BIODIVERSITAS ISSN: 1412-033X Volume 20, Number 5, May 2019 E-ISSN: 2085-4722 Pages: 1374-1379 DOI: 10.13057/biodiv/d200529 The potential of indigenous bacteria from oil sludge for biosurfactant production using hydrolysate of agricultural waste NI’MATUZAHROH 1,♥ , SILVIA KURNIA SARI 1 , IRINE PUSPA NINGRUM 1 , APRILLA DILA PUSFITA 1 , LISA MARJAYANDARI 1 , NASTITI TRIKURNIADEWI 1 , SYAHRIAR NUR MAULANA MALIK IBRAHIM 1 , FATIMAH 1 , TRI NURHARIYATI 1 , TINI SURTININGSIH 1 , HANIF YULIANI 2 1 Department of Biology, Faculty of Science and Technology, Universitas Airlangga, Kampus C Mulyorejo Surabaya 60115, East Java, Indonesia. Tel.: +62-31-5936501, Fax.: +62-31-5926804. ♥ email: nimatuzahroh@fst.unair.ac.id 2 Agency for The Assessment and Application of Technology. Jl. Raya Puspiptek, Serpong, Tangerang Selatan 15311, Banten, Indonesia. Manuscript received: 31 January 2019. Revision accepted: 26 April 2019. Abstract. Ni’matuzahroh, Sari SK, Ningrum IP, Pusfita AD, Marjayandari L, Trikurniadewi N, Ibrahim SNMM, Fatimah, Nurhariyati T, Surtiningsih T, Yuliani H. 2019. The potential of indigenous bacteria from oil sludge for biosurfactant production using hydrolysate of agricultural waste. Biodiversitas 20: 1374-1379. Biosurfactants are amphipathic compounds which are useful in various fields of health, industry, and remediation. Biosurfactants are produced by bacteria that grow in hydrocarbon or sugar substrates. Hydrolysis product of agricultural waste can be used as a biosurfactant production medium. This research aims to obtain biosurfactant producing bacteria from Balongan oil sludge, Indonesia. The ability to grow and produce biosurfactant by indigenous bacteria was tested using a medium of Synthetic Mineral Water (SMW) added by 209.3 ppm of rice straw hydrolysis product (RSHP). The growth of bacteria was evaluated through Total Plate Count (TPC) and biosurfactant production was evaluated through measurement of emulsification activity and surface tension. Six indigenous bacteria were capable to produce biosurfactants in the RSHP. Emulsification activity was not detected, but surface tension reduction was founded. The best biosurfactant was indicated by surface tension value of 53.56 mN/m with TPC value of 20.07 CFU/mL at the 5 th day of incubation by BP (1) 5. The indigenous bacteria were identified as Propionibacterium BP (1) 1, Propionibacterium BP (1) 3, Bacillus BP (1) 4, Corynebacterium BP (1) 5, Corynebacterium BP (1) 8, and Rothia BP (1) 6. Utilization of sugar as hydrolysis product of agricultural waste is an innovation of raw materials for biosurfactant production. Keywords: Agricultural waste, biosurfactant, indigenous bacteria, oil sludge, rice straw INTRODUCTION Biosurfactants are amphipathic compounds which are useful in various fields of health, industry, and remediation. Biosurfactants have low toxicity, easy manufacture, and wide application (Elazzazy et al. 2015). Biosurfactants are produced by bacteria that grow in hydrocarbon environments and can be secreted on the surface or outside cells in growth media with noticeable by surface tension reduction and emulsifying activities. (Kosaric 1993). Biosurfactant contains hydrophobic and hydrophilic molecules. Biosurfactant production by bacteria requires carbon nutrients, one of which is a sugar substrate. The use of agricultural waste as a supplier of carbon sources in the form of sugar substrates as a result of hydrolysis has not been further exposed. The results of hydrolysis of agricultural waste can be used as a medium for biosurfactant production. Organic material in organic waste is a source of micronutrients (Wahyono 2011). The use of agricultural waste has been groundbreaking as an alternative material for biosurfactant production. Utilization of agricultural wastes (barley bran, trimming vine shoots, corn cobs, and Eucalyptus globulus chips) for biosurfactant production by bacteria have been done to reduce production costs (Moldes et al. 2007). Rice straw decomposing also has been successfully used for biosurfactant production by Pseudomonas aeruginosa BSZ-07 (Quizhuo et al. 2008). One of agricultural waste that can produce hydrolyzing sugar is rice straw. According to the Indonesian Center for Rice Research, in the East Java region for March 2018, rice yields reached 2,026,739 tons (BB Padi 2018) and produced 12-15 tons per hectare of rice straw. Rice straw contains polysaccharides in lignocellulose. Lignocellulose is an abundant material, renewable resources, and less attention (Peralta et al. 2012). In rice straw, lignocellulose contains 32% cellulose, 24% hemicellulose, and 14% lignin (Chandel et al. 2007 in Novalina, 2014). Rice straw also produces 40-43% of carbons. The high cellulose and hemicellulose content can be used as a result of hydrolysis of rice straw and carbon for biosurfactant-producing bacteria. In this study, Penicillium sp. H9 was used to hydrolysis rice straw and its hydrolysis product called rice straw hydrolysis product (RSHP) was used as substrate for biosurfactant production. Indonesia has a diversity of microorganisms that have the potential to be explored, one of which is a group of bacteria. Hydrocarbonoclastic bacteria in oil sludge are known to produce biosurfactants. Biosurfactant production by indigenous or soil bacteria has been carried out (Amani et al. 2011; Ni'matuzahroh et al. 2017; Lee et al. 2018). This study reveals the ability of indigenous bacteria to grow and produce biosurfactant and knowing the prospect of utilizing RSHP for alternative substrate for biosurfactant production.