Core-shell bio-gel microreactor for efficient hydrogen production through multi-bacterial synergistic catalysis

The acceleration of industrial processes has led to water bodies saturated with organic waste, prompting the need for efficient green energy solutions. Here, we designed a recyclable core–shell bio-gel reactor using Rhodopseudomonas palustris & CdS as the core and Escherichia coli & Fe₃O₄ as the shell. This stratified architecture enabled metabolic compartmentalization, reducing inter-strain competition and enhancing hydrogen production. Bio-formed CdS nanoparticles boosted the acetate and ethanol-to-hydrogen conversion rates of R. palustris by 1.3 and 3 times, respectively. Surface-modified Fe₃O₄ on E. coli allowed complete reactor recovery and improved light utilization. Metabolic coupling between the strains created a micro-autotrophic cycle, sustaining bacterial activity for long-term hydrogen production. The reactor achieved a glucose-to-hydrogen conversion rate of 4.27 mol·H₂·mol⁻¹·Glucose⁻¹, surpassing single-strain systems. This study presents a novel approach for efficient biohydrogen production and offers insights into chemically structured microbial communities.