Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger
نویسندگان
چکیده
Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.
منابع مشابه
Discovery and characterization of ionic liquid-tolerant thermophilic cellulases from a switchgrass-adapted microbial community
BACKGROUND The development of advanced biofuels from lignocellulosic biomass will require the use of both efficient pretreatment methods and new biomass-deconstructing enzyme cocktails to generate sugars from lignocellulosic substrates. Certain ionic liquids (ILs) have emerged as a promising class of compounds for biomass pretreatment and have been demonstrated to reduce the recalcitrance of bi...
متن کاملProduction of Bacterial-Derived Enzymes in Aspergillus Niger with Applications in Lignocellulosic Biofuel Production
The development biofuels from Lignocellulosic (LC) biomass, which includes a variety of plant feedstocks such as agricultural and forestry residues and dedicated energy crops, is one route to clean and renewable alternatives to petroleum-base fuel. The first step in converting plant biomass to fuels is breaking down cellulose, the most abundant plant cell wall polymer, into fermentable sugars. ...
متن کاملCellulose hydrolysis with thermo- and alkali-tolerant cellulases in cellulose- dissolving superbase ionic liquids
متن کامل
Bioethanol potentials of corn cob hydrolysed using cellulases of Aspergillus niger and Penicillium decumbens
Corn cob is a major component of agricultural and domestic waste in many parts of the world. It is composed mainly of cellulose which can be converted to energy in form of bioethanol as an efficient and effective means of waste management. Production of cellulolytic enzymes were induced in the fungi Aspergillus niger and Penicillium decumbens by growing them in mineral salt medium containing al...
متن کاملTHE EFFECT OF IONIC STRENGTH ON THE BINDING OF SODIUM N-DODECYL SULPHATE TO ASPERGILLUS NIGER CATALASE
The binding of sodium n-dodecyl sulphate (SDS) to Aspergillus niger catalase in various ionic strengths at pH 6.4 and a temperature of 27? and 37?C has been studied over a range of SDS concentrations using equilibrium dialysis and fluorescence spectroscopy techniques. The binding data were used and interpreted in terms of theoretical models (Scatchard Equation and Wyman Binding Potential). ...
متن کامل