Characterization and antifungal properties of rhamnolipids produced by mangrove sediment bacterium Pseudomonas aeruginosa strain KVD-HM52

Deepika, K.V.; Sridhar, P.; Bramhachari, Pallaval Veera

doi:10.1016/j.bcab.2015.09.009

Cited by 47 publications

(18 citation statements)

References 51 publications

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“…Further ESI-MS analysis of those parent ions gave fragment ions and shown in Fig. 4B, 4C, and 4D The parent ions at 651.5669 was dominant and could be assigned to dirhamnolipid [Rha-Rha-C 10 -C 10 + H] + , which was consistent with previous reports for P.aeruginosa SWP4, LBI and NY3 (Deepika et al, 2015;Lan et al, 2015;Titschke et al, 2005). The parent ions at m/z 481.3649, 509.3302.4, 679.5126 and 449.3254 were less abundant and could be assigned to [Rha-C 8 -C 8 +H] + , [Rha-Rha-C 10 +H] + , [Rha-Rha-C 12 +H] + , and [Rha-Rha-C 10 -C 12 +H] + , respectively.…”

Section: Structural Analysis Of Biosurfactantssupporting

confidence: 89%

Effects of nutrition optimization strategy on rhamnolipid production in a Pseudomonas aeruginosa strain DN1 for bioremediation of crude oil

Sun

Dong

et al. 2016

Biocatalysis and Agricultural Biotechnology

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An indigenous rhamnolipid biosurfactant-producing Pseudomonas aeruginosa strain DN1 was isolated from petroleum-contaminated soil samples which could use crude oil as the sole carbon and energy source. A high yield of 25.9 g/L rhamnolipid mixture was achieved in a shake flask by nutrition optimization strategy based on high throughput screening of strain DN1, supplemented with palm oil and 5.0g/L sodium nitrate at a C/N ratio of 20. These rhamnolipids reduced the surface tension of water from 45.23 to 25.88 mN/m with a critical micelle concentration of 50 mg/L, and were able to emulsify several hydrocarbons and showed excellent emulsification (100%).

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Section: Structural Analysis Of Biosurfactantssupporting

confidence: 89%

Effects of nutrition optimization strategy on rhamnolipid production in a Pseudomonas aeruginosa strain DN1 for bioremediation of crude oil

Sun

Dong

et al. 2016

Biocatalysis and Agricultural Biotechnology

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“…F. oxysporum , B. cinerea , Mucor spp. and many more [ 1 , 7 , 81 – 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.…”

Section: Rhamnolipidsmentioning

confidence: 99%

Microbial production of rhamnolipids: opportunities, challenges and strategies

2017

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Rhamnolipids are a class of biosurfactants which contain rhamnose as the sugar moiety linked to β-hydroxylated fatty acid chains. Rhamnolipids can be widely applied in many industries including petroleum, food, agriculture and bioremediation etc. Pseudomonas aeruginosa is still the most competent producer of rhamnolipids, but its pathogenicity may cause safety and health concerns during large-scale production and applications. Therefore, extensive studies have been carried out to explore safe and economical methods to produce rhamnolipids. Various metabolic engineering efforts have also been applied to either P. aeruginosa for improving its rhamnolipid production and diminishing its pathogenicity, or to other non-pathogenic strains by introducing the key genes for safe production of rhamnolipids. The three key enzymes for rhamnolipid biosynthesis, RhlA, RhlB and RhlC, are found almost exclusively in Pseudomonas sp. and Burkholderia sp., but have been successfully expressed in several non-pathogenic host bacteria to produce rhamnolipids in large scales. The composition of mono- and di-rhamnolipids can also be modified through altering the expression levels of RhlB and RhlC. In addition, cell-free rhamnolipid synthesis by using the key enzymes and precursors from non-pathogenic sources is thought to not only eliminate pathogenic effects and simplify the downstream purification processes, but also to circumvent the complexity of quorum sensing system that regulates rhamnolipid biosynthesis. The pathogenicity of P. aeruginosa can also be reduced or eliminated through in vivo or in vitro enzymatic degradation of the toxins such as pyocyanin during rhamnolipid production. The rhamnolipid production cost can also be significantly reduced if rhamnolipid purification step can be bypassed, such as utilizing the fermentation broth or the rhamnolipid-producing strains directly in the industrial applications of rhamnolipids.

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“…The bacterium was isolated from soils with hydrocarbon contaminated industrial zone and identified as a P. aeruginosa (ESOG € U-BK B 053). Seed culture was incubated in nutrient broth at overnight and then rhamnolipid production was performed in mineral salt medium (MSM) consisting of (g/L) NH 4 [19,20] and incubated at 35°C and 150 rpm for 72 h. Carbon source for this medium was added as 20 g/L sucrose. The pH of mineral salt medium has not been adjusted.…”

Section: Production Of Rhamnolipidmentioning

confidence: 99%

The true methodology for rhamnolipid: Various solvents affect rhamnolipid characteristics

Çakmak

Güngörmedi

Dıkmen

et al. 2017

Euro J Lipid Sci & Tech

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Rhamnolipid, among the most effective biosurfactants, is a glycolipid‐type biosurfactant primarily produced by Pseudomonas aeruginosa. In this study, rhamnolipid production was carried out using a strain of P. aeruginosa and it is aimed to compare rhamnolipid biopolymers obtained from various extraction methods using glycine (RG), hydrochloric acid (RH), diethyl ether (RD), ethyl acetate (RE). Comparison analyses were performed through NMR, FTIR techniques and viscosity, density measurements apart from determination of rhamnolipid yields. It can be concluded that rhamnolipid from diethyl ether for extraction is far from molecular structure to reference rhamnolipid molecule according to instrumental analyses performed. Besides, the yield of this rhamnolipid is much more than other rhamnolipids extracted through other methods but this is misleading because the value in there may be total sugar content apart from rhamnolipid. Therefore, RD extraction method can be said to be non‐selective process for rhamnolipid obtained. In RH method, some functional group peaks belonging to rhamnolipid were not observed. NMR analysis showed that some CH groups were not observed in the RG method. However, especially NMR and FTIR analyses showed that rhamnolipid obtained from RE method represented more accurate rhamnolipid based on reference molecule. Practical applications: This study showed that rhamnolipid production and its comparative analyses using various solvent extraction methods. Comparison analyses were carried out through NMR, FTIR techniques and viscosity, density measurements as well as determination of rhamnolipid yields. Different solvents affect seriously characteristics of rhamnolipid, which were defined in the previous literature reports. Especially, some methods are not selective ways for mentioning true biomolecule. To avoid misleading characterization information in the literature, these extraction methods were discussed through comparison methods such as NMR, FTIR analyses, and quantification measurements. Rhamnolipid biopolymers obtained from various extraction methods using glycine (RG), hydrochloric acid (RH), diethyl ether (RD), ethyl acetate (RE) are compared through NMR, FTIR techniques, and viscosity, density measurements. These analyses show that rhamnolipid obtained from RE method represents more accurate rhamnolipid based on reference molecule.

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Characterization and antifungal properties of rhamnolipids produced by mangrove sediment bacterium Pseudomonas aeruginosa strain KVD-HM52

Cited by 47 publications

References 51 publications

Effects of nutrition optimization strategy on rhamnolipid production in a Pseudomonas aeruginosa strain DN1 for bioremediation of crude oil

Effects of nutrition optimization strategy on rhamnolipid production in a Pseudomonas aeruginosa strain DN1 for bioremediation of crude oil

Microbial production of rhamnolipids: opportunities, challenges and strategies

The true methodology for rhamnolipid: Various solvents affect rhamnolipid characteristics

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