Production and characterization of glycolipid biosurfactant from Streptomyces enissocaesilis HRB1 and its evaluation for biomedical and bioremediation applications

Abstract

The aim of this investigation is to produce and characterize biosurfactant from Streptomyces sp. HRB1 and to evaluate its biomedical and bioremediation potential. Biosurfactant producing property of Streptomyces sp. HRB1 isolated from petroleum contaminated soil was confirmed by hemolytic and oil spread assays. Based on the results of FT-IR spectral and GC-MS analysis, the biosurfactant was confirmed as glycolipid type. Biosurfactant from Streptomyces sp. HRB1 exhibited 71% inhibition against Pseudomonas aeruginosa biofilm formation, 77.33% quorum sensing inhibition property against Chromobacterium violeceum MTCC 2656, more than 80% inhibition in antioxidant assays namely, DPPH, ABTS, and metal chelation, promising anti-proliferative activity against leukemia and myeloma cells with low IC 50 values, 96% decolorization of malachite green within 48 h of reaction time, and minimal toxicity against normal cell lines in dose-dependent manner. The taxonomic position of the potential strain HRB1 was further confirmed as Streptomyces enissocaesilis HRB1 based on their phenotypic and molecular characteristics. To conclude, Streptomyces enissocaesilis HRB1 isolated from petroleum-contaminated soil is a promising source for low-cost production of glycolipid biosurfactant with potential biomedical and environmental applications such as antiphytofungal, antibiofilm, anti-quorum sensing, antioxidant, anticancer, and dye degradation properties.

Glycolipid Biosurfactants in Skincare Applications: Challenges and Recommendations for Future Exploitation

“…Therefore, the in vitro wound healing effects of sophorolipid biosurfactants demonstrated by Maeng et al (2018) [27] is a significant step towards the identification of potential novel natural ingredients for use in wound care formulations to accelerate chronic wound healing and to reduce reliance on skin grafting. In another study on the characterisation of the cytotoxic effects of sophorolipids by Lydon and colleagues [59], concentrations up to 0.5 mg mL −1 of acidic sophorolipids (Acidic SL) had no significant cytotoxic effects on either human umbilical vein endothelial cells, human dermal microvascular endothelial cells, or spontaneously transformed human keratinocytes (HaCaT cells) after 24 h. More recently, Manikkasundaram and colleagues [42] extracted a glycolipid biosurfactant from Streptomyces enissocaesilis, HRB1, characterising it to identify the molecular structure. Although the exact congener of glycolipid was not reported, the authors evaluated the biomedical and bioremediation potential of the glycolipid extract [42].…”

“…In another study on the characterisation of the cytotoxic effects of sophorolipids by Lydon and colleagues [59], concentrations up to 0.5 mg mL −1 of acidic sophorolipids (Acidic SL) had no significant cytotoxic effects on either human umbilical vein endothelial cells, human dermal microvascular endothelial cells, or spontaneously transformed human keratinocytes (HaCaT cells) after 24 h. More recently, Manikkasundaram and colleagues [42] extracted a glycolipid biosurfactant from Streptomyces enissocaesilis, HRB1, characterising it to identify the molecular structure. Although the exact congener of glycolipid was not reported, the authors evaluated the biomedical and bioremediation potential of the glycolipid extract [42]. It was demonstrated that the crude glycolipid biosurfactant inhibited the formation of 71% P. aeruginosa biofilms at treatment concentrations of 512 µg mL −1 and exhibited antioxidant properties at 1000 µg mL −1 [42].…”

“…Consequently, sophorolipids and rhamnolipids are gaining significant traction for use in the food, pharmaceutical, and skincare industries [12,19,[35][36][37][38]. However, low product yield and sophisticated production processes alongside limited structural variability are among the paramount challenges affecting the utilisation of these biosurfactants in academic and industrial research, especially for the skincare and pharmaceutical applications [3,21,27,[39][40][41][42]. Additionally, in the bioactivity assessment of sophorolipids and rhamnolipids, most studies lack sufficient comparative experimental controls such as the use of a synthetic surfactant, whose effects on skin cells or skin bacteria can be compared directly with these glycolipids in studies where the investigations of suitable natural and skin-compatible alternatives to synthetic surfactants for potential skincare applications is a priority [27,42].…”

“…However, low product yield and sophisticated production processes alongside limited structural variability are among the paramount challenges affecting the utilisation of these biosurfactants in academic and industrial research, especially for the skincare and pharmaceutical applications [3,21,27,[39][40][41][42]. Additionally, in the bioactivity assessment of sophorolipids and rhamnolipids, most studies lack sufficient comparative experimental controls such as the use of a synthetic surfactant, whose effects on skin cells or skin bacteria can be compared directly with these glycolipids in studies where the investigations of suitable natural and skin-compatible alternatives to synthetic surfactants for potential skincare applications is a priority [27,42]. Furthermore, most in vitro studies on the effects of these glycolipids on skin cells and bacteria were conducted using 2D in vitro cell cultures, thus, the inability of these cell culture models to accurately represent the in vivo human skin and the skin microenvironment [31,42].…”

“…Additionally, in the bioactivity assessment of sophorolipids and rhamnolipids, most studies lack sufficient comparative experimental controls such as the use of a synthetic surfactant, whose effects on skin cells or skin bacteria can be compared directly with these glycolipids in studies where the investigations of suitable natural and skin-compatible alternatives to synthetic surfactants for potential skincare applications is a priority [27,42]. Furthermore, most in vitro studies on the effects of these glycolipids on skin cells and bacteria were conducted using 2D in vitro cell cultures, thus, the inability of these cell culture models to accurately represent the in vivo human skin and the skin microenvironment [31,42]. Nevertheless, in recent years, the use of metabolic engineering, microbial enzymes, optimisation of cell culture media and fermentation techniques, utilisation of purified and chemically characterised glycolipid congeners in bioassays, and 3D in vitro cultures have been the emerging strategies to overcoming the above-mentioned obstacles in biosurfactant research and applications [12,21,24,35,43].…”