Researcher(s)
- Ryan Kim, Environmental Engineering, University of Delaware
Faculty Mentor(s)
- Daniel Cha, Civil and Environmental Engineering, University of Delaware
Abstract
Bioplastics made from polyhydroxyalkanoates (PHAs) are biodegradable and can potentially be sourced from organic waste. While environmentally friendly in usage, sustainable production of these bioplastics is held back by chemicals needed for sterilization and PHA extraction and recovery. The goal of this study is to evaluate the potential use of halophilic microorganisms for sustainable production of PHA based bioplastics. The study hypothesizes that PHA producing halophilic cultures will not require sterilization in a high saline media, nor will they require solvents to extract and gather PHA granules.
Out of 96 strains of bacteria isolated from concrete samples, 10 halophiles were identified based on higher growth rates in high saline growth media ranging between 1% to 10% NaCl (w/v). Halophiles were streaked onto agar plates, then colonies on agar plates were transferred to liquid cultures (10% NaCl growth media). Once sufficient growth was observed, liquid cultures were centrifuged and the cells were transferred to 10% NaCl low nutrient media intended for PHA accumulation. Bacteria samples will then be stained with lipid-specific dyes (e.g., Sudan Black B), and observed under microscope for the presence of PHA granules. Halophilic cultures identified to have accumulated PHAs will be evaluated for osmotic pressure induced lysis and the release of the PHA granules in fresh water without the presence of solvents.