Biosurfactant Production by Azotobacter chroococcum Isolated from the Marine Environment

Abstract

Preliminary characterization of a biosurfactant-producing Azotobacter chroococcum isolated from marine environment showed maximum biomass and biosurfactant production at 120 and 132 h, respectively, at pH 8.0, 38 degrees C, and 30 per thousand salinity utilizing a 2% carbon substrate. It grew and produced biosurfactant on crude oil, waste motor lubricant oil, and peanut oil cake. Peanut oil cake gave the highest biosurfactant production (4.6 mg/mL) under fermentation conditions. The biosurfactant product emulsified waste motor lubricant oil, crude oil, diesel, kerosene, naphthalene, anthracene, and xylene. Preliminary characterization of the biosurfactant using biochemical, Fourier transform infrared spectroscopy, and mass spectral analysis indicated that the biosurfactant was a lipopeptide with percentage lipid and protein proportion of 31.3:68.7.

A novel bioemulsifier produced by Exiguobacterium sp. strain N4-1P isolated from petroleum hydrocarbon contaminated coastal sediment

“…A summary of such ndings is shown in Table 1, along with their identied bioemulsier compositions. Bacterial trains belonging to genera including Acinetobacter, 12 Aeribacillus, 13 Alcaligenes, 14 Amycolatopsis, 15 Azotobacter, 16 Bacillus, 17 Beijerinckia, 18 Corynebacterium, 19 Enterobacter, 20 Geobacillus, 13 Halomonas, 21 Klebsiella, 22 Myroides, 23 Pedobacter, 24 Propionibacterium, 25 Pseudomonas, 26 Solibacillus, 27 Streptomyces, 28 Variovorax, 29 have been reported to be bioemulsier producers (Table 1). To date, however, no strains belong to the genus of Exiguobacterium have been reported as bioemulsier producers.…”

Aislamiento e identificación de levaduras degradadoras de hidrocarburos aromáticos, presentes en tanques de gasolina de vehículos urbanos

“…Para degradar los contaminantes, los microorganismos deben tener procesos metabólicos para optimizar el contacto entre las células microbianas y las sustancias orgánicas, como la producción de biosurfactantes, además de la producción de oxigenasas y peroxidasas, que se encargan de mediar la conversión de los contaminantes orgánicos paso a paso en productos intermedios del metabolismo (Atlas, 1981), como ácidos, cetonas, aldehídos, alcoholes, entre otros (Itah et al, 2009). Aunque tradicionalmente se ha documentado el consumo mediado por la producción de biosurfactantes, cuya utilidad resulta en un mayor aprovechamiento del hidrocarburo al aumentarse la disponibilidad de éste por medio de la emulsificación (Thavasi et al, 2009), se ha destacado recientemente (Ángeles et al (2017), que el modelo predominante de aprovechamiento de hidrocarburos en tanques de biorreactores sería por contacto directo, al observarse que en ausencia de biosurfactantes, se presenta el mayor consumo de diésel por parte del consorcio bacteriano. En condiciones de baja humedad dentro del tanque, la incorporación de los hidrocarburos en las células por contacto directo sería más eficiente, al no haber una interfase predominante de agua-combustible, en donde pudiera llevarse a cabo el proceso de emulsificación.…”

Screening and identification of Pseudomonas aeruginosa AB4 for improved production, characterization and application of a glycolipid biosurfactant using low-cost agro-based raw materials

“…The partially purified extract was examined for haemolytic activity, 12 drop collapse test, 15 CTAB-MB assay, 12,13 surface tension, 12 oil spreading test 6 and emulsification index (EI%) assay. 12 The emulsification stability was determined every 24 h, 7th day, and later monthly for 4 months.…”

“…18 The IR spectra of purified rhamnolipid were recorded on the FTIR-spectrophotometer (Bruker IFS113V, Germany), in the range 4000-400 cm −1 spectral region at a resolution of 2 cm −1 , using a 0.23 mm KBr liquid cell. 6,9 Mass spectrometric (MS) analysis of the partially purified biosurfactant fraction under investigation and reference rhamnolipids (95% purity) were carried out in a Polaris Q ion-trap mass spectrometer (Thermo Scientific Inc., USA) equipped with thermo TR-5 MS SQC (5%) silicone column (30 m × 0.25 mm ID) and NIST-LIB software for matching the compound. Reference rhamnolipid solutions and biosurfactant samples under investigation were infused into the mass spectrometer at a flow rate of 1 µL min −1 using helium as carrier gas at 280…”

“…1,2,3 With an increased environmental awareness among consumers, emphasis on a sustainable harmony with global environment, and stringent new legislation(s) aiming at ecosystem protection, have prompted consideration of natural bio-surfactants as an alternative to the existing petrochemicalbased synthetic chemical surfactants. Currently, biosurfactants have been increasingly attracting attention and considerable applied interest in pharmaceutical, food processing and cosmetic industries as a multi-functional material due to such unique attributes as (i) feasibility of fermentative production using economical renewable resources 4,5 , (ii) functionality in ppm quantities under extreme conditions, 2 (iii) potential for tailormade applications, (iv) lower toxicity, 4,5 (v) environment-friendly characteristics 4 , (vi) better foaming useful in ore processing 6 and (vii) higher biodegradability.…”