Airlift bioreactor using a bacterial mixed culture improves hydrocarbon degradation in contaminated salty water

Abstract

a b s t r ac tHydrocarbon pollution in salty media is an important and long-lasting problem worldwide, especially it is not attended to. A mixed culture constituted by Xanthomonas sp., Acinetobacter bouvetii, Shewanella sp. and Defluvibacter lusatiensis was employed to degrade a hydrocarbon blend, composed of hexadecane (HXD), phenanthrene (PHE) and pyrene (PYR) (25:1:1 v/w/w). The degradation was assayed in two salty conditions (0-35 g L -1 NaCl) and the kinetics were described by the reparametrized Gompertz model. The mixed culture was halotolerant and able to degrade the three hydrocarbons, both in serological bottles and in an airlift bioreactor (ALB) in the presence and absence of salt. Hydrocarbon degradation in serological bottles was preferable to HXD and then to PHE and PYR. The presence of salt decreased the Gompertz parameter values for bacterial growth and hydrocarbon degradation. When salty media were used, the maximum degradation extent diminished in both serological bottles and ALB. Hydrodynamic was fundamental to enhance the hydrocarbon degradation efficiency, that is, pneumatic agitation provided in ALB enhanced the interfacial surface reducing the culture time from 14 to 5 d, almost cancelling the lag time required for hydrocarbon degradation. Our results suggest the use of ALB as a good method to remediate hydrocarbon-contaminated water bodies.

Tourism sustainability, Official Mexican Standards and the fulfillment of the human right to a healthy environment: Hydrocarbons, plastics, and bioremediation

“…Our group has developed biotechnological proposals such as the degradation of hydrocarbons in concentrations found in tourist areas (such as Quintana Roo, Veracruz and San Luis Potosí) using microbial consortia and various bioreactors capable of carrying out this process. Other works from our research group and other groups (Khan et al 2017, Nápoles-Álvarez al. 2017) have demonstrated that oil pollution could be treated through remediation.…”

Production of hydrocarbon-degrading microorganisms using agricultural residues of Mangifera indica L. and Carica papaya as carbon source

“…However, many of these treatments do not eliminate hydrocarbons, but instead transfer them from one place to another, while also producing other toxic compounds (Lizardi-Jiménez et al 2013;Rhodes 2014). A well-studied alternative without these disadvantages is the use of bioremediation, in which microbial biomass is used to consume hydrocarbons (Lizardi-Jiménez et al 2013;Nápoles-Álvarez et al 2017;Rhodes 2014;Thapa et al 2012;Tzintzun-Camacho et al 2012). However, there have been limited studies focussing on substances that can be used as a carbon source in inoculum production, since hydrocarbons, like n-alkanes or motor oil, are classically used for hydrocarbon-degrading (hydrocarbonoclastic) inoculum production (Kadri et al 2018) due to the belief that this kind of microorganism requires the presence of hydrocarbons (Santisi et al 2015).…”