A new coumarin-based "OFF-ON" fluorescent sensor for HS detection in HeLa cells.

A new "OFF-ON" coumarin-based fluorescent probe for HS detection was designed and successfully developed through O-sulfonylation between a dabsyl quencher and 7-hydroxy-4-methylcoumarin as a fluorescent reporter, based on a FRET approach. This HS responsive probe, utilizing HS assisted thiolysis of a sulfonate ester as the sensing strategy, demonstrated excellent performance towards HS with a limit of detection (LoD) of 1.64 µM, along with superb selectivity, good stability and high specificity towards HS without interference from other biomarkers and analytes.

Cocultures of and Induce the Secretion of Bacteriocin-like Substances against .

Lactic acid bacteria (LAB) were screened from (red sea bass), and their antimicrobial activities were evaluated against two species isolated from the , namely, (AV) and (AJ). Three LAB isolates, MU8 (EF_8), MU2 (EFL_2), and MU9 (EFL_9), were found to inhibit both AV and AJ; however, their cell-free supernatant (CFS) did not do so. Interestingly, bacteriocin-like substances (BLS) induced by cocultures of EF_8 with AV exhibited the highest antimicrobial activity against both sp.