Shift in methanogenic community in protein degradation using different inocula

Su In Kim; Chayanee Chairattanawat; Eunji Kim; Seokhwan Hwang

doi:10.1016/j.biortech.2021.125145

Shift in methanogenic community in protein degradation using different inocula

Bioresour Technol. 2021 Aug:333:125145. doi: 10.1016/j.biortech.2021.125145. Epub 2021 Apr 15.

Authors

Su In Kim¹, Chayanee Chairattanawat¹, Eunji Kim¹, Seokhwan Hwang²

Affiliations

¹ Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Republic of Korea.
² Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Republic of Korea. Electronic address: shwang@postech.ac.kr.

PMID: 33906017
DOI: 10.1016/j.biortech.2021.125145

Abstract

Anaerobic digestion (AD) of protein-rich wastes is problematic due to production of ammonia and hydrogen sulfide. In this work, eight inocula were used in batch AD of solutions of gelatin and gluten at 3 g COD substrate/1g VSS inoculum. AD plants from which inocula originated were treating food waste or food wastewater, wastewater sludge, or a combination of them. Inocula were evaluated by fitting methane production data using the modified Gompertz model. Sequencing of 16 s rRNA of microorganisms showed that Methanoculleus was dominant in inocula from plants that were treating food waste, and Methanosaeta was dominant in the others. The maximum methane production rate varied by a factor of three for each substrate: 2.734-7.438 mLCH₄ gCOD^-1 d^-1 for gelatin, and 1.950 to 5.532 mLCH₄ gCOD^-1 d^-1 for gluten. This study demonstrates that inoculum must be chosen appropriately when treating proteinaceous waste by AD.

Keywords: Anaerobic digestion; Inoculum; Methanogen population; Protein.

MeSH terms

Anaerobiosis
Bioreactors*
Food
Methane
Proteolysis
Refuse Disposal*
Sewage

Substances

Sewage
Methane