Sustainable biosurfactant production from secondary feedstock—recent advances, process optimization and perspectives

Abstract

Biosurfactants have garnered increased attention lately due to their superiority of their properties over fossil-derived counterparts. While the cost of production remains a significant hurdle to surpass synthetic surfactants, biosurfactants have been anticipated to gain a larger market share in the coming decades. Among these, glycolipids, a type of low-molecular-weight biosurfactant, stand out for their efficacy in reducing surface and interfacial tension, which made them highly sought-after for various surfactant-related applications. Glycolipids are composed of hydrophilic carbohydrate moieties linked to hydrophobic fatty acid chains through ester bonds that mainly include rhamnolipids, trehalose lipids, sophorolipids, and mannosylerythritol lipids. This review highlights the current landscape of glycolipids and covers specific glycolipid productivity and the diverse range of products found in the global market. Applications such as bioremediation, food processing, petroleum refining, biomedical uses, and increasing agriculture output have been discussed. Additionally, the latest advancements in production cost reduction for glycolipid and the challenges of utilizing second-generation feedstocks for sustainable production are also thoroughly examined. Overall, this review proposes a balance between environmental advantages, economic viability, and societal benefits through the optimized integration of secondary feedstocks in biosurfactant production.

A Low-Cost Ecofriendly Oxidation Process to Manufacture High-Performance Polymeric Biosurfactants Derived from Municipal Biowaste

“…Enhanced sustainability of rhamnolipid and sophorolipid biosurfactant production has been attempted by employing second-generation feedstocks [ 59 , 60 , 61 , 62 ], specifically industrial residual biomass waste streams such as sunflower oil, waste fried oil, jatropha oil, and animal fat (as hydrophobic substrates), and sugarcane molasses, soy molasses, glycerol (as hydrophilic substrates), and food waste. In this scenario, municipal unsorted food waste (MBW) and its anaerobic digestates are the most sustainable waste materials to use as potential waste feedstock.…”

“…For the bacterial sophorolipids and rhamonlipids biosurfactants [ 6 ] representing model products to be matched for performance by the chemical surfactants according to scheme 2, the employed approaches to improve their productivity are the optimization of culture conditions, the selection of robust microorganisms, the genetic modification of microorganisms, and the development of novel cost-effective downstream processes [ 60 , 61 , 72 , 73 , 74 ]. In spite of the great amount of research, according to the authors of the present work, the major factor hindering the scale-up of the results obtained by previous workers to the industrial level is the application of processes based on biotechnology that do not allow a real, consistent breakthrough in the end product cost reduction.…”

“…Therefore, as with many biosurfactants, rhamnolipids fail to reach the marketplace and substitute for conventional chemical surfactants. In conclusion, bacterial surfactants must face several challenges in process design, downstream processing, and low yields [ 73 ], process adaptability and optimization, socio-economic impacts and sustainability benefits, and regulatory barriers [ 60 , 61 , 70 ]. Based on the results of the present work, the authors think that, rather than trying to improve rhamnolipids production by biotechnological process, the optimization of the photochemical process and rhamnolipid-like products, according to scheme 2, offers more perspective concerning the development of low-cost biosurfactants matching the properties and performance of rhamnolipids and sophorolipids, and therefore being competitive with current commercial surfactants derived from fossil sources from all viewpoints.…”

Unlocking the Potential of Mannosylerythritol Lipids: Properties and Industrial Applications

“…Concerning bioprocess development, of which a detailed review is outside the scope of this manuscript, while the reported maximum productivities of SLs and RLs are 3.7 and 1.54 g/L/h, respectively, MELs' maximum productivities are significantly lower at values of 0.59 g/L/h [115]. In addition to lower productivity and consequent needs for CAPEX investment, other important cost-drivers are related to the use of pure substrates and the downstream process, which represents approximately 60% of the total production cost [3].…”

Microbial communities in petroleum refinery effluents and their complex functions

“…Rhamnolipid, a glycolipid extensively studied, comprises of 2 molecules of fatty acids (β-hydroxydecanoic acid) and 2 molecules of rhamnose sugar. The genus Pseudomonas , which includes Pseudomonas aeruginosa and Pseudomonas cepacian , is the most prolific generator of Rhamnolipids, although other bacterial species including Serratia rubidaea and Lysinibacillus sphaericus can also create them ( Miao et al, 2024 ).…”