Extremophilic microorganisms live in extreme environmental conditions such as high or low temperature, high or low pH, high concentration of salt and accordingly are classified as thermophilic, psychrophilic, alkaliphilic, acidophilic and halophilic respectively. They adapt themselves to the extreme conditions by producing novel biomolecules like heat shock proteins, cold active enzymes, compatible solutes and exopolysaccharides. Extremophilic microorganisms maintain their cellular integrity with the help of exopolysaccharide (EPS) which constitutes slime or a hydrated matrix that keeps the cells embedded. EPS are composed of carbohydrates and some amino acids. Thermophilic microorganisms namely Thermus, Geobacillus, Bacillus, Thermococcus and halophilic microorganisms namely Halomonas, Halobacillus, Haloferax and Halococcus are reported and well-studied for production of EPS. The EPSs exhibit emulsifying, viscofying and antioxidant properties that find applications in food industry, oil recovery and anticancer agents.
Decaprenoxanthin (DPXT) is an unusual bacterial C50 carotenoid that has historically received limited attention despite its well-defined structure. For decades, carotenoid research and industrial development have been dominated by C40 carotenoids, leaving longer-chain carotenoids largely overlooked. Recent discoveries, particularly from microorganisms inhabiting Antarctic and other extreme environments, have repositioned DPXT as an adaptive pigment shaped by intense environmental pressures. Its extended polyene chain and membrane-associated behavior suggest roles in membrane stabilization and protection against ultraviolet radiation and oxidative stress, features that may hold relevance for food and biotechnological applications. This review integrates historical and recent knowledge on DPXT, covering its structural characteristics, biosynthetic pathways, ecological function, and emerging technological relevance. Special attention is given to microbial sources, particularly Actinomycetota from extreme environments, and to recent advances in microbial genomics, metabolic engineering, and sustainable bioprocess development that enable the production and exploration of C50 carotenoids beyond their native extremophilic context. The analysis highlights DPXT as a representative example of stress-resilient carotenoids, with physicochemical and membrane-interacting properties that may offer advantages for future food and biotechnological systems. Although significant challenges remain in cultivation strategies, yield optimization, and downstream recovery, advances in microbial cell factories and green extraction technologies open new opportunities for valorizing C50 carotenoids. This review bridges extremophile microbiology, carotenoid biochemistry, and sustainable food innovation, positioning DPXT as an emerging molecule that may expand the functional and structural landscape of carotenoids relevant to food science.
Antimicrobial resistance (AMR) is a global threat driven by the interplay between microbial evolution and human activity. Antimicrobial use in human and veterinary medicine, as well as in agriculture, accelerates the selection and dissemination of resistant bacteria and genes across interconnected human, animal, and environmental reservoirs. These dynamic exchanges render single-sector interventions ineffective. A One Health approach integrating human, animal, and environmental health is therefore essential to understand and mitigate the emergence and spread of AMR. This chapter focuses on bacterial antimicrobial resistance, addressing key concepts, major challenges, and emerging technologies within a One Health framework. Advances in next-generation sequencing and omics technologies have transformed our capacity to resolve AMR at unprecedented scale and resolution. These tools enable the tracking of resistance genes and high-risk clones across ecosystems, uncover transmission pathways, and identify key drivers of dissemination. Such insights support real-time epidemiological surveillance, outbreak detection, and targeted interventions. However, translating these advances into routine practice remains a major challenge, requiring harmonized methodologies, data integration, and cross-sector coordination. Addressing AMR demands sustained collaboration across disciplines and stakeholders, including clinicians, veterinarians, farmers, researchers, policymakers, industry, and the public. And framing AMR as a shared ecological and societal responsibility underscores the urgency of coordinated global action. We call for the urgent integration of One Health principles into surveillance, policy, and innovation to preserve antimicrobial effectiveness and safeguard future health.
