Evaluation of microalgal strains and microalgal consortium for higher lipid productivity and rich fatty acid profile towards sustainable biodiesel production

This present study has attempted to screen four microalgal strainsChlorella vulgaris, Coelastrellasp.Scenedesmus dimorphusandChlorococcumsp. and consortium for biodiesel application.Coelastrella sp. was found to show marginally higher optical density of 1.13 on 19th day whereas C. vulgaris and S. dimorphus consortium showed 1.59 OD. Regarding the dry cell weight, S. dimorphus and Chlorella vulgaris was found to yield higher DCW at about 0.544 and 0.508 g/L, respectively. In outdoor pond raceway pond, C. vulgaris and S. dimorphus yielded 0.76-0.80 g/L while consortium showed 0.87 g/L biomass. In the case of lipid content, S. dimorphus, C. vulgaris and consortium accumulated 36.4, 35.5 and 39.2% lipids, respectively in lab, whereas in outdoor raceway pond it was 26.4, 32.3 and 34.5%, respectively. The fatty profile of Chlorella and Scenedesmus sp. showed linolelaidic acid, and cis-8,11,14-eicosatrienoic acid as prevalent fatty acids whereas the consortium has 53.5% oleic acid than other fatty acids.

Enhancing starch accumulation/production in Chlorococcum humicola through sulphur limitation and 2,4- D treatment for butanol production

Depleting fuel resources is a global concern worldwide due to the unstable and cost of fuel resources. Increased transportation has gradually depleted the fossil-based fuel resources leading to find a cost-effective, readily available, and renewable source. Considering these issues, various private and government organizations have focussed on producing bio-based fuels from natural sources. In this scenario, algae are a potential emerging source of feedstock or biomass for biobutanol production, which can effectively replace fossil fuels and their environmental drawbacks. The present study focussed on evaluating the potential of freshwater microalga Chlorococcum humicola isolated from temple pond as feedstock for biobutanol production using Clostridium acetobutylicum. The results indicated that C. humicola produced 846.33 μgmg^-1of starch under full strength Chu10 medium. While under sulphur and phosphorus limitation, the accumulation of starch was 947.33 μg mg^-1 and 766.67 μgmg^-1, respectively. Also, C. humicola was exposed to different concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D). At 10μgml^-1 of 2,4-D, the highest starch concentration of 989μgmg^-1was achieved in C. humicola. Finally, starch in C. humicola were hydrolysed and ABE fermentation was performed using C. acetobutylicum under anaerobic condition in a 5 L automated fermenter. After 72 h of fermentation, the fermented broth is analyed in Gas Chromatography showing the fermented product containing Acetone: Butanol: Ethanol. The present study is the first report on the production of biobutanol from C. humicola isolated from Temple pond. This study emphasizes the importance of local isolates of microalgae as a third-generation substrate to produce butanol to replace fossil-based fuels.

Core/shell nanoparticles: Synthesis, investigation of antimicrobial potential and photocatalytic degradation of Rhodamine B

Bacterial pathogenicity is becoming a major cause of morbidity and mortality around the globe. Researchers are tirelessly finding solutions to cure or prevent infections caused by bacterial pathogens. Nanotechnology is a fast-growing area of research, effectively influencing and preventing bacterial growth. Nanoparticles (NPs) of silver, copper and gold are being used to kill bacterial pathogens in the past years but the toxicity of NPs at higher concentrations remains a major problem. Therefore, in the present study, Co₃O₄@ZrO₂ (CoZ) core/shell NPs were synthesized using a simple sol-gel method. The synthesized NPs were characterized using different analytical techniques revealing the absorption bands at 456 and 277 nm with crystalline size of ~600 nm core/shell. The functional groups and oxidation states were characterized using FTIR analysis. Further bactericidal properties of core/shell of Co₃O₄@ZrO₂ NPs were tested against Gram negative (Escherichia coli, Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus, Bacillus subitilis) pathogens. The core/shell CoZ NPs showed maximum growth inhibitions against S. aureus and P. aeruginosa. At the highest concentration of 200 μg/mL, the maximum zone of inhibition was observed. The synthesized CoZ NPs was also subjected to photocatalytic degradation of rhodamine B in 180 min under visible light irradiation. The present study could be an innovative and efficient research for both biomedical and wastewater treatment applications.

Chitosan nanopolymers: An overview of drug delivery against cancer

Cancer is becoming a major reason for death troll worldwide due to the difficulty in finding an efficient, cost effective and target specific method of treatment or diagnosis. The variety of cancer therapy used in the present scenario have painful side effects, low effectiveness and high cost, which are some major drawbacks of the available therapies. Apart from the conventional cancer therapy, nanotechnology has grown extremely towards treating cancer. Nanotechnology is a promising area of science focusing on developing target specific drug delivery system for carrying small or large active molecules to diagnose and treat cancer cells. In the field of nanoscience, Chitosan nanopolymers (ChNPs) are been emerging as a potential carrier due to their biodegradability and biocompatibility. The easy modification and versatility in administration route of ChNPs has attracted attention of researchers towards loading chemicals, proteins and gene drugs for target specific therapy of cancer cells. Therefore, the present review deals with the growing concern towards cancer therapy, introduction of ChNPs, mode of action and other strategies employed by researchers till date towards cancer treatment and diagnosis ChNPs.

Biosynthesis and characterization of hydroxyapatite and its composite (hydroxyapatite-gelatin-chitosan-fibrin-bone ash) for bone tissue engineering applications

Hydroxyapatite (HAp) is a bioactive and biocompatible material possessing osteoconductive properties used widely in the biomedical sector. In the present study, synthesis of hydroxyapatite (HAp) using a Klebsiella pneumoniae SM24 (phosphate solubilizing bacteria) isolated from the slaughterhouse. HAp synthesized using biological source showed efficient and positive enzymatic activity in the National Botanical Research Institute Phosphate Medium (NBRIP). Characterization of HAp using FTIR revealed the presence of phosphate group hydroxyapatite and XRD spectra showed polycrystalline nature. The morphological characterization of HAp using FESEM revealed the mesoporous structure and EDX spectrum indicated presence of Ca and P as the major components. In addition, a new bone composite was prepared using the synthesized HAp, Gelatine (G), Chitosan (C), Fibrin (F) and Bone ash (HApGCF) using Simulated Body Fluid (SBF) solution. The confirmation of chemical and structural characteristics of HApGCF bone composite was achieved using FTIR, XRD and SEM analyses. The HApGCF bone composite was tested over osteoblast MG-63 cells showing effective biocompatibility and osteoblast attachment on the composite surface. Therefore, the present report proposes the in vitro application of HApGCF bone composite as a replacement for major bone damage and injury in a biocompatible and non-toxic way.

One pot synthesis and anti-biofilm potential of copper nanoparticles (CuNPs) against clinical strains of Pseudomonas aeruginosa

Pseudomonas aeruginosa, an opportunistic pathogen frequently associated with nosocomial infections, is emerging as a serious threat due to its resistance to broad spectrum antimicrobials. The biofilm mode of growth confers resistance to antibiotics and novel anti-biofilm agents are urgently needed. Nanoparticle based treatments and therapies have been of recent interest because of their versatile applications. This study investigates the anti-biofilm activity of copper nanoparticles (CuNPs) synthesized by the one pot method against P. aeruginosa. Standard physical techniques including UV-visible and Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy were used to characterize the synthesized CuNPs. CuNP treatments at 100 ng ml(-1) resulted in a 94, 89 and 92% reduction in biofilm, cell surface hydrophobicity and exopolysaccharides respectively, without bactericidal activity. Evidence of biofilm inhibition was also seen with light and confocal microscope analysis. This study highlights the anti-biofilm potential of CuNPs, which could be utilized as coating agents on surgical devices and medical implants to manage biofilm associated infections.