Physical characterization of biosurfactant Rhamno NR22 produced by Pseudomonas Aeruginosa (Ps.NR.22): article

Pseudomonas aeruginosa (Ps.NR.22) is an opportunistic pathogen that have ability to produce glycolipids. Rhamno NR22 is essentially class of glycolipid that consist of one or mostly two 3-hydroxy fatty acids with a different chain of lengths that have a connection with one or two rhamno molecules. Rhamno NR22 was successfully produced by using Phosphate-limited proteose peptone-glucose-ammonium salt (PPPGAS) medium. The extraction of Rhamno NR22 was run by centrifuge at 10000 rpm and 4 oC for 15 minutes before it went through freeze dryer to powderized the Rhamno NR22. Thermogravimetric analysis (TGA) and nuclear magnetic resonance (NMR) analysis are applicable as a tools to understand the characteristics of Rhamno NR22. TGA reveal the mass lose in a Rhamno NR22 sample as a function of temperature and time. At 900°C, the Rhamno NR22 still remains at 5 mg in 90 minutes. It remarks the endurance of Rhamno NR22. ¹H-NMR spectrum was recorded due to the purity of Rhamno NR22. The obtained of multiplicity represent the assignment (-CH₃-) and (-CH-OH-) on rhamnose moiety while several assignment such as (-CH(O)-CH₂COO) and (-(CH₂)-CH(O)-CH₂COO-) on β-hydroxyfatty acids. The fuctional group, chemical bond and chemical structure study from NMR produced dirhamnolipid which classified as hydrophobic. Hence, the result indicate the physical characterization of rhamno NR22.