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In this work, a mixed biofilm composed by Pseudomonas monteilii P26 and Gordonia sp. H19 was formed using polyurethane foam (PUF) as immobilization support, for crude oil removal from artificial sea water. Fresh immobilized cells and immobilized cells that were stored at 4°C for two months before use were assessed. The oil removal assays were carried out at microcosm scale at 4, 15 and 30°C. A viability loss of P. monteilii P26 was observed after the storage. The highest removal value (75%) was obtained at 30°C after 7days using fresh immobilized cells on PUF. Enhanced oil bioremoval was obtained at 4°C and 15°C with the previously stored immobilized cells compared to the fresh immobilized cells. Crude oil sorption on the different systems was responsible for the removal of 22-33% oil at the different temperatures. In conclusion, an economic tool for petroleum bioremediation is proposed., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The biotechnology sector is continually seeking sustainable and more economical bioprocesses. Fermentation media produced with cheap components or wastes reduce production costs. Moreover, if wastes are used, they contribute to avoid environmental pollution. In this work, microbial growth media based on molasses or acidified glycerol as carbon sources and fertilizer as nitrogen source were tested for the production of a whole-cell catalyst that could be used in Cr(VI)-containing wastewater treatments. Results showed that the highest biomass production yield was obtained with a medium containing acidified glycerol 5% v/v and fertilizer 0.6% v/v. The biomass produced using this medium was immobilized in calcium alginate beads and used as catalyst in the biotransformation of Cr(VI) into Cr(III). The catalyst could be efficiently used for 5 reduction cycles of 40mg/l Cr(VI) each. Cr(III) retention assays were performed to determine whether Cr(III) could be retained by the catalyst avoiding its solubilization in the supernatants. The retention capacity of the catalyst at 32°C and pH 3.0 was 3mg Cr(III)/g. Both an alternative and economical fermentation medium is here proposed for the optimization of Cr(VI)-containing wastewater treatment., (Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)