Methylxanthines are ubiquitous purine alkaloids in nature and have rich biological activities and functions. Today, the demand for methylxanthine is increasing but its production is low. This issue prevents its widespread use in many industrial fields, such as pharmaceuticals, food manufacturing, and chemical engineering. To address these issues, this review provides a comprehensive and systematic exploration of methylxanthines, delving into their biological structures, detailed biosynthetic pathways, and the latest research trends. These findings serve as valuable references for researchers, fostering advancements in the optimization of synthesis processes for methylxanthines and their derivatives and promoting their application across diverse industrial fields, such as medicine, food, and chemical engineering. By bridging fundamental research and practical applications, this work aims to advance the understanding of methylxanthine compounds, enhance their production efficiency, and contribute to healthcare and technological progress.

Mandelic acid (MA) is a valuable α-hydroxy acid with applications in pharmaceuticals, cosmetics, and fine chemicals. While chemical synthesis is well established, concerns over toxicity and sustainability have driven interest in microbial production. Here, we engineered Escherichia coli for de novo MA biosynthesis by integrating enzyme screening, metabolic flux optimization, and pathway regulation. We first screened and identified an efficient hydroxymandelate synthase (HMAS) homolog from Actinosynnema mirum for MA synthesis, and subsequently enhanced the shikimate pathway along with the supply of the precursors erythrose-4-phosphate (E4P) and phosphoenolpyruvate (PEP). Additionally, CRISPR interference (CRISPRi) was employed to repress competing pathways and redirect flux toward MA production. High-cell-density cultivation (HCDC) in a 5 L bioreactor demonstrated the strain’s industrial potential, achieving an MA titer of 9.58 g/L, the highest reported for microbial production. This study provides a systematic metabolic engineering approach for efficient MA biosynthesis from glucose, offering a foundation for sustainable large-scale production, demonstrating not only genetic-level optimizations, but also effective process scaling through high-cell-density cultivation, highlighting the power of pathway engineering in microbial cell factories.

With global data expected to reach 175 zettabytes by 2025, traditional storage methods face unprecedented challenges, including security risks, limited durability, and high maintenance costs associated with centralized infrastructure. While DNA-based storage systems have demonstrated high density and chemical stability, most existing methods focus primarily on static storage, lacking effective strategies for secure and controllable information transmission. Coli Bond offers a revolutionary approach by combining the molecular precision of DNA storage with the controllable dynamics of synthetic biology, providing an innovative platform for data encryption and storage. In this system, controllable dynamics refer to information transfer regulated by caffeine concentration and temperature. The system leverages synthetic biology to engineer an auxotrophic Escherichia coli strain with a caffeine degradation pathway, enabling precise control of information transfer through conditional growth. A temperature-sensitive self-destruction mechanism ensures irreversible destruction of stored information under specific conditions, preventing unauthorized access and enhancing data security. Experimental validation demonstrated the system’s stability and reliability under various real-world conditions, including survival and function in commercial beverages, during transmission cycles, and under temperature variation. The results confirmed high transmission efficiency during initial contact and a rapid decline in strain viability after multiple transfers, providing an inherent layer of security. By integrating the high density of DNA storage with the dynamic control capabilities of synthetic biology, “Coli Bond” offers a secure and adaptable platform for the storage and transmission of DNA-encoded information, paving the way for future advancements in information storage and transmission technologies.