Antibacterial activity of bryozoan-associated bacteria from Tulamben, Bali

Inappropriate use of antibiotics has led to the emergence of antibiotic-resistant bacteria, so additional sources of antibiotics are needed. There are around 6000 species of bryozoans, but only a few have been explored as natural products. Past studies have shown that bryozoans may have anticancer, antibacterial, antileukaemia, antiparasitic, and antimalarial capacities. To determine potential antibacterial activity from bryozoan-associated bacteria, five different bryozoans were collected from Batuniti slope, Tulamben area, Bali, Indonesia. A total of 47 actinobacteria isolates from different agar were tested against seven pathogenic multidrug resistant (MDR) bacteria. Results from antibacterial assays show four different associated isolates that have the potential to inhibit pathogenic bacteria (strong to weak inhibition grades). Isolates such as Bacillus paralicheniformis , Staphylococcus cohnii , Kocuria palustris , and Oceanobacillus iheyensis were identified through 16S rRNA barcoding. In previous studies, these isolates had not been found in bryozoan-associated bacteria, therefore, this study revealed new findings of a potential antibacterial agent from bryozoan microorganisms.