Project 7. Enzymatic Degradation of biomaterials by Neurospora. (D. Salas, Chemistry, K. Lee, Biology)

Background. Cellulose is a naturally occurring polymer, widely considered to be the most abundant organic molecule on Earth but difficult to degrade. However, many fungi have enzymatically degrade cellulose to glucose monomers: The first step is to separate the microfibrils ([1]) and form single 1,4-?-D-glucan chains; In the second step, the fungus secretes ?(1,4)-D-glucan cellobiohydrolase to cleave the single cellulose chains into cellobiose; Finally, the cellobiose is absorbed into the fungal hyphae [2]. This process has been well documented across many different fungi, such as Saccharomyces cervisiae (Baker’s Yeast), Aspergillus niger (black mold), and Penicillium chrysogenum (source of penicillin) [3].  Neurospora is a genus within this phylum including Neurospora discrete, which is the deepest branching species within the genus [4,5]. There is little published information on the catabolic enzymes N. discreta uses to degrade cellulose. It is believed that this organism uses similar enzymes, although they may have slightly different primary structures.

Research. We attempted to confirm that N. discreta hydrolyzes biomaterials in a similar manner as other fungi using a structure-property and biological approach. The structure property will be analyzed using ATR-FTIR, TgA and SEM analysis. We will focus in understanding the diffusive path taken by the various enzymes to degrade the biomaterial. Preliminary data suggest that N. discreta creates a gradient as it decomposes avicel. While it is difficult to isolate the various catabolic, the data indicate an increased concentration of cellobiose and glucose near mycelia and more avicel near the center.

Student activities. The student will work Dr Lee and Dr Salas labs. First, the student will synthesize and blend the biomaterial components using ionic liquids at different percent composition and ionic. Upon coagulation, the biomaterials will be dried and crunched. To confirm that N. discreta uses similar catabolic processes, the specific strain of fungus will be selected. The student will then grow the fungus on the substrate, confirm the mycelia formation and perform film preparation using flash freezing technique. Upon completion, the student will analyze each sample using FT-IR and TgA. The SEM data will be collected by a qualified undergraduate or graduate student.