Response surface method for polyhydroxybutyrate (PHB) bioplastic accumulation in Bacillus drentensis BP17 using...

Area of Science:

• Biotechnology and Industrial Microbiology
• Polymer Science
• Sustainable Materials

Background:

• Polyhydroxybutyrate (PHB) is a valuable biodegradable biopolymer with diverse applications in packaging, medicine, and coatings.
• Efficient and cost-effective production of PHB is crucial for its widespread adoption.
• Agricultural waste presents an underutilized resource for sustainable biopolymer synthesis.

Purpose of the Study:

• To isolate and identify a bacterial strain capable of high polyhydroxybutyrate (PHB) production.
• To optimize fermentation conditions for maximizing PHB yield using response surface methodology (RSM).
• To characterize the properties of PHB produced by the selected bacterial strain.

Main Methods:

• Isolation and taxonomic identification of an endospore-forming bacterium (Bacillus drentensis strain BP17) from composted soil.
• Optimization of culture conditions (pineapple peel solution, TSB concentration, pH, inoculum size, temperature, and time) using RSM with a central composite rotatable design (CCRD).
• Characterization of PHB molecular weight, polydispersity, thermal stability, melting point, and degradation temperature.

Main Results:

• Bacillus drentensis strain BP17 was identified as a high PHB producer.
• Optimized fermentation conditions significantly increased PHB yield to 5.55 g/L from 0.17 g/L under non-optimized conditions.
• The produced PHB exhibited a molecular weight of 1.15x10^5 Da, a melting temperature of 172°C, and a degradation temperature of 228°C.

Conclusions:

• Bacillus drentensis strain BP17 is a promising candidate for the industrial production of polyhydroxybutyrate (PHB).
• Pineapple peel can serve as a cost-effective carbon source for PHB synthesis, promoting the utilization of agricultural waste.
• Optimized fermentation processes are key to achieving high yields of PHB for sustainable applications.