Influence of rhamnolipids, produced by Pseudomonas aeruginosa NCAIM(P), B001380 on Cr(VI) removal capacity in liquid medium

• Main Authors: Avramović Nataša S., Nikolić-Mandić Snežana D., Karadžić Ivanka M.
• Format: Article
• Language: English
• Published: Serbian Chemical Society 2013-01-01
• Series: Journal of the Serbian Chemical Society
• Subjects: rhamnolipids; chromium (VI); Pseudomonas; bioremediation
• Online Access: http://www.doiserbia.nb.rs/img/doi/0352-5139/2013/0352-51391200115A.pdf

Pseudomonas aeruginosa NCAIM(P), B001380, a propitious bacterial strain isolated from mineral cutting oil was identified to be chromium tolerant and a producer of biosurfactant rhamnolipid (RL) with potential application in heavy metal bioremediation. Culture growth, RL production and Cr(VI) removal capacity of the strain in the presence of 50 mg L-1 (I) and 100 mg L-1 of Cr(VI) (II) were studied. Maximum of RL production were found in the late-stationary phase at 72 h for both Cr(VI)-amended cultures: I (236 mg L-1) and II (160 mg L-1), as well as the maximum of Cr(VI) removal capacity: 70 % (I) and 57 % (II). The amount of Cr in RL preparation II was 22 mg mg-1 determined by flame atomic absorption spectroscopy (FAAS). Appearance of a new band at 914 cm-1 in infrared (IR) spectrum of RL (II) indicated a significant proof for possible coordination of CrO42-ion with RL. The effect of Cr(VI) on monorhamnolipids (RL1) and dirhamnolipids (RL2) distribution and its ratio were studied by electrospray ionization mass spectrometry (ESI-MS). An increase was observed in a RL2/RL1 ratio for II compared to control.