The research aims to understand the effect of supplementation of bacterial IAA produced by Bacillus aryabhattai, Lysinibacillus boronitolerans and Pseudomonas putida on the growth and productivity of white oyster mushroom (Pleurotus ostreatus (Jacq.) P.Kumm) through in vitro and in vivo assay. In vitro experiment was done through an addition of bacterial supernatant into PDA and measured the diameter (mm) of the mycelia. In vivo treatment was carried out through the addition of 50 % bacterial supernatant into growth media of mushroom cultivation (baglog) followed by measuring the mycelia length throughout the baglog for growth and number of fruiting bodies, wet weight of fruiting bodies, diameter of pileus, and stipe length for productivity. In vitro results revealed that there was a significant difference (p>0.05) of mycelia growth between treatments on 4th-6th days of incubation. Supernatant of L. boronitolerans gave the best mycelia growth with a diameter of 84.86 ± 5.45 mm. In vivo results showed that there was a significant difference of mycelia growth between treatments at 2nd-5th weeks of incubation. Supernatant of P. putida gave the best effect on enhancing P. ostreatus productivity with the average of 6.89 ± 4.59 for number of fruiting bodies, 116.33 ± 22.58 g for wet weight of fruiting bodies, 8.84 ± 2.44 cm for the diameter of pileus and 7.80 ± 1.72 cm for the stipe length. Experiment results showed that bacterial supernatant which contains IAA have the ability to enhance the mycelia growth and it corresponds with the IAA concentration produced, while supplementation of bacterial supernatant did not show any significant effects on the productivity of P. ostreatus.