Characterization of trehalose lipids produced by a unique environmental isolate bacteriumRhodococcus qingshengiistrain FF

The Application of Glycolipid-Type Microbial Biosurfactants as Active Pharmaceutical Ingredients for the Treatment and Prevention of Cancer

Pharmaceutical scientists have researched the potential of secondary metabolites biosynthesized by microorganisms as active pharmaceutical ingredients (APIs) for the treatment of cancer. Ideally, these APIs should possess anticancer bioactivity that specifically targets tumor cells while having little cytotoxic effect on healthy tissue. Biosurfactants are microbial secondary metabolites with surface-active properties and individual bioactivities that have the potential to either destroy cancer cells in a targeted fashion or prevent tumor cell formation. Currently, the best-studied class of microbial biosurfactants for the purpose of anticancer bioactivity is glycolipids, which contain a hydrophilic sugar moiety bonded to a hydrophobic fatty acid. Anticancer investigations are mainly carried out using in vitro models that show that compounds belonging to each of the four sub-classes of microbial glycolipid have significant anticancer bioactivity. The targeted action of this activity appears to be highly dependent on a specific congener molecular structure with nuanced alterations in structure leading to the killing of both tumor and healthy cells. This review compiles the current literature relating to glycolipid anticancer activity and provides a critical appraisal of exploiting the bioactivity of these compounds as novel anticancer agents. Finally, we propose several suggestions on how this research could be improved moving forward via method standardization.

Glycolipid and Lipopeptide Biosurfactants: Structural Classes and Characterization-Rhamnolipids as a Model

In recent years, biosurfactants (BS) produced by various bacteria, fungi and yeast strains have attracted much interest because of their unique properties and potential applications in many industries ranging from bioremediation to agriculture and biomedical to cosmetics. Glycolipids are a popular group of BS that include rhamnolipids, sophorolipids, mannosylerythritol, trehalose lipids, xylolipids and cellobiose lipids. Lipopeptides e.g., surfactins, iturins and fengycins are of major biotechnological interest because of their antitumor, immunomodulatory, and antimicrobial activities effects. This review addresses the structural properties of glycolipids and lipopeptides, their main domains of application as well as the screening tests of BS production. Glycolipids are mostly composed of a carbohydrate moiety linked to a ß-hydroxy fatty acid chain with a glycosidic bond. The properties of glycolipids are related to the nature of the carbohydrate moiety and the length of the fatty acid chain. The lipopeptide structure is mainly composed of a linear or cyclic peptide linked to fatty acids of different chain lengths. The structural complexity of these compounds requires various analytical techniques for characterization and quantification. As an example, the analytical techniques used for the characterization of rhamnolipids are presented in this review. RLs are very promising BS with a wide range of applications in various fields, such as cosmetics, food science, pharmaceuticals, and environmental remediation.

Exploring Biosurfactants as Antimicrobial Approaches

Antibacterial resistance is one of the most important global threats to human health. Several studies have been performed to overcome this problem and infection-preventive approaches appear as promising solutions. Novel antimicrobial preventive molecules are needed and microbial biosurfactants have been explored in that scope. Considering their structure, these biomolecules can be divided into different classes, glycolipids and lipopeptides being the most studied. Besides their antimicrobial activity, biosurfactants have the advantage of being biocompatible, biodegradable, and non-toxic, which favor their application in several areas, including the health sector. Often, the most difficult infections to fight are associated with biofilm formation, particularly in medical devices. Strategies to overcome micro-organism attachment are thus emergent, and it is possible to take advantage of the antimicrobial/antibiofilm properties of biosurfactants to produce surfaces that are more resistant to the deposition/attachment of bacteria. Approaches such as the covalent bond of biosurfactants to the medical device surface leading to repulsive physical-chemical interactions or contact killing can be selected. Simpler strategies such as the absorption of biosurfactants on surfaces are also possible, eliminating micro-organisms in the vicinity. This review will focus on the physical and chemical characteristics of biosurfactants, their antimicrobial activity, antimicrobial/antibiofilm approaches, and finally on their structure-activity relationship.

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.

A Novel Biosurfactant-Based Oil Spill Response Dispersant for Efficient Application under Temperate and Arctic Conditions

Synthetic oil spill dispersants have become essential in offshore oil spill response strategies. However, their use raises significant concerns regarding toxicity to phyto- and zooplankton and other marine organisms, especially in isolated and vulnerable areas such as the Arctic and shorelines. Sustainable alternatives may be developed by replacing the major active components of commercial dispersants with their natural counterparts. During this study, interfacial properties of different types of glycolipid-based biosurfactants (rhamnolipids, mannosylerythritol lipids, and trehalose lipids) were explored in a crude oil-seawater system. The best-performing biosurfactant was further mixed with different nontoxic components of Corexit 9500A, and the interfacial properties of the most promising dispersant blend were further explored with various types of crude oils, weathered oil, bunker, and diesel fuel in natural seawater. Our findings indicate that the most efficient dispersant formulation was achieved when mannosylerythritol lipids (MELs) were mixed with Tween 80 (T). The MELs-T dispersant blend significantly reduced the interfacial tension (IFT) of various crude oils in seawater with results comparable to those obtained with Corexit 9500A. Importantly, no leaching or desorption of MELs-T components from the crude oil-water interface was observed. Furthermore, for weathered and more viscous asphaltenic bunker fuel oil, IFT results with the MELs-T dispersant blend surpassed those obtained with Corexit 9500A. This dispersant blend also demonstrated effectiveness at different dosages (dispersant-to-oil ratio (DOR)) and under various temperature conditions. The efficacy of the MELs-T dispersant was further confirmed by standard baffled flask tests (BFTs) and Mackay-Nadeau-Steelman (MNS) tests. Overall, our study provides promising data for the development of effective biobased dispersants, particularly in the context of petroleum exploitation in subsea resources and transportation in the Arctic.

Biodesulfurization of organosulfur compounds by a trehalose biosurfactant producing Gordonia sp. isolated from crude oil contaminated soil

Certain factors hinder the commercialization of biodesulfurization process, including low substrate-specificity of the currently reported desulfurizing bacteria and restricted mass transfer of organic-sulfur compounds in biphasic systems. These obstacles must be addressed to clean organic-sulfur rich petro-fuels that pose serious environmental and health challenges. In current study, a dibenzothiophene desulfurizing strain, Gordonia rubripertincta W3S5 (source: oil contaminated soil) was systematically evaluated for its potential to remove sulfur from individual compounds and mixture of organic-sulfur compounds. Metabolic and genetic analyses confirmed that strain W3S5 desulfurized dibenzothiophene to 2-hydroxybiphenyl, suggesting that it follows the sulfur specific 4 S pathway. Furthermore, this strain demonstrated the ability to produce trehalose biosurfactants (with an EI24 of 53%) in the presence of dibenzothiophene, as confirmed by TLC and FTIR analyses. Various genome annotation tools, such as ClassicRAST, BlastKOALA, BV-BRC, and NCBI-PGAP, predicted the presence of otsA, otsB, treY, treZ, treP, and Trehalose-monomycolate lipid synthesis genes in the genomic pool of strain W3S5, confirming the existence of the OtsAB, TreYZ, and TreP pathways. Overall, these results underscore the potential of strain W3S5 as a valuable candidate for enhancing desulfurization efficiency and addressing the mass transfer challenges essential for achieving a scaled-up scenario.

Microbial surfactants: characteristics, production and broader application prospects in environment and industry

Microbial surfactants are green molecules with high surface activities having the most promising advantages over chemical surfactants including their ability to efficiently reducing surface and interfacial tension, nontoxic emulsion-based formulations, biocompatibility, biodegradability, simplicity of preparation from low cost materials such as residual by-products and renewable resources at large scales, effectiveness and stabilization under extreme conditions and broad spectrum antagonism of pathogens to be part of the biocontrol strategy. Thus, biosurfactants are universal tools of great current interest. The present work describes the major types and microbial origin of surfactants and their production optimization from agro-industrial wastes in the batch shake-flasks and bioreactor systems through solid-state and submerged fermentation industries. Various downstream strategies that had been developed to extract and purify biosurfactants are discussed. Further, the physicochemical properties and functional characteristics of biosurfactants open new future prospects for the development of efficient and eco-friendly commercially successful biotechnological product compounds with diverse potential applications in environment, industry, biomedicine, nanotechnology and energy-saving technology as well.

Update on new trend and progress of the mechanism of polycyclic aromatic hydrocarbon biodegradation by Rhodococcus, based on the new understanding of relevant theories: a review

Rapid industrial and societal developments have led to substantial increases in the use and exploitation of petroleum, and petroleum hydrocarbon pollution has become a serious threat to human health and the environment. Polycyclic aromatic hydrocarbons (PAHs) are primary components of petroleum hydrocarbons. In recent years, microbial remediation of PAHs pollution has been regarded as the most promising and cost-effective treatment measure because of its low cost, robust efficacy, and lack of secondary pollution. Rhodococcus bacteria are regarded as one of main microorganisms that can effectively degrade PAHs because of their wide distribution, broad degradation spectrum, and network-like evolution of degradation gene clusters. In this review, we focus on the biological characteristics of Rhodococcus; current trends in PAHs degradation based on knowledge maps; and the cellular structural, biochemical, and enzymatic basis of degradation mechanisms, along with whole genome and transcriptional regulation. These research advances provide clues for the prospects of Rhodococcus-based applications in environmental protection.

A comprehensive review on production of bio-surfactants by bio-degradation of waste carbohydrate feedstocks: an approach towards sustainable development

The advancement of science and technology demands chemistry which is safer, smarter and green by nature. The sustainability of science thus requires well-behaved alternates that best suit the demand. Bio-surfactants are surface active compounds, established to affect surface chemistry. In general, microbial bio-surfactants are a group of structurally diverse molecules produced by different microbes. A large number of bio-surfactants are produced during hydrocarbon degradation by hydrocarbonoclistic microorganisms during their own growth on carbohydrates and the production rate is influenced by the rate of degradation of carbohydrates. The production of such biological surfactants is thus of greater importance. This write up is a dedicated review to update the existing knowledge of inexpensive carbohydrate sources as substrates, microorganisms and technologies of biosurfactant production. This is an economy friendly as well as sustainable approach which will facilitate achieving some sustainable development goals. The production is dependent on the fermentation strategies, different factors of the microbial culture broth and downstream processing; these all have been elaborately presented in this article.

Sustainable production of biosurfactants via valorisation of industrial wastes as alternate feedstocks

Globally, the rapid increase in the human population has given rise to a variety of industries, which have produced a variety of wastes. Due to their detrimental effects on both human and environmental health, pollutants from industry have taken centre stage among the various types of waste produced. The amount of waste produced has therefore increased the demand for effective waste management. In order to create valuable chemicals for sustainable waste management, trash must be viewed as valuable addition. One of the most environmentally beneficial and sustainable choices is to use garbage to make biosurfactants. The utilization of waste in the production of biosurfactant provides lower processing costs, higher availability of feedstock and environmental friendly product along with its characteristics. The current review focuses on the use of industrial wastes in the creation of sustainable biosurfactants and discusses how biosurfactants are categorized. Waste generation in the fruit industry, agro-based industries, as well as sugar-industry and dairy-based industries is documented. Each waste and wastewater are listed along with its benefits and drawbacks. This review places a strong emphasis on waste management, which has important implications for the bioeconomy. It also offers the most recent scientific literature on industrial waste, including information on the role of renewable feedstock for the production of biosurfactants, as well as the difficulties and unmet research needs in this area.

Toxicity evaluation of the metabolites derived from the degradation of phenanthrene by one of a soil ubiquitous PAHs-degrading strain Rhodococcus qingshengii FF

Rhodococcus qingshengii strain FF is a soil ubiquitous strain that has a high polycyclic aromatic hydrocarbons (PAHs) biodegradation capability. In this work, phenanthrene was used as a PAH model compound. The accumulated pattern of the metabolites of phenanthrene by strain FF was investigated, and their toxicity to Vibrio fischeri, effect on microbiota diversity of farmland soil and influence on seed of wheat were evaluated. Total of 29 main intermediates were observed for the phenanthrene degradation process. Pyrogallol was the predominant accumulated metabolite, and 59% of the accumulated metabolites were oxygen-containing PAHs that have only one benzene ring. The acute toxicity assessment showed the accumulated metabolites in later phase were more toxic to Vibrio fischeri. Microbe and wheat seed response to the different stages of phenanthrene metabolites indicated pollution significantly decreased microbial richness and evenness of farmland soil and lower germinal length, root length or root number of wheat seed. These results indicated that not only the elimination of PAHs, but also the easily accumulated metabolites produced during the PAHs degradation process should be paid enough attention. The comprehensive evaluation of toxicity during the degradation process would provide useful information for the use of microbe-orientated strategies in PAHs bioremediation.

Immobilization of Rhodococcus qingshengii strain FF on the surface of polyethylene and its adsorption and biodegradation of mimic produced water

Low pH and high salinity characteristic of produced water (PW) posed a big challenge for the direct biological treatment. The immobilization of R. qingshengii strain FF, which degraded petroleum effectively under low pH, and application of immobilized R. qingshengii strain FF in treating mimic PW was studied in this work. The immobilization of R. qingshengii strain FF on the surface of polyethylene foam (PEF), one type of waste packaging materials, was optimized using the response surface methodology. Under optimum conditions, cell density of R. qingshengii strain FF immobilized on the surface of PEF reached 388 mg (cells)/g(PEF). In addition, a few factors, including hydraulic retention time (HRT), pH and salinity, were studied for treating mimic PW using immobilized R. qingshengii strain FF. The result of this study demonstrated that TPH degradation efficiency of PW by immobilized R. qingshengii strain FF reached above 90% when HRT was longer than 8 h. Weak acid and high salinity conditions only moderately decreased TPH. Asphalt, alkanes and aromatic hydrocarbon contained in petroleum can be degraded to some extent. These results indicated that immobilized R. qingshengii strain FF can be used as a highly efficient strain which could be used in biological treatment of real PW.

Bio-based rhamnolipids production and recovery from waste streams: Status and perspectives

Bio-based rhamnolipid production from waste streams is gaining momentum nowadays because of increasing market demand, huge range of applications and its economic and environment friendly nature. Rhamnolipid type biosurfactants are produced by microorganisms as secondary metabolites and have been used to reduce surface/interfacial tension between two different phases. Biosurfactants have been reported to be used as an alternative to chemical surfactants. Pseudomonas sp. has been frequently used for production of rhamnolipid. Various wastes can be used in production of rhamnolipid. Rhamnolipids are widely used in various industrial applications. The present review provides information about structure and nature of rhamnolipid, production using different waste materials and scale-up of rhamnolipid production. It also provides comprehensive literature on various industrial applications along with perspectives and challenges in this research area.

Establishment and application of a novel fluorescence-based analytical method for the rapid detection of viable bacteria in different samples

A rapid method for readily detecting the total numbers of viable bacterial cells in numerous samples (including surface water, solid inoculants, and soil samples) is reported using a newly developed hand-held fluorometer and a fluorescent dye Calcein UltraGreen™ AM. Compared to the traditional plate counting method that requires 48 hours of cultivation, the newly established method does not require any incubation time, making the detection method faster and more convenient. The portable rapid detection fluorometer has a wide dynamic range of relative fluorescence intensity from 45 to 30 133. It can detect bacterial concentration ranging from 10⁵ to 10¹⁰ cells per mL. This newly established method has good applicability for accurately and quickly detecting the cell number of viable bacteria in various samples. The results of the fluorescence-based method were compared with those of the traditional plate counting method, and it was found that the relative standard deviation was less than 6%. This new rapid measurement system provides a robust method for the rapid on-site detection of viable bacteria.

Bacterial Natural Disaccharide (Trehalose Tetraester): Molecular Modeling and in Vitro Study of Anticancer Activity on Breast Cancer Cells

Isolation and characterization of new biologically active substances affecting cancer cells is an important issue of fundamental research in biomedicine. Trehalose lipid was isolated from Rhodococcus wratislaviensis strain and purified by liquid chromatography. The effect of trehalose lipid on cell viability and migration, together with colony forming assays, were performed on two breast cancer (MCF7-low metastatic; MDA-MB231-high metastatic) and one "normal" (MCF10A) cell lines. Molecular modeling that details the structure of the neutral and anionic form (more stable at physiological pH) of the tetraester was carried out. The tentative sizes of the hydrophilic (7.5 Å) and hydrophobic (12.5 Å) portions of the molecule were also determined. Thus, the used trehalose lipid is supposed to interact as a single molecule. The changes in morphology, adhesion, viability, migration, and the possibility of forming colonies in cancer cell lines induced after treatment with trehalose lipid were found to be dose and time dependent. Based on the theoretical calculations, a possible mechanism of action and membrane asymmetry between outer and inner monolayers of the bilayer resulting in endosome formation were suggested. Initial data suggest a mechanism of antitumor activity of the purified trehalose lipid and its potential for biomedical application.