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Microbial lipid metabolism is an attractive route for producing aliphatic chemicals, commonly referred to as oleochemicals. The predominant metabolic engineering strategy centers on heterologous thioesterases capable of producing fatty acids of desired size. To convert acids to desired oleochemicals (e.g. fatty alcohols, ketones), metabolic engineers modify cells to block beta-oxidation, reactivate fatty acids as coenzyme-A thioesters, and redirect flux towards termination enzymes with broad substrate utilization ability. These genetic modifications narrow the substrate pool available for the termination enzyme but cost one ATP per reactivation - an expense that could be saved if the acyl-chain was directly transferred from ACP- to CoA-thioester. In this work, we demonstrate an alternative acyl-transferase strategy for producing medium-chain oleochemicals. Through bioprospecting, mutagenesis, and metabolic engineering, we developed strains of Escherichia coli capable of producing over 1 g/L of medium-chain free fatty acids, fatty alcohols, and methyl ketones using the transacylase strategy.

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Integrated electrochemical sensing platforms in wearable devices have great prospects in biomedical applications. However, traditional electrochemical platforms are generally fabricated on airtight printed circuit boards, which lack sufficient flexibility, air permeability, and conformability. Liquid metals at room temperature with excellent mobility and electrical conductivity show high promise in flexible electronics. This paper presents a miniaturized liquid metal-based flexible electrochemical detection system on fabric, which is intrinsically flexible, air-permeable, and conformable to the body. Taking advantage of the excellent fluidity and electrical connectivity of liquid metal, a double-layer circuit is fabricated that significantly miniaturizes the size of the whole system. The linear response, time stability, and repeatability of this system are verified by resistance, stability, image characterization, and potassium ferricyanide tests. Finally, glucose in sweat can be detected at the millimolar level using this sensing system, which demonstrates its great potential for wearable and portable detection in biomedical fields, such as health monitoring and point-of-care testing.

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Low‐melting point metals and alloys, as emerging 3D printing ink, have attracted more and more attention especially for flexible or intelligent conductors and electronics. However, achieving 3D continuity of liquid metal structures or patterns using a common method is still challenging and worth pursuing. In this study, a generalized method is proposed for 3D printing structures made of low melting gallium‐based alloys with diverse melting points, which should greatly expand their applications. The mechanism for shaping liquid metal inks relies on the combination actions between electrocapillarity and oxidation, which significantly reduces the high surface tension as well provides solid frame for the inner liquid metals. Taken galinstan as an example, the printing conditions, including the viscosity of hydrogel, positive voltage (0–15 V), calcium chloride concentration, and velocity (the movement speed of the printing head) are explored to optimize the process. The printed galinstan is characterized to observe the morphology and elemental analysis of the surface oxide layer. During the process, the chemical reagents are all safe and non‐toxic, which is in line with the green product requirements. This printing method shall have broad application prospect in flexible electronics, biosensors, biomedical engineering, contrast agent in vivo, and other fields.