Application Of Two Different Fungal Species For Biological Pretreatment In An Integrated Lignocellulosic Biofuels Paradigm

Open Access
Author:
Maher, Taylor Jacob
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Wayne Roger Curtis, Thesis Supervisor
  • Wayne Roger Curtis, Honors Advisor
  • Michael John Janik, Faculty Reader
Keywords:
  • Biofuels
  • Lignocellulose
  • Fungus
  • Pretreatment
  • Chemical Engineering
Abstract:
The push for a replacement of fossil fuels with renewable energy sources has stimulated research in the area of liquid biofuels. Lignocellulosic biofuels are considered “second-generation” and would improve upon current liquid biofuel technologies, the majority of which create competition between food and fuel. In order to achieve sufficient production levels, pretreatment of the lignocellulosic material is necessary. Fungal pretreatment by white-rot fungi has been recognized as a possible alternative to expensive, energy intensive pretreatments such as steam hydrolysis. Two white-rot fungi, Phanerochaete chrysosporium and Ceriporiopsis subvermispora, are examined in this study for their potential use as a fungal pretreatment prior to a consortium mediated bioprocess, which is achieved by a bacteria and yeast co-culture. In this study, preliminary growth observations were made for the two fungi that give relevant insight into the complications that may arise in trying to effectively compare their performance as a pretreatment. Although growth was accomplished for both of these organisms, the growth rate of each one is different depending on the substrate. A method was developed to prepare fungal degraded samples for Sum-frequency Generation (SFG) but it is suggested that this method be further developed for future analyses. Preliminary data is difficult to interpret without acquiring more quantitative information about lignin and cellulose degradation. Also, preliminary efforts were made at obtaining carbon, nitrogen, and energy balance information surrounding the pretreatment by each of these different species of white-rot fungi. Results showed the optimal growth of P.chrysosporium led to a shift of 10% of the nitrogen from biomass into chitin, a shift that could potentially make this nitrogen accessible for C. phytofermentans, the bacteria of interest in the consortium bioprocess. Based on this work it appears that with improvements in fungal culturing, a large scale biomass conversion process that utilizes fungal pretreatment may be a viable alternative that is compatible with a fully integrated biofuel production paradigm.