Industrial sludge active bacteria potency test of PT surabaya industrial estate rungkut (SIER) as a heavy metal bioremediator and biofertilizer

Heavy metal contamination is a crucial problem to solve because it leads to
poisoning, phytotoxicity and soil fertility reduction. Microbial assisted bioremediation is
proposed to solve the problem due to their ability to adapt and mitigate heavy metal adverse
effect. This study was aimed to determine the diversity of bacterial colonies, the level of
tolerance of bacterial isolates, and the ability of bacterial isolates to produce plant growth
hormone and secondary metabolites. Heavy metal tolerance tests were carried out on 6
bacterial isolates, namely S1aB1, S1aB2, S1bB4, S2aB5, S3aB7, and S4bB11. S4bB11 was found as
the isolate with the highest growth pattern based on spectrophotometry optical density (OD)
when the isolate grown in Pb and Hg supplemented environment. Further GC-MS analysis on
S4bB11 detected several metabolites that play a role in heavy metal bioremediation namely α
Ketoglutaric acid, diaminopimelic acid and mannose. In addition, the presence of growth
hormones (3indole acetic acid and kinetin) were also detected. Thus, the bacteria was predicted
to have dual functions, both as industrial waste bioremediator and biofertilizer.