Biosynthesis of Nanoparticles from Halophiles

Abstract

Nanobiotechnology is a multidisciplinary branch of nanotechnology which includes fabrication of nanomaterials using biological approaches. Many bacteria, yeast, fungi, algae and viruses have been used for synthesis of various metallic, metal sulfi de, metal oxide and alloy nanoparticles , since the fi rst report on biosynthesis of cadmium sulfi de quantum dots by Candida glabrata and Schizosaccharomyces pombe in 1989. These nanofactories offer a better size control through compartmentalization in the periplasmic space and vesicles, and are usually capped by stabilizing cellular metabolites. Halophiles depending on their salt requirements may be classifi ed as slight, moderate and extreme halophiles. They are found in marine and/or hypersaline environments. These organisms are known to encounter metals in their environment as the econiches they inhabit serve as ecological sinks for metals. Metal based nanoparticle synthesis by halophilic organisms is in its infancy and has only been reported in few organisms. This chapter aims to shed light on the various halophilic organisms and their by-products that have been exploited for nanomaterial synthesis, the mechanisms that may be involved in the nanomaterial fabrication and the possible applications of the fabricated nanoparticles. A special section would be dedicated for the bioavailability of metals to halophiles under varying salinity conditions.

Pharmacological, pharmaceutical, cosmetic and diagnostic applications of sulfated polysaccharides from marine algae and bacteria

“…Presence of carboxyl, hydroxyl and methoxyl groups in MBSF17 stabilised silver nanoparticles by forming a coating. Nanoparticles thus produced demonstrated broad spectrum antimicrobial effect (Srivastava and Kowshik, 2015).…”

“…The polysaccharide has exhibited characteristic viscoelastic, pseudoplastic and thixotropic behavior (Raveendran et al, 2013b;Srivastava and Kowshik, 2015).…”

“…Mauran has been reported to show immunomodulatory and anticancer effects owing to its high sulfate content (Srivastava and Kowshik, 2015). It also possesses antioxidant, antihemolytic and antithrombogenic activities .…”

“…Application of magnetic hyperthermia along with administration of drug-loaded mauran naoparticles resulted in killing of 80% of cancer cells within a very short time (Balasubramanian et al, 2014). Mauran has been reported to stabilize ZnS:Mn 2+ quantum dots(QDs) thereby improving biocomapatibility and lowering the cytotoxicity potential (Srivastava and Kowshik, 2015).…”

Absorption, distribution, metabolism and elimination (ADME) and toxicity profile of marine sulfated polysaccharides used in bionanotechnology

“…But, techniques currently available involve harmful chemicals and also deleterious processing conditions thereby ultimately yielding hydrophobic and water-insoluble quantum dots with doubtful safety profile. Thus, suitable stabilization techniques should be employed for capping of quantum dots with biocompatible polymers to enhance their biocompatibility and improve their cellular uptake (Raveendran et al, 2014;Srivastava et al, 2015). Therefore, potential of nanomaterials can be expanded and flexibility in applications can be enhanced by exploring new natural polymers which can be used alone or can be combined with different synthetic polymers to alter absorption, biodistribution, biodegradation, elimination, cytotoxicity, biocompatibility, stability, and site-specificity (Raveendran et al, 2017).…”