Arining Rizky Handayani, Sitoresmi Prabaningtyas, Frida Kunti Setiowati
Phosphate-solubilizing bacteria and vitamin B12 producers play an important role in microalgae growth and can be used in microalgae cultivation with a co-culture system. Bacteria that are in long-term culture have high resistance to environmental conditions. The study aims to determine the potential of phosphate solubilizing bacteria and producing vitamin B12 from the long-term Ranu Grati water culture which was taken 4 years ago, namely on February 26, 2018. The method used is by isolating bacteria to pikovskaya and PYBG media, then positive bacteria tested its ability quantitatively using a UV-Vis spectrophotometer. Ten bacterial isolates with different colony morphology were found in the samples used in this study. The results obtained were that 3 bacteria could dissolve phosphate and 10 bacteria that could produce vitamin B12 out of a total of 10 bacterial isolates. Bacterial isolates that have the highest potential as phosphate solubilizers and vitamin B12 producers were "isolate 9" with a phosphate concentration of 3.27 mg/L and a vitamin B12 concentration of 1.75 mg/L. © 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, 65112, Indonesia
