Genetic characterization of a novel Salinicola salarius isolate applied for the bioconversion of agro-industrial wastes into polyhydroxybutyrate

Shymaa A Abdelrahman ¹, Olfat S Barakat ², Marwa N Ahmed ²

⁰Department of Microbiology, Faculty of Agriculture, Cairo University, El-Gamaa Street, Giza, 12613, Egypt. Shymaa.a.abdelrahman@agr.cu.edu.eg.

Microbial Cell Factories +

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February 17, 2024

View abstract on PubMed

Summary

A novel Salinicola salarius strain, ES021, was identified as a robust producer of polyhydroxybutyrate (PHB), an eco-friendly plastic alternative. Optimized conditions and molasses feedstock significantly boosted PHB yield, demonstrating a sustainable production strategy.

Area Of Science

Microbiology and Biotechnology
Polymer Science
Environmental Science

Background

Polyhydroxybutyrate (PHB) offers a biodegradable alternative to conventional plastics.
Marine bacteria are increasingly explored for their potential in producing biopolymers.
Isolation and characterization of novel PHB-producing microorganisms are crucial for sustainable bioplastics.

Purpose Of The Study

To isolate and characterize a new halophilic bacterium, Salinicola salarius, as a polyhydroxybutyrate (PHB) producer.
To identify genes involved in PHB biosynthesis in the isolated strain through whole genome analysis.
To optimize fermentation conditions and utilize cost-effective substrates for enhanced PHB production.

Main Methods

Isolation and screening of marine bacteria from the New Suez Canal for PHB accumulation.
Whole genome sequencing and analysis to identify genes related to PHB synthesis (e.g., phaCAB, phaJ).
Optimization of environmental parameters (temperature, shaking rate) and carbon sources (molasses, whey).
Bioreactor cultivation for upscaling PHB production and characterization using FTIR, GC-MS, and NMR.

Main Results

Salinicola salarius ES021 strain exhibited the highest PHB accumulation among 17 isolates.
Key genes including fadA, fabG, P3W43_16340, phaJ, and fadB were identified for PHB production.
Optimal conditions (30°C, 110 rpm, 48h) and molasses feedstock (5% sucrose) yielded 13.34 g/L PHB.
Upscaled production in a 20 L bioreactor achieved a biomass of 25.12 g/L and PHB of 12.88 g/L.

Conclusions

Salinicola salarius ES021 is a potent natural producer of PHB from agro-industrial waste.
Genome analysis revealed potential genes governing PHB production pathways.
The study supports sustainable and cost-effective strategies for PHB bioplastic development.

Keywords:

Bioplastic FTIR GC–MS Polyhydroxybutyrate (PHB) Salinicola salaries