scholarly journals Production of Biosurfactants by Ascomycetes

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Michele Alves Sanches ◽  
Isabella Galvão Luzeiro ◽  
Ana Cláudia Alves Cortez ◽  
Érica Simplício de Souza ◽  
Patrícia Melchionna Albuquerque ◽  
...  
Keyword(s):  
Surface Tension ◽  
Filamentous Fungi ◽  
Environmental Conditions ◽  
Chemical Characterization ◽  
Reduce Surface Tension ◽  
Synthetic Surfactants

Surfactants are utilized to reduce surface tension in aqueous and nonaqueous systems. Currently, most synthetic surfactants are derived from petroleum. However, these surfactants are usually highly toxic and are poorly degraded by microorganisms. To overcome these problems associated with synthetic surfactants, the production of microbial surfactants (called biosurfactants) has been studied in recent years. Most studies investigating the production of biosurfactants have been associated mainly with bacteria and yeasts; however, there is emerging evidence that those derived from fungi are promising. The filamentous fungi ascomycetes have been studied for the production of biosurfactants from renewable substrates. However, the yield of biosurfactants by ascomycetes depends on several factors, such as the species, nutritional sources, and environmental conditions. In this review, we explored the production, chemical characterization, and application of biosurfactants by ascomycetes.

Air embolism: possible role of surfactant on recompression

1982 ◽  
Vol 52 (1) ◽  
pp. 119-123 ◽  
Author(s):  
B. A. Hills ◽  
R. E. Barrow
Keyword(s):  
Surface Tension ◽  
Decompression Sickness ◽  
Air Embolism ◽  
Pulmonary Vasculature ◽  
Physiological Conditions ◽  
Arterial Blood ◽  
Dipalmitoyl Lecithin ◽  
Reduce Surface Tension ◽  
The Relationship

The relationship between surface tension and surface area has been measured on each of three common pulmonary surfactants - dipalmitoyl lecithin (DPL), dipalmitoyl phosphatidylethanolamine, and sphyngomyelin-under simultaneously simulated physiological conditions. These are selected to simulate the state of any surfactant that has migrated onto the surface of venous bubbles filtered by the pulmonary vasculature. It is concluded that, in the absence of shunt vessels, only DPL could reduce surface tension enough to allow pulmonary gas emboli to escape into arterial blood and then only after compression. This finding is discussed in relation to the delay in any appearance of bubbles in arterial blood and the possible facilitation of the release of asymptomatic lung bubbles by recompression therapy. The suggestion is made to reconsider stopping recompression of a subject with peripheral decompression sickness (the bends) at the depth of relief rather than risk releasing pulmonary gas emboli by further recompression. It is also demonstrated how the introduction of 1-min stops into compression can avoid surface tension falling to the low values at which it is theoretically possible for venous bubbles to escape into arterial blood during pulmonary hypertension.

SU-8 Processing on a Variety of Substrates

1999 ◽  
Vol 605 ◽  
Author(s):  
Yuh-Min Chiang ◽  
Mark Bachman ◽  
Hung-Pin Chang ◽  
Charles Chu ◽  
G. P. Li
Keyword(s):  
Surface Tension ◽  
Aspect Ratio ◽  
Surface Properties ◽  
Silicon Wafer ◽  
Environmental Conditions ◽  
High Aspect Ratio ◽  
Silicon Substrates

AbstractSU-8 has become a popular material for micromachining high aspect ratio structures. Typically, SU-8 is spun on a polished silicon wafer for processing. After patterning, the SU-8 is used for micromachined structures directly (such as fluidic channels) or as a mold for electroforming. Non-silicon substrates offer the possibility of cheaper processing, improved mold designs, and multi-material devices. Successful SU-8 processing depends strongly on surface properties of the substrate itself as well as environmental conditions during the processing. We explore the issues involved in transferring SU-8 technology to non-silicon substrates such as glass, plastics and metals. Issues such as wettability, adhesion, and surface tension are explored in this study. The findings indicate the merits of non-spinning approaches, such as dipping, spraying, and brushing and point to new SU-8 processes.

scholarly journals Lipid polarity gradient formed by ω-hydroxy lipids in tear film prevents dry eye disease

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Masatoshi Miyamoto ◽  
Takayuki Sassa ◽  
Megumi Sawai ◽  
Akio Kihara
Keyword(s):  
Surface Tension ◽  
Dry Eye ◽  
Tear Film ◽  
Lower Eyelid ◽  
Dry Eye Disease ◽  
Water Evaporation ◽  
Eye Disease ◽  
Reduce Surface Tension ◽  
And Function ◽  
Deficient Mice

Meibum lipids form a lipid layer on the outermost side of the tear film and function to prevent water evaporation and reduce surface tension. (O-Acyl)-ω-hydroxy fatty acids (OAHFAs), a subclass of these lipids, are thought to be involved in connecting the lipid and aqueous layers in tears, although their actual function and synthesis pathway have to date remained unclear. Here, we reveal that the fatty acid ω-hydroxylase Cyp4f39 is involved in OAHFA production. Cyp4f39-deficient mice exhibited damaged corneal epithelium and shortening of tear film break-up time, both indicative of dry eye disease. In addition, tears accumulated on the lower eyelid side, indicating increased tear surface tension. In Cyp4f39-deficient mice, the production of wax diesters (type 1ω and 2ω) and cholesteryl OAHFAs was also impaired. These OAHFA derivatives show intermediate polarity among meibum lipids, suggesting that OAHFAs and their derivatives contribute to lipid polarity gradient formation for tear film stabilization.

scholarly journals Production and chemical characterization of pigments in filamentous fungi

Microbiology ◽  
2016 ◽  
Vol 162 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Patrícia Nirlane da Costa Souza ◽  
Tahuana Luiza Bim Grigoletto ◽  
Luiz Alberto Beraldo de Moraes ◽  
Lucas M. Abreu ◽  
Luís Henrique Souza Guimarães ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Chemical Characterization

scholarly journals Regulation of fungal decomposition at single-cell level

2020 ◽  
Vol 14 (4) ◽  
pp. 896-905 ◽  
Author(s):  
Michiel Op De Beeck ◽  
Carl Troein ◽  
Syahril Siregar ◽  
Luigi Gentile ◽  
Giuseppe Abbondanza ◽  
...  
Keyword(s):  
Single Cell ◽  
Filamentous Fungi ◽  
Environmental Conditions ◽  
Extracellular Polymeric Substances ◽  
Chemical Imaging ◽  
Single Cell Level ◽  
Cell Level ◽  
Environmental Variations ◽  
Fungal Decomposition

AbstractFilamentous fungi play a key role as decomposers in Earth’s nutrient cycles. In soils, substrates are heterogeneously distributed in microenvironments. Hence, individual hyphae of a mycelium may experience very different environmental conditions simultaneously. In the current work, we investigated how fungi cope with local environmental variations at single-cell level. We developed a method based on infrared spectroscopy that allows the direct, in-situ chemical imaging of the decomposition activity of individual hyphal tips. Colonies of the ectomycorrhizal Basidiomycete Paxillus involutus were grown on liquid media, while parts of colonies were allowed to colonize lignin patches. Oxidative decomposition of lignin by individual hyphae growing under different conditions was followed for a period of seven days. We identified two sub-populations of hyphal tips: one with low decomposition activity and one with much higher activity. Active cells secreted more extracellular polymeric substances and oxidized lignin more strongly. The ratio of active to inactive hyphae strongly depended on the environmental conditions in lignin patches, but was further mediated by the decomposition activity of entire mycelia. Phenotypic heterogeneity occurring between genetically identical hyphal tips may be an important strategy for filamentous fungi to cope with heterogeneous and constantly changing soil environments.

Relation Between Shear Viscosity and Morphology in Lung Surfactant Monolayer

2001 ◽  
Vol 7 (S2) ◽  
pp. 126-127
Author(s):  
Junqi Ding ◽  
Heidi E. Warriner ◽  
Joseph A. Zasadzinski
Keyword(s):  
Surface Tension ◽  
Palmitic Acid ◽  
Shear Viscosity ◽  
High Surface ◽  
Lung Surfactant ◽  
High Surface Tension ◽  
Entire Lung ◽  
Two Dimensional Flow ◽  
Reduce Surface Tension ◽  
Surfactant Composition

The primary function of lung surfactant monolayers (LS) is to control and reduce surface tension in the lung permitting easy breathing. to do this, the monolayer must maintain coverage of the entire lung surface during the rapid surface area changes which accompany breathing. We use a magnetic needle viscometer and optical microscopy to determine the relationship between monolayer shear viscosity, which controls its two-dimensional flow properties, and synthetic lung surfactant composition. We show that, within a specific range, palmitic acid interacts with DPPC/POPG to make lung surfactant rigid at low surface tension (or high surface pressure) and fluid at high surface tension. This enables the monolayer to attain near zero surface tensions during compression yet respread easily at high surface tension More palmitic acid makes the monolayer more rigid and eventually increases the collapse surface tension while reducing the readsorption rate at high surface tension.

Effect of Ethoxylation and Molecular Weight of Cationic Surfactants on Nucleate Boiling in Aqueous Solutions

2004 ◽  
Vol 126 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Juntao Zhang ◽  
Raj M. Manglik
Keyword(s):  
Molecular Weight ◽  
Surface Tension ◽  
Aqueous Solutions ◽  
Cationic Surfactants ◽  
Bubble Dynamics ◽  
Surfactant Solution ◽  
Dynamic Surface Tension ◽  
Nucleate Boiling ◽  
Dynamic Surface ◽  
Reduce Surface Tension

Saturated, nucleate pool boiling on a horizontal, cylindrical heater and the associated bubble dynamics in aqueous solutions of cationic surfactants of different molecular weight and ethoxylation or ethylene oxide (EO) content, are experimentally investigated. Boiling curves qw″∝ΔTsat for different concentrations and photographic records of the salient features of the ebullient behavior are presented, along with a characterization of interfacial properties (surface tension and contact angle). The surfactant additive significantly alters the nucleate boiling in water and enhances the heat transfer. The enhancement increases with concentration, with an optimum obtained in solutions at or near the critical micelle concentration (c.m.c.) of the surfactant. The photographic and visual observations indicate a markedly different boiling behavior than that of water, as well as between pre- and post-c.m.c. solutions. A lower molecular weight surfactant tends to reduce surface tension faster, and show better enhancement performance than its higher molecular weight counterpart. With EO groups in its molecular chain the surfactant solution becomes more hydrophilic, and the higher wettability tends to suppress nucleation, thereby weakening the boiling process. Also, enhancement in pre-micellar solutions is shown to depend on the dynamic surface tension, and the number of EO groups in and molecular weight of the surfactant.

scholarly journals Chemical Characterization, Nutritional and Bioactive Properties of Physalis peruviana Fruit from High Areas of the Atacama Desert

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2699
Author(s):  
Patricio Muñoz ◽  
Felipe Parra ◽  
Mario J. Simirgiotis ◽  
Germán F. Sepúlveda Chavera ◽  
Claudio Parra
Keyword(s):  
Pseudomonas Syringae ◽  
Environmental Conditions ◽  
Atacama Desert ◽  
Chemical Characterization ◽  
Physalis Peruviana ◽  
Bioactive Properties ◽  
Ic50 Value ◽  
Zn Content ◽  
Antioxidant And Antimicrobial Activity ◽  
Solanaceae Family

Physalis peruviana L. belongs to the Solanaceae family and produces a spherical fruit used to treat various diseases. However, the chemical composition, nutritional characterization, and bioactive properties of the P. peruviana growing in the Andean region of the Atacama Desert have not been conducted so far. The results showed clear differences in the nutritional and bioactive characteristics of the fruits grown in arid environmental conditions, which were comparable to those from countries with a production tradition. The fruits studied showed a higher Ca, Cu, Mn, P, and Zn content and bioactive compounds such as flavonoids and tannins than those reported in the literature. UHPLC was performed to determine the main phenols. Gallic acid was identified as the predominant phenolic compound in this species (303.63 mg/100 g FW), of which to our knowledge no previous study has reported similar concentrations in this species. Moreover, Cape gooseberry extract has antioxidant and antimicrobial activity against Gram-positive and Gram-negative bacteria. Pseudomonas syringae (MIC 0.313 mg/mL and MBC 1.25 mg/mL) was the most susceptible bacterium. Meanwhile, Erwinia rhapontici was the most resistant bacterium (MIC and MIB 5.00 mg/mL). Furthermore, it was found to inhibit α-amylase activity with an IC50 value (39.28 µg/mL) similar to that of acarbose (35.74 µg/mL). These results expand the knowledge of the species cultivated in arid environmental conditions and suggest an alternative for the potential use of this fruit to manage chronic diseases such as diabetes.

Interfacial Behaviour of Saponin Based Surfactant for Potential Application in Cleaning

2021 ◽  
Vol 58 (2) ◽  
pp. 146-152
Author(s):  
Gajendra Rajput ◽  
Niki Pandya ◽  
Darshan Soni ◽  
Harshal Vala ◽  
Jainik Modi
Keyword(s):  
Surface Tension ◽  
Aqueous Medium ◽  
Potential Application ◽  
Natural Basis ◽  
Aquatic Life ◽  
Amphiphilic Molecules ◽  
Foaming Power ◽  
Interfacial Behaviour ◽  
New Type ◽  
Synthetic Surfactants

Abstract Amphiphilic molecules reduce the surface tension of the aqueous medium and are widely used in industrial and domestic applications due to this property. Nowadays, amphiphilic molecules on a natural basis are in great demand to replace synthetic surfactants and thus contribute to the reduction of environmental problems. Approximately 60% of the material based on surfactants end up in seawater, which is dangerous for aquatic life. We are proposing a new type of material, which is a surfactant on a natural basis, biodegradable and an environmentally friendly alternative. Here we focus on tea saponin and study its properties such as surface tension, foaming, skin mildness, cleanability. Tea is naturally acidic, reduces the surface tension to 31.4 mN/m, has a greater foaming power, is ultra-mild to skin, and has excellent cleaning properties. The results show that tea has excellent surface activity, which is why tea can be used as a green substitute for synthetic surfactants.

Pulmonary surfactant

1984 ◽  
Vol 62 (11) ◽  
pp. 1121-1133 ◽  
Author(s):  
Fred Possmayer ◽  
Shou-Hwa Yu ◽  
J. Marnie Weber ◽  
Paul G. R. Harding
Keyword(s):  
Surface Tension ◽  
Pulmonary Surfactant ◽  
Liquid Interface ◽  
Biological Assays ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Essential Properties ◽  
Surfactant Activity ◽  
Mammalian Lung ◽  
Reduce Surface Tension ◽  
Air Liquid Interface

The mammalian lung is stabilized by a specialized material, the pulmonary surfactant, which acts by reversibly reducing the surface tension at the air–liquid interface of the lung during breathing. Pulmonary surfactant contains approximately 90% lipid and 10% proteins. Dipalmitoyl phosphatidylcholine, the major lipid component, appears to be primarily responsible for the ability to reduce surface tension to near 0 dyn/cm (1 dyn = 10 μN). The other components of pulmonary surfactant promote the adsorption and spreading of this disaturated lecithin at the air–liquid interface. Surfactant activity can be accessed by physical and biological assays. Apparent discrepancies between the results obtained with the Wilhelmy plate surface balance and the pulsating bubble surfactometer have led to the suggestion that separate "protein-facilitated" (catalytic type) and "protein-mediated" (chemical type) processes may be involved in adsorption and (or) spreading at the different surfactant concentrations used with these two techniques. Artificial surfactants, which mimic the essential properties of the natural product with the pulsating bubble surfactometer, can be produced with synthetic lipids. Treatment of prematurely delivered infants suffering from the neonatal respiratory distress syndrome with lipid extracts of pulmonary surfactant leads to a marked improvement in gaseous exchange.

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