Pertumbuhan Biofilm Konsorsium Bakteri Pada Degradasi Plastik Low-Density Polyethylene (Ldpe) Dengan Variasi Suhu Dan Ph

Viernanda, Violita Nur (2026) Pertumbuhan Biofilm Konsorsium Bakteri Pada Degradasi Plastik Low-Density Polyethylene (Ldpe) Dengan Variasi Suhu Dan Ph. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Akumulasi limbah plastik, khususnya Low-Density Polyethylene (LDPE), menjadi salah satu permasalahan lingkungan karena bersifat hidrofobik dan sulit terdegradasi secara alami. Biodegradasi menggunakan konsorsium bakteri merupakan salah satu pendekatan yang ramah lingkungan karena memanfaatkan aktivitas enzim untuk menguraikan rantai polimer menjadi senyawa yang lebih sederhana. Penelitian ini bertujuan menganalisis pengaruh variasi suhu (30°C, 37°C, dan 45°C) dan pH (6, 7, dan 8) terhadap pertumbuhan konsorsium bakteri, pembentukan biofilm, perubahan sifat hidrofobisitas permukaan, dan kehilangan berat LDPE. Konsorsium bakteri yang digunakan terdiri atas empat isolat, yaitu M3 (Pseudomonas sihuiensis), M5 (Bacillus cereus), S5, dan S6 yang diisolasi dari perairan Sungai Surabaya. Proses biodegradasi dilakukan selama 12 minggu menggunakan media Mineral Salt Medium (MSM) dengan potongan LDPE sebagai sumber karbon. Analisis dilakukan melalui pengukuran optical density (OD₆₀₀ nm), hidrofobisitas permukaan, dan persentase kehilangan berat plastik. Hasil penelitian menunjukkan bahwa kombinasi suhu 30°C dan pH 7 merupakan kondisi optimum bagi pertumbuhan konsorsium bakteri, sedangkan persentase kehilangan berat LDPE tertinggi diperoleh pada suhu 45°C dan pH 7 sebesar 15,09%. Aktivitas biodegradasi juga meningkatkan hidrofilisitas permukaan LDPE yang ditunjukkan oleh meningkatnya diameter tetesan air dan menurunnya diameter tetesan minyak. Secara keseluruhan, variasi suhu dan pH memengaruhi pertumbuhan konsorsium bakteri serta efektivitas biodegradasi LDPE, dengan pH 7 sebagai kondisi yang paling mendukung proses biodegradasi.
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The accumulation of plastic waste, particularly Low-Density Polyethylene (LDPE), has become a major environmental concern due to its hydrophobic nature and resistance to natural degradation. Biodegradation using bacterial consortia has emerged as an environmentally friendly approach by utilizing enzymatic activities to break down polymer chains into simpler compounds. This study aimed to analyze the effects of different temperatures (30°C, 37°C, and 45°C) and pH levels (6, 7, and 8) on bacterial consortium growth, biofilm formation, changes in surface hydrophobicity, and LDPE weight loss. The bacterial consortium consisted of four isolates, namely M3 (Pseudomonas sihuiensis), M5 (Bacillus cereus), S5, and S6, isolated from the Surabaya River. Biodegradation was carried out for 12 weeks using Mineral Salt Medium (MSM) supplemented with LDPE fragments as the sole carbon source. Analyses included optical density (OD₆₀₀) measurement, surface hydrophobicity assessment, and percentage of plastic weight loss. The results showed that the combination of 30°C and pH 7 provided the optimum conditions for bacterial consortium growth, whereas the highest LDPE weight loss (15.09%) was achieved at 45°C and pH 7. Biodegradation activity also increased the hydrophilicity of the LDPE surface, as indicated by an increase in water droplet diameter and a decrease in oil droplet diameter. Overall, temperature and pH significantly influenced bacterial consortium growth and LDPE biodegradation efficiency, with pH 7 providing the most favorable condition for the biodegradation process across the observed parameters.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Biodegradasi, LDPE, Konsorsium bakteri, pH, Suhu, Bacterial consortia, Biodegradation, Temperatur
Subjects:	Q Science > QR Microbiology > QR74.8 Bacteria T Technology > TD Environmental technology. Sanitary engineering > TD427.P62 Microplastics--Environmental aspects.
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Biology > 46201-(S1) Undergraduate Thesis
Depositing User:	Violita Nur Viernanda
Date Deposited:	31 Jul 2026 04:02
Last Modified:	31 Jul 2026 04:02
URI:	http://repository.its.ac.id/id/eprint/141075

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