Pseudomonas aeruginosa TMN was used to produce rhamnolipid (RL) from a variety of carbon and nitrogen substrates. The most favorable carbon sources for RL production were glucose and glycerol (both at 40 g/L), giving a RL yield of 0.3 and 0.25 g/L, respectively. Meanwhile, sodium nitrate appeared to be the preferable nitrogen source, resulting in a RL production of 0.34g/L. Rhamnolipid production from P. aeruginosa TMN was affected by temperature, pH and agitation rate, with 37 ºC, pH 7 and 200 rpm agitation favorable for rhamnolipid production. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and electro spray ionization - mass spectrometry (ESI - MS) analyses indicated that the purified product contained one type of commonly found rhamnolipid, which is L-rhamnosyl-L-rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate. The rhamnolipid product can reduce the surface tension of water to 34 mN/m with a critical micelle concentration of nearly 18.75 mg/L and emulsified kerosene by 46%. P. aeruginosa TMN strain is a potential source of rhamnolipid biosurfactant, which could be used for the development of bioremediation processes in the marine environment.
1 February 2012 in Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
A Series of chalcone derivatives containing pyrazole ring was prepared and their cytotoxicity against different human cell lines, including breast (MCF-7), colon (HCT-116) liver (HEPG2) cell lines, as well as normal melanocyte HFB4 was evaluated. Two of these chalcone derivatives with different IC50 and chemical configuration were chosen for molecular studies in detail with MCF-7 cells. Our data indicated that the two compounds prohibit proliferation, angiogenesis, cell cycle progression and induce apoptosis of breast cancer cells. This inhibition is mediated by up regulation of tumor suppressor p53 associated with arrest in S-G2/M of cell cycle. This work provides a confirmation of antitumor activity of the novel chalcones and assists the development of new agents for cancer treatment.