Biodegradation of waste used cooking oil by lipolytic fungi: An in vitro study; Biodegradación de residuos de aceite usado de cocina por hongos lipolíticos: Un estudio in vitro

Abstract

The waste used cooking oil (WUCO) is one of the most serious factors of water pollution because it is able to create a layer that hinders the passage of oxygen and is difficult to remove. In order to demonstrate the capacity and efficiency of in vitro biodegradation of WUCO by lipolytic fungi, a study was conducted with three genera of fungi from industrial effluents of palm oil (Penicilium, Aspergillus and Amorphoteca). The efficiency of experimental biodegradation was evaluated in a container with equal parts (300 mL) of WUCO and tap water, where they were inoculated: ± 104 conidia/mL for individual experiments, ± 503 conidia/mL for a dual evaluation (two genera) and ± 33 300 conidia/mL for an evaluation of the three fungi. For each experiment three replicates were performed and all were incubated at 27 and 30 ºC for up to eight days. Lipolytic activity levels among genera of fungi were significant during the first days of the experiment (p < 0.05), normalizing to eighth day (p = 0.573). The combination of the three fungi improved the efficiency of biodegradation (p < 0.001), comparable with the eight-day evaluation of individual experiments (p = 0.012). All experiments at 27 ºC had better efficiency (p < 0.001). The three lipolytic fungi have high capacity and efficiency of biodegradation of WUCO in vitro after eight days of incubation at 27 ºC. © 2020 Elsevier B.V., All rights reserved.