Presentation Information
[1ASBA-16]A Bacillus subtilis mutant displaying artificial cellulosomes on the germination-inhibited spore surface
○Ken-ichi Yoshida1, Akari Yamaguchi1, Shu Ishikawa1 (1. Kobe University (Japan))
Keywords:
Bacillus subtilis,cellulosome,Clostridium thermocellum,spore
Inedible plant biomass is a renewable resource for chemical production, and promoting its utilisation can reduce dependence on fossil resources, enabling the realisation of a sustainable and carbon-neutral society. Plant biomass consists of sugar polymers such as cellulose, which can be broken down and converted into various chemicals. Despite this potential, challenges remain in plant biomass decomposition technology, necessitating improvements in efficiency and costs.
Certain microorganisms, such as Clostridium thermocellum, can efficiently decompose plant biomass using an enzyme complex called a cellulosome, which consists of diverse polysaccharide-degrading enzymes bound to a structural protein scaffoldin. On the other hand, Bacillus subtilis is a bacterium used for protein production and forms spores with high physical stability. This study aims to develop a novel bioprocess that enables efficient decomposition of plant biomass using B. subtilis spores with surface-presented cellulosomes. This is achieved by constructing artificially designed cellulosomes derived from C. thermocellum on the spore surface of B. subtilis.
We designed mini-CipA—a compacted version of scaffoldin as the assembly foundation of the artificial cellulosome—and fused it to CotZ, which is displayed stably on the spore surface. This required the deletion of 10 proteases inherent to B. subtilis. Subsequently, we produced endoglucanase, exoglucanase, and xylanase in the mother cell during the sporulation phase, and we successfully detected at least endoglucanase and xylanase activities in purified spores, indicating these enzymes accumulated on mini-CipA to form the artificial cellulosome on the spore surface. However, spores germinate when nutrient conditions improve, causing them to lose the cellulosome. Consequently, we also succeeded in predominantly inhibiting germination by deleting multiple genes involved in the germination process.
In summary, we demonstrated the potential to develop novel plant biomass decomposition technologies using B. subtilis spores presenting the cellulosome on their surface. This lecture will discuss the future direction of development.
Certain microorganisms, such as Clostridium thermocellum, can efficiently decompose plant biomass using an enzyme complex called a cellulosome, which consists of diverse polysaccharide-degrading enzymes bound to a structural protein scaffoldin. On the other hand, Bacillus subtilis is a bacterium used for protein production and forms spores with high physical stability. This study aims to develop a novel bioprocess that enables efficient decomposition of plant biomass using B. subtilis spores with surface-presented cellulosomes. This is achieved by constructing artificially designed cellulosomes derived from C. thermocellum on the spore surface of B. subtilis.
We designed mini-CipA—a compacted version of scaffoldin as the assembly foundation of the artificial cellulosome—and fused it to CotZ, which is displayed stably on the spore surface. This required the deletion of 10 proteases inherent to B. subtilis. Subsequently, we produced endoglucanase, exoglucanase, and xylanase in the mother cell during the sporulation phase, and we successfully detected at least endoglucanase and xylanase activities in purified spores, indicating these enzymes accumulated on mini-CipA to form the artificial cellulosome on the spore surface. However, spores germinate when nutrient conditions improve, causing them to lose the cellulosome. Consequently, we also succeeded in predominantly inhibiting germination by deleting multiple genes involved in the germination process.
In summary, we demonstrated the potential to develop novel plant biomass decomposition technologies using B. subtilis spores presenting the cellulosome on their surface. This lecture will discuss the future direction of development.
Comment
To browse or post comments, you must log in.Log in