Akademik Veri Yönetim Sistemi
Bioprocess and Biosystems Engineering, 2026 (SCI-Expanded, Scopus)
Microorganisms, especially their co-cultures, that can degrade pollutants in non-sterile wastewater without requiring external nutrient supplementation, are important for sustainable wastewater treatment practices. This study aimed to (1) perform biodegradation of triclosan (TCS) using co-culture of locally isolated Bacillus licheniformis AEM2 (GenBank: PQ856279) and Lysinibacillus fusiformis AEM5 (GenBank: PQ856280), (2) analyze degradation byproducts and biodegradation pathway of TCS, (3) examine in vitro cytotoxicity of degradation byproducts, and (4) develop a non-sterile culture process for TCS biodegradation. In mono-culture strategy, TCS-containing mineral salt broth medium (MSBM) was inoculated with 1 mL of preculture of either AEM2 or AEM5. In co-culture strategy, two bacteria were simultaneously inoculated into the culture media at the different inoculum volumes (between 0.25, 0.50, and 0.75 mL/100 mL for each bacterium, with a total inoculum volume of 1 mL). The co-culture C (0.25 mL of AEM2 pre-culture + 0.75 mL of AEM5 pre-culture) (80.62% degradation efficiency) exhibited higher TCS degradation potential than mono-cultures and other co-culture formulations (p < 0.05). Under the optimized culture conditions (initial pH 7.0, temperature 25 °C and incubation time 72 h), the co-culture C achieved complete degradation (100%) of 10 mg/L TCS in MSBM. The main degradation products were low-chlorinated or chlorine-free phenolic intermediates. Oxygenases and dehalogenases were predicted to be responsible for biodegradation of TCS. In contrast to the parent compound TCS, its degradation products did not cause a statistically significant cell toxicity within the concentration range of 5–80 µg/mL (p > 0.05). The co-culture C could degrade 88.55% of 10 mg/L TCS within 72 h in non-sterile wastewater, which no external nutrients were added. To the best of our knowledge, this study investigates for the first time the TCS biodegradation potential of B. licheniformis and L. fusiformis, and evaluates the effectiveness of a non-sterile, bacteria-based co-culture system for TCS remediation.