Bacterial Production of Gellan Gum as a Do-It-Yourself Alternative to Agar

Abstract

Lack of access to reagents and equipment can make performing microbiology experiments difficult in K-12 classrooms and do-it-yourself (DIY) science settings. We demonstrate how the bacterium Sphingomonas paucimobilis can be used to synthesize gellan gum, an alternative to agar, with materials available to DIY scientists and educators. The method involves microwaving cultures of S. paucimobilis after a two-step growth procedure, supplementing them with additional media components as necessary, and then pouring plates. Gellan gum produced in the S. paucimobilis culture acts as a solidifying agent and provides a resilient surface that supports growth of microbes, including Escherichia coli and Saccharomyces cerevisiae. This procedure offers a unique opportunity to experiment with microbial production of an extracellular polysaccharide and to cheaply and sustainably source a reagent for research.