Chemical Surfactants Research Articles

Environmental comparative study of biosurfactants production and optimization using bacterial strains isolated from Egyptian oil fields

Biosurfactants have recently gained popularity because they have numerous benefits over chemical synthetic surfactants, including higher biodegradability, lower toxicity, higher foaming, environmental compatibility, and effective properties under harsh conditions. This study aimed to produce effective biosurfactants by selected bacterial strains isolated from Egyptian oil fields to improve oil recovery and investigate their environmental aspects for microbial enhanced oil recovery. The selected strains were incubated in a new proposed nutrient medium H to produce biosurfactants with optimum surface and emulsification activities. Stability studies were conducted to examine the tolerance of produced biosurfactants in harsh reservoir conditions. Core flooding tests were performed to investigate the potential of produced biosurfactants in enhancing oil recovery. The environmental risk assessment was conducted to investigate if there are any possible threats of the selected bacterial strains. Results showed that selected bacterial strains Bacillus licheniformis and Bacillus subtilis could produce effective biosurfactants that reached their maximum surface activity after 24 h of incubation by reducing the surface tension from 71.8 mN/m to 27.13 mN/m and 25.74 mN/m, and the interfacial tension against kerosene from 48.4 mN/m to 1.27 mN/m and 0.38 mN/m at critical micelle concentration of 0.06 g/l and 0.04 g/l, respectively. The produced biosurfactants by Bacillus licheniformis and Bacillus subtilis showed significant emulsification activity against crude oil with emulsification indices of 50.2% and 63.7%, respectively. High stability was observed at high temperatures for a long-time period and more than 60% of their surface and emulsification activities were maintained over a wide range of pH and salinity. It was also found that 31.41–39.35% of additional oil could be recovered by the produced biosurfactants. Finally, Bacillus licheniformis and Bacillus subtilis are environmentally safe, have no potential for toxicity, and no risk could occur for MEOR.

Effect of dual-modified CNTs on strength and chloride resistance of cementitious systems

This study is undertaken to explore, first, the dispersibility of dual-modified carbon nanotubes (CNTs) by way of non-covalent modification. Various non-ionic and ionic surfactants were employed and mutually combined with varying relative proportions. Then, the best few combinations from the dispersion test were used further for producing mortar mixtures reinforced with CNTs. These samples were later assessed for their mechanical strength and chloride resistance. A suite of morphological, thermal and microstructural characterisations was carried out to understand the underlying mechanisms. The results show that, compared with the single modification, the dispersibility of CNT could be improved more significantly by way of the dual modification. In particular, 70–90% of non-ionic surfactant, in proportion to the total surfactant addition, imparted the best dispersibility to CNTs in an aqueous solution. In addition, X-ray diffraction, thermogravimetric analysis, mercury intrusion porosimetry and scanning electron microscopy outputs reveal that the enhanced dispersion of CNTs by dual modification promoted the hydration process and the ensuing microstructure evolution of mortar specimens. Together, these offset the strength reduction imparted by entrained pores when introducing chemical surfactants and, more importantly, empowered the chloride resistance of CNT-reinforced mortars.

Enhanced Oil Recovery using a Combination of Biosurfactants.

Biosurfactants are surface-active compounds capable of reducing the surface tension between two phases of different polarities. Biosurfactants have been emerging as promising alternatives to chemical surfactants due to less toxicity, high biodegradability, environmental compatibility and tolerance to extreme environmental conditions. Here, we illustrate the methods used for screening of microbes capable of producing biosurfactants. The biosurfactant producing microbes were identified using drop collapse, oil spreading, and emulsion index assays. Biosurfactant production was validated by determining the reduction in surface tension of the media due to growth of the microbial members. We also describe the methods involved in characterization and identification of biosurfactants. Thin layer chromatography of the extracted biosurfactant followed by differential staining of the plates was performed to determine the nature of the biosurfactant. LCMS, 1H NMR, and FT-IR were used to chemically identify the biosurfactant. We further illustrate the methods to evaluate the application of the combination of produced biosurfactants for enhancing residual oil recovery in a simulated sand pack column.

Treatment of personal care product wastewater for reuse by integrated electrocoagulation and membrane filtration processes

In this scientific paper, the treatment performance of integrated electrocoagulation and membrane filtration process was investigated for the treatment of personal care product wastewater via responce surface methodology (RSM). The effect of electrode material (iron (Fe), aluminum (Al), stainless steel (SS), titanium (Ti), and graphite (Gr)), current density (50–150 A/m2), initial pH (4–10), and retention time (120–240 min) on chemical oxygen demand (COD), surfactant, oil-grease and microplastic removal was investigated. The SS cathode displayed the highest removal efficiency. RSM was employed to adjust the operating parameters: 50 A/m2 of current density, pH = 4, and 180 min of electrolysis reaction time, where the highest COD removal efficiency was 89.6%, surfactant elimination reached 99.4%, and oil-grease reduction was 99.3% acquired with the SS electrode pairs. The EC pretreated wastewater was passed through different membrane systems: ultrafiltration (UP150), nanofiltration (NF270 and NF90), and reverse osmosis (BW30 and SW30). The utilization of SW30 membrane has enhanced COD removal efficiency and reached 99.18% and each of surfactant, oil-grease, and microplastic removal efficiencies were enhanced as well. The ultimate outcomes displayed the significant ability of the studied combined processes to treat efficiently the tested wastewater and enhanced subsequently its final quality.

Application of response surface methodology for a feasibility study of producing stable semi-aphron fluids using natural materials

ABSTRACT Due to the drilling problems in fractured reservoirs, multiphase lightweight fluids are essential. To produce lightweight fluids and to achieve the desired stability, a variety of chemical and natural surfactants are used. However, natural surfactants are more in demand due to environmental issues and challenges. The goal of this research is to produce a lightweight fluid using a combination of natural materials. Moreover, colloidal gas aphron (CGA) based drilling fluids are prepared at 5,000 to 10,000 rpm stirring speed; therefore in this research, the production feasibility of stable multiphase fluid (called semi-aphron) was investigated at a lower stirring speed (1,500 rpm) without Xanthan Gum polymer. The applied natural raw materials, were Acanthophyllum bracteatum root (ABR), Glycyrrhiza glabra root (GGR), and Tetraclinis articulata fruit (TAF) powders that were mixed with Persian Gulf seawater. Three models of response surface methodology (RSM) were utilized to assess the effects of natural materials concentration (0 to 0.2%wt.) on the stability and drained volume (DV) of the liquid phase at 25°C and 70°C. The utilized models were central composite design (CCD), typical custom design (TCD), and modified custom design (MCD). Based on the results, the optimum concentration for ABR, GGR, and TAF were 0.2%, 0.1%, and 0.1% wt., respectively. The produced fluids, using the combination of natural materials, had better stability than the base fluid (using SDS). The optimum concentration of natural material delayed the drainage of the liquid by about 70% at ambient temperature (25°C), and by about 50% at 70°C. The MCD model showed better-predicted R2 at ambient temperatures and 70°C (0.91 and 0.88, respectively) than the other two models, and would estimate the amount of DV better. The results showed that ABR and TAF had an inverse effect on DV at 25°C; thus, ABR and TAF increased semi-aphron stability, whereas GGR increased DV and semi-aphron instability. The results of this study can be considered for the application of native natural materials (ABR, GGR, and TAF) in the production of light drilling fluids, which reduces the environmental challenges of drilling fluids.

Reduced deactivation of mechanochemically delaminated hierarchical zeolite MCM-22 catalysts during 4-propylphenol cracking

The delamination of MCM-22 using shear forces in a vibratory ball mill, rather than chemical surfactants and sonication, is illustrated. The resulting material has comparable or improved physical properties compared to chemically delaminated MCM-22 without a significant loss of acid sites. The mechanical treatment affected the initial rate of 4-propylphenol cracking to phenol and propylene, a model reaction for lignin-derived aromatics, much less than chemical delamination. It also shows improved deactivation resistance for this reaction known to experience fast deactivation by pore blockage.

Carbon nanofibers (CNFs) dispersed in ultra-high performance concrete (UHPC): Mechanical property, workability and permeability investigation

This paper presents experimental data on the effect of carbon nano-fiber (CNF) dispersion on mechanical behavior, workability, and permeability of ultra-high-performance concrete containing CNF (UHPC-CNF). The addition of CNFs in concrete has been shown to provide improved performance. However, an inhomogeneous distribution of CNFs in the cement matrix can result in no impact or decreased mechanical performance. Due to the van der Waal's forces and hydrophobic surface properties of the CNFs, good dispersion in mix fluids and cement paste is challenging. Experimental studies of UHPC-CNF with different dispersion methods are provided. Further mixing with optimized UHPC paste allowed for the investigation of the optimal dosage of CNFs, impact on porosity, compressive strength, flexural strength, hydration rate, and slump. Scanning electron microscopy (SEM) analysis visually revealed the effect of dispersion. The results indicate that shear mixing and subsequent ultrasonic dispersion with chemical surfactants can provide a well-dispersion liquid admixture of CNFs resulting in high mechanical performance of UHPC-CNFs composites. The water permeability and chloride resistance of optimized UHPC-CNFs composites were further evaluated with the wicking test and ponding test to reveal improved performance for these properties as well.

Creation of a Hydrodynamic Digital Model of a Laboratory Core Experiment of Surfactant Polymer Impact on Oil Recovery, in Order to Determine Parameters for Further Full-Scale Simulation

The work aimed to solve the problem of determining, validating, and transferring model parameters of flooding using chemical enhanced oil recovery (EOR) from a core experiment to a full-scale hydrodynamic model. For this purpose, a digital hydrodynamic model describing the process of oil displacement by the surfactant and polymer solution on the core is created and the digital model is matched to achieve convergence with the historical data. This approach allows the uncertainties associated with the limited number of experiments to be removed to fully describe the parameters of the chemical surfactant polymer flooding model and form a database that could subsequently be replicated at various field sites, having the composition of reservoir fluids and distribution of rock composition in the core material as the basis. Besides, the digital model allows for verification of physical and chemical properties of surfactants and polymers, values of the adsorption of chemical agents on rocks, and the behavior of relative permeability in the hydrodynamic model of EOR before making predictions on the full-scale model and to improve the quality of forecast cases.

Application of a biosurfactant from Pseudomonas cepacia CCT 6659 in bioremediation and metallic corrosion inhibition processes

Biosurfactants are capable of meeting the challenges of the oil industry by reducing its social, economic, and environmental impacts. The aim of the present study was to produce a biosurfactant from Pseudomonas cepacia CCT6659 in 2.0-L and 5.0-L bioreactors and evaluate its long-term stability over 120 days of storage. Ecotoxicological tests were performed with Artemia salina larvae during the use of the biosurfactant to increase in solubilisation of heavy oil in seawater compared to the use of a chemical surfactant. The biosurfactant was also applied as a bioremediation agent for sand contaminated with a petroleum product and as an inhibitor of corrosion on metallic surfaces. A concentration of 35.0 g/L of the biosurfactant was achieved in the 5.0-L reactor and low toxicity to the bioindicator was found, with an approximate 40% reduction in the mortality rate compared to the chemical surfactant. The stability of the biosurfactant was demonstrated by the maintenance of its tensioactive properties throughout the entire storage period. Besides its advantageous bioremediating capacity, with the removal of 94.5% of oil from sand, the biosurfactant proved to be an effective inhibitor of both metallic corrosion and microbial biofilm, with minimal loss of mass (15.7%) compared to the control condition, demonstrating its potential for industrial applications.

Study on improving the hydrophilicity of coal by a biosurfactant-producing strain screened from coal

In order to improve the hydrophilicity of coal and solve the potential environmental problems caused by chemical surfactants, in this study, a biosurfactant-producing bacteria (PLD01) was screened from coal through biochemical test screen. The species, biosurfactant types and composition analysis of the strain were studied. PLD01 was identified by 16S rRNA, and exhibited 99% sequence similarity with Pseudomonas bacteria. Fourier Transform Infrared Spectrophotometer (FTIR) analysis showed the presence of N-H, carboxyl groups, and glycosidic bonds in biosurfactants, which were determined as glycolipids. Liquid Chromatography-Mass Spectrometry (LC-MS) analysis showed that the biosurfactants had Mono-rhamno-mono-lipidic congeners (Rha-C12), Di-rhamno-mono-lipidic congeners (Rha-Rha-C10), and Mono-rhamno-di-lipidic congeners (Rha-C12-C10/Rha-C10-C12). Finally, the analysis of the potential and performance of PLD01 to produce surfactants revealed that it was an effective biosurfactant. The yield of biosurfactant was 4.35 g/L when OD600 = 1.34 and cultured for 7 d. The critical micelle concentration (CMC) of the separated biosurfactant was as low as 50.0 mg/L, which reduced the surface tension of water from 72.8 mN/m to 40.6 mN/m. The modified wetting effect was better than the common chemical surfactant sodium dodecyl sulfate (SDS). Therefore, the biosurfactant-producing bacteria have good engineering application prospects.

Integrative description of changes occurring on zebrafish embryos exposed to water-soluble crude oil components and its mixture with a chemical surfactant

The effects of crude oil spills are an ongoing problem for wildlife and human health in both marine and freshwater aquatic environments. Bioassays of model organisms are a convenient way to assess the potential risks of the substances involved in oil spills. Zebrafish embryos (ZFE) are a useful to reach a fast and detailed description of the toxicity of the pollutants, including both the components of the crude oil itself and substances that are commonly used for crude oil spill mitigation (e.g. surfactants). Here, we evaluated the survival rate, as well as histological, morphological, and proteomic changes in ZFE exposed to Water Accumulated Fraction (WAF) of light crude oil and in mixture with Dioctyl Sulfosuccinate Sodium (DOSS, e.g. CEWAF: Chemically Enhanced WAF), a surfactant that is frequently used in chemical dispersant formulations. Furthermore, we compared the hydrocarbon concentration of WAF and CEWAF of the sublethal dilution. In histological, morphological, and gene expression variables, the ZFE exposed to WAF showed less changes than those exposed to CEWAF. Proteomic changes were more dramatic in ZFE exposed to WAF, with important alterations in spliceosomal and ribosomal proteins, as well as proteins related to eye and retinal photoreceptor development and heart function. We also found that the concentration of high molecular weight hydrocarbons in water was slighly higher in presence of DOSS, but the low molecular weight hydrocarbons concentration was higher in WAF. These results provide an important starting point for identifying useful crude-oil exposure biomarkers in fish species.

Rhamnolipids as Green Stabilizers of nZVI and Application in the Removal of Nitrate From Simulated Groundwater.

Environmental contamination caused by inorganic compounds is a major problem affecting soils and surface water. Most remediation techniques are costly and generally lead to incomplete removal and production of secondary waste. Nanotechnology, in this scenario with the zero-valent iron nanoparticle, represents a new generation of environmental remediation technologies. It is non-toxic, abundant, cheap, easy to produce, and its production process is simple. However, in order to decrease the aggregation tendency, the zero-iron nanoparticle is frequently coated with chemical surfactants synthesized from petrochemical sources, which are persistent or partially biodegradable. Biosurfactants (rhamnolipids), extracellular compounds produced by microorganisms from hydrophilic and hydrophobic substrates can replace synthetic surfactants. This study investigated the efficiency of a rhamnolipid biosurfactant on the aggregation of nanoscale zer-valent iron (nZVI) and its efficiency in reducing nitrate in simulated groundwater at pH 4.0. Two methods were tested: 1) adding the rhamnolipid during chemical synthesis and 2) adding the rhamnolipid after chemical synthesis of nZVI. Scanning electron microscopy field emission, X-ray diffractometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, Dynamic Light Scattering, and zeta potential measurements were used to characterize bare nZVI and rhamnolipid-coated nZVI. The effects of the type of nZVI and initial NO3 concentration were examined. Nanoscale zer-valent iron with the addition of the rhamnolipid after synthesis achieved the best removal rate of nitrate (about 78%), with an initial nitrate concentration of 25 mg L−1. The results suggest that nZVI functionalized with rhamnolipids is a promising strategy for the in situ remediations of groundwater contaminated by NO3, heavy metal, and inorganic carbon.

Molecular optimization of castor oil maleate as demulsifier for water-in-crude oil emulsions

The formation of stable water-in-oil emulsions is a frequent problem in the oil industry. In general, the difficulty of processing, unwanted water co-production, and damage to machinery are the main issues. Chemical demulsifying additives are used to destabilize petroleum emulsions. In this context, new environmentally friendly demulsifying components are being developed, preferably those produced from low-cost sources. This work synthesized five chemical surfactants based on castor oil maleate (MACO). These additives were characterized by Fourier transform infrared (FTIR), gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR). The demulsification activity was studied through bottle tests on emulsions formulated with two Brazilian oils. A performance scan evaluated different molecular structures and concentrations of the demulsifiers (100 to 5000 ppm) to determine an optimum demulsifier molecular structure. Dynamic interfacial tension measurements were performed to elucidate the demulsification activity at the water-oil interface under the same experimental conditions as the bottle tests. The Ward and Tordai equation was applied according to asymptotic approximations to assess the diffusivity of additives. All results were discussed correlating the demulsifying mechanisms, performance at the interface, and the possibility of applying the additives. All additives showed demulsifying behavior in the form of a water dropper. The demulsifier containing 2.3 mols of maleic anhydride incorporated with 1.0 mol of castor oil showed more significant activity, with a maximum water resolution of 90% for both emulsion systems.

Study of the Adsorption Behavior of Surfactants on Carbonate Surface by Experiment and Molecular Dynamics Simulation.

Surfactants adsorption onto carbonate reservoirs would cause surfactants concentrations decrease in surfactant flooding, which would decrease surfactant efficiency in practical applications of enhanced oil recovery (EOR) processes. Different surfactants could be classified as cationic surfactants, anionic surfactants, non-ionic surfactants according to the main charge, or be classified as chemical surfactant and bio-surfactant according to the surfactant origin. However, the research on different type surfactants adsorption on carbonate reservoirs surface differences was few. Therefore, five representative surfactants (CTAB, SDS, TX-100, sophorolipid, rhamonilipid) adsorption effect onto carbonate reservoirs surface was studied. Owing to the fact that the salinity and temperature in underground carbonate reservoirs were high during the EOR process, it is vital to study the salinity effect and temperature effect on surfactant adsorption. In this study, different surfactants species, temperature and salinity adsorption onto carbonate reservoirs were studied. The adsorption isotherms were fitted by Langmuir, Freundlich, Temkin and Linear models, and the first three models fitting effect were good. The results showed that cationic surfactants adsorption quantity was higher than anionic surfactants, and the non-ionic surfactants adsorption quantity was the lowest. When the temperature increased, the surfactants adsorption would decrease, because the adsorption process was exothermic process, and increasing temperature would inhibit the adsorption. The higher salinity would increase surfactants adsorption because higher salinity could compress electric double layer. In order to decrease surfactants adsorption, SiO2 nanoparticles and TiO2 nanoparticles were added to surfactants solutions, and then surfactants could adsorb onto nanoparticles surface, then the steric hindrance between surfactant molecules would increase, which could decrease surfactants adsorption. Contact angle results indicated that surfactants adsorption made the carbonate reservoir wettability alteration. In the end, surfactants (with or without SiO2 nanoparticles) adsorption onto carbonate reservoirs mechanism were studied by molecular dynamics simulation. The simulation results indicated that the surfactants molecules could adsorb onto SiO2 nanoparticles surface, and then the surfactants adsorption quantity onto carbonate rocks would decrease, which was in accordance with the experiments results.

Opportunities and critical issues related to the use of amendments as sustainable remediation techniques

This study aims to analyse the opportunities and critical issues related to the use of amendments as remediation techniques. The performance of amendments (Aerobic Bioremediation, In Situ Chemical Oxidation and Surfactants) was compared with the performance of other groundwater remediation technologies (Air Sparging, Pump&Treat, Multi-Phase Extraction, Pump&Reinjection, Monitoring Natural Attenuation) based on a dataset of 180 contaminated sites. The considered factors are: effectiveness of the remediation; cost to remediate; operational time; environmental sustainability. The occurrence and types of amendment-related issues analyzed were studied on the 40 sites where the amendments had been applied. Issues occurred in 20% of the 40 analyzed cases and consisted of: a) partial or total occlusion of the monitoring wells and by-product formation, for example heavy metals (5%); b) uncontrolled increase in contaminant concentrations and potential downstream migration (8%); c) byproduct formation without well obstruction (7%). For each critical event, a detailed analysis was conducted to understand the processes (pH-Eh equilibria, contaminant desorption, hydraulic conductivity reduction), to highlight the design and procedural gaps (surplus of amendment, injection method selection, contaminant removal by purge). However, it has been observed that the issues can be avoided or mitigated with an accurate design, pilot tests performance, with the application of delivery and monitoring protocols, and at least with a prompt response adopting a corrective action plan, if necessary. The use of amendments turns out to be an effective solution: in 64% of the analyzed sites, it led to a significative reduction of the contamination within one year from the application. The cost is about one third if compared to the average of the other technologies. The operational time is about half the average operational time of the other technologies. Based on the results of sustainability analysis, amendments technologies reduce the production of waste, energy and water consumption, and they minimize air emissions. Considering the sustainability in its broadest sense (environmental, economic, and temporal), it is possible to state that the remediation by amendments is the most sustainable and would meet the interest of all the stakeholders.

Simple and efficient isolation of plant genomic DNA using magnetic ionic liquids

BackgroundPlant DNA isolation and purification is a time-consuming and laborious process relative to epithelial and viral DNA sample preparation due to the cell wall. The lysis of plant cells to free intracellular DNA normally requires high temperatures, chemical surfactants, and mechanical separation of plant tissue prior to a DNA purification step. Traditional DNA purification methods also do not aid themselves towards fieldwork due to the numerous chemical and bulky equipment requirements.ResultsIn this study, intact plant tissue was coated by hydrophobic magnetic ionic liquids (MILs) and ionic liquids (ILs) and allowed to incubate under static conditions or dispersed in a suspension buffer to facilitate cell disruption and DNA extraction. The DNA-enriched MIL or IL was successfully integrated into the qPCR buffer without inhibiting the reaction. The two aforementioned advantages of ILs and MILs allow plant DNA sample preparation to occur in one minute or less without the aid of elevated temperatures or chemical surfactants that typically inhibit enzymatic amplification methods. MIL or IL-coated plant tissue could be successfully integrated into a qPCR assay without the need for custom enzymes or manual DNA isolation/purification steps that are required for conventional methods.ConclusionsThe limited amount of equipment, chemicals, and time required to disrupt plant cells while simultaneously extracting DNA using MILs makes the described procedure ideal for fieldwork and lab work in low resource environments.

A Cumulative Effect by Multiple-Gene Knockout Strategy Leads to a Significant Increase in the Production of Sophorolipids in Starmerella Bombicola CGMCC 1576.

Sophorolipids (SLs), an important biosurfactant produced by S. bombicola, were one of the most potential substitutes for chemical surfactants. Few reports on the transcriptional regulation of SLs synthesis and the engineered strains with high-yield SLs were available. In this study, a Rim9-like protein (Rlp) and three transcription factors (ztf1, leu3, gcl) were mined and analyzed, and a progressive enhancement of SLs production was achieved through cumulative knockouts of three genes. The sophorolipid production of ΔrlpΔleu3Δztf1 reached 97.44 g/L, increased by 50.51% than that of the wild-type strain. Compared with the wild-type strain, the flow of glucose to SLs synthesis pathways was increased, and the synthesis of branched-chain amino acids was reduced in ΔrlpΔleu3Δztf1. The amount of UDP-glucose, the substrate for two glycosyltransferases, also increased, and the expression level of the key genes sble and UGPase for SLs synthesis increased by 2.2 times, respectively. The multiple-gene knockout strategy was proved to be highly effective to construct the engineered strain with high-yield SLs production, and this strain was a superior strain for industrial fermentation of SLs and reduced SLs production costs.

Biosurfactants: Potential and Eco-Friendly Material for Sustainable Agriculture and Environmental Safety—A Review

With the present climate change and increasing world population, there is an urgent need to discover creative, efficient, and cost-effective natural products for the benefit of humanity. Biosurfactants are produced by various microorganisms that have several distinct properties compared to other synthetic surfactants, including mild production conditions, multifunctionality, higher biodegradability, and lower toxicity of living cells synthesis of active compounds. Due to their surface tension reducing, emulsion stabilizing, and biodegrading properties of these in place of chemical surfactants, they are generating huge demand in terms of research and usage. Biosurfactants are widely used in the food industry as food-formulation ingredients and antiadhesive agents as emulsifiers, de-emulsifiers, spreading agents, foaming agents, and detergents that find application in various fields such as agriculture, industrial sectors, and environmental recreation. Recent research focused more on heavy metal bioremediation from compost was achieved using biosurfactants-producing bacteria, which resulted in an improvement in compost quality. Although a number of studies on biosurfactants synthesis have been reported, very limited information on its cinematics and the consumption of renewable substrates are available. In this review paper, we made an attempt to critically review biosurfactants, their usage, research related to them, and challenges faced.

Biosurfactants and Their Biodegradability: A Review and Examination

Surfactants are extensively employed in industrial, agricultural, and food, cosmetics and pharmaceuticals applications. Chemically produced surfactants cause environmental and toxicological hazards. Recently, considerable research has led to environmentally friendly procedures for the synthesis of several forms of biosurfactants from microorganisms. In comparison to chemical surfactants, biosurfactants have several advantages, such as biodegradability, low toxicity and ease of availability of raw materials. This paper offers an in-depth review of the types of surfactants, the need for bio-surfactants, their types and advantages, especially biodegradability. It also examines the biodegradability of selected four surfactants and finds that the biosurfactant is more easily biodegradable than the chemical surfactants.

Human Lactobacillus Biosurfactants as Natural Excipients for Nasal Drug Delivery of Hydrocortisone.

The inclusion of a chemical permeation enhancer in a dosage form is considered an effective approach to improve absorption across the nasal mucosa. Herein we evaluated the possibility of exploiting biosurfactants (BS) produced by Lactobacillus gasseri BC9 as innovative natural excipients to improve nasal delivery of hydrocortisone (HC). BC9-BS ability to improve HC solubility and the BS mucoadhesive potential were investigated using the surfactant at a concentration below and above the critical micelle concentration (CMC). In vitro diffusion studies through the biomimetic membrane PermeaPad® and the same synthetic barrier functionalized with a mucin layer were assessed to determine BC9-BS absorption enhancing properties in the absence and presence of the mucus layer. Lastly, the diffusion study was performed across the sheep nasal mucosa using BC9-BS at a concentration below the CMC. Results showed that BC9-BS was able to interact with the main component of the nasal mucosa, and that it allowed for a greater solubilization and also permeation of the drug when it was employed at a low concentration. Overall, it seems that BC9-BS could be a promising alternative to chemical surfactants in the nasal drug delivery field.