The isolation of the fungus was carried out using an indirect isolation method. After surface sterilization with 70% EtOH for 15s; the root of mangrove plant S. caseolaris was rinsed in sterile water. The fungus Campylocarpon sp. HDN13-307 was cultured under static conditions at 28 ℃ in 1000 mL Erlenmeyer flasks containing 300 mL liquid medium containing maltose (2%), mannitol (2%), glucose (1%), sodium glutamate (1%), yeast extract (0.3%), corn syrup (0.1%), KH₂PO₄ (0.05%), and MgSO₄.7H₂O (0.03%) dissolved in naturally collected seawater (Huiquan Bay, Yellow Sea, Qiangdao, China). After 30 days of cultivation, the whole broth (40 L) was filtered through cheesecloth to separate into supernatant and mycelia.