The Co-Isolation of Lactic Acid Bacteria (LAB) and A Related Pathogenic Strain from Pangasius Nasutus

Authors : Nur Hannah Rashıdah HAJA MOHIDEEN, Nurul Sakinah ALİAS, Nur Nazifah MANSUR, Tengku Haziyamin TENGKU ABDUL HAMİD

Pages : 143-154

Doi:10.38001/ijlsb.1268388

View : 98 | Download : 90

Publication Date : 2023-08-15

Article Type : Research Paper

Abstract :Catfish species Pangasius nasutus, or locally known as Patin Buah is one of a popular aquaculture product in Malaysia. Probiotic strain is an attractive alternative to conventional antibiotics in managing aquaculture diseases. Pangasius can be a source of bacterial strain in developing suitable probiotic useful in Pangasius rearing. This study highlights on the isolation of LAB strains from the selected tissues from P. nasutus which are the heart, stomach, and intestines. These strains were subjected to morphological, biochemical, and genotypic characterisations. Three different strains were isolated from fish tissues, H-Hn from heart; S-Hn from stomach; and I-Sk from intestine. Biochemical characterisation were consistent with ribosomal rRNA sequencing, in which strain H-Hn insert ignore into journalissuearticles values(acc. No. MW504962); is highly similar insert ignore into journalissuearticles values(100%); to Lactococcus lactis, and both I-Sk insert ignore into journalissuearticles values(MW504964); and S-Hn insert ignore into journalissuearticles values(MW504963); are similar insert ignore into journalissuearticles values(99%); to Lactococcus garvieae. All strains appeared to be non-spore forming, non-motile, Gram-positive coccus, catalase and citrate negative, and fermenting sugar. Unlike H-Hn, both H-Sk and I-Sk strains were able to grow at 6.5% NaCl and at higher temperature insert ignore into journalissuearticles values(45°C);. The antimicrobial properties were assessed using agar disk diffusion assay against several indicator organisms insert ignore into journalissuearticles values(Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus and Vibrio parahaemolyticus);. These strains exhibited varying degree of inhibitory properties against the indicator organisms. Strain H-Hn inhibited E. coli and V. parahaemolyticus. Meanwhile, strains I-Sk and S-Hn showed a rather broad-spectrum inhibition. From P. nasutus, other L. lactis strain, a pathogenic species from L. garvieae could also be found especially in their gut tissues. The presence of L. garvieae in commercial P. nasutus should raise some concern to those who like to consume this fish. Meanwhile, the LAB strains isolated has probiotics potential that can be commercially used in the managing fish diseases in aquaculture.
Keywords : Pangasius nasutus, Lactococcus lactis, lactococcus garvieae, aquaculture probiotic