SummaryPeroxisomes are thought to have played a key role in the evolution of metabolic networks of photosynthetic organisms by connecting oxidative and biosynthetic routes operating in different compartments. While the various oxidative pathways operating in the peroxisomes of higher plants are fairly well characterized, the reactions present in the primitive peroxisomes (microbodies) of algae are poorly understood. Screening of a Chlamydomonas insertional mutant library identified a strain strongly impaired in oil remobilization and defective in Cre05.g232002(CrACX2), a gene encoding a member of the acyl-CoA oxidase/dehydrogenase superfamily. The purified recombinant CrACX2 expressed in Escherichia coli catalyzed the oxidation of fatty acyl-CoAs into trans-2-enoyl-CoA and produced H 2 O 2 . This result demonstrated that CrACX2 is a genuine acyl-CoA oxidase, which is responsible for the first step of the peroxisomal fatty acid (FA) β-oxidation spiral. A fluorescent protein-tagging study pointed to a peroxisomal location of CrACX2. The importance of peroxisomal FA β-oxidation in algal physiology was shown by the impact of the mutation on FA turnover during day/night cycles. Moreover, under nitrogen depletion the mutant accumulated 20% more oil than the wild type, illustrating the potential of β-oxidation mutants for algal biotechnology. This study provides experimental evidence that a plant-type FA β-oxidation involving H 2 O 2 -producing acyl-CoA oxidation activity has already evolved in the microbodies of the unicellular green alga Chlamydomonas reinhardtii.

Efficient and earth‐abundant materials with multifunctional electrocatalytic properties within a wide range of pH are the new darlings for developing green energy conversion and storage techniques. A novel porous covalent phenanthroline framework (Fe‐Phen‐COFs) that involved Fe‐DMSO (dimethyl sulfoxide) coordination complexes is successfully synthesized using 3, 8‐dibromophenanthroline and 1, 3, 5‐benzenetriboronicacid trivalent alcohol ester as a rigid building block via Suzuki coupling reaction. Fe‐Phen‐COFs as the self‐carrier enriched with Fe, S, N, and C is pyrolyzed to produce N‐S‐codoping carbons with embedded core–shell Fe3C and FeS composite nanostructures (FeS/Fe3C@N‐S‐C). The FeS/Fe3C@N‐S‐C‐800 obtained by pyrolysis at 800 °C exhibits efficient trifunctional electrocatalytic activity for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) within a wide pH range. Impressively, the ORR half‐potential of FeS/Fe3C@N‐S‐C‐800 reaches 0.87 V in 0.1 m KOH, more positive than the previously reported Pt‐free electrocatalysts. It could be utilized as the advanced air electrode materials in zinc–air batteries, which exhibit an excellent power density and cycling stability superior to those of Pt/C‐based zinc–air battery. Thermal conversion of novel Fe‐Phen‐COFs provides an effective strategy to prepare high‐performance trifunctional electrocatalytic materials for the new‐generation powerful energy conversion technologies.