Abstract:
In the present study, the production of surface active compounds from Aureobasidium pullulans strain YTP6-14 was investigated. In the medium containing 5% of glucose, biosurfactant (BS) was released and dissolved in culture broth whereas those in form of heavy oil (HO) were found as droplets. The obtained BS and HO were analyzed by HPLC. The fractions with high activity at retention time of 11.154 and 11.161 minutes were found to processes Massioa lactone (168 Da) as analyzed by GC/MS. Crude HO was also characterized by pseudomolecular [M+Na]+ ions in MALDI-TOF/MS, the spectra of (m/z) were corresponded to Liamocin A1, Liamocin B1, Liamocin B2, Liamocin Ara-A1, Liamocin Ara-B1, Exophilin A1, Exophilin A1-H₂O Exophilin A1 + 4Ac and Exophilin B2. Cells disruption by ultrasonicator revealed the release of BS. As carbon sources for BS and HO production, 5% of glycerol produced the highest BS of 1.81 g/L at day 5 while 5% of cassava flour hydrolysate produced the highest HO of 7.37 g/L at day 7. CMC of BS and HO were 42.28 mg/L and 13.80 mg/L respectively. Both, BS and HO resisted to wide range of NaCl concentrations, pH, temperatures and autoclave condition. Moreover, they displayed good emulsifying activity with olive oil and able to retain these emulsifying form more than 90% when left on for 60 days. In addition, BS and HO inhibited biofilm formation of Streptococcus sobrinus 6715 by 24.73% and 53.16% respectively. While the inhibited formations of Streptococcus mutans were 88.86% and 91.10% respectively. Based on the above properties, HO and BS from A. pullulans strain YTP6-14 are high efficiency bioactive compounds and valuable for industrial applications.