Author Date

2020-12-07

Degree Name

Department

Physiology and Developmental Biology

College

Life Sciences

Defense Date

2020-12-14

Publication Date

2020-12-18

First Faculty Advisor

Dr. Jaron Hansen

First Faculty Reader

Dr. Zach Aanderud

Honors Coordinator

Dr. Roy Silcox

Keywords

Anaerobic digestion, caldicellulosiruptor bescii, biodegradability, pretreatment, biomass, methane

Abstract

The biogas output efficiency of controlled anaerobic digestion (AD) can be enhanced by several different pretreatment methods to produce renewable energy. According to the literature, there are pros and cons to each pretreatment method. Biological pretreatment provides environmentally safe and renewable means for enhancing biodegradability and net energy output. Current research has yet to reliably demonstrate the ability of bacterial strains, such as Caldicellulosiruptor bescii (C. bescii), to digest common waste substrates in efficient ways. Novel methods in key intermediate molecular quantification and alkalinity tracking are used here to explore C. bescii’s ability to digest lignocellulosic material in dairy manure. High-Pressure Liquid Chromatography (HPLC) and colorimetric titration are used to track acetate and lactate as well as total solubilized basic components. Acetate and lactate are key precursors to enhanced production of methane gas. HPLC aided tests revealed significant millimolar increases in these molecular intermediates post pretreatment (~5-10mM). Patterns in alkalinity throughout the pretreatment and AD processes are set forth and supported by titration data to show minor decreases in alkalinity during pretreatment and subsequent increases during AD. The data suggest that C. bescii can efficiently digest this substrate and contribute in substantial ways to increases in net renewable energy output.