Utilization of mango kernel oil for the rhamnolipid production by Pseudomonas aeruginosa DR1 towards its application as biocontrol agent K. Sathi Reddy, M. Yahya Khan, K. Archana, M. Gopal Reddy, Bee Hameeda ⇑ Department of Microbiology, Osmania University, Hyderabad 500 007, India highlights  Mango kernel oil (MKO) as a novel substrate for biosurfactant production.  MKO and synthetic fatty acids as substrates for rhamnolipid production.  The biosurfactant was identified as rhamnolipid by TLC, ATR-FTIR and LC–MS.  Rhamnolipid was evaluated as bio control agent against fungal phyto- pathogens. graphical abstract Kernel milling Mango kernel powder Rhamnolipids Soxhlet extraction Mango kernel Fermentation 40 - 60 0 C Mango kernel oil P. aeruginosa DR1 O OH OH OH CH3 O O O OH O H2C H2C CH3 CH3 m n m,n = 4 to 8 Kernel residue article info Article history: Received 5 August 2016 Received in revised form 8 September 2016 Accepted 9 September 2016 Available online 13 September 2016 Keywords: Pseudomonas aeruginosa Biosurfactant Rhamnolipids Mango kernel oil Antifungal activity abstract Mango kernel oil (MKO), derived from mango kernels, considered to be one of the highly generated agro- industrial waste, is assessed for its use as substrate for sustainable production of rhamnolipids. In the present study, MKO in combination with glucose gave maximum rhamnolipid yield of 2.8 g/l which reduced the surface tension of water from 72 to 30 mN/m, holding a CMC of 80 mg/l and also showed high emulsification activity (73%) with diesel. Cell free broth was found to be stable even at high temper- ature (autoclaved at 121 °C for 30 min), pH value (up to pH 12) and salinity (up to 20% NaCl). The LC–MS data showed mono-rhamnolipid to be predominant congener followed by di-rhamnolipid in presence of MKO. Whereas, di-rhamnolipid was abundant when a combination of MKO with glucose was used. The produced rhamnolipid mixture showed good antifungal activity against various phytopathogens. Ó 2016 Elsevier Ltd. All rights reserved. 1. Introduction Surfactants are surface active chemical compounds extensively used in various industries. Nearly all the surfactants commercially accessible today are derived from petrochemical sources (Aparna et al., 2012). Since the traditional chemical surfactants are synthesized from non-renewable petroleum sources, they are priced and pose potential risks to the environment due to their recalcitrant nature. As a result, attention is being drawn towards different environmental friendly approaches for the synthesis of these surface active compounds, mainly towards microbial derived surfactants or biosurfactants (Aparna et al., 2012; Lotfabad et al., 2009). Biosurfactants derived from microorganisms exhibit various benefits over their chemical counterparts such as lower toxicity, higher biodegradability, high specificity, stability at extremes of temperature, pH, salinity and their possible production from differ- ent renewable sources (Borah et al., 2015; Geys et al., 2014). This dynamic nature of biosurfactants have been employed in oil recov- ery, bioremediation (Chuang et al., 2010; Sajna et al., 2015), micro- bial fuel cells preparation (Zheng et al., 2015), agricultural, food and pharmaceutical industries (Anjum et al., 2016; Zhang et al., 2016). http://dx.doi.org/10.1016/j.biortech.2016.09.041 0960-8524/Ó 2016 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: drhami2009@gmail.com (B. Hameeda). Bioresource Technology 221 (2016) 291–299 Contents lists available at ScienceDirect Bioresource Technology journal homepage: www.elsevier.com/locate/biortech