Mining the biomass deconstructing capabilities of rice yellow stem borer symbionts

TY - JOUR

T1 - Mining the biomass deconstructing capabilities of rice yellow stem borer symbionts

AU - Singh, Rahul

AU - Bennett, Joseph Philip

AU - Gupta, Mayank

AU - Sharma, Medha

AU - Eqbal, Danish

AU - Alessi, Anna

AU - Dowle, Adam

AU - McQueen Mason, Simon John

AU - Bruce, Neil Charles

AU - Yazdani, Syed Shams

N1 - This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

PY - 2019/10/24

Y1 - 2019/10/24

N2 - Efficient deconstruction of lignocellulosic biomass into simple sugars inan economically viable manner is a prerequisite for its global acceptance as afeedstock in bioethanol production. This is achieved in nature by suites of enzymeswith the capability of efficiently depolymerizing all the components of lignocellulose.Here we provide detailed insight into the repertoire of enzymes produced bymicroorganisms enriched from the gut of the crop pathogen rice yellow stem borer (Scirpophaga insertulas ).Results: A microbial community was enriched from the gut of the rice yellow stemborer for enhanced rice straw degradation by sub-culturing every 10 days, for oneyear, in minimal medium with rice straw as the main carbon source. The enrichedculture demonstrated high cellulolytic and xylanolytic activity in the culture supernatant.Metatranscriptomic and metaexoproteomic analysis revealed a large array of enzymespotentially involved in rice straw deconstruction. The consortium was found to encodegenes ascribed to all 5 class of carbohydrate active enzymes (GHs, GTs, CEs, PLsand AAs), including Carbohydrate-Binding Modules (CBMs), categorized in theCarbohydrate-Active enZYmes (CAZy) database. The GHs were the most abundantclass of CAZymes. Predicted enzymes from these CAZy classes have the potential todigest each cell wall components of rice straw i.e. cellulose, hemicellulose, pectin,callose and lignin. Several identified CAZy proteins appeared novel, having anunknown or hypothetical catalytic counterpart with a known class of CBM. To validatethe findings, one of the identified enzymes that belongs to the GH10 family wasfunctionally characterized. The enzyme expressed in E. coli efficiently hydrolyzedbeechwood xylan, and pretreated and untreated rice straw.Conclusions: This is the first report describing the enrichment of lignocellulosedegrading bacteria from the gut of the rice yellow stem borer to deconstruct rice straw,identifying a plethora of enzymes secreted by the microbial community when growingon rice straw as a carbon source. These enzymes could be important candidates forbiorefineries to overcome the current bottlenecks in biomass processing.

AB - Efficient deconstruction of lignocellulosic biomass into simple sugars inan economically viable manner is a prerequisite for its global acceptance as afeedstock in bioethanol production. This is achieved in nature by suites of enzymeswith the capability of efficiently depolymerizing all the components of lignocellulose.Here we provide detailed insight into the repertoire of enzymes produced bymicroorganisms enriched from the gut of the crop pathogen rice yellow stem borer (Scirpophaga insertulas ).Results: A microbial community was enriched from the gut of the rice yellow stemborer for enhanced rice straw degradation by sub-culturing every 10 days, for oneyear, in minimal medium with rice straw as the main carbon source. The enrichedculture demonstrated high cellulolytic and xylanolytic activity in the culture supernatant.Metatranscriptomic and metaexoproteomic analysis revealed a large array of enzymespotentially involved in rice straw deconstruction. The consortium was found to encodegenes ascribed to all 5 class of carbohydrate active enzymes (GHs, GTs, CEs, PLsand AAs), including Carbohydrate-Binding Modules (CBMs), categorized in theCarbohydrate-Active enZYmes (CAZy) database. The GHs were the most abundantclass of CAZymes. Predicted enzymes from these CAZy classes have the potential todigest each cell wall components of rice straw i.e. cellulose, hemicellulose, pectin,callose and lignin. Several identified CAZy proteins appeared novel, having anunknown or hypothetical catalytic counterpart with a known class of CBM. To validatethe findings, one of the identified enzymes that belongs to the GH10 family wasfunctionally characterized. The enzyme expressed in E. coli efficiently hydrolyzedbeechwood xylan, and pretreated and untreated rice straw.Conclusions: This is the first report describing the enrichment of lignocellulosedegrading bacteria from the gut of the rice yellow stem borer to deconstruct rice straw,identifying a plethora of enzymes secreted by the microbial community when growingon rice straw as a carbon source. These enzymes could be important candidates forbiorefineries to overcome the current bottlenecks in biomass processing.

M3 - Article

SN - 1754-6834

JO - Biotechnology for biofuels

JF - Biotechnology for biofuels

ER -