Nitrogen-containing　heterocycles　are　especially　considered　＇privileged＇　structural　scaffolds　for　the　development　of　new　drugs.　However,　traditional　methods　of　organic　synthesis　are　mainly　based　on　thermal　cycloaddition　reaction;　thus,　the　exploration　of　new　strategies　for　the　rapid　assembly　of　N-heterocycles　under　mild　conditions　is　highly　desirable.　Here,　we　developed　a　new　method　that　visible　light　along　with　1　mol　%　cercosporin,　which　is　one　of　the　perylenequinonoid　pigments　with　excellent　properties　of　photosensitization　and　can　be　easily　produced　by　a　new　isolated　endophytic　fungus　Cercospora　sp.　JNU001　strain　with　high　yield　through　microbial　fermentation,　catalyzes　the　synthesis　of　1,2,3-thiadiazoles　and　1,4,5,6-tetrahydropyridazines　by　a　photocatalytic　process　with　good　regioselectivity　and　broad　functional-group　compatibility　under　mild　conditions.　Thus,　a　bridge　between　microbial　fermentation　and　organic　photocatalysis　for　the　construction　of　nitrogen-containing　heterocycles　was　set　up　in　a　sustainable,　environmentally　friendly　manner.　©　2019　American　Chemical　Society.