Biological removal of dyes from effluents of textile and dyestuff manufacturing industry offers some distinct advantages over the commonly used chemicals and physicochemical methods. These include possible mineralization of the dyes to harmless inorganic compounds like carbon dioxide and water, and formation of a lesser quantity of relatively harmless sludge. Removal of dyes from these wastewaters has been reviewed with respect to biological decolorization as well as complete biodegradation of the dye molecules. Emerging techniques with reference to biological treatment of these wastewaters have been discussed under aerobic, anaerobic, and combined anaerobic–aerobic systems. Advantages and limitations of different biological methods have been highlighted, and future studies to establish these techniques for their applications on industrial scale have been suggested.
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.
Background: Gold 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. Results: In 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. Conclusion: The 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.
1 May 2009 in Journal of Molecular Catalysis B: Enzymatic
Sophorolipid induces ROS generation in C. albicans leading to mitochondrial dysfunction and ER stress followed by the release of Ca2+ ions (from the ER lumen) that enter mitochondria and further magnify ROS generation leading to cell death.