Incorporation, fate, and turnover of free fatty acids in cyanobacteria.

Fatty acids are important molecules in bioenergetics and also in industry. The phylum cyanobacteria consists of a group of prokaryotes that typically carry out oxygenic photosynthesis with water as an electron donor and use carbon dioxide as a carbon source to generate a range of biomolecules, including fatty acids. They are also able to import exogenous free fatty acids and direct them to biosynthetic pathways.

Combinatorial assembly and optimisation of designer cellulosomes: a galactomannan case study.

Background: Designer cellulosomes are self-assembled chimeric enzyme complexes that can be used to improve lignocellulosic biomass degradation. They are composed of a synthetic multimodular backbone protein, termed the scaffoldin, and a range of different chimeric docking enzymes that degrade polysaccharides. Over the years, several functional designer cellulosomes have been constructed.

Glycosylation of hyperthermostable designer cellulosome components yields enhanced stability and cellulose hydrolysis.

Biomass deconstruction remains integral for enabling second-generation biofuel production at scale. However, several steps necessary to achieve significant solubilization of biomass, notably harsh pretreatment conditions, impose economic barriers to commercialization. By employing hyperthermostable cellulase machinery, biomass deconstruction can be made more efficient, leading to milder pretreatment conditions and ultimately lower production costs.

Creation of a functional hyperthermostable designer cellulosome.

Background: Renewable energy has become a field of high interest over the past decade, and production of biofuels from cellulosic substrates has a particularly high potential as an alternative source of energy. Industrial deconstruction of biomass, however, is an onerous, exothermic process, the cost of which could be decreased significantly by use of hyperthermophilic enzymes. An efficient way of breaking down cellulosic substrates can also be achieved by highly efficient enzymatic complexes called cellulosomes.

Evaluation of Thermal Stability of Cellulosomal Hydrolases and Their Complex Formation.

Enzymatic breakdown of plant biomass is an essential step for its utilization in biorefinery applications, and the products could serve as substrates for the sustainable and environmentally friendly production of fuels and chemicals. Toward this end, the incorporation of enzymes into polyenzymatic cellulosome complexes-able to specifically bind to and hydrolyze crystalline cellulosic materials, such as plant biomass-is known to increase the efficiency and the overall hydrolysis performance of a cellulase system. Despite their relative abundance in various mesophilic anaerobic cellulolytic bacteria, there are only a few reports of cellulosomes of thermophilic origin.

Advanced Cloning Tools for Construction of Designer Cellulosomes.

Cellulose deconstruction is achieved in nature through two main enzymatic paradigms, i.e., free enzymes and enzymatic complexes (called cellulosomes).

Enhancement of cellulosome-mediated deconstruction of cellulose by improving enzyme thermostability.

Background: The concerted action of three complementary cellulases from Clostridium thermocellum, engineered to be stable at elevated temperatures, was examined on a cellulosic substrate and compared to that of the wild-type enzymes. Exoglucanase Cel48S and endoglucanase Cel8A, both key elements of the natural cellulosome from this bacterium, were engineered previously for increased thermostability, either by SCHEMA, a structure-guided, site-directed protein recombination method, or by consensus-guided mutagenesis combined with random mutagenesis using error-prone PCR, respectively. A thermostable β-glucosidase BglA mutant was also selected from a library generated by error-prone PCR that will assist the two cellulases in their methodic deconstruction of crystalline cellulose.

Significance of relative position of cellulases in designer cellulosomes for optimized cellulolysis.

Degradation of cellulose is of major interest in the quest for alternative sources of renewable energy, for its positive effects on environment and ecology, and for use in advanced biotechnological applications. Due to its microcrystalline organization, celluose is extremely difficult to degrade, although numerous microbes have evolved that produce the appropriate enzymes. The most efficient known natural cellulolytic system is produced by anaerobic bacteria, such as C.