Sustainable Removal of Phenol using Bacillus Tequilensis Immobilized in Alginate: Influence of Biomass and Exposure Time

Abstract

The impact of phenol on natural environments is a critical environmental issue due to its high toxicity and recalcitrance. Therefore, the search for new alternatives for phenol removal involves adopting sustainable and safe strategies. The objective of this research was to determine phenol removal efficiency at different treatment times and biomass concentrations using Bacillus tequilensis immobilized in alginate, isolated from soils of the Lomas del Cerro Campana, Peru—an ecosystem that has never been explored for its microbiological resources in bioremediation. The isolated microbial culture was taxonomically identified through molecular analysis of the 16S rRNA gene, and its tolerance to phenol (100–2000 ppm) was evaluated. For the phenol removal assays, cells were immobilized in 3% sodium alginate at different cell density concentrations (OD₆₀₀ = 0.5, 1.0, and 1.5) and exposed for 3, 5, and 7 days. A multilevel factorial experimental design was applied at 30 °C, 150 rpm, and an initial pH of 7. Bacillus tequilensis QCM11 exhibited tolerance up to 1000 ppm of phenol and achieved 28.58 ± 1.99 % phenol removal at an OD₆₀₀ of 0.5 under immobilized conditions. These results confirm its potential as a sustainable biotechnological alternative for optimizing phenol bioremediation applications.