The　effects　of　temperatures　(15-55　degrees　C)　on　the　alkaline　fermentation　of　sewage　sludge　were　investigated　in　semi-continuous　stirred　tank　reactors　(semi　-　CSTR)　at　the　pH　of　10.　The　highest　soluble　chemical　oxygen　demand　(SCOD)　yield　was　obtained　at　55　degrees　C　(764.2　mg/(gVS　L　d)),　while　the　highest　short　chain　fatty　acids　(SCFAs)　yield　was　observed　at　55　degrees　C　(319.8　mg/(gVS　L　d)),　1.5　times　higher　than　SCFAs　yield　at　55　degrees　C　(209.5　mg/(gVS　L　d)).　The　proportion　of　the　intercellular　organic　substances　being　transferred　to　the　slime　layer　of　sludge　flocs　increased　from　29%　at　15　degrees　C　to　54%　at　55　degrees　C.　But　only　a　small　part　of　soluble　organic　substances　in　the　slime　layers　was　converted　to　SCFAs　at　55　degrees　C.　The　dewaterability　of　sludge　was　better　at　35　degrees　C　than　that　at　55　degrees　C.　Microbiological　community　analysis　showed　the　acid-producing　microorganisms　at　the　medium　temperatures　(25　degrees　C　and　35　degrees　C)　were　more　diverse　and　abundant　than　those　at　the　low　(15　degrees　C)　and　high　temperatures　(55　degrees　C).　Clodtridium　and　Bacillus　in　Firmicutes　and　Gamma　proteobacterium　in　Proteobacteria　were　the　dominant　functional　bacterial　species　for　high　SCFA　accumulation.　(C)　2014　Published　by　Elsevier　Ltd.