Genetic Cell-Surface Modification for Optimized Foam Fractionation

Abstract

DH5αλpir pTNS1DH5αλpir harboring plasmid pTNS1 Choi et al., 2005 DH5αλpir pSK02 DH5 αλpir harboring Tn7 delivery vector pSK02 for chromosomal integration; containing rhlAB genes from P. aeruginosa PA01 Bator et al., 2020 P. taiwanensis VLB120 wild type Panke et al., 1998 P. putida DOT-T1E wild type Ramos et al., 1998 S12 wild type Hartmans et al., 1990 KT2440 wild type Bagdasarian et al., 1981

Uncoupling Foam Fractionation and Foam Adsorption for Enhanced Biosurfactant Synthesis and Recovery

“…The applied RL and HAA production hosts P. putida KT2440 ∆flag_RL, and P. putida KT2440 ∆ lapF _HAA were constructed as described previously [ 24 ]. Briefly, for the RL and HAA production strains, mini-Tn7 delivery transposon vectors pSK02 [ 64 ], harboring the rhlAB genes and pKS03 [ 24 ], harboring the rhlA gene, were integrated into the genome as described by Zobel et al [ 65 ]. For this purpose, rhlAB genes were isolated and amplified from the pathogen P. aeruginosa .…”

“…For the determination of the maximum adsorption of HAAs by the applied C 18 silica-based ODS-A material, HAAs were purified via preparative HPLC, according to a modified RL purification method from Blesken et al [ 24 ]. For HAA purification, the elution gradient of the method was maintained at 100% acetonitrile until a retention time of 55 min.…”

“…To reduce production costs and prevent health concerns, efforts to develop a competitive non-pathogenic RL and HAA production host have increased significantly over the last two decades [ 12 , 20 , 21 , 22 ]. In this study, we use Pseudomonas putida KT2440 strains with a corresponding integration of the rhlA and rhlB genes as constructed previously [ 23 , 24 , 25 ].…”

“…Due to hydrophobic surface structures, bacterial cells also adsorb on the interface. To reduce biomass content in the foam, engineered P. putida strains with genetic deletions of such hydrophobic surface structures were recently reported [ 24 ]. Briefly, bacterial cells lacking the flagellum or the large adhesion protein F agglomerate in the foam to a lower extent than P. putida KT2440 without surface modifications.…”

Coupling an Electroactive Pseudomonas putida KT2440 with Bioelectrochemical Rhamnolipid Production

“…However, the costly aeration and the subsequent problems with strong reactor foaming still impose severe technical challenges [ 12 ]. This also hinders the scale-up of the process towards the industrial production of rhamnolipids and it requires substantial technical effort to overcome this challenge [ 13 , 14 , 15 , 16 ]. To reduce this bottleneck, which comes with the need for sufficient oxygen supply for aerobic growth and product synthesis, we here explore an alternative approach for rhamnolipid production using P. putida as a biocatalyst under oxygen-limitation in bioelectrochemical systems (BESs).…”