초록
<P><B>Abstract</B></P><P><B>BACKGROUND:</B> Sal (<I>Shorea robusta</I>) deoiled seed cake extract (SDOCE) was assessed for its suitability as a cheap natural substrate for lipase production under submerged fermentation. The bacterial isolate <I>Aeromonas</I> sp. S1 isolated from dairy industry was used for lipase production. Both the isolate and its lipase were shown to be potential tools for treatment of dairy wastewater containing higher organic load.</P><P><B>RESULTS:</B> On substituting tributyrin with SDOCE, lipase production was enhanced 24‐fold (195 U mL<SUP>−1</SUP>) compared with the initial 8.13 U mL<SUP>−1</SUP> lipase activity. Maximum lipase production was obtained at pH 8.0 and incubation temperature 30 °C. The lipase had pH and temperature optima of 10.0 and 55 °C, respectively. The isolate and its crude enzyme preparation were checked separately for applicability in dairy wastewater treatment. The isolate was able to reduce chemical oxygen demand (COD) by 93%, oil and grease (O&G) by 75%, and total suspended solids (TSS) by 47% after 96 h of treatment. Enzymatic preparation gave 86% reduction of COD after 12 h and 75 and 45% reduction of O&G and TSS, respectively, after 96 h of treatment.</P><P><B>CONCLUSION:</B> Overall, the study shows the usefulness of Sal seed deoiled cake, a cheap agro‐industrial by‐product for the production of lipase. The isolate and its lipase can also be used effectively for the treatment of dairy wastewater. Copyright © 2011 Society of Chemical Industry</P>