Table 1 Applications of rhamnolipids

Oil recovery

Microbial enhanced oil recovery (MEOR)

Increase amount of recoverable oil aided by rhamnolipid-producing microorganisms

[73]

[2, 74]

Bioremediation

Bioremediation of petroleum at contaminated sites

Addition of rhamnolipids improves solubility of hydrocarbons to facilitate degradation

[46, 75,76,77,78]

Bioremediation of heavy metal at contaminated lands or in water treatment plant; rhamnolipids can be applied in foaming-surfactant technology to remove heavy metal contaminants

[2, 11, 79]

Bioremediation of pesticides at agricultural fields; addition of rhamnolipids can enhance degradation of chemical pesticides

[11, 79]

Pest control

As emulsifier, spreaders and dispersing agent in pesticide formulations

[2, 79]

As bio-pesticide against agricultural pests; rhamnolipids have insecticidal activity against green peach aphids and Aedes aegypti larvae

[43, 80]

Crop protection

As biocontrol agent against several phytopathogenic fungi; addition of rhamnolipids or rhamnolipid-containing cell-free broth are effective in inhibiting growth of phytopathogens, e.g. F. oxysporum, B. cinerea, Mucor spp. and many more

[1, 7, 81,82,83,84]

As stimulant for plant immunity; induced genes involved in plant’s defense system in tobacco, wheat and Arabidopsis thaliana; induced biosynthesis of plant hormones important for signaling pathways involved in plant immunity

[43]

Food processing

As food ingredients or additives functioning as emulsifier, solubilizer, foaming and wetting agent

[7]

As antimicrobial agent preventing food spoilage and for sanitization; rhamnolipids inhibit growth of foodborne pathogenic bacteria, e.g. L. monocytogenes, B. subtilis; rhamnolipids also prevent formation of biofilms due to their anti-adhesive nature

[1, 85, 86]

As a source of (l)-rhamnose; enzymatic hydrolysis of rhamnolipids to obtain (l)-rhamnose, a raw material for production of flavor compounds

[42, 87]

Medical use

As biofilm control agent to prevent medical device-related infections; inhibit biofilm formation; synergistic effect with caprylic acid to inhibit biofilms of more resistant pathogens, e.g. P. aeruginosa and S. aureus

[2, 88, 89]

As anticancer agent; rhamnolipids inhibit growth of many human cancer cell lines, e.g. HI-60, BV-173, SKW-3, JMSU-1 and Hela cells

[2, 19]

Protein folding

Aid in folding of outer membrane protein A

[90]

Microbial fuel cells

Improve power density output of microbial fuel cells

[91]

Synthesis of nanoparticles

As structure-directing agent in nanoparticle synthesis

[92]