Advances in biochemical engineering/biotechnology最新文献

Research progress of active compounds and biological activities of medicinal mushroom-Ganoderma spp., Hericium spp., Phellinus spp., and Cordyceps spp. were summarized systematically. The main active compounds of medicinal mushrooms included are polysaccharides, proteins, triterpenes, meroterpenoids, polyphenols and nitrogen-containing compounds. The biological activities of the compounds cover immunomodulatory activity, antitumor activity, hypoglycemic activity, hepatoprotective activity, and activity of regulation of intellectual flora.

A Sustainable Development Goals (SDGs) based analysis is presented here for business development of the production of edible and medicinal mushrooms using agro-wastes in the Southern Cone of South America. This circular economy approach using edible and medicinal mushroom production on lignocellulosic residues is discussed by analysing both its advantages and drawbacks. Among its main benefits, it is notable that mushroom cultivation using lignocellulosic residues promotes innovation aimed at environmental sustainability, facilitating diversification of the labour supply and the transfer of science to the socio-cultural sphere, which also increases the availability of healthy foods. However, there are some bottlenecks in the process, such as the continuous supply chain of substrates for fungal growth, the lack of equipment and infrastructure for the implementation of cultivation systems in extreme habitats, as well as authorization requirements and other limitations related to a non-fungiphilic culture society. Therefore, this chapter tries to provide key tools for establishing sustainable guidelines for the procurement of local healthy food and other products derived from mushroom cultivation using agricultural residues in the region, which might bloom due to an SDGs-based circular economy approach.

Cyanobacteria, the evolutionary originators of oxygenic photosynthesis, have the capability to convert CO₂, water, and minerals into biomass using solar energy. This process is driven by intricate bioenergetic mechanisms that consist of interconnected photosynthetic and respiratory electron transport chains coupled. Over the last few decades, advances in physiochemical analysis, molecular genetics, and structural analysis have enabled us to gain a more comprehensive understanding of cyanobacterial bioenergetics. This includes the molecular understanding of the primary energy conversion mechanisms as well as photoprotective and other dissipative mechanisms that prevent photodamage when the rates of photosynthetic output, primarily in the form of ATP and NADPH, exceed the rates that cellular assimilatory processes consume these photosynthetic outputs. Despite this progress, there is still much to learn about the systems integration and the regulatory circuits that control expression levels for optimal cellular abundance and activity of the photosynthetic complexes and the cellular components that convert their products into biomass. With an improved understanding of these regulatory principles and mechanisms, it should be possible to optimally modify cyanobacteria for enhanced biotechnological purposes.

Although the handling and exploitation of cyanobacteria is associated with some challenges, these phototrophic bacteria offer great opportunities for innovative biotechnological processes. This chapter covers versatile aspects of working with cyanobacteria, starting with up-to-date in silico and in vitro screening methods for bioactive substances. Subsequently, common conservation techniques and vitality/viability estimation methods are compared and supplemented by own data regarding the non-invasive vitality evaluation via pulse amplitude modulated fluorometry. Moreover, novel findings about the influence the state of the pre-cultures have on main cultures are presented. The following sub-chapters deal with different photobioreactor-designs, with special regard to biofilm photobioreactors, as well as with heterotrophic and mixotrophic cultivation modes. The latter topic provides information from literature on successfully enhanced cyanobacterial production processes, augmented by own data.

Biosynthesis involving multi-enzymatic reactions is usually an efficient and economic method to produce plentiful important molecules. To increase the product yield in biosynthesis, the involved enzymes can be immobilized to carriers for enhancing enzyme stability, increasing synthesis efficiency and improving enzyme recyclability. Hydrogels with three-dimensional porous structures and versatile functional groups are promising carriers for enzyme immobilization. Herein, we review the recent advances of the hydrogel-based multi-enzymatic system for biosynthesis. First, we introduce the strategies of enzyme immobilization in hydrogel, including the pros and cons of the strategies. Then we overview the recent applications of the multi-enzymatic system for biosynthesis, including cell-free protein synthesis (CFPS) and non-protein synthesis, especially high value-added molecules. In the last section, we discuss the future perspective of the hydrogel-based multi-enzymatic system for biosynthesis.

The use of cell-free production systems in droplet microfluidic devices has gained significant interest during the last decade. Encapsulating DNA replication, RNA transcription, and protein expression systems in water-in-oil drops allows for the interrogation of unique molecules and high-throughput screening of libraries of industrial and biomedical interest. Furthermore, the use of such systems in closed compartments enables the evaluation of various properties of novel synthetic or minimal cells. In this chapter, we review the latest advances in the usage of the cell-free macromolecule production toolbox in droplets, with a special emphasis on new on-chip technologies for the amplification, transcription, expression, screening, and directed evolution of biomolecules.

Cofactors, such as adenosine triphosphate, nicotinamide adenine dinucleotide, and coenzyme A, are involved in nearly 50% of enzymatic reactions and widely used in biocatalytic production of useful chemicals. Although commercial production of cofactors has been mostly dependent on extraction from microbial cells, this approach has a theoretical limitation to achieve a high-titer, high-yield production of cofactors owing to the tight regulation of cofactor biosynthesis in living cells. Besides the cofactor production, their regeneration is also a key challenge to enable continuous use of costly cofactors and improve the feasibility of enzymatic chemical manufacturing. Construction and implementation of enzyme cascades for cofactor biosynthesis and regeneration in a cell-free environment can be a promising approach to these challenges. In this chapter, we present the available tools for cell-free cofactor production and regeneration, the pros and cons, and how they can contribute to promote the industrial application of enzymes.

Fatty acids and their derivatives are highly valuable chemicals that can be produced through chemical or enzymatic processes using plant lipids. This may compete with human food sources. Therefore, there has been an urge to create a new method for synthesizing these chemicals. One approach is to use microbial cells, specifically cyanobacteria, as a factory platform. Engineering may need to be implemented in order to allow a cost-competitive production and to enable a production of a variety of different fatty acids and derivatives. In this chapter, we explain in details the importance of fatty acids and their derivatives, including fatty aldehydes, fatty alcohols, hydrocarbons, fatty acid methyl esters, and hydroxy fatty acids. The production of these chemicals using cyanobacterial native metabolisms together with strategies to engineer them are also explained. Moreover, recent examples of fatty acid and fatty acid derivative production from engineered cyanobacteria are gathered and reported. Commercial opportunities to manufacture fatty acids and derivatives are also discussed in this chapter. Altogether, it is clear that fatty acids and their derivatives are important chemicals, and with recent advancements in genetic engineering, a cyanobacterial platform for bio-based production is feasible. However, there are regulations and guidelines in place for the use of genetically modified organisms (GMOs) and some further developments are still needed before commercialization can be reached.

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.

One of the grand challenges in bottom-up synthetic biology is the design and construction of synthetic cellular systems. One strategy toward this goal is the systematic reconstitution of biological processes using purified or non-living molecular components to recreate specific cellular functions such as metabolism, intercellular communication, signal transduction, and growth and division. Cell-free expression systems (CFES) are in vitro reconstitutions of the transcription and translation machinery found in cells and are a key technology for bottom-up synthetic biology. The open and simplified reaction environment of CFES has helped researchers discover fundamental concepts in the molecular biology of the cell. In recent decades, there has been a drive to encapsulate CFES reactions into cell-like compartments with the aim of building synthetic cells and multicellular systems. In this chapter, we discuss recent progress in compartmentalizing CFES to build simple and minimal models of biological processes that can help provide a better understanding of the process of self-assembly in molecularly complex systems.