본 연구에서는 양식 붉바리 자치어 장내에서 어류 질병 미생물에 대한 항균활성을 가지고 있는 균을 분리하여 붉바리 probiotics로서의 개발 가능성을 알아보았다. 붉바리 자치어 장내에서 분리된 균들 중 다양한 수온, 염분, 항균력, 항생제 내성을 나타낸 12종을 candidate probiotic 균으로 선발하였다. 12종의 미생물은 16S rRNA gene sequence에 근거하여 G1 (Bacillus licheniformis strain DSM 13), G3 (Bacillus velezensis strain CBMB205), G15 (Brevibacterium frigoritolerans strain DSM 8801), G21 (Bacillus pumilus strain ATCC 7061), J2 (Paracoccus marcusii strain MH1), J7 (Micrococcus yunnanensis strain YIM65004), R8 (Micrococcus aloeverae strain AE-6), R13 (Bacillus tequilensis strain 10b), B1 (Lactobacillus paracasei strain R094), B2 (Lactococcus lactis strain NBRC1 00933), B3 (Lactobacillus plantarum strain JCM1149), B5 (Lactococcus lactis subsp. hordniae strain NBRC 100931)로 동정되었다. 선발된 12종의 장내 미생물은 in vitro 실험에서 어류 질병 미생물 및 항생제 감수성 실험에서 유의할 만한 효능을 가지고 있었다. 온도 및 염분 농도별 실험에서도 일정수를 유지하였으므로 양식 현장에서 사용이 긍정적으로 검토될 수 있음을 시사한다.
In this study, we aimed to explore the potential development of red seabream probiotics by isolating bacteria with antimicrobial activity against fish pathogens from the indigenous gut microbiota of farmed red seabream. Among the isolated strains from the indigenous gut microbiota of red seabream, 12 strains were selected as candidate probiotic bacteria based on their ability to withstand varying water temperatures, salinities, exhibit antimicrobial properties, and antibiotic resistance. These 12 strains were identified using the 16S rRNA gene sequence as follows: G1 (Bacillus licheniformis strain DSM 13), G3 (Bacillus velezensis strain CBMB205), G15 (Brevibacterium frigoritolerans strain DSM 8801), G21 (Bacillus pumilus strain ATCC 7061), J2 (Paracoccus marcusii strain MH1), J7 (Micrococcus yunnanensis strain YIM65004), R8 (Micrococcus aloeverae strain AE-6), R13 (Bacillus tequilensis strain 10b), B1 (Lactobacillus paracasei strain R094), B2 (Lactococcus lactis strain NBRC1 00933), B3 (Lactobacillus plantarum strain JCM1149), and B5 (Lactococcus lactis subsp. hordniae strain NBRC 100931). The selected 12 strains of gut microbiota exhibited significant efficacy in in vitro experiments against fish pathogenic microorganisms and demonstrated notable antibiotic susceptibility. The strains also maintained stability across experiments conducted under varying temperatures and salinities, suggesting their potential positive application in aquaculture settings.