Analysis of bioreduction of iron(III) to iron(II) by bacterial isolate from Semeru volcanic mudflow

Bacterial isolates collected from the Mount Semeru lava with coordinates of LU: 90o 96'126.959"BT: 72o 08'12.318"were analyzed to obtain reduction potential of Fe(III) to Fe(II) by regenerating the bacteria using the 4 quadrantstreak method, preparing liquid cultures which were then reacted with Fe(III) solution, and determining the percentage of iron recovery using UV-Vis spectrophotometer instrument. This study aims to determine the potential of bacterial isolatesin reducing Fe(III) to Fe(II) in order to develop technology to control environmental pollution due to heavy metals by industrial activities. Variables that were varied were the condition of bacterial cells, namely living and dead bacterial cells, as well as bacterial species such as Pseudomonas sp., Bacterium strain BS2049, and Uncultured bacterium clone 1. The results obtained from this study were the percent of iron recovery and the time required to reduce iron by each bacterium. Living Pseudomonas sp. bacteria cells were capable to reduce iron with an incubation time of 1 hour and getting a percentrecovery of 94,05%, while the dead bacterial cells of Pseudomonas sp. managed to reduce iron with an incubation time of6 hours and get a percent recovery of 75,73%. In addition, other bacterial variants, namely living Bacterium strain BS2049cells required 4 hours to reduce iron and obtained a percent recovery value of 93,58% whereas dead Bacterium strain BS2049 cells obtained a percent recovery of 53,61% after reducing iron for 4 hours. Living Uncultured bacterium clone 1bacterial cells were capable to reduce iron with an incubation time of 96 hours and obtained a percent recovery of 101,26%,whilst dead Uncultured bacterium clone 1 bacterial cells did not show any ability to reduce iron, which was indicated by the percent recovery value of 0%.