Sulistya Ika Ramadhani, Sitoresmi Prabaningtyas, Agung Witjoro, Rina Triturani Saptawati, Achmad Rodiansyah
Biofuel is an alternative to fossil fuels that are environmentally friendly with low emissions. Biofuel from biomass microalgae, especially Chlorella vulgaris, has an essential role in biofuel production. Increasing biomass microalgae was done by co-culture between microalgae and bacteria. This research aims to determine the potential of bacterial isolates to produce the IAA hormone and identify the highest isolate with the ability to synthesis IAA from four lakes in East Java. This research was conducted by culturing bacterial isolates in the Tryptic Soy Broth (TSB) to add tryptophan media in various periods of incubation. The absorbance was measured with UV-Vis spectrophotometry at a wavelength of 530 nm for determining IAA-production from bacterial isolates. The results showed that the "12" code bacterial isolate from Ranu Grati produced the highest IAA hormone concentration, with an average of 30.23 ppm. The morphological characterization of the highest IAA-producing bacteria showed that isolate included the Enterobacteriaceae group and phenotypic characterization include Enterobacter cloacae complex (ECC). © 2020, Society for Indonesian Biodiversity. All rights reserved.
Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Cakrawala No. 5, Kota Malang, 65145, East Java, Indonesia