Exopolymeric substances (EPS) produced by petroleum microbial consortia

Abstract

Durante o monitoramento de ensaios de biodegradação com consórcios microbianos recuperados de amostras de petróleo do campo Pampo Sul, Bacia de Campos, RJ, observou-se a produção de substâncias exopoliméricas (EPS) a qual ocorria independentemente do processo de biodegradação. Para potencializar essa produção utilizou-se um meio mineral enriquecido com glicose e 9,10-di-hidrofenantreno, n-nonadecano, ácido nonadecanóico, petróleo levemente biodegradado (P1) e petróleo severamente biodegradado (P2) como fontes de carbono. A análise dos EPS por infravermelho e espectrometria de massas com ionização por electrospray (MS-ESI) revelou uma mistura de isoformas de surfactina, que reduziu a tensão superficial da água e do meio Zinder de 72,4 e 55,7 para 28,6 mN m −1. Além disso, demonstraram capacidade de formar emulsões de diferentes óleos em água, com resultados até melhores que de surfactantes comerciais, como Tween 80. A produção dos EPS não foi inibida por nenhum dos substratos testados.Microbial consortia recuperated of crude oil samples from the Pampo Sul field, Campos Basin, RJ, produced biosurfactants in mineral media containing glucose and 9,10-dihydrophenantrene, n-nonadecane, nonadecanoic acid, slightly biodegraded crude oil (P1) or heavily biodegraded crude oil (P2) as carbon sources. The production of exopolimeric substances (EPS) and petroleum biodegradation do not necessarily occur simultaneously. The EPS analyses by infrared and eletronspray ionization mass spectrometry (ESI-MS) revealed a mixture of surfactine isoforms. The biosurfactants reduced the surface tension of water and Zinder medium from 72.4 and 55.7 to 28.6 mN m −1 . Additionally, this surfactant emulsified different oils in water with performances similar to or better than of a conventional surfactant, Tween 80.

Could petroleum biodegradation be a joint achievement of aerobic and anaerobic microrganisms in deep sea reservoirs?

“…The aerobic biodegradation process was stimulated by adsorbing oil on sterilized sand and by using 2 g wet cells/30 mg P1 oil/40 mL aqueous Zinder medium ( Zinder et al 1984 ). The cells were centrifuged from the enrichment experiment as previously described ( da Cruz et al 2008 ). Aerobic consortia was set up in Erlenmeyer flasks incubated in a shaker with temperature and agitation control (30°C and 150 rpm) during 60 days.…”

“…ClO 4 - → ClO 3 - → ClO 2 - → Cl - + O 2 ( Coates 1999 ; Derek 2000 ; Xu et al 2004 ). This oxygen might be trapped into biofilms and build micro aerobic environments, stimulating aerobic bacterial growth and an aerobic biodegradation lifecycle under a specific microbial arrangement ( Shen 1996 , da Cruz 2010 , Figure 1a ). Gradual consumption of the oxygen content would generate an anoxic atmosphere and the beginning of an anaerobic lifecycle following a different microbial arrangement (Figure 1b ).…”

Rhamnolipid produced by <i>Pseudomonas aeruginosa</i> USM-AR2 facilitates crude oil distillation

“…In addition, biosurfactant activity was also confi rmed by the emulsifying activity of rhamnolipid in supernatant on crude oil TK-1 and AG-2 (Table 1). Compared to Tween 80, rhamnolipid displayed better performances or higher emulsifying activity for both crude oils, thus confi rming its interfacial activity and enabling their use for emulsifying purposes (Cruz et al, 2010).…”

Identification of Staphylococcus strain CH1-8 and its oil-degradation

“…High concentration of these compounds in aquatic environments are considered as serious types of hazardous pollutants because of decrease oxygen transfer rate into the aerobic process (Noh et al, 2012;Becker et al, 1999;Stoll and Gupta, 1997). Since the potential danger from oil pollution, mechanical fat separation or floatation have commonly used as procedures for oil and grease removing, however they are considered insufficient (Cruz et al, 2010;Cammarota and Annajr, 1998;Stams and Oude, 1997). Therefore, the use of microorganisms and their metabolites for removing fat, oil and grease into miscible molecules have been studied i.e., the strains of Pseudomonas fluorescens, Chromobacterium vinosum, Aspergillus niger, Humicola lanuginosa (Yamane, 1987), Rhizopus delemar (Tuter et al, 1998) and Candida rugosa (Chamorro et al, 1998).…”