Bioconversion of biodiesel refinery waste in the bioemulsifier by Trichosporon mycotoxinivorans CLA2

De, Domingues Vitor, Souza, Lula Ivana, Gonçalves Daniel, Dos

Description

The microbial bioemulsifiers was surface active compounds, are more effective in stabilizing oil-in-water emulsions. The yeasts have been isolated to produce bioemulsifiers from vegetable oils and industrial wastes. Results Trichosporon mycotoxinivorans CLA2 is bioemulsifier-producing yeast strain isolated from effluents of the dairy industry, with ability to emulsify different hydrophobic substrates. Bioemulsifier production (mg/L) and the emulsifying activity (E 24 ) of this strain were optimized by response surface methodology using mineral minimal medium containing refinery waste as the carbon source, which consisted of diatomaceous earth impregnated with esters from filters used in biodiesel purification. The highest bioemulsifier production occurred in mineral minimal medium containing 75 g/L biodiesel residue and 5 g/L ammonium sulfate. The highest emulsifying activity was obtained in medium containing 58 g/L biodiesel refinery residue and 4.6 g/L ammonium sulfate, and under these conditions, the model estimated an emulsifying activity of 85%. Gas chromatography and mass spectrometry analysis suggested a bioemulsifier molecule consisting of monosaccharides, predominantly xylose and mannose, and a long chain aliphatic groups composed of octadecanoic acid and hexadecanoic acid at concentrations of 48.01% and 43.16%, respectively. The carbohydrate composition as determined by GC-MS of their alditol acetate derivatives showed a larger ratio of xylose (49.27%), mannose (39.91%), and glucose (10.81%). 1 H NMR spectra confirmed by COSY suggested high molecular weight, polymeric pattern, presence of monosaccharide’s and long chain aliphatic groups in the bioemulsifier molecule. Conclusions The biodiesel residue is an economical substrate, therefore seems to be very promising for the low-cost production of active emulsifiers in the emulsification of aromatics, aliphatic hydrocarbons, and kerosene.

Sujets

• Yeast
• Response surface methodology
• Diatomaceous earth

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 21
• Langue: English

Extrait

de Souza Monteiroet al. Biotechnology for Biofuels2012,5:29 http://www.biotechnologyforbiofuels.com/content/5/1/29

R E S E A R C H

Bioconversion of biodiesel refinery waste in the bioemulsifier byTrichosporon mycotoxinivoransCLA2 1,2* 1 2 3,4 Andrea de Souza Monteiro , Vitor Souza Domingues , Marcus VD Souza , Ivana Lula , 1,5 6 1 Daniel Bonoto Gonçalves , Ezequias Pessoa de Siqueira and Vera Lúcia dos Santos

Open Access

Abstract Background:The microbial bioemulsifiers was surface active compounds, are more effective in stabilizing oilin water emulsions. The yeasts have been isolated to produce bioemulsifiers from vegetable oils and industrial wastes. Results:Trichosporon mycotoxinivoransCLA2 is bioemulsifierproducing yeast strain isolated from effluents of the dairy industry, with ability to emulsify different hydrophobic substrates. Bioemulsifier production (mg/L) and the emulsifying activity (E ) of this strain were optimized by response surface methodology using mineral minimal medium containing 24 refinery waste as the carbon source, which consisted of diatomaceous earth impregnated with esters from filters used in biodiesel purification. The highest bioemulsifier production occurred in mineral minimal medium containing 75 g/L biodiesel residue and 5 g/L ammonium sulfate. The highest emulsifying activity was obtained in medium containing 58 g/L biodiesel refinery residue and 4.6 g/L ammonium sulfate, and under these conditions, the model estimated an emulsifying activity of 85%. Gas chromatography and mass spectrometry analysis suggested a bioemulsifier molecule consisting of monosaccharides, predominantly xylose and mannose, and a long chain aliphatic groups composed of octadecanoic acid and hexadecanoic acid at concentrations of 48.01% and 43.16%, respectively. The carbohydrate composition as determined by GCMS of their alditol acetate derivatives showed a larger ratio of xylose (49.27%), 1 mannose (39.91%), and glucose (10.81%). H NMR spectra confirmed by COSY suggested high molecular weight, polymeric pattern, presence of monosaccharide’s and long chain aliphatic groups in the bioemulsifier molecule. Conclusions:The biodiesel residue is an economical substrate, therefore seems to be very promising for the lowcost production of active emulsifiers in the emulsification of aromatics, aliphatic hydrocarbons, and kerosene. Keywords:Bioemulsifier, Yeasts, Response surface methodology, Biodiesel residue, Diatomaceous earth

Background Microbial bioemulsifiers are classified as high molecular weight surface-active compounds (SACs) that are effect- ive in stabilizing oil-in-water emulsions [1]. Microorgan- isms synthesize a wide variety of high molecular weight SACs, which are composed of amphipathic polysacchar- ides, proteins, lipopolysaccharides, lipoproteins or com- plex mixtures of these biopolymers [2]. Microbial SACs have marked advantages over chem- ically synthesized surface-active compounds and can

* Correspondence: [e-mail] 1 Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, C.P. 486, 31270901 Belo Horizonte, MG, Brazil 2 Laboratório de Pesquisa em Microbiologia–Faculdade de Ciências da Saúde, Universidade Vale do Rio Doce, Governador Valadares, MG, Brazil Full list of author information is available at the end of the article

replace conventional surfactants in many areas, including agriculture and the textile, cosmetic and pharmaceutical industries [3]. In the environmental sector, microbial SACs have promising applications in bioremediation and waste treatment by participating in the removal of haz- ardous materials [2,4]. Their advantages over chemically synthesized compounds are numerous: they have many potential applications due to their novel structural char- acteristics and physical properties; they are produced from renewable substrates; they can be readily modified by genetic engineering, biologically or biochemically; and they are biodegradable [5]. Microbial SACs have recently been intensively studied because of their useful functional properties, such as emulsification, phase separation, wetting, foaming,

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