Potential of Antarctic lipase from Acinetobacter johnsonii Ant12 for treatment of lipid-rich wastewater: screening, production, properties and applications

Abstract

The present study aimed to screen and optimize lipase production by the Antarctic strain Acinetobacter johnsonii Ant12 for lipid-rich wastewater treatment. Lipase production was successfully enhanced threefold through optimization of culture conditions. The optimum crude lipase activity was observed at 50 °C with high stability in a wide temperature range. The lipase also exhibited high activity and stability in the presence of solvents, metal ions, and surfactants. The crude lipase was used for the treatment of lipid-rich wastewater, which poses a significant challenge, as traditional removal methods are often inefficient or non-eco-friendly. In this study, bioaugmentation with Ant12 resulted in substantial lipid reduction in synthetic as well as real-world wastewater. Multiple linear regression analysis showed that lipid concentration and time were the most significant factors influencing lipid degradation. Bioaugmentation of real-world wastewater with Ant12 cells resulted in 84% removal of lipids in 72 h, while its crude lipase degraded 73.7% of lipids after 24 h. Thus, the specific rate of lipid degradation was higher for crude lipase (0.095/h) than the whole cell treatment (0.031/h). Economic analysis revealed that crude lipase production was much cheaper, faster and more eco-friendly than purified or partially purified lipase production, which justifies its use in wastewater treatment. The high activity of enzyme also implicates its application as a detergent additive. In our knowledge, it is the first study to establish A. johnsonii isolate from Antarctica for lipid-rich wastewater treatment.