AUTHOR=Faridy Nastaran , Torabi Ehssan , Pourbabaee Ahmad Ali , Osdaghi Ebrahim , Talebi Khalil 

TITLE=Efficacy of novel bacterial consortia in degrading fipronil and thiobencarb in paddy soil: a survey for community structure and metabolic pathways

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1366951

DOI=10.3389/fmicb.2024.1366951

ISSN=1664-302X

ABSTRACT=<sec id="sec1001"><title>Introduction</title><p>Fipronil (FIP) and thiobencarb (THIO) represent widely utilized pesticides in paddy fields, presenting environmental challenges that necessitate effective remediation approaches. Despite the recognized need, exploring bacterial consortia efficiently degrading FIP and THIO remains limited.</p></sec><sec id="sec2001"><title>Methods</title><p>This study isolated three unique bacterial consortia—FD, TD, and MD—demonstrating the capability to degrade FIP, THIO, and an FIP + THIO mixture within a 10-day timeframe. Furthermore, the bioaugmentation abilities of the selected consortia were evaluated in paddy soils under various conditions.</p></sec><sec id="sec3001"><title>Results</title><p>Sequencing results shed light on the consortia’s composition, revealing a diverse bacterial population prominently featuring <italic>Azospirillum</italic>, <italic>Ochrobactrum</italic>, <italic>Sphingobium</italic>, and <italic>Sphingomonas</italic> genera. All consortia efficiently degraded pesticides at 800 µg/mL concentrations, primarily through oxidative and hydrolytic processes. This metabolic activity yields more hydrophilic metabolites, including 4-(Trifluoromethyl)-phenol and 1,4-Benzenediol, 2-methyl-, for FIP, and carbamothioic acid, diethyl-, S-ethyl ester, and Benzenecarbothioic acid, S-methyl ester for THIO. Soil bioaugmentation tests highlight the consortia’s effectiveness, showcasing accelerated degradation of FIP and THIO—individually or in a mixture—by 1.3 to 13-fold. These assessments encompass diverse soil moisture levels (20 and 100% <italic>v/v</italic>), pesticide concentrations (15 and 150 µg/g), and sterile conditions (sterile and non-sterile soils).</p></sec><sec id="sec4001"><title>Discussion</title><p>This study offers an understanding of bacterial communities adept at degrading FIP and THIO, introducing FD, TD, and MD consortia as promising contenders for bioremediation endeavors.</p></sec>