Production of biofuels and other value-added products from lignocellulose breakdown requires the coordinated metabolic activity of varied microorganisms. The increasing global demand for biofuels encourages the development and optimization of production strategies. Optimization in turn requires a thorough understanding of the microbial mechanisms and metabolic pathways behind the formation of each product of interest. Hydrolysis of lignocellulosic biomass is a bottleneck in its industrial use and often affects yield efficiency. The accessibility of the biomass to the microorganisms is the key to the release of sugars that are then taken up as substrates and subsequently transformed into the desired products. While the effects of different metabolic intermediates in the overall production of biofuel and other relevant products have been studied, the role of proteins and their activity under anaerobic conditions has not been widely explored. Shifts in enzyme production may inform the state of the microorganisms involved; thus, acquiring insights into the protein production and enzyme activity could be an effective resource to optimize production strategies. The application of proteomic analysis is currently a promising strategy in this area. This review deals on the aspects of enzymes and proteomics of bioprocesses of biofuels production using lignocellulosic biomass as substrate.

Hydrogels are gaining widespread popularity in the biomedical field due to their extraordinary properties, such as biocompatibility, biodegradability, zero toxicity, easy processing, and similarity to physiological tissue. They have applications in controlled drug release, wound dressing, tissue engineering, and regenerative medicine. Among these applications, hydrogels as a controlled drug delivery system stands out, which releases active substances in precise amounts and at specific times. To explore the latest advances in the design of hydrogels, a literature review of articles published in indexed scientific journals, in Scopus and Science Direct, was carried out. This review aimed to discover and describe the most innovative hydrogel research with applications in the biomedical field; hydrogels synthesized with polymers of different origins were selected, such as; i. Natural (dextran, agarose, chitosan, etc.); ii. Synthetic (polyacrylamide, polyethylene glycol, polyvinyl alcohol, etc.); iii. Composites (interpenetrants, hybrid crosslinkers, nanocomposites, etc.). Comparative analysis revealed that hydrogels with composite materials show the most promise. These composite hydrogels combine the advantages of different polymers or incorporate additional components, offering enhanced properties and functionalities. In summary, hydrogels are versatile biomaterials with immense potential in biomedicine. Their unique properties make them suitable for diverse applications. However, innovative designs and formulations must continue to be explored to further advance the capabilities of hydrogels and expand their biomedical applications.

Background/Objectives: Capsaicin is the principal pungent compound in chili peppers and is increasingly recognized as a multifunctional phytochemical with systemic effects beyond its sensory properties. It has been linked to metabolic regulation, neuroprotection, inflammation control, and cancer modulation. This review aims to provide an integrative synthesis of capsaicin’s metabolism, its interaction with the gut microbiome, and its physiological implications across organ systems. Methods: We conducted a critical literature review of recent in vivo and in vitro studies exploring capsaicin’s metabolic fate, biotransformation by host enzymes and gut microbes, tissue distribution, and molecular pathways. The literature was analyzed thematically to cover gastrointestinal absorption, hepatic metabolism, microbiota interactions, and systemic cellular responses. Results: Capsaicin undergoes extensive hepatic metabolism, producing hydroxylated and dehydrogenated metabolites that differ in transient receptor potential vanilloid type 1 (TRPV1) receptor affinity and tissue-specific bioactivity. It crosses the blood–brain barrier, alters neurotransmitter levels, and accumulates in brain regions involved in cognition. In addition to its systemic effects, capsaicin appears to undergo microbial transformation and influences gut microbial composition, favoring short-chain fatty acid producers and suppressing pro-inflammatory taxa. These changes contribute to anti-obesity, anti-inflammatory, and potentially anticancer effects. Dose-dependent adverse outcomes, such as epithelial damage or tumor promotion, have also been observed. Conclusions: Capsaicin represents a diet-derived bioactive molecule whose systemic impact is shaped by dynamic interactions between host metabolism and the gut microbiota. Clarifying its biotransformation pathways and context-specific effects is essential for its safe and effective use in metabolic and neurological health strategies.

The global production of biomethane is rapidly emerging as a sustainable alternative to fossil fuels for energy generation. Biogas, where methane (CH4) is usually one of the main components, is generated through the anaerobic digestion (AD) of various organic substrates, including animal manure, organic wastes, and wastewater. The efficiency of the AD process depends on key operational parameters and reactor designs that optimize microbial activity and gas yield. However, inhibitory compounds such as heavy metals, ammonia, and volatile fatty acids (VFAs) can significantly impact microbial metabolism and biogas production. To enhance substrate availability for microbial degradation, different pretreatment methods are often employed, as well as current advances in the AD focused on DIET enhancement and co-digestion technologies. This chapter provides a comprehensive overview of common substrates for AD, the impact of operational parameters, and strategies to mitigate the effects of inhibitory compounds. It also examines the latest advancements in reactor designs for effective monitoring and control of the digestion process. Additionally, the chapter explores biogas production for electrical energy generation, along with the purification technologies required to upgrade biogas to biomethane. Finally, it discusses the applications and value-added products derived from biomethane and its integration into circular economy frameworks. It involves the advantages and gaps hindering the full implementation of AD-derived energy worldwide.