Biosurfactant and bioemulsifier as promising molecules produced by Mucor hiemalis isolated from Caatinga soil

BACKGROUND: The present study describes the production of biosurfactant (BS) and emulsifier (BE) by the filamentous fungus Mucor hiemalis UCP 0039, as well as the characterization and stability of the both biomolecules for environmental or industrial applications. RESULTS: Biosurfactants and bioemulsifiers are amphiphilic compounds and are produced as extracellular molecules. The results showed that bioproduct obtained by shaker condition reduced the water surface tension of 72 to 32 mN/m and reached an emulsification index of 96%, while the static cultivation resulted in a biomolecule with a surface tension of 40 mN/m and an emulsification index of 96%, suggesting the production of a biosurfactant and bioemulsifier, respectively. The compounds showed glycolipid nature but the biosurfactant presented cationic charge, while the bioemulsifier, anionic charge. Thus, the results confirmed that M. hiemalis produced two distinct biomolecules under different parameters and in the same culture medium. CONCLUSIONS: It is the first time that biosurfactant and emulsifier production has been described in the same medium and under different physical conditions by Mucor hiemalis. Both biomolecules showed thermal stability, as well as have significant effect on the viscosity of hydrophobic compounds, indicating the excellent potential for environmental safety or industrial applications to improve the efficiency of sustainable and economic technologies.

Cloning and heterologous expression of a hydrophobin gene Ltr. hyd from the tiger milk mushroom Lentinus tuber-regium in yeast-like cells of Tremella fuciformis

Background: Hydrophobins are small proteins secreted by filamentous fungi, which show a highly surface activity. Because of the signally self-assembling abilities and surface activities, hydrophobins were considered as candidates in many aspects, for example, stabilizing foams and emulsions in food products. Lentinus tuber-regium, known as tiger milk mushroom, is both an edible and medicinal sclerotium-producing mushroom. Up to now, the hydrophobins of L. tuber-regium have not been identified. Results: In this paper, a Class I hydrophobin gene, Ltr.hyd, was cloned from L. tuber-regium and expressed in the yeast-like cells of Tremella fuciformis mediated by Agrobacterium tumefaciens. The expression vector pGEH-GH was under the control of T. fuciformis glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter. The integration of Ltr.hyd into the genome of T. fuciformis was confirmed by PCR, Southern blot, fluorescence observation and quantitative real-time PCR (qRT-PCR). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that recombinant hydrophobin rLtr.HYD with an expected molecular mass of 13 kDa was extracted. The yield of rLtr.HYD was 0.66 mg/g dry weight. The emulsifying activity of rLtr.HYD was better than the typical food emulsifiers sodium caseinate and Tween 20. Conclusions: We evaluated the emulsifying property of hydrophobin Ltr.HYD, which can be potentially used as a food emulsifier.

Effects of baicalin, matrine, glycyrrhetinic acid and emodin in three kinds of emulsifier cream system on transdermal absorption in vitro / 中国中药杂志

To study effects of APG, Span-Tween and A6/25 emulsifier cream system on transdermal absorption in vitro of baicalin, matrine, glycyrrhetinic acid and emodin in emulsifier. Permeations studies were carried out in vitro with excised mice skin by improved Franz diffusion cells. The cumulative penetration amounts and the retention amounts of Chinese herbal medicinal ingredients in three kinds of emulsifier cream systems were determined by HPLC. The effects of different Chinese herbal medicinal ingredients in the same emulsifier system and the same herbal medicinal ingredients in different emulsifier systems on cumulative permeation amount, skin retention amount and permeation rate were investigated. According to the results, the order of different Chinese herbal medicinal ingredients in same kinds of emulsifier system by the cumulative permeation amount and the permeation rate were matrine>baicalin>glycyrrhetinic acid>emodin. With respect to the effect of different emulsifier systems on cumulative permeation amount and permeation rate of the same herbal medicinal ingredients, glycyrrhetinic acid and emodin showed no significant difference, Span-Tween emulsifier cream system had higher cumulative permeation amount and permeation rate. The cumulative permeation amount and the permeation rate of Chinese herbal medicinal ingredients in the three kinds of emulsifier cream systems had an identical regularity. However, the cumulative permeation amount, the skin retension amount and the permeation rate of the same herbal medicinal ingredients in different emulsifier systems had no regularity.

The application research progress of pickering emulsion in pharmaceutical field / 中国药学杂志

Pickering emulsions stabilized by solid microparticles, having the advantages of strong interfacial stability, non-toxicity and eco-friendliness compared with the traditional surfactant-stabilized emulsions, have been the focus of considerable researches in recent years. In this review, the application studies on Pickering emulsions were summarized from the following aspects:the stabilization theory about Pickering emulsions, solid microparticles used in Pickering emulsions, the applications of Pickering emulsions in pharmaceutical field and the new Pickering emulsion stabilized by drug nanocrystalline itself. These research progress would promote and expand the application of Pickering emulsions in pharmaceutical field.

Methodology exploration of test for haemolysis and agglomeration of colored injections and emulsion injections / 中国药学杂志

OBJECTIVE: To supplement and improve the method of haemolysis and agglomeration test of Pharmacopoeia of the People's Republic of China (2010 edition) thus to exclude the interference of colored injections and emulsion injections on haemolysis test.

Evaluation of emulsifier stability of biosurfactant produced by Saccharomyces lipolytica CCT-0913

Surface-active compounds of biological origin are widely used for many industries (cosmetic, food, petrochemical). The Saccharomyces lipolytica CCT-0913 was able to grow and produce a biosurfactant on 5 percent (v/v) diesel-oil at pH 5.0 and 32ºC. The cell-free broth emulsified and stabilized the oil-in-water emulsion through a first order kinetics. The results showed that the initial pH value and temperature influenced the emulsifier stability (ES), which was the time when oil was separated. The biosurfactant presented different stabilization properties for vegetable and mineral oil in water solution, despite the highest values of the ES occurring with vegetable oil. The biosurfactant presented smallest ES when compared to commercial surfactants; however, this biosurfactant was not purified.

Os tensoativos de origem biológica são amplamente utilizados em diversas aplicações. O microrganismo Saccharomyces lipolytica CCT-0913 possui a habilidade de crescer em 5 por cento (v/v) óleo diesel a pH 5,0 e 32ºC e produzir biosurfactante. O caldo fermentado livre de células e produzido por S. lipolytica emulsiona e estabiliza emulsões óleo em água de acordo com uma cinética de primeira ordem. Os resultados mostram que o valor do pH inicial e a temperatura influenciam a estabilidade emulsificante (ES), que é medido pelo tempo que a quantidade de óleo. O biosurfactante apresenta diferentes valores de estabilidade emulsificante para óleos vegetais e minerais em emulsões óleo-água, os maiores valores de ES ocorrem nas emulsões utilizando óleo vegetal. O biosurfactante apresenta valores baixos de ES quando comparado com emulsificantes comerciais, entretanto sem sofrer nenhum processo de purificação.

Study on the Influence Factors for the Preparation of Reverse Microemulsions and the Optimization of Its Formula / 中国药房

OBJECTIVE:To study the effect of oil phase,emulsifier and drugs on reverse microemulsion.METHODS:Pseudo-ternary phase diagram was adopted to study the effect of Span-80/Tween-80(emulsifier),thymopentin(model drug), long-chain glyceride,medium-chain glyceride,non-glyceride(oil phase).on the preparation of reverse microemulsions.Optimal formula of reverse microemulsions was selected.RESULTS:The largest water-in-oil(W/O)area was obtained in reverse microemulsion which was prepared using medium-chain glyceride as oil phase.Final formula was confirmed and contained distilled water/ Span-80/Tween-80/caprylic/capric triglyceride(2∶3∶6∶9).In addition,thymopentin was incorporated into the aqueous phase.CONCLUSIONS:The preparation of reverse microemulsions will be influenced by emulsifier,constitution of oil phase and drug.The influence factors for the actual preparation of reverse microemulsions should be optimized.

Selection of De-emulsification Strains and Optimization of Fermentation Conditions / 微生物学通报

Petroleum-field emulsions,which are produced in the process of exploration,production and re-covery,represent a major environmental and processing problem for the petroleum industry.Biological de-mulsifier as a biological agent,will become a novel method of petroleum-field emulsions demulsifier instead of chemical demulsifier for its high efficiency,low cost,high adoptability,environment-friendly,repeated use.A set of high efficiency and convenient method was established to isolate de-emulsification strain and studied on the fermentation conditions of the de-emulsification strains.A de-emulsification strains,isolated from a petroleum-contaminated site,was evaluated for its de-emulsification capabilities using a kero-sene/water model emulsion system keeping stable for more than 200 hours which was mixed by stirring Tween 60-water(0.072%,V/V)and Span 60-oil(0.028%,V/V)at the ratio(oil:water)of 6.5:3.5.We have isolated two strains with high and steady de-emulsification activity by separation and purification,blood-plate test,excluding-oil test and de-emulsifying test.The average de-emulsification rates were more than 80.0% at 24 h.The two strains are both belonging to bacillus by traditional and molecular genetic iden-tification.By optimizing the demulsification bacteria fermentation conditions,the fermentation conditions,which is the most suitable for accumulating the fermentation products,were determined as follows:tem-perature 25?C,stirring speed160 r/min,pH 9,inoculated quantities 20%.When the fermentation conditions were temperature 35?C,stirring speed120 r/min,pH 9,inoculated quantities 2%,the fermentation products appeared the highest activities of demulsification.

Comparison among Several Preparation Methods for Pseudo-ternary Phase Diagrams of Pharmaceutical Microemulsions / 中国药房

OBJECTIVE:To evaluate and compare the current preparation methods for pseudo-ternary phase diagrams of pharmaceutical microemulsions.METHODS:Pseudo-ternary phase diagrams were prepared by using Tween-80,OP and lecithin as emulsifiers respectively,alcohol as assistant emulsifiers,isopropyl myristate or aethylis oleas as the oil phase,the difference in phase diagrams obtained with different preparation methods was compared with regard to the accuracy and au-thenticity of valid point.RESULTS:To O/W surfactant,difference in the area of phase diagrams was small,but the dis-tinction of accuracy and authenticity of valid point was great.To W/O surfactant,difference in the area of phase diagrams was great.CONCLUSION:It is recommended to select the preparation method according to the characteristics of the constituents and the types of microemulsions in order to establish accurate and dependable phase diagram,the end point of titration should be judged comprehensively.