Evaluation of Microalgae’s Plastic Biodeterioration Property by a Consortium of Chlorella sp. and Cyanobacteria sp.

Prakash Bhuyar,Natanamurugaraj Govindan,Sudhakar Muniyasamy,Mohd Hasbi Ab Rahim,Gaanty Pragas Maniam,Ho Xuan Feng,Sathyavathi Sundararaju

doi:10.5755/j01.erem.77.3.25317

Abstract

Malaysia is one of the top eight countries that has a drawback of mismanaged plastic waste. This study intended to investigate polymer degradation using the biological technique with the help of microalgae to minimise the time required for biodegradation. This research article aims to identify the collected sample with the most suitable microalgae for the biodegradation of microplastic and to analyse the biodegradation of the polymer by microalgae. The results revealed that the consortium of Chlorella sp. and Cyanobacteria sp. were able to deteriorate low-density polyethene (LDPE sample) through several stages, and this was confirmed by UV-Spec, FESEM, EDX, CHNO, FTIR and DSC analysis. The results obtained revealed that microalgae producing exopolysaccharides (EPS) decreased the carbon and oxygen ratio. According to SEM micrographs, microalga may colonise, agglomerate, and adhere microplastics to its surface, regardless of its fractional size. The EDX analysis showed that the initial composition of carbon was 92.30 ± 1.23 %, while after the incubation, the carbon composition started decreasing from 53.18 % to 39.12 ± 1.08 %. Finally, there was a 37.91 % decrease in carbon weight from elemental analysise

Highlights

The amount of plastic trash that flows into the oceans every year is widely increasing
There are many types of plastics like polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), low-density polyethylene (LDPE) and high-density PE (HDPE), only a few among them are mainly used for commercial purposes (Ojha et al, 2017; Park et al, 2019)
It is observed that the consortium of microalgae has been effectively attached on the low-density polyethylene surface with the highest aggregation

Summary

Introduction

The amount of plastic trash that flows into the oceans every year is widely increasing. Its degradation has become a significant problem nowadays, while 25 million tons of plastic waste accumulate every year (Govindan et al, 2019). There are three traditional methods commonly used to treat polyethylene waste (recycling, landfill, and incineration) (Mostafa et al, 2018). Several studies indicate that polyethylene could be degraded by photo-degradation and chemical degradation methods (Genovese et al, 2016; Peixoto et al, 2017) In addition, biodegradation of polyethylene occurs by two mechanisms: hydro-biodegradation and oxo-biodegradation (Singh and Sharma, 2008). The usage of enzymes and microbes for the bioremediation of plastics can still break down the larger polymeric molecules into simple forms (Saengsawang et al, 2020)

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Conclusion