(201y) Fabrication of a Microwell Array for High Throughput Screening and Discovery of Bacterial Interactions

Authors: 
McGinley, L., Kansas State University
Barua, N., Kansas State University
Hansen, R., Kansas State University
Understanding how different types of rhizobacteria interact with each other will allow for the development of synthetic blends of bacteria that can be used as sustainable biofertilizers and biocontrol agents. These bio-based strategies have the potential for lower environmental impact, are less expensive, and are more sustainable over the long-term than current methods. However, our current capability to implement these bio-based strategies is highly limited, largely because most bacterial interactions are unknown. The overall goal of this work looks to develop a novel, lab-on-a-chip device that will help the microbiologist discover unknown bacterial interactions that occur within these systems. Current microbiology tools are limited in that they are low throughput and can only observe interactions between large colonies. With this tool, interactions between thousands of unique bacterial species can be studied simultaneously. The silicon microwells are fabricated with a thin layer of parylene and etched with a photoresist. Arrays were originally only compatible with anaerobic organisms, as the bacteria were trapped between the arrays and a glass coverslip. This set up limited the oxygen supply to bacteria, inhibiting the growth and interactions between aerobic organisms. PDMS coverslips were developed to replace the glass, which promoted the diffusion of oxygen to bacteria. This advancement allows for device compatibility with aerobic organisms, greatly expanding the number of organisms this tool can screen for. Surface treatments, such as WGA or BSA, are used to functionalize the microwell array to further promote bacteria adhesion, growth, and interaction. The newly developed tool will have major impacts on the ways that microbiologists study bacterial interactions in any microbiome.