Lyophilization and Preservation Techniques for Extended Storage of Terephthalic acid Degrading Pseudomonas sp: Procedural Steps and Protective Agents

The uncontrolled release of industrial waste into nature leads to increased environmental pollution, posing serious threats to ecosystem balance. Terephthalic acid (TA) is a fundamental component used in the production of polyethylene terephthalate (PET), which finds applications in a wide range of industrial products, including plastic bottles, polyester fibers, and packaging materials. Effectively removing TA from wastewater systems can be achieved through various biotechnological methods. In this context, bioremediation bacteria play a critical role in environmental protection by providing sustainable solutions for wastewater management. The aim of this study is to investigate the effects of different protective and lyophilization methods on the biodegradation activity and bacterial viability of Pseudomonas sp. over specific storage periods. Various cryoprotectant agents (CPAs), including skim milk, sucrose, silica gel, and nutrient broth, were tested in different concentrations and combinations to improve storage conditions. Furthermore, optimization of freeze-drying (FD) and liquid drying (SD) techniques was conducted. The lyophilized products were evaluated for their ability to degrade TA and for microorganism viability after 1, 15, and 30 weeks. Results indicated that the highest viability after 30 weeks was observed in samples treated with skim milk. Additionally, the freeze-drying method demonstrated superior performance compared to liquid-drying method for all cryoprotectant types.