Marine sponges are distributed in the water, from the intertidal zones to thousands of meters deep. They are primitive multicellular invertebrates that live in benthic environments and are bound to solid substrates. Filter feeders, sponges have many microscopic pores on their surface, which allow water to enter and circulate via a network of canals where microbes and organic particles are filtered out and absorbed. Marine fungi are widespread in the oceans and colonize different ecological niches; they are found associated with organisms of all trophic levels and can act as saprobes, symbionts, and parasites. Compared with other marine microorganisms, marine fungus is relatively understudied. Fungi associated with sponges have been discovered to be a promising source of pharmacologically active compounds with unique anticancer, antibacterial, and antiviral properties.

In the Present study we focused on the production and statistical optimization of media components for Indole-3 acetic acid (IAA) production from P.fluorescens BCPBMS-1, it was isolated from Marine sponge Callyspongia diffusa . This sponge was collected from Gulf of Mannar, Southeast coast of India. We optimized the low-cost agricultural residue based medium for IAA production. In our study Soya bean husk used as a substrate for Indole-3-acetic acid (IAA) production. Fermentation variables were selected based on the Plackett-Burman design and were optimized by response surface methodology. The maximum IAA concentration 1.7474 µg/ml was predicted in medium containing 3.1064% Soya bean husk, Yeast extract 0.8323%, Salinity 9.0765 ppt, pH 6.3108 temperature 27.5524℃, incubation time 64.7475hrs. These predicted values were also verified through experiments as a result we got 1.74 µg/ml. The excellent correlation observed between predicted and measured values of this statistical model hence, this method may recommend for the industrial purpose.