The Potential of Digested Sludge-Assimilating Microflora for Biogas Production from Food Processing Wastes

Area of Science:

• Biotechnology
• Environmental Science
• Microbiology

Background:

• Food processing wastes (FPWs) present a significant disposal challenge.
• Optimizing biogas production from FPWs requires careful selection and acclimatization of seed microflora.
• The composition of FPWs varies widely, necessitating adaptable microbial consortia.

Purpose of the Study:

• To evaluate the biogas production potential of digested sludge-assimilating and biogas-yielding soil (DABYS) and enteric (DABYE) microflorae.
• To assess the adaptability of these microflorae when used as seed cultures for diverse FPWs.
• To understand the microbial community shifts and metabolic activities during biogas production from FPWs.

Main Methods:

• Subculturing of DABYS and DABYE microflorae.
• Feeding subcultured microflorae with various types of FPWs (animal-derived, vegetable, fruit, crop).
• Analysis of biogas composition (methane, hydrogen) and microbial populations (methanogenic archaea).
• Enzyme activity assessment (cellulase, pectinase, protease).

Main Results:

• Subcultured microflorae successfully produced biogas from most FPWs, with notable exceptions like orange peel.
• Microflorae utilizing animal-derived FPWs showed significant methanogenic archaeal populations and methane production.
• Microflorae fed with plant-derived FPWs produced hydrogen, with diminished methanogenic archaea after repeated subculturing.
• Evidence suggests hydrolysis of carbohydrates and proteins in FPWs by microbial enzymes.

Conclusions:

• DABYS and DABYE microflorae exhibit robust adaptability to a wide range of FPWs.
• The heterogeneity of seed microflora contributes to rapid adaptation to different waste streams.
• While promising for waste valorization, further enhancements are needed for industrial-scale biogas yield.