLOGÍA GENERAL SAMIGE; 2017

Asociación Civil de Microbiología General

The increasing interest to renewablelignocellulosic materials for the production of environment-friendly chemicalsand biofuels boosts the search of new carbohydrate-active enzymes (Cazymes) andmicrobial strains. In this study, we analyze the draft genomes of two highlyhemicellulolytic bacteria isolated from industrial liquor samples from thelocal paper industry to unravel their xylan degrading pathways. Gene annotationswere carried out using Rapid Annotations Subsystems Technology (RAST) 2.0.BlastP was employed to find orthologous genes between the translated proteins fromthe predicted open reading frames of both genomes and a local databaseconsisting on the translated proteins of the141 genomes of the Paenibacillaceaefamily members available on NCBI database up to date. Only bidirectional matcheswere considered. To identify potential Cazymes, translated proteins were submittedto the dbCAN database. The genome sizes were 7.1 Mb (Paenibacillus sp. AR247) and 6.0 Mb (Cohnella sp. AR92), which contained 7159 and 5439 coding sequences,respectively. 51 orthologous genes were found by the BlastP analysis, most ofwhich corresponded to ribosomal genes. The phylogenetic tree built on the basisof those concatenated gene sequences showed Cohnellagenus (including the strain AR92) as a monophyletic group within theparaphyletic group of Paenibacillusspp., while the strain AR247 was found to be related to Paenibacillus sp.P1XP2, Paenibacillus pini JCM 16418, Paenibacillus sp. IHBB 10380, forming a wellsupported clade. Both genomes displayed multiple genes encoding a broad varietyof extracellular and cell-wall (SLH domians) of endo-b-1,4-xylanases (GHs 10;11; 30 and 43), some of which also showed CBM domains (mainly CBM9; 22; 6).Sequences encoding potential intracellular exo-oligoxylanase (GH8) andb-xylosidases (GHs 39; 43; 51and 52) were identified, which might be responsiblefor processing the products released by the extracellular enzymes. Finally, theoverall assimilation could beperformed by intracellular debranching enzymesa-glucuronidase (GH67), a-arabinofuranosidase (GHs 43 and 51) andacetylxylanesterase (mainly CEs 1 and 4). The redundancy of GH genes observedin the analyzed genomes, the predicted enzyme architectures and their cellular localizationare in agreement with other well descripted Paenibacillusspecies. Therefore, the strains AR247 and AR92 might display similarstrategies for the degradation of xylan.