Isolasi, Identifikasi, dan Uji Potensi Bakteri Laut sebagai Agen Bioremediasi Logam Berat Kromium (Cr) - Nasywa Fajriatun Nisa Suparman; Endah Retnaningrum (Jurnal Sumberdaya Alam dan Lingkungan, 2023)
ABSTRAK Pencemaran air oleh logam berat terjadi akibat perkembangan industri seperti tekstil, electroplating, dan penyamakan kulit. Kromium (Cr) merupakan salah satu logam berat yang dihasilkan dengan tingkat toksisitas tinggi bagi makhluk hidup bahkan dalam konsentrasi rendah. Upaya penanggulangan yang ramah lingkungan dilakukan dengan metode bioremediasi dapat memanfaatkan kemampuan bakteri resisten logam berat. Penelitian ini bertujuan untuk mengisolasi, mengidentifikasi, dan melakukan uji potensi reduksi logam berat kromium oleh bakteri laut resisten kromium. Penelitian ini menggunakan bahan sampel air laut, pasir Pantai Samas dan Pantai Pandansimo, media kultur Zobell marine broth 2216, serta logam berat K2Cr2O7. Langkah awal penelitian dilakukan dengan pengambilan sampel air laut dan pasir pantai. Selanjutnya dilakukan isolasi, seleksi, karakterisasi morfologi sel dan biokimia serta identifikasi bakteri resisten kromium untuk diuji potensi reduksinya. Hasil tiga isolat terseleksi memiliki kemampuan resistensi tertinggi terhadap kromium. Proses identifikasi menunjukkan bahwa dua isolat, yaitu PSAA1 dan SMCS21 diduga merupakan anggota genus Proteus, sedangkan satu isolat PSAA8 diduga merupakan anggota genus Micrococcus. Ketiga isolat bakteri PSAA8, SMCS21, dan PSAA1 menunjukkan kemampuan reduksi kromium dengan efisiensi reduksi secara berurutan sebesar 22.54%, 21.54%, dan 18.44%. Sehingga ketiga isolat bakteri laut disimpulkan memiliki potensi sebagai agen bioremediasi untuk mengurangi konsentrasi logam berat kromium dari lingkungan perairan. Kata kunci: Bakteri Laut, bioremediasi, kromium, Micrococcus, Proteus ABSTRACT Water pollution by heavy metals occurs as a result of industrial developments such as textiles, electroplating and leather tanning. Chromium (Cr) is one of the heavy metals that is produced with a high level of toxicity to living things even in low concentrations. Environmentally friendly countermeasures carried out by the bioremediation method can utilize the ability of heavy metal resistant bacteria. This study aims to isolate, identify, and test the potential reduction of chromium heavy metal by chromium-resistant marine bacteria. This study used seawater samples, sand from Samas Beach and Pandansimo Beach, culture media Zobell marine broth 2216, and heavy metal K2Cr2O7 solution. The initial step of the research was carried out by taking samples of seawater and beach sand. Furthermore, isolation, selection, morphological, cell and biochemical characterization were carried out as well as identification of chromium resistant bacteria to test their reduction potential. The results of the three selected isolates had the highest resistance ability to chromium. The identification process showed that two isolates, namely PSAA1 and SMCS21 were suspected to be members of the genus Proteus, while one isolate PSAA8 was suspected to be a member of the genus Micrococcus. The three bacterial isolates PSAA8, SMCS21, and PSAA1 showed the ability to reduce chromium with reduction efficiencies of 22.54%, 21.54%, and 18.44% respectively. So that the three marine bacterial isolates were concluded to have potential as bioremediation agents to reduce the concentration of the heavy metal chromium from the aquatic environment. Keywords:  Bioremediation, chromium, marine Bacteria, Micrococcus, Proteus