广藿香百秋李醇分子调控及合成生物学研究进展

百秋李醇是广藿香主要活性成分之一,也是《中国药典》中评价广藿香药材的重要指标,可通过天然提取或合成生物学工程两种方式获得。广藿香中百秋李醇含量低,是其规模化应用的瓶颈。本文从百秋李醇的合成途径、分子调控机制和合成生物学工程三方面综述近年来相关研究进展,为百秋李醇的开发与应用提供参考。

Advancements in biocatalysis:From computational to metabolic engineering

Through several waves of technological research and un‐matched innovation strategies,bio‐catalysis has been widely used at the industrial level.Because of the value of enzymes,methods for producing value‐added compounds and industrially‐relevant fine chemicals through biological methods have been developed.A broad spectrum of numerous biochemical pathways is catalyzed by enzymes,including enzymes that have not been identified.However,low catalytic efficacy,low stability,inhibition by non‐cognate substrates,and intolerance to the harsh reaction conditions required for some chemical processes are considered as major limitations in applied bio‐catalysis.Thus,the development of green catalysts with multi‐catalytic features along with higher efficacy and induced stability are important for bio‐catalysis.Implementation of computational science with metabolic engineering,synthetic biology,and machine learning routes offers novel alternatives for engineering novel catalysts.Here,we describe the role of synthetic biology and metabolic engineering in catalysis.Machine learning algorithms for catalysis and the choice of an algorithm for predicting protein‐ligand interactions are discussed.The importance of molecular docking in predicting binding and catalytic functions is reviewed.Finally,we describe future challenges and perspectives.

Industry 5.0-The Relevance and Implications of Bionics and Synthetic Biology

Bionics （the imitation or abstraction of the ＂inventions＂ of nature） and, to an even greater extent, syn- thetic biology, will be as relevant to engineering development and industry as the silicon chip was over the last 50 years. Chemical industries already use so-called ＂white biotechnology＂ for new processes, new raw materials, and more sustainable use of resources. Synthetic biology is also used for the devel- opment of second-generation biofuels and for harvesting the sun＇s energy with the help of tailor-made microorganisms or biometrically designed catalysts. The market potential for bionics in medicine, en- gineering processes, and DNA storage is huge. ＂Moonshot＂ projects are already aggressively focusing on diseases and new materials, and a US-led competition is currently underway with the aim of creating a thousand new molecules. This article describes a timeline that starts with current projects and then moves on to code engineering projects and their implications, artificial DNA, signaling molecules, and biological circuitry. Beyond these projects, one of the next frontiers in bionics is the design of synthetic metabolisms that include artificial food chains and foods, and the bioengineering of raw materials; all of which will lead to new insights into biological principles. Bioengineering will be an innovation motor just as digitalization is today. This article discusses pertinent examples of bioengineering, particularly the use of alternative carbon-based biofuels and the techniques and perils of cell modification. Big data, analytics, and massive storage are important factors in this next frontier. Although synthetic biology will be as pervasive and transformative in the next 50 years as digitization and the Intemet are today, its ap- plications and impacts are still in nascent stages. This article provides a general taxonomy in which the development of bioengineering is classified in five stages （DNA analysis, bio-circuits, minimal genomes, protocells, xenobiology） from the familiar to the unknown, with implications for safety and security, in- dustrial development, and the development of bioengineering and biotechnology as an interdisciplinary field. Ethical issues and the importance of a public debate about the consequences of bionics and syn- thetic biology are discussed.

Technique and Technology in the Composition Mantra： Considerations Some Analytical Considerations

This paper relates to Stockhausen＇s composition method of the 1970s based on the concept called ＂formula＂. This method is in part a derivation and in part an improvement of serialism. Stockhausen applied it in his works starting from 1970, with the composition Mantra for two pianos and ring modulator, and refined it during his whole life. This paper will discuss the formula＇s concept and his application. In particular, the author tries to analyze the first composition where the formula＇s method is applied under two different points of view： the composition method and the rule of technology in the composition.

Mosaic of the Curved Human Retinal Images Based on the Scale-Invariant Feature Transform

To meet the needs in the fundus examination,including outlook widening,pathology tracking,etc.,this paper describes a robust feature-based method for fully-automatic mosaic of the curved human retinal images photographed by a fundus microscope. The kernel of this new algorithm is the scale-,rotation-and illumination-invariant interest point detector & feature descriptor-Scale-Invariant Feature Transform. When matched interest points according to second-nearest-neighbor strategy,the parameters of the model are estimated using the correct matches of the interest points,extracted by a new inlier identification scheme based on Sampson distance from putative sets. In order to preserve image features,bilinear warping and multi-band blending techniques are used to create panoramic retinal images. Experiments show that the proposed method works well with rejection error in 0.3 pixels,even for those cases where the retinal images without discernable vascular structure in contrast to the state-of-the-art algorithms.

Enzyme engineering in microbial biosynthesis of terpenoids:progress and perspectives

Terpenoids,known for their structural and functional diversity,are highly valued,especially in food,cosmetics,and cleaning products.Microbial biosynthesis has emerged as a sustainable and environmentally friendly approach for the production of terpenoids.However,the natural enzymes involved in the synthesis of terpenoids have problems such as low activity,poor specificity,and insufficient stability,which limit the biosynthesis efficiency.Enzyme engineering plays a pivotal role in the microbial synthesis of terpenoids.By modifying the structures and functions of key enzymes,researchers have significantly improved the catalytic activity,specificity,and stability of enzymes related to terpenoid synthesis,providing strong support for the sustainable production of terpenoids.This article reviews the strategies for the modification of key enzymes in microbial synthesis of terpenoids,including improving enzyme activity and stability,changing specificity,and promoting mass transfer through multi-enzyme collaboration.Additionally,this article looks forward to the challenges and development directions of enzyme engineering in the microbial synthesis of terpenoids.

Metabolic engineering of Streptomyces coelicolor for enhanced prodigiosins (RED) production

Bacterial prodigiosins are red-colored secondary metabolites with multiple activities,such as anticancer,antimalarial and immunosuppressive,which hold great potential for medical applications.In this study,dramatically enhanced prodigiosins(RED) production in Streptomyces coelicolor was achieved by combinatorial metabolic engineering,including inactivation of the repressor gene ohkA,deletion of the actinorhodin(ACT) and calcium-dependent antibiotic(CDA) biosynthetic gene clusters(BGCs) and multi-copy chromosomal integration of the RED BGC.The results showed that ohkA deletion led to a 1-fold increase of RED production over the wild-type strain M145.Then,the ACT and CDA BGCs were deleted successively based on the AohkA mutant(SBJ101).To achieve multi-copy RED BGC integration,artificial ΦC31 attB site(s) were inserted simultaneously at the position where the ACT and CDA BGCs were deleted.The resulting strains SBJ102(with a single deletion of the ACT BGC and insertion of one artificial attB site) and SBJ103(with the deletion of both BGCs and insertion of two artificial attB sites) produced 1.9-and 6-fold higher RED titers than M145,respectively.Finally,the entire RED BGC was introduced into mutants from SBJ101 to SBJ103,generating three mutants(from SBJ104 to SBJ106) with chromosomal integration of one to three copies of the RED BGC.The highest RED yield was from SBJ106,which produced a maximum level of 96.8 mg g^(-1) cell dry weight,showing a 12-fold increase relative to M145.Collectively,the metabolic engineering strategies employed in this study are very efficient for the construction of high prodigiosin-producing strains.