Summary Hydrogen is a promising alternative to fossil fuel for a source of clean energy. Thermophilic biohydrogen production is beneficial for obtaining high H2 production yield. This review recapitulates the basic metabolic pathways in bacteria for hydrogen production and the enzymes involved in various thermophilic hydrogen producing pathways in microorganisms. It also focuses on the current status of thermophilic biohydrogen production through fermentation of commercially viable substrates, such as agricultural residues. The use of metabolic engineering to attain certain physiological desirable characteristics in H2‐producing microorganisms, culture conditions, and types of bioreactors to be used are reviewed. Major obstacles in industrial production of biohydrogen like low volumetric hydrogen production and its environmental impact are identified. The review has further identified current limitations in the commercial thermophilic hydrogen production and suggested methods like the use of heat exchangers and effluent recirculation to reduce the production cost. Copyright © 2015 John Wiley & Sons, Ltd.

Chronic lead exposure is related to many health diseases in mammals. Exposure to lead forms reactive oxygen species reducing body antioxidant enzymes inflicting injury to numerous macromolecules or cell necrosis. Recent studies have revealed oxidative stress as the vital mechanism for lead toxicity. Lead is found to be toxic to several organ systems such as hematopoietic, skeletal, renal, cardiac, hepatic, and reproductive systems and extremely toxic to the central nervous system (CNS). Curcumin, an active ingredient of the dietary spice, and nanocurcumin, a nanoform of curcumin, are found to decrease toxicity due to lead in various organ systems in mouse models. Higher bioavailability, chelating property, and retention time of nanocurcumin over bulk curcumin may pave the way to expand the utility of nanocurcumin to remove lead toxicity from various organ systems within humans.