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Candida albicans causes superficial and life-threatening systemic infections. These are difficult to treat often due to drug resistance, particularly because C. albicans biofilms are inherently resistant to most antifungals. Sophorolipid (SL), a glycolipid biosurfactant, has been shown to have antimicrobial and anticancer properties. In this study, we investigated the effect of SL on C. albicans biofilm formation and preformed biofilms. SL was found to inhibit C. albicans biofilm formation as well as reduce the viability of preformed biofilms. Moreover, SL, when used along with amphotericin B (AmB) or fluconazole (FLZ), was found to act synergistically against biofilm formation and preformed biofilms. Effect of SL on C. albicans biofilm formation was further visualized by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), which revealed absence of hyphae, typical biofilm architecture and alteration in the morphology of biofilm cells. We also found that SL downregulates the expression of hypha specific genes HWP1, ALS1, ALS3, ECE1 and SAP4, which possibly explains the inhibitory effect of SL on hyphae and biofilm formation.

Ordered mesoporous materials (OMMs) are interesting matrixes for nanomedicine applications such as innovative drug delivery systems. Here, we compare the behavior of the widely studied SBA-15 mesoporous silica with that of the less investigated MSE (a periodic mesoporous organosilica whose silicon atoms are alternatively connected by means of -Si-O-Si- and -Si-CH(2)-CH(2)-Si- groups) toward the adsorption (pH 7.0 and 9.6) and in vitro release (pH 7.4; T = 37 degrees C) of an antimicrobial protein (hen egg white lysozyme). Both OMMs have a hexagonal ordered mesoporous structure and texture, as confirmed by SAXS, TEM, and N(2) adsorption isotherms, but differ for the chemical composition and surface charge density, as determined by ATR-FTIR spectroscopy and potentiometric titrations, respectively. Rather than the structural and textural features, the different chemical composition of SBA-15 and MSE seems to be responsible for the different lysozyme loading and release and for the different stability toward the lixiviating action of the physiological medium (pH 7.4; T = 37 degrees C)

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Immobilization of Pseudomonas fluorescens lipase (Pfl) on the chemically modified, or unmodified, surface of SBA‐15 mesoporous silica has been achieved. X‐ray diffraction (XRD), transmission electron microscopy (TEM), and N2 physisorption are used to monitor the effect of surface functionalization on the structural and textural features of the SBA‐15 silica support. The enzyme loading strongly depends on the type of enzyme–support interaction, the maximal loading of the chemisorbed lipase being about twice that of the physisorbed (502 and 256 mgprotein ${{\rm g}{{- 1\hfill \atop {\rm support}\hfill}}}$ respectively). The resulting biocatalysts, regardless of the different loading, are tested with a hydrolytic catalytic assay. Despite the lower loading, the physically immobilized Pfl is more active than that which is chemically immobilized. Both biocatalysts are also active in a green process for biodiesel production, leading to almost full conversion of sunflower oil and ethanol into the corresponding ethyl esters after about 7 h at 30 °C, atmospheric pressure, and in solvent‐free conditions. Recycling experiments showed that the chemically immobilized Pfl was still active after twenty reaction cycles whereas the physically immobilized Pfl lost its activity after the tenth cycle.

BackgroundGold nanoparticles (AuNPs) have found wide range of applications in electronics, biomedical engineering, and chemistry owing to their exceptional opto-electrical properties. Biological synthesis of gold nanoparticles by using plant extracts and microbes have received profound interest in recent times owing to their potential to produce nanoparticles with varied shape, size and morphology. Marine microorganisms are unique to tolerate high salt concentration and can evade toxicity of different metal ions. However, these marine microbes are not sufficiently explored for their capability of metal nanoparticle synthesis. Although, marine water is one of the richest sources of gold in the nature, however, there is no significant publication regarding utilization of marine micro-organisms to produce gold nanoparticles. Therefore, there might be a possibility of exploring marine bacteria as nanofactories for AuNP biosynthesis.ResultsIn the present study, marine bacteria are exploited towards their capability of gold nanoparticles (AuNPs) production. Stable, monodisperse AuNP formation with around 10 nm dimension occur upon exposure of HAuCl4 solution to whole cells of a novel strain of Marinobacter pelagius, as characterized by polyphasic taxonomy. Nanoparticles synthesized are characterized by Transmission electron microscopy, Dynamic light scattering and UV-visible spectroscopy.ConclusionThe potential of marine organisms in biosynthesis of AuNPs are still relatively unexplored. Although, there are few reports of gold nanoparticles production using marine sponges and sea weeds however, there is no report on the production of gold nanoparticles using marine bacteria. The present work highlighted the possibility of using the marine bacterial strain of Marinobacter pelagius to achieve a fast rate of nanoparticles synthesis which may be of high interest for future process development of AuNPs. This is the first report of AuNP synthesis by marine bacteria.

Ordered mesoporous materials (OMMs) have a pore size suitable to host proteins. Previous works have shown how to tune the amount of adsorbed protein by changing pH or ionic strength of the adsorbing solution. Here we investigated the adsorption of lysozyme on a functionalized SBA-15 (SBA-15-NH(2)) as a function of added salts. For the first time, it was ascertained that the amount of adsorbed protein follows a reversed Hofmeister series for anions (sodium salts), SCN(-) > ClO(4)(-) > Br(-) > NO(3)(-) > Cl(-) > SO(4)(2-), whereas for cations (chloride salts) the sequence was Na(+) > Li(+) > K(+) > Cs(+). These findings not only demonstrate a specific effect of the Na(+) SCN(-) ion pair in favoring the adsorption at a solid surface but confirm also the role of the biologically important sodium ions. In addition, the process was found to be more effective at 0.2 M than at 0.8 M, thus indicating that adsorption also depends on the added salt concentration.

Microbes develop several strategies to survive in the adverse condition such as biofilm formation, attaining non-dividing state, altering drug target or drug, thereby increases the burden of drug dosage. to combat these issues, nanoparticles have shown an alternative approach for new treatment strategy but synthesis via chemical synthetic route limits their application in biomedical field. Here, green method for the synthesis of gold nanoparticles using sophorolipid (SL) is discussed that is characterized by various techniques. initially, the antimicrobial activity was checked against metabolically active state of microbes; Gram-positive Staphylococcus aureus and Gram-negative Vibrio cholerae using XTT assay and growth kinetics assay. Results suggested higher efficacy of nanoparticles for Gramnegative, therefore further analyzed against Escherichia coli that confirmed its potency for the same. AuNPs-SL also signifies its efficiency at least metabolically active state; non dividing cells and biofilm of these microbes. induced morphological changes were studied by SeM that revealed Aunps-SL led to disruption of cell membrane and leakage of intracellular fluid to the surroundings. Inhibition of respiratory enzymes activity also plays a crucial role in bactericidal action as indicated by LDH assay. Synergy of AuNPs-SL with different antibiotics was also analyzed using checkerboard assay. These results suggested the possible use of AuNPs-SL as an antimicrobial therapy in the field of nanomedicine. In recent years, the emergence of antimicrobial resistance has been recognized as one of the most compelling problem in the field of biomedical sciences. Development of resistance has been reported even against the newly invented drug candidates. The reasons behind the emergence of bacterial resistance are complicated, but it can be discriminated as, partly due to the selection of bacterial mutants by antibiotics and partly due to reduced dosage intake by patients that lead to reduced levels of antibiotics which in turn, trigger bacterial resistance. Multiplying (logarithmic phase) and non-multiplying (stationary phase, dormant or latent) are two different states of bacterial existence 1. Among different survival strategies under adverse conditions, formation of biofilm and achieving dormant or non dividing phase are the privilege one 2. A survey conducted by National Institutes of Health and Centre of Disease control suggested that most of the infection (nearly 65-80%) occurred by biofilm formation 3. Biofilms are complex mixtures of bacteria, containing both states of bacterial existence; multiplying and non-multiplying bacteria 4. In biofilm, cellular metabolic activity is reduced and cells are more resistant to drugs. A significant proportion of most human bacterial infectious disease (nearly 60%) 5 is encompassed by non-multiplying bacteria and these are not easily killed by antibiotics 6. Multiplying bacteria are killed easily in presence of antibiotics as compared to non-multiplying ones. Therefore, designing better t...