Novel Organic Solvent Nanofiltration Approaches for Microbial Biosurfactants Downstream Processing

Recent progress in microbial biosurfactants production strategies: Applications, technological bottlenecks, and future outlook

Biosurfactants are surface-active compounds produced by numerous microorganisms. They have gained significant attention due to their wide applications in food, pharmaceuticals, cosmetics, agriculture, and environmental remediation. The production efficiency and yield of microbial biosurfactants have improved significantly through the development and optimization of different process parameters. This review aims to provide an in-depth analysis of recent trends and developments in microbial biosurfactant production strategies, including submerged, solid-state, and co-culture fermentation. Additionally, review discusses biosurfactants' applications, challenges, and future perspectives. It highlights their advantages over chemical surfactants, emphasizing their biodegradability, low toxicity, and diverse chemical structures. However, the critical challenges in commercializing include high production costs and low yield. Strategies like genetic engineering, process optimization, and downstream processing, have been employed to address these challenges. The review provides insights into current commercial producers and highlights future perspectives such as novel bioprocesses, efficient microbial strains, and exploring their applications in emerging industries.

Promising Application, Efficient Production, and Genetic Basis of Mannosylerythritol Lipids

Mannosylerythritol lipids (MELs) are a class of glycolipids that have been receiving increasing attention in recent years due to their diverse biological activities. MELs are produced by certain fungi and display a range of bioactivities, making them attractive candidates for various applications in medicine, agriculture, and biotechnology. Despite their remarkable qualities, industrial-scale production of MELs remains a challenge for fungal strains. Excellent fungal strains and fermentation processes are essential for the efficient production of MELs, so efforts have been made to improve the fermentation yield by screening high-yielding strains, optimizing fermentation conditions, and improving product purification processes. The availability of the genome sequence is pivotal for elucidating the genetic basis of fungal MEL biosynthesis. This review aims to shed light on the applications of MELs and provide insights into the genetic basis for efficient MEL production. Additionally, this review offers new perspectives on optimizing MEL production, contributing to the advancement of sustainable biosurfactant technologies.

A review on the upstream production and downstream purification of mannosylerythritol lipids

Biosurfactants are natural compounds with remarkable surface-active properties that may offer an eco-friendly alternative to conventional surfactants. Among them, mannosylerythritol lipids (MELs) stand out as an intriguing example of a glycolipid biosurfactant. MELs have been used in a variety of sectors for various applications, and are currently commercially produced. Industrially, they are used in the pharmaceutical, cosmetic, food, and agricultural industries, based on their ability to reduce surface tension and enhance emulsification. However, despite their utility, their production is comparatively limited industrially. From a bioprocessing standpoint, two areas of interest to improve the production process are upstream production and downstream (separation and purification) product recovery. The former has seen a significant amount of research, with researchers investigating several production factors: the microbial species or strain employed, the producing media composition, and the production strategy implemented. Improvement and optimization of these are key to scale-up the production of MELs. On the other hand, the latter has seen comparatively limited work presented in the literature. For the most part traditional separation techniques have been employed. This systematic review presents the production and purification methodologies used by researchers by comprehensively analyzing the current state-of-the-art with regards the production, separation, and purification of MELs. By doing so, the review presents different possible approaches, and highlights some potential areas for future work by identifying opportunities for the commercialization of MELs.

Unlocking the potential of biosurfactants: Production, applications, market challenges, and opportunities for agro-industrial waste valorization

Biosurfactants are eco-friendly compounds with unique properties and promising potential as sustainable alternatives to chemical surfactants. The current review explores the multifaceted nature of biosurfactant production and applications, highlighting key fermentative parameters and microorganisms able to convert carbon-containing sources into biosurfactants. A spotlight is given on biosurfactants' obstacles in the global market, focusing on production costs and the challenges of large-scale synthesis. Innovative approaches to valorizing agro-industrial waste were discussed, documenting the utilization of lignocellulosic waste, food waste, oily waste, and agro-industrial wastewater in the segment. This strategy strongly contributes to large-scale, cost-effective, and environmentally friendly biosurfactant production, while the recent advances in waste valorization pave the way for a sustainable society.

Substrates of Opposite Polarities and Downstream Processing for Efficient Production of the Biosurfactant Mannosylerythritol Lipids from Moesziomyces spp

Biosurfactants can replace fossil-driven surfactants with positive environmental impacts, owing to their low eco-toxicity and high biodegradability. However, their large-scale production and application are restricted by high production costs. Such costs can be reduced using renewable raw materials and facilitated downstream processing. Here, a novel strategy for mannosylerythritol lipid (MEL) production explores the combination of hydrophilic and hydrophobic carbon sources sideways with a novel downstream processing strategy, based on nanofiltration technology. Co-substrate MEL production by Moesziomyces antarcticus was threefold higher than using D-glucose with low levels of residual lipids. The use of waste frying oil instead of soybean oil (SBO) in co-substrate strategy resulted in similar MEL production. Moesziomyces antarcticus cultivations, using 3.9 M of total carbon in substrates, yields 7.3, 18.1, and 20.1 g/L of MEL, and 2.1, 10.0, and 5.1 g/L of residual lipids, for D-glucose, SBO, and a combination of D-Glucose and SBO, respectively. Such approach makes it possible to reduce the amount of oil used, offset by the equivalent molar increase in D-glucose, improving sustainability and decreasing residual unconsumed oil substrates, facilitating downstream processing. Moesziomyces spp. also produces lipases that broken down the oil and, thus, residual unconsumed oils are in the form of free fatty-acids or monoacylglycerol, which are smaller molecules than MEL. Therefore, nanofiltration of ethyl acetate extracts from co-substrate-based culture broths allows to improve MEL purity (ratio of MEL per total MEL and residual lipids) from 66 to 93% using 3-diavolumes.

Green Surfactants (Biosurfactants): A Petroleum-Free Substitute for Sustainability-Comparison, Applications, Market, and Future Prospects

Surfactants are a group of amphiphilic molecules (i.e., having both hydrophobic and hydrophilic domains) that are a vital part of nearly every contemporary industrial process such as in agriculture, medicine, personal care, food, and petroleum. In general surfactants can be derived from (i) petroleum-based sources or (ii) microbial/plant origins. Petroleum-based surfactants are obvious results from petroleum products, which lead to petroleum pollution and thus pose severe problems to the environment leading to various ecological damages. Thus, newer techniques have been suggested for deriving surfactant molecules and maintaining environmental sustainability. Biosurfactants are surfactants of microbial or plant origins and offer much added advantages such as high biodegradability, lesser toxicity, ease of raw material availability, and easy applicability. Thus, they are also termed "green surfactants". In this regard, this review focused on the advantages of biosurfactants over the synthetic surfactants produced from petroleum-based products along with their potential applications in different industries. We also provided their market aspects and future directions that can be considered with selections of biosurfactants. This would open up new avenues for surfactant research by overcoming the existing bottlenecks in this field.