Carotenoids are important precursors of a variety of compounds: the C₂₀-retinoids, the C₁₅-phytohormones, and the C₉- to C₁₃-aromas. Among the last type, C₁₃-carotenoid-derived compounds (norterpenoids/norisoprenoids) such as ionones and damascones, constitute an essential aroma note in tea, grapes, roses, tobacco, and wine. Extraction of carotenoid-derived aroma compounds from plant sources is not economically realistic or considerably expensive. The biotechnological production of aroma compounds represents a feasible alternative and offers the production of enantiomerically pure molecules which can be labeled as “natural.” To date, research in the production of ionones or the C₁₀-compound, safranal, has mainly been focused on plant dioxygenases that cleave carotenoids in the positions between carbons 9 and 10 (9^′-10^′) or 7 and 8 (7^′-8^′), respectively. Although relatively little is known about the microbial conversion of carotenoids into compounds with aroma due to the well known advantages of manipulating microorganisms, the aim of this work is to review the current state of the research in microbial production of norisoprenoids and other aroma compounds derived from carotenoid cleavage.

Several microaerophilic parasites such as Giardia lamblia, Trichomonas vaginalis, and Plasmodium falciparum are major disease-causing organisms and are responsible for spreading infections worldwide. Despite significant progress made in understanding the metabolism and molecular biology of microaerophilic parasites, chemotherapeutic treatment to control it has seen limited progress. A current proposed strategy for drug discovery against parasitic diseases is the identification of essential key enzymes of metabolic pathways associated with the parasite’s survival. In these organisms, glucose-6-phosphate dehydrogenase::6-phosphogluconolactonase (G6PD:: 6PGL), the first enzyme of the pentose phosphate pathway (PPP), is essential for its metabolism. Since G6PD:: 6PGL provides substrates for nucleotides synthesis and NADPH as a source of reducing equivalents, it could be considered an anti-parasite drug target. This review analyzes the anaerobic energy metabolism of G. lamblia, T. vaginalis, and P. falciparum, with a focus on glucose metabolism through the pentose phosphate pathway and the significance of the fused G6PD:: 6PGL enzyme as a therapeutic target in the search for new drugs.

Tuberculosis (TB) is a bacterial disease that remains a global health threat due to the millions of deaths attributed to it each year. The emergence of drug resistance has exacerbated and further increased the challenges in the fight against this illness. Despite the preventive measures using the application of the Bacillus Calmette-Guérin vaccine, the desired immunization outcome is not as high as expected. Conventional TB treatments exhibit serious limitations, such as adverse effects and prolonged duration, leading to a pressing need for alternative and more effective treatment options. Despite significant efforts, it took nearly four decades for diarylquinoline to become the most recently approved medicine for this disease. In addition, various possibilities, such as the usage of medications used for many other conditions (repurposed drugs), have been explored in order to speed up the process of achieving faster outcomes. Natural compounds derived from various sources (microorganisms, plants, and animals) have emerged as potential candidates for combating TB due to their chemical diversity and their unique modes of action. Finally, efforts towards the generation of novel vaccines have received considerable attention. The goal of this paper was to perform an analysis of the current state of treating drug-resistant TB and to evaluate possible approaches to this complicated challenge. Our focus is centered on highlighting new alternatives that can be used to combat resistant strains, which have potentiated the health crisis that TB represents.