No abstract

Micro/nanoplastics (MP/NPs) are emerging global pollutants that garnered enormous attention due to their potential threat to the ecosystem in virtue of their persistence and accumulation. Notably, United Nations Environment Programme (UNEP) yearbook in 2014 proposed MPs as one among ten emergent issues that the Earth is facing today. MP/NPs can be found in most regularly used products (primary microplastics) or formed by the fragmentation of bigger plastics (secondary microplastics) and are inextricably discharged into the environment by terrestrial and land-based sources, particularly runoff. They are non-degradable, biologically incompatible, and their presence in the air, soil, water, and food can induce ecotoxicological issues and also a menace to the environment. Due to micro size and diverse chemical nature, MP/NPs easily infiltrate wastewater treatment processes. This communication reviews the current understanding of MP/NPs occurrence, mobility, aggregation behavior, and degradation/assimilation in terrestrial, aquatic (fresh & marine), atmospheric depositions, wetlands and trophic food chain. This communication provide current perspectives and understanding on MP/NPs concerning (1) Source, occurrence, distribution, and properties (2) Impact on the ecosystem and its services, (3) Techniques in detection and identification and (4) Strategies to manage and mitigation.

Microalgae are multifaceted photosynthetic microorganisms with emerging business potential. They are present ubiquitously in terrestrial and aquatic environments with rich species diversity and are capable of producing significant biomass. Traditionally, microalgal biomass is being used as food and feed in many countries around the globe. The production of microalgal-based bioactive compounds at an industrial scale through biotechnological interventions is gaining interest more recently. The present review provides a detailed overview of the key algal metabolites, which plays a crucial role in nutraceutical, functional foods, and animal/aquaculture feed industries. Bioactive compounds of microalgae known to exhibit antioxidant, antimicrobial, antitumor, and immunomodulatory effects were comprehensively reviewed. The potential microalgal species and biological extracts against human pathogens were also discussed. Further, current technologies involved in upstream and downstream bioprocessing including cultivation, harvesting, and cell disruption were documented. Establishing microalgae as an alternative supplement would complement the sustainable and environmental requirements in the framework of human health and well-being.

Phytoremediation is a plant based environmental cleanup technology to contain (rendering less toxic), sequester and degrade contaminated susbtrates. As can be seen from data metrics, it is gaining cosiderable importance globally. Phytoremediation approach is being applied for cleanup of inorganic (potentially toxic metals), organic (persistent, emergent, poly-acromatic hydrocarbons and crude oil etc.) and co-contaminated (mixture of inorganic and organic) and/or polluted sites globally. Recently new approaches of utilizing abundantly available natural organic amendments have yielded significant results. Ricinus communis L. (Castor bean) is an important multipurpose crop viz., Agricultural, Energy, Environmental and Industrial crop. The current status of knowledge is abundant but scattered which need to be exploited for sustainable development. This review collates and evaluates all the scattered information and provides a critical view on the possible options for exploiting its potential as follows: 1. Origin and distribution, 2. Lead toxicity bioassays, 3. Progress in arbuscular mycorrhizal fungi-assisted phytoremediation, 4. Promising bioenergy crop that can be linked to pytoremediation, 5. A renewable source for many bioproducts with rich chemical diversity, 6. It is a good biomonitor and bioindicator of atmospheric pollution in urban areas, 7. Enhanced chelate aided remediation, 8. Its rhizospheric processes accelerate natural attenuation, 9. It is suitable for remediation of crude oil contaminated soil, 10. It is an ideal candidate for aided phytostabilization, 11. Castor bean is a wizard for phytoremediation and 12. Its use in combined phytoextraction and ecocatalysis. Further, the knowledge gaps and scope for future research on sustainable co-generation of value chain and value addition biobased products for sustainable circular economy and environmental security are described in this paper.

Ultraviolet radiation (UV) altered plant metabolism. Hence Trigonella foenum-graecum L. (Fenugreek) exposed to UV-B radiation for studying the bioactive changes that may be useful in captive farming. UV-B treatment altered plant growth, and extent of alterations depended on the duration of radiation treatment. Photosynthetic pigments such as chlorophyll and carotenoids decreased after radiation exposure. But bioactive components such as anthocyanin, flavonoids, and phenolics increased after UV-B treatment. Phenylalanine lyase enzyme activity and peroxidase activity also increased with 4.0 hr UV-B exposure even though 8.0 hr exposure decreased the activity of these enzymes. Total lipid content of the plants increased after UV-B exposure. Changes in aromatic oil composition observed due to UV-B exposure, and the changes pointed shifting of plant metabolism towards the synthesis of short chain fatty acid contain lipids and non-enzymatic antioxidants.