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Growth characteristics of selected fungi on polyvinyl chloride film
Abstract:
The objective of this study was to determine if plasticized polyvinyl chloride film would support the growth of any of nine species of fungi. The film was suspended in distilled water with no nutrients or with glucose or ammonium sulfate. Spores of each of the test species were inoculated into the suspension medium, and the mixture was incubated at 30 degrees C for up to 18 weeks. Most species were found to be capable of utilizing the film for carbon or nitrogen when the other nutrient was supplied. Only two species, Aspergillus fischeri and Paecilomyces sp., were found to be capable of utilizing components of the film without added nutrients. Components of the polyvinyl chloride film were then incorporated into mineral salts medium to determine if these components could serve as carbon sources in the presence of ammonium nitrate. The only component found to be utilized by all the fungi as a carbon source was epoxidized oil, a plasticizer-stabilizer. Calcium-zinc stearate was an available carbon source for all except the Penicillium and Verticillium strains. The only other component utilized was a stearamide, which was metabolized solely by the Aspergillus sp. Only the stearamide contained enough nitrogen to serve as a primary source in the film. The compound, however, did not support growth of fungi in the presence of glucose. It was theorized that either the nitrogen of the stearamide was more readily available to the fungi in the whole film due to the presence of trace nutrients or the nitrogen was supplied by exogenous sources.
Insights
Plasticized polyvinyl chloride (PVC) film supports fungal growth, with some species utilizing its components as carbon or nitrogen sources. Epoxidized oil and calcium-zinc stearate were key carbon sources for most fungi tested.
Area of Science:
- Mycology
- Materials Science
- Environmental Microbiology
Background:
- Plasticized polyvinyl chloride (PVC) is a widely used material.
- Understanding the biodegradability of plastics is crucial for environmental impact assessment.
- Fungal degradation of synthetic polymers is an area of active research.
Purpose of the Study:
- To investigate the potential of plasticized PVC film to support fungal growth.
- To identify specific fungal species capable of utilizing PVC film components.
- To determine which components of plasticized PVC serve as carbon and nitrogen sources for fungi.
Main Methods:
- Nine fungal species were inoculated onto plasticized PVC film in distilled water, with and without added nutrients (glucose, ammonium sulfate).
- Incubation was performed at 30°C for up to 18 weeks.
- Individual PVC film components were tested as carbon sources in mineral salts medium with ammonium nitrate.
Main Results:
- Most tested fungi could utilize PVC film components for carbon or nitrogen when supplemented with nutrients.
- Aspergillus fischeri and Paecilomyces sp. utilized film components even without added nutrients.
- Epoxidized oil was a universal carbon source; calcium-zinc stearate was utilized by most, and stearamide by Aspergillus sp. only.
- Stearamide was the only component providing sufficient nitrogen, but did not support growth with glucose present.
Conclusions:
- Plasticized PVC film can be utilized by various fungi, particularly when essential nutrients are available.
- Specific plasticizers and stabilizers within PVC films, such as epoxidized oil, are readily metabolized by fungi.
- The bioavailability of nitrogen from PVC components like stearamide may be influenced by other factors in the film or environment.