Advances in biochemical engineering/biotechnology最新文献

Microbial strains, communities, and enzymes process side-streams into valuable products in a microbiological biorefinery. Proactive engineering and manufacturing of related bioreactors and other equipment is crucial. Production processes should be engineered in a seamless collaboration, so that the equipment optimally supports the biorefinery's function. This chapter presents various ways to educate microbiological biorefinery principles and operations for professionals. This education can occur in the classroom and hands-on, in biorefinery pilots, laboratories or purification plants.

The circular bioeconomy connects waste recycling with utilizing organic biomass waste for bioenergy, bio-based materials, and biochemical production. This integration promotes efficient resource utilization, reduced greenhouse gas emissions, and sustainable economic growth. Several technologies such as composting, anaerobic digestion, biochar production, gasification, pyrolysis, pelletization, and advanced thermal conversion technologies are utilized to manage agricultural waste efficiently. Waste-to-energy systems and food waste valorization techniques are employed to convert agro-waste into renewable energy sources such as bioethanol, biodiesel, and biogas through fermentation, transesterification, and anaerobic digestion. These biofuels offer renewable alternatives to fossil fuels, reducing greenhouse gas emissions and dependence on non-renewable resources. Rice husk, a globally abundant agricultural waste, can be utilized for energy production through technologies like direct combustion and fast pyrolysis. Biobutanol, synthesized from acetone-butanol-ethanol fermentation of agricultural residues like orange peel, presents a promising fuel option. Agricultural waste can also serve as feedstock for bio-based chemicals like organic acids, solvents, and polymers, reducing reliance on petroleum-based chemicals. Agro-waste materials like grass, garlic peel, and rice bran have shown potential for dye adsorption in wastewater treatment applications. Moreover, agricultural waste can be repurposed as animal feed, contributing to waste reduction and providing sustainable nutrition for livestock. Plant seeds and green biomass offer sustainable protein sources, while residues like straw and sawdust can be used for mushroom cultivation. Agro-waste biopolymers like starch and cellulose can be transformed into biodegradable plastics and biocomposites, offering eco-friendly alternatives. Additionally, agro-waste materials like straw, rice husks, and bamboo can be processed into construction materials, reducing environmental impact in building projects. Extracts from plant residues and fruit pomace can be utilized in pharmaceuticals, nutraceuticals, and cosmetics. Valorizing agro-waste for food, feed, fibers, and fuel offers opportunities to minimize waste and maximize resource efficiency, resulting in high-value products.

Euglena gracilis is neither a plant nor an animal. It generates its energy from light and CO₂ purely photoautotrophically or it assimilates a carbon source chemoheterotrophically and transforms its chloroplasts into proplastids resulting in an animal cell structure. E. gracilis is a unicellular protist with a length of about 50 μm and developed by secondary endosymbiosis. For this reason, the chloroplasts have three membranes instead of a double membrane with a positive effect on the lipid content. It has no cell wall and is therefore easily bioavailable to humans. Euglena produces large amounts of vitamin E α-tocopherol and the β-1,3-glucan paramylon in granule form and has a good amount of lipids. Thanks to its contractile vacuole, Euglena is able to grow in a wide pH range from around pH 1-11. Cultivation in the acidic range thus simplifies cultivation on a technical scale under axenic conditions and enhances the solubility of solids and trace elements.

Cyanobacteria as phototrophic microorganisms bear great potential for biotechnological application and a truly sustainable bioeconomy. Besides production of biomass and natural compounds, CO₂-based production of diverse value-added compounds with engineered strains enjoys ever-growing interest. Representatives of the genera Synechocystis and Synechococcus are the most used cyanobacterial model organisms for this purpose, with studies ranging from basic research to their utilization as cell factories. For both genera, genetic tools become more and more established, being, however, still far less advanced compared to those available for heterotrophic workhorse strains. Production of CO₂-based compounds, typically established on a proof-of-concept basis, ranges from highly complex products such as pigments, proteins, and hormones to more simple bulk products such as biofuels and commodity chemicals. For some small molecules, e.g., isobutyraldehyde, 2,3-butanediol, L-lactic acid, sucrose, and ethanol, the gram per liter scale has been achieved. The general benefits of cyanobacterial photobiotechnology are the use of light as energy source and the capacity to use CO₂ via photosynthetic carbon fixation. Additionally, the photosynthetic apparatus offers the opportunity to directly utilize electrons derived from photosynthetic water oxidation for redox biotransformations. In this respect, several enzymes have successfully been implemented in cyanobacterial strains, and high specific rates comparable to those achieved with heterotrophs have been reached. Moreover, oxygenic photosynthesis provides an ideal framework to implement oxyfunctionalization reactions also benefitting from the intracellular in situ supply of O₂. This chapter summarizes the recent advances in cyanobacterial biotechnology with a focus on Synechocystis and Synechococcus strains, encompassing both biotransformation reactions and CO₂-based product formation. Additionally, we discuss advantages and limitations of cyanobacterial chassis strains and give perspectives for future research and required measures to establish this unique group of bacteria in industrial biotechnology.

The conversion of agricultural wastes to value-added products has emerged as a pivotal strategy in fostering economic transformation. This chapter explores the transformative potential of converting agricultural residues into valued commodities that contribute to sustainability and economic growth. Agricultural wastes, often considered environmental liabilities, possess untapped benefits with great economic value. By employing innovative technologies, these wastes can be converted into a range of value-added products, such as substrates for agricultural production, biofuels, organic fertilizers, natural dyes, pharmaceuticals, and packaging materials. This approach not only mitigates the environmental impact of waste disposal but also provides new revenue streams for farmers, entrepreneurs and governments. In the economic landscape, the creation of value-added products from agricultural wastes serves as a catalyst for job creation, income generation, and rural development. Additionally, the development of a value chain around agricultural waste-derived products strengthens the resilience of the agricultural sector while diversifying the sources of income for farmers and reducing their dependence on major crops as income source. It also fosters innovation by encouraging the development of new technologies and industrial processes for efficient waste utilization and creation of novel products with diverse applications. From the environmental perspective, the conversion of agricultural waste to valuable products reduces environmental pollution, mitigates climate change, and improves the quality of life. The production of biofuels from agricultural residues has the potential to address energy security concerns, provide alternative and renewable energy sources, and allow for energy sufficiency. This chapter exposes the hidden economic potentials in agricultural wastes for farmers, entrepreneurs, policymakers, and government to explore. The transformation of agricultural wastes into value-added products if fully harnessed will play a critical role in the economic transformation of many nations across the globe while addressing the environmental challenges that come with waste management and industrialization.

Intensive agricultural production generates a lot of residues yearly, exhausting and depleting the soils and accumulating pesticides and mineral fertilizers. Although introducing the no-till technologies is related to the reduction of tillage, leaving most of the plant residues on the field and decreasing fertigation, the global crop residues are estimated to be 2800 million tons per year. They could be successfully utilized via several approaches integrated into the circular bioeconomy concept. Thus, stopping the existing vicious circle of digging most of the primary materials such as fossil fuels, the vast application of chemical fertilizers, gaining increased or restored biodiversity, capturing CO₂ into the soils and enhancing the organic content, having cleaner underground waters, soils and crop production, and finally improved quality of life. The transformation of these residues into value-added products faces various technological and commercialization difficulties that limit their fuller utilization. In the present chapter, we aim to describe the production of agricultural residues in the EU and present their properties and technologies for biological valorization. In addition, the potential risks associated with the micro- and nano-plastics content of agricultural residues are discussed.

Methanogenic archaea convert bacterial fermentation intermediates from the decomposition of organic material into methane. This process has relevance in the global carbon cycle and finds application in anthropogenic processes, such as wastewater treatment and anaerobic digestion. Furthermore, methanogenic archaea that utilize hydrogen and carbon dioxide as substrates are being employed as biocatalysts for the biomethanation step of power-to-gas technology. This technology converts hydrogen from water electrolysis and carbon dioxide into renewable natural gas (i.e., methane). The application of methanogenic archaea in bioproduction beyond methane has been demonstrated in only a few instances and is limited to mesophilic species for which genetic engineering tools are available. In this chapter, we discuss recent developments for those existing genetically tractable systems and the inclusion of novel genetic tools for thermophilic methanogenic species. We then give an overview of recombinant bioproduction with mesophilic methanogenic archaea and thermophilic non-methanogenic microbes. This is the basis for discussing putative products with thermophilic methanogenic archaea, specifically the species Methanothermobacter thermautotrophicus. We give estimates of potential conversion efficiencies for those putative products based on a genome-scale metabolic model for M. thermautotrophicus.

In this chapter, we discuss the necessity of novel chassis organisms for the production of natural products to steer away from petrochemical approaches and the usage of common model organisms. We present the social amoeba Dictyostelium discoideum as a novel host for the production of complex organic substances and exploration of cryptic biosynthetic routes of secondary metabolites. We shed light on the genetic repertoire of the amoeba in terms of natural product biosyntheses and give an overview of growth characteristics, genetic engineering tools, and cultivation methodologies from shake flasks to stirred-tank bioreactors. Finally, an outlook is made on the perspective of D. discoideum as the chassis for biotechnological production and discovery of novel active substances.

Continuous, on-demand, and, most importantly, contextual data regarding individual biomarker concentrations exemplify the holy grail for personalized health and performance monitoring. This is well-illustrated for continuous glucose monitoring, which has drastically improved outcomes and quality of life for diabetic patients over the past 2 decades. Recent advances in wearable biosensing technologies (biorecognition elements, transduction mechanisms, materials, and integration schemes) have begun to make monitoring of other clinically relevant analytes a reality via minimally invasive skin-interfaced devices. However, several challenges concerning sensitivity, specificity, calibration, sensor longevity, and overall device lifetime must be addressed before these systems can be made commercially viable. In this chapter, a logical framework for developing a wearable skin-interfaced device for a desired application is proposed with careful consideration of the feasibility of monitoring certain analytes in sweat and interstitial fluid and the current development of the tools available to do so. Specifically, we focus on recent advancements in the engineering of biorecognition elements, the development of more robust signal transduction mechanisms, and novel integration schemes that allow for continuous quantitative analysis. Furthermore, we highlight the most compelling and promising prospects in the field of wearable biosensing and the challenges that remain in translating these technologies into useful products for disease management and for optimizing human performance.

The detection of a protein analyte and use of this type of information for disease diagnosis and physiological monitoring requires methods with high sensitivity and specificity that have to be also easy to use, rapid and, ideally, single step. In the last 10 years, a number of DNA-based sensing methods and sensors have been developed in order to achieve quantitative readout of protein biomarkers. Inspired by the speed, specificity, and versatility of naturally occurring chemosensors based on structure-switching biomolecules, significant efforts have been done to reproduce these mechanisms into the fabrication of artificial biosensors for protein detection. As an alternative, in scaffold DNA biosensors, different recognition elements (e.g., peptides, proteins, small molecules, and antibodies) can be conjugated to the DNA scaffold with high accuracy and precision in order to specifically interact with the target protein with high affinity and specificity. They have several advantages and potential, especially because the transduction signal can be drastically enhanced. Our aim here is to provide an overview of the best examples of structure switching-based and scaffold DNA sensors, as well as to introduce the reader to the rational design of innovative sensing mechanisms and strategies based on programmable functional DNA systems for protein detection.