Biosurfactant production by Serratia marcescens SS-1 and its isogenic strain SMdeltaR defective in SpnR, a quorum-sensing LuxR family protein.
Serratia marcescens SS-1 and its SpnR-defective isogenic mutant, SMdeltaR, produced an extracellular surfactant able to decrease surface tension of water from 72 to 37 dyne cm(-1) (SMdeltaR strain) and to 45 dyne cm(-1) (SS-1 strain). The biosurfactant also emulsified kerosene and diesel with a maximum emulsion index of 77% (diesel and kerosene) for the SMdeltaR strain, and 72% (kerosene) and 40% (diesel) for the SS-1 strain. Deletion of spnR gene appeared to enhance biosurfactant production. Model simulations suggest that biosurfactant production by the two strains was growth-associated. The SMdeltaR strain had a yield coefficient of 22-32% g dry cell(-1), which is 32-50% higher than that of the SS-1 strain.
Wei
Yu-Hong
YH
Graduate Institute of Biotechnology and Bioinformatics, Yuan Ze University, Taoyuan 320, Taiwan.
Lai
Hsin-Chih
HC
Chen
Shan-Yu
SY
Yeh
Mao-Song
MS
Chang
Jo-Shu
JS
D004655:Emulsions / Q000737:chemistry; D005742:Gasoline; D005818:Genetic Engineering / Q000379:methods; D007648:Kerosene; D012097:Repressor Proteins; D012706:Serratia marcescens / Q000145:classification / Q000254:growth & development* / Q000378:metabolism*; D013045:Species Specificity; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry* / Q000378:metabolism*; D015534:Trans-Activators / Q000172:deficiency*
D004655:Emulsions; D005742:Gasoline; D007648:Kerosene; D012097:Repressor Proteins; D013501:Surface-Active Agents; D015534:Trans-Activators; C064778:LuxR autoinducer binding proteins