Biochemical methane potential of microalgae biomass using different microbial inocula.

Area of Science:

• Biotechnology
• Environmental Science
• Microbiology

Background:

• Microalgae biomass is a promising feedstock for bioenergy via anaerobic digestion (AD).
• Optimizing AD performance requires understanding the anaerobic microbiome's role.
• Current research often overlooks the microbiome when assessing methane yield.

Purpose of the Study:

• To correlate methane yield with specific anaerobic microbiome characteristics.
• To compare the efficacy of microalgae-adapted versus sewage sludge-adapted anaerobic inocula.
• To investigate the impact of digestion temperature on methane production.

Main Methods:

• Testing different anaerobic sludge sources (microalgae-adapted and sewage sludge-adapted).
• Analyzing the anaerobic microbiome composition.
• Measuring methane yield at various temperatures (psychrophilic, mesophilic, thermophilic).

Main Results:

• Sludge adapted to sewage sludge did not improve methane yield from microalgae.
• Microalgae-adapted sludge showed increased methane yield with higher digestion temperatures.
• Thermophilic digestion with microalgae-adapted sludge yielded significantly higher methane (up to 108.2 mL CH4 g COD-1).
• Specific microbial communities (Firmicutes, Proteobacteria, hydrogenotrophic methanogens) were identified in effective inocula.

Conclusions:

• Utilizing tailored anaerobic microbiomes can enhance methane yield from microalgae.
• This approach may reduce the need for pretreatment steps to improve biogas production.
• Microbiome adaptation is key for optimizing bioenergy recovery from microalgae.