TITLE:
Preliminary Studies on the Microbial Degradation of Plastic Waste Using Aspergillus niger and Pseudomonas sp.
AUTHORS:
A. O. Ogunbayo, O. O. Olanipekun, I. A. Adamu
KEYWORDS:
Biodegradation, Synthetic Plastic, Low Density Polyethylene, Pseudomonas sp., Aspergillus niger, Biodegradability
JOURNAL NAME:
Journal of Environmental Protection,
Vol.10 No.5,
May
17,
2019
ABSTRACT: The possibility of
microbial degradation of plastic waste was investigated by isolating
microorganisms present in dumpsite containing low-density
polyethylene (LDP). Aspergillus niger (fungi) and Pseudomonas sp.
(bacteria) were identified and subsequently used to biodegrade plastic waste.
The medium was made up of 0.2 g of MgSO4, 1.0 g of KH2PO4,
1.0 g of K2HPO4, 1.0 g of NH4NO3,
0.02 g of CaCl2, 0.05 g of FeCl3 in 1000 ml water. 10 ml
of the medium containing the bacteria and/or fungi was poured into test tubes
and 0.1 g of the plastic sample (Pure water sachet)
pre-treated with ethanol was introduced into the tubes. The pH of the medium
was adjusted to 7.2, 5.4 and 6.0 for Pseudomonas sp., Aspergillus niger and the mixed culture respectively. Each
experiment was carried out aerobically at room temperature and incubated on a
rotary shaker at 120 rpm.
The weight loss in each experiment was monitored at 10 days interval for 60
days. The total weight loss after 60 days was 7.2%, 12.4%, 15% for degradation
with Pseudomonas sp., Aspergillus niger and the mixed
culture respectively. From this study it can be inferred that Pseudomonas sp. and Aspergillus niger have the ability to degrade plastics. It can also be inferred that Aspergillus niger degraded plastics
better than Pseudomonas sp. and there was synergy between the two
microorganisms since the mixed culture gave a higher degradation.