Phthalic Acid Ester Degradation by the Synergistic Consortium of Bacillus infantis, Atlantibacter hermannii, Bacillus subtilis and Stutzerimonas stutzeri: A Sustainable Approach for Environment Cleanup

Abstract

Phthalic Acid Esters (PAEs) are persistent pollutant and endocrine disruptors used as plasticizers. As these phthalates are not covalently bounded to its matrix, they are leached out from the plastic matrix. These leached out phthalates causes pollution of water, and soil. This study aims to evaluate the synergistic degradation efficiency of a novel four-member bacterial consortium, JPN, against Dibutyl Phthalate (DBP) and Benzyl Butyl Phthalate (BBP). It also addresses the limitations of narrow substrate specificity in existing microbial strains. Consortium JPN comprises of Bacillus infantis, Atlantibacter hermannii, Bacillus subtilis and Stutzerimonas stutzeri which were isolated from plastic-contaminated sites. Optimization was conducted using the One-Factor-at-a-Time (OFAT) method, followed by statistical validation using Box-Behnken Design (BBD). Degradation was measured and validated through High-Performance Liquid Chromatography (HPLC) and Fourier Transform Infrared Spectroscopy (FTIR). Statistical analysis confirmed that the model is significant. Optimal conditions were identified as pH 8.0, temperature 25 °C, and a 10% (v/v) inoculum size. Under these parameters, consortium JPN demonstrated exceptional metabolic adaptability by achieving 99% degradation efficiency for both DBP and BBP within a rapid 24 h. incubation period. Unlike typical isolates restricted to either low or high molecular weight derivatives, consortium JPN can effectively overcome structural resistance in diverse phthalates. These findings highlights that these newly identified strains are rapid and potential for bioremediation of endocrine disruptors in contaminated ecosystems.