To　construct　a　heterotrophic　axenic　system　of　Chlorella　sorokiniana　FZU60,　the　symbiotic　bacteria　were　isolated　and　identified,　and　the　effects　of　eight　common　antibiotics　(cefotaxime,　kanamycin,　neomycin,　ampicillin,　streptomycin,　tetracycline,　chloramphenicol,　and　erythromycin)　on　the　cell　growth　of　symbiotic　bacteria　and　C.　sorokiniana　FZU60　were　investigated.　Results　showed　that　the　main　symbiotic　bacteria　were　Bacillus　(78.76%)　and　Methylobacterium　(3.14%).　Besides,　10　mg/L　cefotaxime,　10　mg/L　tetracycline,　100　mg/L　kanamycin,　and　100　mg/L　erythromycin　showed　excellent　inhibitory　effect　on　these　two　symbiotic　bacteria　but　no　obvious　effect　on　the　cell　growth　of　C.　sorokiniana　FZU60.　Based　on　the　above-mentioned　results,　the　inhibition　effect　of　different　antibiotic　combinations　on　symbiotic　bacteria　of　C.　sorokiniana　FZU60　was　further　investigated.　It　was　found　that　the　heterotrophic　axenic　system　could　be　successfully　constructed　by　using　the　combination　of　10　mg/L　cefotaxime,　10　mg/L　tetracycline,　and　100　mg/L　kanamycin.　Moreover,　C.　sorokiniana　FZU60　could　maintain　stable　and　axenic　growth　after　three　generations.　The　experimental　results　would　provide　theoretical　reference　and　experimental　basis　for　the　preparation　of　axenic　microalgal　seed　for　high-cell-density　heterotrophic　cultivation　of　C.　sorokiniana.　©　2023　Science　and　Technology　of　Food　Industry.　All　rights　reserved.