TY - JOUR
T1 - A Classical Molecular Dynamics Simulation Study of Interfacial and Bulk Solution Aggregation Properties of Dirhamnolipids
AU - Luft, Charles M.
AU - Munusamy, Elango
AU - Pemberton, Jeanne E.
AU - Schwartz, Steven D.
PY - 2020/2/6
Y1 - 2020/2/6
N2 - The rhamnolipids are a unique class of biosurfactants produced by the bacteria Pseudomonas aeruginosa. These molecules display a high level of surface activity as well as biodegradability. In this study nonionic dirhamnolipid was investigated by utilizing molecular dynamics simulation at the air-water interface as well as in bulk water. Detailed structural analysis is presented for both the interfacial simulations and the simulations in solution. A systematic comparison was made between our previous work on the monorhamnolipid at the air-water interface and in bulk water. The presence of a second rhamnose group in dirhamnolipid did not show any significant change in the aggregation at the air-water interface. An increase in the molecular weight resulted in the larger surface area per monomer for dirhamnolipid compared to monorhamnolipid at the air-water interface. However, aggregation of dirhamnolipid in bulk water was affected by the presence of a second rhamnose group. Dirhamnolipid aggregates into micellar structure around ∼N22 which was lower than the monorhamnolipid aggregation number ∼N40. The hydrophobic component of the dirhamnolipid was enhanced to balance the higher hydrophilic component. An increase in alkyl chain length has shown that the enhanced hydrophobic component supports the formation of micellar aggregates up to ∼N30 and above, which was not observed in dirhamnolipid with a shorter alkyl chain length.
AB - The rhamnolipids are a unique class of biosurfactants produced by the bacteria Pseudomonas aeruginosa. These molecules display a high level of surface activity as well as biodegradability. In this study nonionic dirhamnolipid was investigated by utilizing molecular dynamics simulation at the air-water interface as well as in bulk water. Detailed structural analysis is presented for both the interfacial simulations and the simulations in solution. A systematic comparison was made between our previous work on the monorhamnolipid at the air-water interface and in bulk water. The presence of a second rhamnose group in dirhamnolipid did not show any significant change in the aggregation at the air-water interface. An increase in the molecular weight resulted in the larger surface area per monomer for dirhamnolipid compared to monorhamnolipid at the air-water interface. However, aggregation of dirhamnolipid in bulk water was affected by the presence of a second rhamnose group. Dirhamnolipid aggregates into micellar structure around ∼N22 which was lower than the monorhamnolipid aggregation number ∼N40. The hydrophobic component of the dirhamnolipid was enhanced to balance the higher hydrophilic component. An increase in alkyl chain length has shown that the enhanced hydrophobic component supports the formation of micellar aggregates up to ∼N30 and above, which was not observed in dirhamnolipid with a shorter alkyl chain length.
UR - http://www.scopus.com/inward/record.url?scp=85079079136&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85079079136&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcb.9b08800
DO - 10.1021/acs.jpcb.9b08800
M3 - Article
C2 - 31958226
AN - SCOPUS:85079079136
VL - 124
SP - 814
EP - 827
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
SN - 1520-6106
IS - 5
ER -