Effect of triclosan on phosphate solubilising bacteria in mangrove ecosystem: In-vitro and In-vivo

Triclosan (TCS) is a widely used biocide found in medicinal, household, and personal care products, frequently detected in various environmental matrices, posing significant threats to microbial communities and overall ecosystem functioning. This study evaluates the in vivo and in vitro effects of triclosan (TCS) on phosphate-solubilising bacteria (PSB) in mangrove ecosystems. Two experimental approaches were employed: a microcosm ( in vivo ) study and a laboratory (in vitro) analysis. Five isolated PSB strains— Sphingomonas paucimobilis , Rhizobium radiobacter , Serratia ficaria , Klebsiella oxytoca , and Klebsiella pneumoniae —were selected from the mangrove ecosystem for investigation. The minimum inhibitory concentration (MIC) results revealed that Klebsiella pneumoniae exhibited the highest resistance to TCS among the tested strains. In vivo experiments demonstrated a significant reduction in soil-available phosphorus and enzymatic activities, including acid and alkaline phosphatase, dehydrogenase, and fluorescein diacetate (FDA) activity, in TCS-exposed samples throughout the exposure period. In vitro results showed that phosphate solubilisation decreased significantly with increasing TCS concentrations in all strains except Klebsiella pneumoniae . Overall, TCS effectively inhibited the growth of PSB in mangrove ecosystems. This study is the first to report the impact of TCS on PSB in mangroves and provides valuable data for future research on microbial communities in such environments. • Five bacterial strains identified and characterized as PSB from mangrove ecosystem. • Klebsiella pneumoniae was most resistant to triclosan. • In-vivo triclosan exposure inhibited soil enzymes ALP, dehydrogenase and FDA. • Triclosan inhibited phosphate solubilization activity in-vitro.