By Dr. Michael Cohen | cohenm@sonoma.edu
Replacing petroleum-based plastics with zero-carbon plastics will be essential for creating a sustainable society. Polylactate (PLA) bioplastic technically meets the non-toxic and biodegradable standards to be labeled “Compostable” but cannot currently be processed by most commercial composting facilities or in home compost piles due to its slow rate of degradation. In the Department of Biology, research begun this semester by undergraduate student Belle Ehrmantraut along with project supervisor Prof. Michael Cohen seeks to test the ability of photosynthetic microorganisms to initiate the degradation of PLA and thereby make it suitable for widescale composting.
The launching of this project has required a team effort. Project co-supervisor Prof. Joseph Lin constructed the system with funding from a School of Science and Technology Innovation and Strategic Priorities Award. Instructional Support Technician Stephanie Thibault provided invaluable assistance to the project in obtaining microbial strains and preparing growth media. The PLA for the experiments was kindly donated by Aseem Das of World Centric in Rohnert Park, which supplies Sonoma State Culinary Services with the containers, utensils, plates and cups that are used across campus. Recently, the research team was fortunate to secure assistance for composting experiments from John Kopshever of The Ranch at Sonoma Mountain, a new composting facility just down the street from Sonoma State at Petaluma Hill Rd. and East Railroad Ave. Monitoring of molecular transitions that occur in the PLA during various stages of the degradation process will be carried out by project collaborator Prof. Seiko Ito at Baika University, Japan.
The photosynthetic microorganisms cultivated in the system are known to release biopolymers having a variety of potential practical uses. Investigating the means to harvest and utilize these biopolymers is another important aspect of the project that will be conducted in collaboration with Dr. Nina Kamennaya at Ben-Gurion University of the Negev, Israel. The focus of this research will be to determine the potential of these biopolymers to remove heavy metals from contaminated waters. Prof. Cohen was recently awarded a fellowship by the Chinese Academy of Sciences to visit China over the next two summers to work with Drs. Xiofang Li and Likun Wang at the Center for Agricultural Resources Research on the development of biologically-based technologies for remediation of metal-contaminated environments.
The experimental system at Sonoma State is expected to operate for several years and will support both individual student research projects and classroom laboratories in Environmental Microbiology (BIOL 338) and General Bacteriology (BIOL 340) taught by Prof. Cohen.