Surface forces and properties of foam films from rhamnolipid biosurfactants

Cohen, R.; Exerowa, D.

doi:10.1016/j.cis.2007.04.018

Cited by 53 publications

(25 citation statements)

References 51 publications

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“…Last, but not least, their production by renewable resources provides further impetus for serious consideration of biological surfactants as possible alternatives of the commonly used industrial chemicals. The achievements of the microbial production of biosurfactants and various aspects concerning their potential commercial application regarding bioremediation of soils polluted with heavy metals are well documented and summarized in a number of reviews [76,77].…”

Section: Biofrothersmentioning

confidence: 99%

Flotation Frothers: Review of Their Classifications, Properties and Preparation

Khoshdast¹

2011

TOMPJ

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Abstract:The importance of frothers in flotation is widely acknowledged, particularly in terms of their role with respect to bubble size, and the stability and mobility of the froth phase. These factors play a significant role in the kinetic viability of the process, and the overall recovery and the grade that can be achieved from a flotation cell or circuit. About 60 years ago, Wrobel [1] presented a comprehensive review of flotation frothers, their action, properties and structures. However, during recent six decades flotation reagent technology has undergone considerable evolutions and innovations. The aim of the present review is to provide an updated, comprehensive database comprising recent developments in flotation frother technology as well as some historical aspects. Different types of flotation frothers are discussed regarding to their classifications, properties, and preparation methods. New classification schemes have been suggested in parallel with introducing new characterization criteria. New classes of frothers are actually conventional frothers modified by incorporating certain functional "group" or "atoms" into their molecular structure. Like particle surface modifiers, frothers are also influenced by biotechnology, leading to introducing a new class of frothers named as "biofrothers".

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Section: Biofrothersmentioning

confidence: 99%

Flotation Frothers: Review of Their Classifications, Properties and Preparation

Khoshdast¹

2011

TOMPJ

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“…The rhamnolipid standard did not disperse the biofilm as well as the rhamnolipids in the PA14 WT supernatant, possibly because the ratios of the rhamnolipids are critical for biofilm dispersal activity. For example, the ratio between rhamnolipids and mono rhamnolipids affects the mixture properties (e.g., foam thickness, surface electric parameters) 40 and changes the emulsification index and antimicrobial 140 properties 41 . In addition, the rhamnolipid standard was not pure (90%), and the growth condition used to produce the rhamnolipids is unknown.…”

Section: Discussionmentioning

confidence: 99%

Rhamnolipids fromPseudomonas aeruginosaDisperse the Biofilms of Sulfate-Reducing Bacteria

Wood

Zhu

Miller

et al. 2018

Preprint

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Biofilm formation is an important problem for many industries. Desulfovibrio vulgaris is the representative sulfate-reducing bacterium (SRB) which causes metal corrosion in oil wells and drilling equipment, and the corrosion is related to its biofilm formation. Biofilms are extremely difficult to remove since the cells are cemented in a polymer matrix. In an effort to eliminate SRB biofilms, we 5 examined the ability of supernatants from Pseudomonas aeruginosa PA14 to disperse SRB biofilms. We found that the P. aeruginosa supernatants dispersed more than 98% of the biofilm. To determine the genetic basis of this SRB biofilm dispersal, we examined a series of P. aeruginosa mutants and found that mutants rhlA, rhlB, rhlI, and rhlR, defective in rhamnolipids production, had significantly reduced levels of SRB biofilm dispersal. Corroborating these results, purified rhamnolipids dispersed SRB biofilms, and 10 rhamnolipids were detected in the P. aeruginosa supernatants. Hence, P. aeruginosa supernatants disperse SRB biofilms via rhamnolipids. In addition, the supernatants of P. aeruginosa dispersed the SRB biofilms more readily than protease in M9 glucose minimum medium and were also effective against biofilms of Escherichia coli and Bacillus subtilis. 52 P. aeruginosa PA14 Δ toxA PA14_49560, Mar2xT7 transposon insertion, Gm R 52 P. aeruginosa PA14 Δ sodM PA14_58000, Mar2xT7 transposon insertion, Gm R 52 P. aeruginosa PA14 Δ rhlA rhlA::Gm, Gm R 53 P. aeruginosa PA14 Δ rhlB PA14_19110, Mar2xT7 transposon insertion, Gm R 52 P. aeruginosa PA14 Δ rhlI PA14_19130, Mar2xT7 transposon insertion, Gm R 52 P. aeruginosa PA14 Δ rhlR PA14_19120, Mar2xT7 transposon insertion, Gm R 52 P. fluorescens wild-type Richard Frazee S. aureus ATCC 29213, wild-type Kenneth Urish

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“…This could be attributed to the low HLB of rhamnolipid (Table 2), which indicates low hydrophilicity, and thus it could not effectively resist the foam drainage. Also, the thin adsorption monolayer of rhamnolipid at the foam film surface [37,38] could also result in low foam stability. Nevertheless, the existence of agitation turned rhamnolipid into a highly foaming surfactant and even made it surpass SDS at a concentration of 20 g/L (Fig.…”

Section: Discussionmentioning

confidence: 99%

Mechanism Study on the Severe Foaming of Rhamnolipid in Fermentation

Long

Sha

Meng

et al. 2016

J Surfact & Detergents

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Although the biosurfactant rhamnolipid has been previously characterized as having low foam ability, its fermentation is largely impeded by severe foaming. Hence, the investigation of this paradox is critically important for improving the mass production of rhamnolipid. Unexpectedly, the hydrophobic cell, instead of rhamnolipid, has been claimed to explain such severe foaming in rhamnolipid fermentation. This study tried to systematically investigate the severe foaming in fermentation, aiming to propose an effective strategy for foam control. The overflowing foam sustained a super high stability in terms of half‐time for over 30 min. The major product of rhamnolipid largely contributed to the severe foaming in the fermentation process whereas other products like cells elicited much more limited effects. Furthermore, the foam stability of the fermentation broth increased with rhamnolipid concentration and noticeably increased with agitation speed. In the classic Bikerman foam test system without stirring, rhamnolipid showed foam stability as low as Tween 20 which is well known for its poor foam stability. However, in a stirring Bikerman system, rhamnolipid exhibited a foam stability almost as high as sodium dodecyl sulfate (SDS) at 10 g/L and even surpassed SDS at a higher concentration of 20 g/L. Hence, the extraordinarily increased foam stability of rhamnolipid with both agitation and concentration could explain the severe foaming at its late‐stage fermentation when rhamnolipid‐rich solution is mechanically agitated.

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Surface forces and properties of foam films from rhamnolipid biosurfactants

Cited by 53 publications

References 51 publications

Flotation Frothers: Review of Their Classifications, Properties and Preparation

Flotation Frothers: Review of Their Classifications, Properties and Preparation

Rhamnolipids fromPseudomonas aeruginosaDisperse the Biofilms of Sulfate-Reducing Bacteria

Mechanism Study on the Severe Foaming of Rhamnolipid in Fermentation

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