Unlocking efficient polyhydroxyalkanoate production by Gram-positive Priestia megaterium using waste-derived...

Area of Science:

• Biotechnology
• Polymer Science
• Microbiology

Background:

• Polyhydroxyalkanoates (PHA) are biodegradable and biocompatible polymers, offering sustainable alternatives to conventional plastics.
• Current PHA production is often limited by Gram-negative bacterial strains that produce endotoxins, restricting biomedical use.
• High production costs, particularly feedstock expenses, hinder the industrial-scale manufacturing of PHA.

Purpose of the Study:

• To isolate and evaluate a Gram-positive bacterial strain for efficient and cost-effective polyhydroxyalkanoate (PHA) production.
• To assess the utilization of waste-derived feedstocks for enhanced PHA yield and economic viability.
• To characterize the produced PHA and elucidate the metabolic pathways involved in its synthesis.

Main Methods:

• Isolation and screening of a novel Gram-positive bacterial strain (GM-4).
• Cultivation of GM-4 using glucose, sugarcane molasses, and corn steep liquor.
• Biomass and PHA quantification, material property characterization, and whole-genome analysis.

Main Results:

• Strain GM-4 achieved high dry cell weight (5.4 g/L) and PHA content (63%) using glucose.
• Efficient utilization of sugarcane molasses and corn steep liquor yielded 13.60 g/L DCW and 9.84 g/L PHA.
• The combination of waste feedstocks significantly boosted biomass growth (2.6-fold) and PHA production (3.1-fold).

Conclusions:

• The Gram-positive strain GM-4 demonstrates significant potential for the sustainable and cost-effective industrial production of polyhydroxyalkanoates.
• Utilization of waste-derived feedstocks like sugarcane molasses and corn steep liquor enhances PHA yield and offers economic and environmental advantages.
• The produced polyhydroxybutyrate exhibits excellent material properties, making it suitable for diverse applications, including biomedical fields.