This study aimed to isolate and identify marine fungi from Bai Tu Long Bay and assess their antimicrobial potential. We successfully isolated twenty strains of marine-derived fungi. The crude extracts from these fungi were tested against pathogenic microorganisms. All twenty strains exhibit some degree of growth inhibition against the tested microorganisms. | Vietnam Journal of Marine Science and Technology 2024 24 1 89 97 Vietnam Academy of Science and Technology Vietnam Journal of Marine Science and Technology journal homepage jmst Antimicrobial activity assessment of crude broth fermented extracts of marine- derived fungi collected from Bai Tu Long Bay North Vietnam Nguyen Thi Hoang Anh1 2 Vu Thi Thu Huyen1 Nguyen Mai Anh1 Doan Thi Mai Huong1 Pham Van Cuong1 Dam Thanh Xuan3 Cao Duc Tuan4 Le Thi Hong Minh1 1 Institute of Marine Biochemistry VAST Vietnam 2 Thai Binh Medical College Thai Binh Vietnam 3 Hanoi University of Pharmacy Hanoi Vietnam 4 Hai Phong University of Medicine and Pharmacy Hai Phong Vietnam Received 22 August 2023 Accepted 23 December 2023 ABSTRACT This study aimed to isolate and identify marine fungi from Bai Tu Long Bay and assess their antimicrobial potential. We successfully isolated twenty strains of marine-derived fungi. The crude extracts from these fungi were tested against pathogenic microorganisms. All twenty strains exhibit some degree of growth inhibition against the tested microorganisms. Notably strains M223 M250 M253 and M256 showed significant antimicrobial activity with MIC values equal to or lower than the positive control. These results highlight the potential of marine fungi as a rich source of antimicrobial agents a finding of considerable importance to marine mycology and pharmaceuticals. Further analysis was conducted on four promising isolates. M253 was identified as Hamigera avellanea while M223 M250 and M256 were found to belong to the Aspergillus genus. These isolates were then analyzed using a phylogenetic tree based on MegaX software. Keywords Aspergillus Antimicrobial activity MIC Marine fungi Hamigera avellanea. Corresponding author at Institute of Marine Biochemistry 18 Hoang Quoc Viet Cau Giay Hanoi Vietnam. E-mail addresses huyenvuibt@ lhminhbk@ https 1859-3097 18868 ISSN 1859-3097 e-ISSN 2815-5904 2024 Vietnam .
