Electronic Theses and Dissertation

Dinda elsa zharifah. (2026). eksplorasi, isolasi, dan identifikasi bakteri dari air kolam tandon tambak garam kajhu aceh besar. [skripsi, universitas syiah kuala]. di bawah bimbingan dr. rahmad rizki fazli, s.pd., m.si., dan dra. erlidawati, m.si. tambak garam kajhu merupakan lingkungan hipersalin yang berpotensi menjadi habitat bakteri halofilik, namun potensi mikroorganisme di dalamnya belum banyak dikaji secara ilmiah. penelitian ini bertujuan mengeksplorasi, mengisolasi, dan mengidentifikasi bakteri halofilik dari kolam tandon tambak garam kajhu melalui pendekatan karakterisasi fenotipik, meliputi morfologi koloni, pewarnaan gram, uji aktivitas urease, uji potensi biosurfaktan, uji halotoleran, dan penentuan kurva pertumbuhan. metode yang digunakan meliputi skrining pada media cair dan padat dengan variasi konsentrasi nacl (5%, 10%, 15%, 20%, dan 25%), dilanjutkan dengan karakterisasi isolat secara makroskopis, mikroskopis, biokimia dan penentuan kurva pertumbuhan. hasil penelitian menunjukkan bahwa bakteri dari sampel salinitas 13% dan 15% mampu tumbuh pada nacl 5–20% namun tidak pada nacl 25%, menandakan karakteristik halofilik sedang. koloni bersifat sirkuler, tepi rata, elevasi naik hingga cembung, berwarna putih kekuningan, dan seluruh isolat bersifat gram negatif dengan bentuk sel kokus (nacl 5–15%) dan basil (nacl 20%). uji urease menunjukkan hasil negatif, sedangkan uji oil spreading test (ost) menunjukkan hasil positif dengan aktivitas biosurfaktan tertinggi pada isolat nacl 5%. uji halotoleran yang negatif mengonfirmasi bahwa seluruh isolat merupakan bakteri halofilik sejati. kurva pertumbuhan menunjukkan empat fase lengkap selama 24 jam. berdasarkan hasil tersebut, disimpulkan bahwa kolam tandon tambak garam kajhu mengandung bakteri halofilik sedang bersifat gram negatif dengan potensi penghasil biosurfaktan yang dapat dikembangkan lebih lanjut dalam bidang bioteknologi. kata kunci: bakteri halofilik, tambak garam kajhu, karakterisasi, biosurfaktan, urease, halotoleran.

Dinda Elsa Zharifah. (2026). Exploration, Isolation, and Identification of Bacteria from the Reservoir Pond Water of the Kajhu Salt Farm Aceh Besar. [Undergraduate Thesis, Syiah Kuala University]. Supervised by Dr. Rahmad Rizki Fazli, S.Pd., M.Si., and Dra. Erlidawati, M.Si. The Kajhu Salt Farm is a hypersaline environment that potentially harbors halophilic bacteria, yet its microbial potential remains largely unexplored. This study aimed to explore, isolate, and identify halophilic bacteria from the Reservoir Pond of the Kajhu Salt Farm through phenotypic characterization, including colony morphology, Gram staining, urease activity, biosurfactant potential, halotolerance, and growth curve analysis. Methods included screening on liquid and solid media with NaCl concentrations of 5%, 10%, 15%, 20%, and 25%, followed by macroscopic, microscopic, and biochemical characterization of isolates, as well as growth curve determination. Results showed that bacteria from 13% and 15% salinity samples grew at NaCl 5–20% but not at 25%, indicating moderate halophilic characteristics. Colonies were circular with entire margins, raised to convex elevation, and yellowish-white in color. All isolates were Gram-negative, with coccoid morphology at NaCl 5–15% and bacillary morphology at NaCl 20%. The urease test yielded negative results, while the Oil Spreading Test (OST) showed positive biosurfactant activity, highest in the NaCl 5% isolate. Negative halotolerance results confirmed that all isolates are true halophiles. The growth curve exhibited four complete phases within 24 hours. Based on these findings, it is concluded that the Reservoir Pond of the Kajhu Salt Farm harbors moderate Gram-negative halophilic bacteria with biosurfactant-producing potential for further biotechnological development. Keywords: halophilic bacteria, Kajhu Salt ponds, characterization, biosurfactant, urease, halotolerance.