Production of Polyhydroxyalkanoates (PHA) by Probiotic Bacteria Bacillus tequilensis for Potentially Used as Drug Carrier

Introduction: Polyhydroxyalkanoate (PHA) is a biopolymer that can be produced by microorganisms from numerous low-cost carbon sources, making it an environmentally friendly material. This study was designed to utilize different food waste (household food waste, spent oils and spent coffee grounds) as nutrient source for the cultivation of microbes to produce polyhydroxyalkanoate (PHA). Methods: The bacterial strain Bacillus tequilensis was grown in 250 mL Erlenmeyer flask each containing 50 mL of mineral salt medium, 25 ml of nutrient broth inoculum and 20 g/L of household food waste, spent ground coffee and spent oils, respectively. The initial pH of the media was 7.0 and the cultured bacteria was incubated at 30 °C, 180 rpm for 72 h as a batch culture. The sample was then extracted and weight, and further analyzed using Fourier Transform Infrared Spectroscopy (FTIR) and High Performance Liquid Chromatography (HPLC). Results: B. tequilensis yielded PHA of 7 % to 8 % (g PHA/g dry cell weight) on average using medium containing household food waste, spent ground coffee and spent oils. FTIR analysis showed the peaks range between 1750-1730 cm-1 which belong to PHA functional groups such as C=O. HPLC chromatogram revealed that the retention time obtained from digested PHA was approximately 4.5 min which was similar to the standard of PHA. Conclusion: This enables the utilization of low-cost waste by probiotic B. tequilensis as a carbon source for the sustainable production of biodegradable PHA for a wide range of applications in medicine.