Search

Marine microorganisms are reported to produce polyhydroxybutyrate (PHB) that has wide range of medical and industrial applications with the advantage of biodegradability. PHBs are synthesized as an energy and carbon storage element under metabolic pressure. The scope of this work is enhancing PHB production using marine microbial isolate, Micrococcus luteus by selectively optimizing various growth conditions such as different media components and growth parameters that influence the cell growth and PHB production were sampled. Micrococcus luteus produced 7.54 g/L of PHB utilizing glucose as a carbon source and ammonium sulphate as a nitrogen source with maximum efficiency. The same optimized operational conditions were further employed in batch fermentation over a time span of 72 h. Interestingly higher cell dry weight of 21.52 g/L with PHB yield of 12.18 g/L and 56.59% polymer content was observed in batch fermentation studies at 64 h. The chemical nature of the extracted polymer was validated with physio-chemical experiments and was at par with the commercially available PHB. This study will spotlight M. luteus as a potential source for large-scale industrial production of PHB with reducing environmental pollutions.

Modern scientific advancements and research on marine microbes has revealed their significance as producers of therapeutic products useful in treating various human diseases. Microbes in marine habitat have evolved to adapt to the harsh condition that prevails in the ocean. Their struggle to compete for space and nutrients has paved way for the synthesis of different novel enzymes possessing distinctive characteristics. Thus, marine habitat hosts many remarkable microorganisms that offer unique biologically active compounds, enzymes endowed with astonishing properties, and mechanism to survive in extreme environmental conditions. The utilization of marine biotic resources grows at an extraordinary growth rate of 12% per annum and is evident from about 4900 patents filed connected with marine genetic resources and 18,000 natural compounds. This concern has boosted research all over the world to explore the untapped potential hidden in marine microbes, which has lot of biotechnological applications that includes bioactive compounds (metabolites) for therapeutics, novel enzymes, cosmetics, and nutraceuticals. This book chapter will meticulously deliberate the utilization of marine resources by biotechnological applications for therapeutics like antibiotics, chemical compounds, biopolymer, enzymes, and various microbial biomedical purposes such as drug delivery and tissue engineering from marine biota (bacteria, fungi, and algae).

In recent years, nanotechnology has reached the limelight of research in applications of medicine and technology. Due to its onset, huge varieties of nanoparticles possessing significant characters are synthesized with broad application fields. Even though these particles are infesting our present life; conflictual views regarding their medical and biological effects are debatable. The non biodegradable nature and nanosize are the alarming features of the nanoparticles that confront potential threats to both environment and biomedical field on its expanding usage. NPs synthesized from heavy metals like lead, mercury and tin are proclaimed as stringent and stable compounds for degradation, hence results in environmental biohazards. The extensive applications of silver nanoparticles in biosensing, cosmetics, medical devices, food and clothing products inflates its human exposure and obviously resulted in toxicity (short and long term). In vitro studies revealed various cytotoxic effects in the cells of mammals such as brain, liver, lung, skin, reproductive organs and vascular system. Furthermore, ingestion, inhalation or injection of nanoparticles in intraperitoneal region resulted in toxic effect of multiple organs inclusively brain. Accounting the metal nanoparticles biohazardous effects like ROS (Reactive oxygen species) generation, DNA damage, protein denaturation and lipid peroxidation has been proved on carbon based nanoparticles, organic lipid based nanoparticles, mineral based nanoparticles, nano diamonds, nano composites, etc. Although, nanotechnology has become an advent field of research nowadays, it is importing significant environmental and health hazards thus couldn’t be beneficial to both society and economy.

Microalgal isolates (Chlorella sp. and Spirulina sp.) and yeast isolates (Candida albicans and Saccharomyces sp.) were employed as the resources of biodiesel production and silver nanoparticle synthesis. The prominent peaks of the FTIR spectrum accustomed the efficient lipid property. The developed profile containing fatty acid methyl ester (FAME) displayed the elevated amount of both saturated (C15:0, C17:0, C21:0) and unsaturated (C17:1, C18:2, C20:4) fatty acids. The physicochemical properties analyzed by using Biodiesel analyzer V1.1.software, confirmed the competency of the isolates for sustainable biodiesel production. Biosynthesis of silvernanoparticles (AgNPs) were accomplished extracellularly by using supernatant of microalgal and yeast culture. The maximum absorbance at 420 and 421 nm under UV–visible spectra showed the presence of nanoparticles. The purity of the synthesized AgNPs were analyzed by XRD analysis. The elemental silver presence was affirmed by EDAX, SEM and AFM, the results revealed spherical crystalline shaped nanoparticles of size ranging from 2.0 to 7.3 nm. The antimicrobial efficacy of the silver nanoparticles (AgNPs) against various clinical pathogens which includes Bacillus sp., E. coli, Klebsiella sp., Proteus sp. and Staphylococcus aureus were observed. However, enhanced antimicrobial activity was displayed by the AgNPs, produced by Candida albicans (12 mm) against Bacillus sp., and E.coli, the nanoparticle produced by Chlorella sp. showed the least antagonistic activity (07 mm).

There are copious of bacteria exist in marine environment and it is very important to screen the potential microbes that has the ability to produce biopolymer polyhydroxybutyrate (PHB) as well as polycyclic aromatic hydrocarbons (PAHs) degradation and conventional plastic high density polyethylene (HDPE) biodegradation. Numerous studies have been investigated individually on either one of characteristic feature like PHB production, PAHs and high density polyethylene (HDPE) degradation, but not all together. Hence, in this study, we tried to screen potential marine microbes that have the ability to perform all three features. We have isolated 203 phenotyphicaly different colonies from 19 different sites (marine soil sediments, marine water and oil spilled marine water) which cover the north east to down south seashore regions of Tamilnadu, India. Of the 203 microbial isolates, the best PHB producing (Micrococcus luteus), PAHs degradation (Klebsiella pneumonia) and HDPE degradation (Brevibacillus borstelensis) microorganisms were identified through 16S rRNA sequencing. Analytical studies confirmed PHB production by fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H & 13C NMR); PAHs degradation by high performance liquid chromatography (HPLC), confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM); HDPE degradation by CLSM, FT-IR and SEM which cover the spectroscopy studies on biological systems.