Phenotypic characterization and comparative genome analysis of two strains of thermophilic, anaerobic, cellulolytic-xylanolytic bacterium Herbivorax saccincola

Publication date: May 2020Source: Enzyme and Microbial Technology, Volume 136Author(s): Shimpei Aikawa, Phakhinee Thianheng, Sirilak Baramee, Umbhorn Ungkulpasvich, Chakrit Tachaapaikoon, Rattiya Waeonukul, Patthra Pason, Khanok Ratanakhanokchai, Akihiko KosugiAbstractThe genome sequences of thermophilic, anaerobic, and cellulolytic-xylanolytic bacterium Herbivorax saccincola strains A7 and GGR1 have recently been determined. Although both strains belong to the same species, A7 is alkaliphilic, non-endospore-forming, and ammonium-assimilating, whereas GGR1 is neutrophilic, endospore-forming, and weak-ammonium-assimilating. To better understand the phenotypic diversity among H. saccincola strains, the genome sequences of A7 and GGR1 were compared. A7 contained three additional genes showing similarity to an alkaline stress-associated ABC-transporter but lacked four endospore formation-associated genes, AUG58543 and AUG58618 (encoding SpoVT), AUG57258 (encoding SpoVS), and AUG58614 (encoding YdhD), all of which were present in GGR1. In addition, A7 contained key ammonia assimilation genes PQQ67145 and PQQ66619, encoding ornithine cyclodeaminase and arginase, respectively, which were absent in GGR1. There was no difference in the number and types of cellulosomal-scaffolding proteins and glycosyl hydrolases between the two strains. However, cellulase and xylanase enzymes from A7 demonstrated greater activity and stability at an alkaline pH compared with those from GGR1, and amino...
Source: Enzyme and Microbial Technology - Category: Biotechnology Source Type: research