Improved biorefinery pathways of marine diatoms using a water miscible ionic liquid and its colloidal solution: efficient lipid extraction and in situ synthesis of fluorescent carbon dots for bio-imaging applications

Carbon dots using a household cleaning liquid as a dopant for iron detection in hydroponic systems

Iron (Fe) is a required micronutrient in plants for the production of chlorophyll and transport of oxygen. A commonly used surrogate for measuring nutrient levels is the measurement of electrical conductivity or total dissolved solids, but this technique is not selective towards any particular dissolved ion. In this study, using a conventional microwave, fluorescent carbon dots (CDs) are produced from glucose and a household cleaning product and applied towards monitoring dissolved ferric iron levels in hydroponic systems through fluorescent quenching. The produced particles have an average size of 3.19 ± 0.76 nm with a relatively high degree of oxygen surface groups. When using an excitation of 405 nm, a broad emission peak is centered at approximately 500 nm. A limit-of-detection of 0.196 ± 0.067 ppm (3.51 ± 1.21 μM) with minimal interference from common heavy metal quenchers and ions found in hydroponic systems was determined. Butterhead lettuce was grown while discretely monitoring iron levels via the CDs for three separate weeks of growth. The CDs displayed a non-significant difference (p > 0.05) in performance when compared to a standard method. These results along with a simple and relatively low-cost production method make the CDs in this study a promising tool for monitoring iron levels in hydroponic systems.

Phylogeny and Fatty Acid Profiles of New Pinnularia (Bacillariophyta) Species from Soils of Vietnam

We studied the morphology, ultrastructure, and phylogeny of eight soil diatom strains assigned to the Pinnularia genus. Six of these strains, identified by us as new species, are described for the first time. We provide a comprehensive comparison with related species and include ecological data. Molecular phylogeny reconstruction using 18S rDNA and rbcL affiliates the new strains with different subclades within Pinnularia, including ‘borealis’, ‘grunowii’ and ‘stomatophora’. We also studied the fatty acid profiles in connection with the emerging biotechnological value of diatoms as a source of lipids. Stearic (36.0–64.4%), palmitic (20.1–30.4%), and palmitoleic (up to 20.8%) acids were the dominant fatty acids in the algae cultured on Waris-H + Si medium. High yields of saturated and monounsaturated fatty acids position the novel Pinnularia strains as a promising feedstock for biofuel production.

3D Natural Mesoporous Biosilica-Embedded Polysulfone Made Ultrafiltration Membranes for Application in Separation Technology

Diatoms are the most abundant photosynthetic microalgae found in all aquatic habitats. In the extant study, the spent biomass (after lipid extraction) of the centric marine diatom Thalassiosira lundiana CSIRCSMCRI 001 was subjected to acid digestion for the extraction of micro composite inorganic biosilica. Then, the resulting three-dimensional mesoporous biosilica material (diatomite) was used as a filler in polysulfone (PSF) membrane preparation by phase inversion. The fabricated PSF/diatomite composite membranes were characterized by SEM-EDX, TGA, and ATR-IR, and their performances were evaluated. The number of pores and pore size were increased on the membrane surface with increased diatomite in the composite membranes as compared to the control. The diatomite composite membranes had high hydrophilicity and thermal stability, lower surface roughness, and excellent water permeability. Membranes with high % diatomite, i.e., PSF/Dia_0.5, had a maximum water flux of 806.8 LMH (Liter/m²/h) at 20 psi operating pressure. High-diatomite content membranes also exhibited the highest rejection of BSA protein (98.5%) and rhodamine 6G (94.8%). Similarly, in biomedical rejection tests, the PSF/Dia_0.5 membrane exhibited a maximum rejection of ampicillin (75.84%) and neomycin (85.88%) at 20 Psi pressure. In conclusion, the mesoporous inorganic biosilica material was extracted from spent biomass of diatom and successfully used in filtration techniques. The results of this study could enhance the application of natural biogenic porous silica materials in wastewater treatment for water recycling.

Phytotoxicological effects of engineered nanoparticles: An emerging nanotoxicology

Recent innovations in the field of nanoscience and technology and its proficiency as a part of inter-disciplinary science has set an eclectic display in innumerable branches of science, a majority in aliened health science of human and agriculture. Modern agricultural practices have been shifting towards the implementation of nanotechnology-based solutions to combat various emerging problems ranging from safe delivery of nutrients to sustainable approaches for plant protection. In these processes, engineered nanoparticles (ENPs) are widely used as nanocarriers (to deliver nutrients and pesticides) due to their high permeability, efficacy, biocompatibility, and biodegradability properties. Even though the constructive nature of nanoparticles (NPs), nanomaterials (NMs), and other modified or ENPs towards sustainable development in agriculture is referenced, the darker side i.e., eco-toxicological effects is still not covered to a larger extent. The overwhelming usage of these trending NMs has led to continuous persistence in the ecosystem, and their interface with the biotic and abiotic community, degradation lanes and intervention, which might lead to certain beneficial or malefic effects. Metal oxide NPs and polymeric NPs (Alginate, chitosan, and polyethylene glycol) are the most used ENPs, which are posing the nature of beneficial as well as environmentally concerning hazardous materials depending upon their fate and persistence in the ecosystem. The cautious usage of NMs in a scientific way is most essential to harness beneficial aspects of NMs in the field of agriculture whilst minimizing the eco-toxicological effects. The current review is focused on the toxicological effects of various NMs on plant physiology and health. It details interactions of plant intracellular components between applied/persistent NMs, which have brought out drastic changes in seed germination, crop productivity, direct and indirect interaction at the enzymatic as well as nuclear levels. In conclusion, ENPs can pose as genotoxicants that may alter the plant phenotype if not administered appropriately.