Aziza Fadhilah, Sitoresmi Prabaningtyas, Frida Kunti Setiowati, Dita Ayu Eka Saputri
Tropical lakes are one of the most likely freshwater aquatic ecosystems as a place of interaction between individuals, especially microalgae and bacteria. Some bacteria may provide nutrients to microalgae, such as the hormone IAA and vitamin B12. In addition, bacteria also play a role in nitrogen fixation, phosphate solubilization, and the production of amylase enzymes for microalgae. This study aimed to determine the effect isolates among the bacteria that produced the highest potency in previous studies. Tests were carried out 8 qualitatively with specific media, including Triptic Soy Agar media, Selective Solid media ½ PYBG, Pikovskaya selective solid media, N-Free selective solid media and Strach Agar. Tests were carried out quantitatively with spectrophotometric methods to determine the concentration of each potential. The results showed that the isolate "28" (Bacillus cereus) had better potential than the other tested isolates, such as nitrogen fixation of 8075 mg/L, amylolytic of 8.78 mg/L, phosphate solvent of 23.40 mg/L, producing 2574 mg/L of vitamin B12 and 27.33 mg/L of IAA hormone. © 2025 American Institute of Physics Inc.. All rights reserved.
Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Semarang Street 5, East Java, Malang City, Indonesia
