Advances in biochemical engineering/biotechnology最新文献

Selenium (Se) is a naturally occurring trace element that is nutritionally essential for humans and animals, but becomes toxic at high concentrations. This laboratory study explored the role of microbes in Se removal from contaminated wastewater via biological transformation and volatilization processes. Microbes could immobilize water-soluble selenate (SeO₄^2-) and selenite (SeO₃^2-) to water-insoluble elemental Se (Se⁰) and transform Se into volatile Se compounds found in the atmosphere. Results of this laboratory study showed that Bacillus cereus, a bacterial strain isolated from wheat straw and biosolid-WTR-sand substrates showed a significant biotransformation ability of reducing selenate and selenite to elemental Se and forming volatile Se organic compounds in wastewater. Overall, microbial Se chemical reduction, methylation, and volatilization are important processes in bioremediation of Se-contaminated wastewater.

Mixed culture cultivation is well renowned for industrial applications due to its technological and economic benefits in bioprocess, food processing, and pharmaceutical industries. A mixed consortium encompasses to achieve growth in unsterile conditions, robustness to environmental stresses, perform difficult functions, show better substrate utilization, and increase productivity. Hence, mixed cultures are being valorized currently and has also augmented our understanding of microbial activities in communities. This chapter covers a wide range of discussion on recent improvements in mixed culture cultivation for microbial bioprocessing and multifarious applications in different areas. The history of microbial culture, microbial metabolism in mixed culture, biosynthetic pathway studies, isolation and identification of strains, along with the types of microbial interactions involved during their production and propagation, are meticulously detailed in the current chapter. Besides, parameters for evaluating mixed culture performance, large-scale production, and challenges associated with it are also discussed vividly. Microbial community, characteristics of single and mixed culture fermentation, and microbe-microbe interactions in mixed cultures have been summarized comprehensively. Lastly, various challenges and opportunities in the area of microbial mixed culture that are obligatory to improve the current knowledge of microbial bioprocesses are projected.

In this study calculation over material and energy balances for bio-refinery product upgrading using membrane filtration (MF, UF, and RO), distillation, and ion-exchanger has been performed. Tests have been made with UF filtration in a pilot plant, separation tests made at lab with ion-exchanger and simulation using ASPEN plus simulator for distillation. Rough economic analysis has been made for the different solutions/techniques.

Biomass pretreatment plays a crucial role in the conversion of lignocellulosic biowaste materials into valuable biofuels and biochemicals. Enzymatic pretreatment, in particular, has gained significant attention due to its eco-friendly nature and efficiency in breaking down complex biomass structures. This comprehensive review aims to provide an overview of enzymes used in biomass pretreatment, including cellulases, hemicellulases, ligninases, and their applications in enhancing the efficiency of biomass conversion processes. The review also discusses recent advancements, challenges, and future prospects in the field of enzymatic biomass pretreatment.

In the context of climate change, resource scarcity, and a growing global population, sustainable processes and the efficient use of raw materials are imperative. Developing best practices to guide the transition toward a circular economy with minimized waste is essential. Agricultural processes offer inspiration, as they traditionally emphasize the utilization of all parts of cultivated plants. Today, however, there is a pressing need to go beyond basic utilization and focus on the upcycling and valorization of agricultural side streams into high-value products. This chapter examines the wine and grape industry, which generates substantial volumes of side streams, including grape pomace, seeds, stems, and wine lees. In recent years, these material streams have attracted attention for their potential as raw materials rich in bioactive compounds - such as diverse polyphenols, dietary fibers, and organic acids - that can be applied across various sectors, including food, cosmetics, pharmaceuticals, and bioenergy. Key methodologies such as extraction, fermentation, and bioconversion are discussed as pathways to recover and enhance these compounds. Case studies of successful valorization initiatives are presented, demonstrating practical applications of side streams for high-value product creation. An example is the BMBF-funded project "Sustainable Beverages" focusing on the development of fermented drinks made from vine leaves that can be offered as a non-alcoholic alternative to wine. By providing an overview of the current research and technologies in wine waste valorization, this chapter serves as a valuable resource for academics, industry professionals, and policymakers seeking to advance sustainable practices within the wine sector. Ultimately, the upcycling of wine industry residues not only reduces environmental impact but also creates new revenue opportunities, driving innovation and sustainability in the industry.

In the research of mixed microbial cultures, the numbers and identifications of individual strains are often only partially unknown. Their metabolic capabilities are also not wholly predictable especially if the joint potential is to be understood. In these kinds of situations, deeper insight into the variable microbial communities cannot be obtained by genetic analysis only. Even more critical than the taxonomic aspect is usually the functional metabolic outcome of the mixed flora in question. The results from such studies as NMR (nucleic magnetic resonance) give a precise view from versatile angles into the biochemical activities during the multiparametric metabolic responses of the microflora as a whole.Originally, metabonomics was mainly used for the pathophysiological research of various microbes or for recording the genetic or biochemical modifications of mixed microflora. This approach offers a tool for monitoring changes in microscopic or otherwise confined ecosystems or at multiple locations from which representative specimens are difficult to obtain. It also offers repeatability in various processes. In microbiological studies, the research group can attain overall views on variable populations and their alterations in time and space.

The expanding field of synthetic biology requires diversification of microbial chassis to expedite the transition from a fossil fuel-dependent economy to a sustainable bioeconomy. Relying exclusively on established model organisms such as Escherichia coli and Saccharomyces cerevisiae may not suffice to drive the profound advancements needed in biotechnology. In this context, Cupriavidus necator, an extraordinarily versatile microorganism, has emerged as a potential catalyst for transformative breakthroughs in industrial biomanufacturing. This comprehensive book chapter offers an in-depth review of the remarkable technological progress achieved by C. necator in the past decade, with a specific focus on the fields of molecular biology tools, metabolic engineering, and innovative fermentation strategies. Through this exploration, we aim to shed light on the pivotal role of C. necator in shaping the future of sustainable bioprocessing and bioproduct development.

Cable bacteria grow as multicellular filaments several centimetres deep into the sediment of freshwaters and oceans. Hereby, cable bacteria show unique characteristics such as electrogenic sulphur oxidation, extremely high conductivity and ability for CO₂ fixation. This offers several possibilities of future applications in biotechnology with an outlook to sustainable processes. So far, research on cable bacteria is mostly concerning metabolism, electron transfer and effect on the surrounding sediment. Cultures are always performed on sediment from the natural habitat and in simple, small-scale reaction tubes, requiring further development for reproducible cultivation with scale-up capabilities. However, based on the known properties of cable bacteria, possible areas of application can already be derived. The use of cable bacteria in bioremediation is a promising approach, as the degradation of hydrocarbons has already been proven. Co-cultivation with plants could open up a further field of application, such as the described reduction of methane emissions from rice fields. Due to the extremely high conductivity of the filaments, cable bacteria are also very promising for incorporation into biodegradable microelectronics. By integrating electrodes into a suitable reactor system, bioelectrochemical processes could be implemented, either with the goal of electron uptake and product formation or for electricity generation.