Talks
Presentation Type
Oral Presentation
Discipline Track
Other
Abstract Type
Research/Clinical
Abstract
Background: Plastic pollution is a global problem of enormous (5.5 billion tons) and growing proportion (1). A promising solution involves fermentation of plastic waste to produce microbial biomass that can be used in a range of applications including compost production. However, few microbial species able to consume plastic waste have been identified, and those that have been, including the recently discovered gram-negative bacterial species Ideonella sakaiensis (I. sakaiensis) which consumes polyethylene terephthalate (PET) (2) – a common throwaway plastic – do so exceedingly slowly (2). Here we report results from a screen of 190 carbon sources to identify small molecule metabolic boosters of amorphous PET degradation by I. sakaiensis.
Methods: Two different Biolog carbon utilization tests (PM1 and PM2A; each a 96-well microplate containing a single control well and 95 different chemicals in the remaining wells) were used to assay for bacterial growth in the presence of 190 different carbon sources and both with and without a small disk of amorphous PET. Microplates were inoculated with I. sakaiensis at a known concentration and bacterial growth was measured by absorbance readings of 600 nm light over time or at a single time-point after 3-4 days of incubation at 30°C with shaking (~300 rpm). Metabolic activity was assessed after 4-5 days by introducing a redox indicator (Biolog redox dye G) to each micro-culture after 3-4 days and measuring the resultant ‘color depth’ after approximately 20 hours.
Results and Conclusions: We identified and have begun further experimenting with a small set of carbon sources (GABA, Gentiobiose, D-Mannitol, m-Inositol, and also 3-25% rich medium (growth medium #802) in YSV minimal medium) that synergistically affect I. sakaiensis growth OR I. sakaiensis growth and metabolism in the presence of amorphous PET plastic. Pair-wise combinations of these carbon sources will be tested for greater effects on I. sakaiensis growth and metabolism. Conditions yielding maximum growth and metabolic synergies will be assayed at a larger scale (3-10 ml cultures) for enhanced degradation of APET plastic.
Recommended Citation
Piedra, Felipe-Andrés and Maresso, Anthony, "Nurturing the environment: Enhancing PET-plastic degradation by a slow-growing miracle microbe" (2024). Research Symposium. 5.
https://scholarworks.utrgv.edu/somrs/2023/talks/5
Included in
Nurturing the environment: Enhancing PET-plastic degradation by a slow-growing miracle microbe
Background: Plastic pollution is a global problem of enormous (5.5 billion tons) and growing proportion (1). A promising solution involves fermentation of plastic waste to produce microbial biomass that can be used in a range of applications including compost production. However, few microbial species able to consume plastic waste have been identified, and those that have been, including the recently discovered gram-negative bacterial species Ideonella sakaiensis (I. sakaiensis) which consumes polyethylene terephthalate (PET) (2) – a common throwaway plastic – do so exceedingly slowly (2). Here we report results from a screen of 190 carbon sources to identify small molecule metabolic boosters of amorphous PET degradation by I. sakaiensis.
Methods: Two different Biolog carbon utilization tests (PM1 and PM2A; each a 96-well microplate containing a single control well and 95 different chemicals in the remaining wells) were used to assay for bacterial growth in the presence of 190 different carbon sources and both with and without a small disk of amorphous PET. Microplates were inoculated with I. sakaiensis at a known concentration and bacterial growth was measured by absorbance readings of 600 nm light over time or at a single time-point after 3-4 days of incubation at 30°C with shaking (~300 rpm). Metabolic activity was assessed after 4-5 days by introducing a redox indicator (Biolog redox dye G) to each micro-culture after 3-4 days and measuring the resultant ‘color depth’ after approximately 20 hours.
Results and Conclusions: We identified and have begun further experimenting with a small set of carbon sources (GABA, Gentiobiose, D-Mannitol, m-Inositol, and also 3-25% rich medium (growth medium #802) in YSV minimal medium) that synergistically affect I. sakaiensis growth OR I. sakaiensis growth and metabolism in the presence of amorphous PET plastic. Pair-wise combinations of these carbon sources will be tested for greater effects on I. sakaiensis growth and metabolism. Conditions yielding maximum growth and metabolic synergies will be assayed at a larger scale (3-10 ml cultures) for enhanced degradation of APET plastic.