Advances in biochemical engineering/biotechnology最新文献

Hydrogen gas (H₂) is one of the potential future sustainable and clean energy carriers that may substitute the use of fossil resources including fuels since it has a high energy content (heating value of 141.65 MJ/kg) when compared to traditional hydrocarbon fuels [1]. Water is a primary product of combustion being a most significant advantage of H₂ being environmentally friendly with the capacity to reduce global greenhouse gas emissions. H₂ is used in various applications. It generates electricity in fuel cells, including applications in transportation, and can be applied as fuel in rocket engines [2]. Moreover, H₂ is an important gas and raw material in many industrial applications. However, the high cost of the H₂ production processes requiring the use of other energy sources is a significant disadvantage. At present, H₂ can be prepared in many conventional ways, such as steam reforming, electrolysis, and biohydrogen production processes. Steam reforming uses high-temperature steam to produce hydrogen gas from fossil resources including natural gas. Electrolysis is an electrolytic process to decompose water molecules into O₂ and H₂. However, both these two methods are energy-intensive and producing hydrogen from natural gas, which is mostly methane (CH₄) and in steam reforming generates CO₂ and pollutants as by-products. On the other hand, biological hydrogen production is more environmentally sustainable and less energy intensive than thermochemical and electrochemical processes [3], but most concepts are not yet developed to production scale.

Cell-free systems for the in vitro production of proteins have revolutionized the synthetic biology field. In the last decade, this technology is gaining momentum in molecular biology, biotechnology, biomedicine and even education. Materials science has burst into the field of in vitro protein synthesis to empower the value of existing tools and expand its applications. In this sense, the combination of solid materials (normally functionalized with different biomacromolecules) together with cell-free components has made this technology more versatile and robust. In this chapter, we discuss the combination of solid materials with DNA and transcription-translation machinery to synthesize proteins within compartments, to immobilize and purify in situ the nascent protein, to transcribe and transduce DNAs immobilized on solid surfaces, and the combination of all or some of these strategies.

Cell-free protein synthesis (CFPS) has emerged as a powerful tool for the rapid synthesis and analysis of various structurally and functionally distinct proteins. These include 'difficult-to-express' membrane proteins such as large multipass ion channel receptors. Owing to their membrane localization, eukaryotic CFPS supplemented with endoplasmic reticulum (ER)-derived microsomal vesicles has proven to be an efficient system for the synthesis of functional membrane proteins. Here we demonstrate the applicability of the eukaryotic cell-free systems based on lysates from the mammalian Chinese Hamster Ovary (CHO) and insect Spodoptera frugiperda (Sf21) cells. We demonstrate the efficiency of the systems in the de novo cell-free synthesis of the human cardiac ion channels: ether-a-go-go potassium channel (hERG) K_V11.1 and the voltage-gated sodium channel hNa_V1.5.

Organisms from across the tree of life have evolved highly efficient mechanisms for sensing molecules of interest using biomolecular machinery that can in turn be quite valuable for the development of biosensors. However, purification of such machinery for use in in vitro biosensors is costly, while the use of whole cells as in vivo biosensors often leads to long sensor response times and unacceptable sensitivity to the chemical makeup of the sample. Cell-free expression systems overcome these weaknesses by removing the requirements associated with maintaining living sensor cells, allowing for increased function in toxic environments and rapid sensor readout at a production cost that is often more reasonable than purification. Here, we focus on the challenge of implementing cell-free protein expression systems that meet the stringent criteria required for them to serve as the basis for field-deployable biosensors. Fine-tuning expression to meet these requirements can be achieved through careful selection of the sensing and output elements, as well as through optimization of reaction conditions via tuning of DNA/RNA concentrations, lysate preparation methods, and buffer conditions. Through careful sensor engineering, cell-free systems can continue to be successfully used for the production of tightly regulated, rapidly expressing genetic circuits for biosensors.

Traditionalists are reluctant to leave the technology they and their forefathers knew. To them the new technology based on the stirred tank bioreactor is too removed from the soil the mushroom comes from. On the other hand, there are examples of applications of a bioreactor which support the change from the old to the new technology. In this chapter Bjarmin Rushton, the creator of the well-known medicinal mushroom company Wellness, gives his view of the much talked about difficulties with cultivation in stirred tanks. These problems, are they real or figment of our imagination? Those who read will find out.