Co-culture　of　microalgae　and　bacteria　is　a　promising　method　for　wastewater　treatment.　The　suitable　selection　of　the　bacteria　in　co-cultures　with　microalgae　is　critical　for　wastewater　treatment.　Three　bacteria,　Exiguobacterium　aurantiacum,　Stenotrophomonas　acidaminiphila,　and　Chryseobacterium　scophthalmus,　were　the　dominant　bacterial　species　in　fermentation　wastewater　treated　by　microalgae　and　activated　sludge.　Pure　cultures　and　co-cultures　of　microalgae　(Chlorella　sorokiniana　L3)　and　these　bacteria　were　evaluated　for　the　treatment　of　fermentation　wastewater,　which　contains　high　concentrations　of　acetate　acid,　butyric　acid,　ethanol　and　butanol.　The　performance　of　the　co-cultures　was　better　than　that　of　pure　cultures　of　microalgae　or　bacteria　for　the　removal　of　four　organic　compounds,　and　the　removal　efficiency　of　volatile　fatty　acids　and　alcohols　in　the　best　co-culture　case　was　increased　by　22.70%　compared　to　that　of　pure　cultures.　Butanol　and　butyric　acid　were　much　more　difficult　for　microalgae　and　bacteria　to　remove　than　were　acetic　acid　and　ethanol.　The　co-cultures　of　Chlorella　sorokiniana　L3　with　Stenotrophomonas　acidaminiphila　or　Chryseobacterium　scophthalmus　had　the　highest　removal　efficiencies　for　the　four　organic　compounds　in　all　treatments.　The　co-cultures　of　Chlorella　sorokiniana　L3　with　Exiguobacterium　aurantiacum,　Stenotrophomonas　acidaminiphila　or　Chryseobacterium　scophthalmus　promoted　not　only　chlorophyll　a　+　b　production　but　also　biomass　accumulation　of　Chlorella　sorokiniana　L3　during　the　3　days　of　cultivation　compared　with　those　in　pure　cultures.　More　than　77.8%　of　NH4+-N,　45.6%　of　total　PO43--P　and　63.7%　of　COD　(chemical　oxygen　demand)　were　removed　in　all　co-cultures.　These　three　bacteria　are　potential　candidates　for　wastewater　treatment　through　co-culture　with　microalgae.