Date of Completion

2025

Document Type

Thesis

Degree Name

Bachelor of Science in Life and Health Sciences

Keywords

Biostimulation, Oil-degrading bacteria, Manila Bay

Abstract

The Manila Bay is prone to oil pollution which requires safe and rapid clean-up responses. This study explored the use of biostimulation in the remediation of oil spills in Manila Bay. The main objective was to identify an optimal fertilizer formulation for increased biodegradation of diesel. Shake-flask microcosms were established and supplied with nutrients in the following C:N:P ratios: 100:10:1, 100:5:1, and 100:2:1. Three groups were supplied with fertilizer once, and 3 were resupplied weekly for 2 weeks. Biodegradation was measured in % degradation and degradation rate by gravimetric analysis of residual diesel. Bacterial growth was measured in % change in bacterial population and growth rate through colony counting. Species identification was done by 16S rRNA gene sequencing. Results showed that all treatment groups except 100:5:1 once and 100:2:1 Weekly were able to degrade significantly more diesel than the control. In terms of C:N:P ratio, the bacterial growth rate of the 100:10:1 Weekly treatment was significantly higher than 100:5:1 Weekly. For frequency of application, the 100:10:1 weekly treatment showed a significantly higher bacterial growth rate than its 100:10:1 Once counterpart. Other measurements showed no significant difference. Oil-degrading bacteria were successfully isolated from Manila Bay water samples and identified to be Janibacter melonis and Kocuria flava. Although further analysis is required to determine optimal fertilizer formulations, the potential of biostimulation for oil spill remediation in Manila Bay was proven by the presence of oil-degrading bacteria and increased diesel degradation after nutrient addition.

First Advisor

April Bermejo Ambita

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