Optimization of Culture Conditions for Polyhydroxybutyrate (PHB) Production in the Positive Bacterial Isolates of the Garden Soil

Author: Mahitha S., Sasi Premila J.M. and Abiya Chelliah D.

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Abstract

Solid plastic waste management issues and global environmental concerns have led to the development of biodegradable plastics which will have similar physical and chemical properties of the conventional plastics. Soil bacteriology possess many different bacteria which possess unique properties. Polyhydroxybutyrates (PHB) are the biological macromolecules produced by numerous soil bacteria and these can be used efficiently as an alternative to conventional plastics. In this research, Polyhydroxybutyrate producing bacteria are isolated from garden soil sample and potent producer identified by Crotonic acid assay. The amount of production of PHB are usually limited due to unbalanced growth conditions and nutrient availability. So these bacteria need optimised condition for maximal production of PHB. Modification of culture conditions, media composition, incubation period, inoculum size, pH, temperature, carbon nitrogen ratio, etc has a notable effect in the production. Slight changes in production conditions alter the bacterial growth in turn making changes in production of PHB. In the present study conducted, the potent strain SM1 was optimised and the optimal conditions were incubation period - 72 hours, inoculum size –2ml, Carbon sources – Glucose, Nitrogen source – Peptone, Carbon: nitrogen ratio – 15:1, Natural source – Rice water, pH –7, Temperature –37°C. Maintaining these optimised conditions during production process, maximum amount of PHB was produced. Further, large scale production can be done in fermenters with these optimised conditions for more production.

Keywords

Polyhydroxybutyrate, Crotonic acid assay, inoculum, fermenters, plastic waste management

Conclusion

The optimised conditions, 2ml inoculum yielded 0.25g/100ml, incubation period 72 hrs – 0.28g/100ml, carbon source glucose – 0.28 g/100ml, nitrogen source peptone – 0.27g/100ml, glucose: peptone (15:1) – 0.31g/100ml, Rice water – 0.28 g/100ml, pH 7- 0.26g/100ml, Temperature 37oC – 0.25 g/100ml. By incorporating the optimised conditions, higher production of polyhydroxybutyrate was achieved.

References

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How to cite this article

Mahitha S., Sasi Premila J.M. and Abiya Chelliah D. (2023). Optimization of Culture Conditions for Polyhydroxybutyrate (PHB) Production in the Positive Bacterial Isolates of the Garden Soil. Biological Forum – An International Journal, 15(3): 192-198.