Francisco José Fernández

The recently proposed Dynamic Gene Hypothesis conceptualizes genes as emergent functional configurations arising from the dynamics of gene regulatory networks (GRNs), rather than viewing them as intrinsically functional DNA sequences. This paper proposes a theoretical framework to explain how transient, context-dependent regulatory configurations can acquire functional stability and progressively integrate into the organization of biological systems. We propose that GRNs operate according to an intrinsic strategy of continuous exploration of alternative configurations, while energy constraints, network architecture, and environmental recurrence bias this exploration toward preferred trajectories. Under recurring environmental conditions, certain configurations may become increasingly reproducible, generating patterns of functional regularity that can stabilize prior to achieving complete structural fixation. Progressive integration can subsequently incorporate these configurations into the internal dynamics of the GRN, while other alternative transient configurations remain available for future exploration. Consequently, this framework proposes a dynamic intermediate pathway connecting adaptive plasticity, functional stabilization, integration, and potential genetic consolidation within GRN dynamics, while also generating experimentally testable predictions regarding recurrence, state-space exploration, network compatibility, and functional integration.

The increasing demand for environmentally sustainable and efficient laundry detergents has prompted the exploration of innovative biotechnological solutions. This study aims to integrate solid fermentation and by-product valorization for high-quality proteases suitable for laundry detergents. Of 486 strains isolated from fruit by-products, 9 were selected for their proteolytic activity, but only 3 showed proteolytic activity in the presence of detergent components. Strain M17, identified as Yarrowia lipolytica (Yl), proved to be the most effective in producing proteolytic extracts with activity similar to that found in commercial detergents. The produced proteases were incorporated into laundry detergent formulations, and their enzyme activity was compared with that of commercial laundry detergents. The results showed that the proteolytic extracts have enzyme activity similar to that of commercial laundry detergents. Culture media were developed to enhance protease production using fruit by-products. The highest activity (43.71 U (g dm)⁻¹) was achieved at C/N = 20.04, while the best productivity (1.37 U (g dm·h)⁻¹) at pH 7.0 and 30 °C was observed. The results demonstrate that culture media based on fruits and vegetable by-products enhance protease yield and activity. This approach not only reduces waste but also adds value to natural resources through an environmentally friendly process. This study underscores the potential of combining solid-state fermentation with by-products. Using Yl in combination with fruit and vegetable by-products is a practical, eco-friendly method for producing high-quality proteases for laundry detergents. This green enzyme innovation offers significant promise for advancing the detergent proteolytic enzymes and promoting sustainable practices in by-product management.

Psacalium decompositum is a shrub indigenous to Northern Mexico and Arizona and New Mexico in the USA. It has been utilized in traditional medicine for the treatment of many ailments, including rheumatic disorders, pain, and diabetes. A chemical analysis of a hexane extract from the rhizomes of P. decompositum revealed the presence of sesquiterpenes, including cacalol, cacalone, maturin, and maturinone, among others. Furthermore, its aqueous fraction was subjected to isolation, resulting in the identification of linear fructooligosaccharides with an eight-unit polymerisation degree (LFOS8). The objective of this study was to ascertain the impact of LFOS8 derived from P. decompositum on the intestinal microbiota of rats through 16S rRNA gene sequencing and bioinformatics analysis. Male Wistar rats were randomly assigned to the following groups (n=8): a control group administered an isotonic saline solution, positive control group treated with chicory inulin (a prebiotic), and experimental group treated with LFOS8 fraction. The positive control and experimental groups of animals demonstrated alterations in their gut microbiota, resulting in an increase in the growth of beneficial bacteria, including bacteria that are considered probiotics and produce butyrate. This research provides insights into the potential therapeutic benefits of P. decompositum.

The intra- and extra-cellular monophenolase and diphenolase activities of the tyrosinase produced by Amylomyces rouxii were determined in submerged culture using Melin-Norkrans medium supplemented with 12.5 mg/L pentachlorophenol (PCP) and 0.1 g/L tyrosine. Maximal intracellular monophenolase activity was 180 U/mL while maximal extracellular monophenolase activity was 80 U/mL, both using p-cresol as substrate. For diphenolase, the highest intracellular activity was 2233 U/mL using 4-tert-butylcatechol (TBC) as substrate and extracellular diphenolase activity was 975 U/mL with catechol as substrate. The peak tyrosinase activity (mono- and diphenolase) was observed at 48 h of culture. The transformant A412-3 exhibited the highest extracellular activities, with a 2.14-fold increase in monophenolase and a 3.02-fold increase in diphenolase activity compared to the parental strain of A. rouxii. Additionally, it was confirmed that the enzyme secreted was in its active form. Extracellular tyrosinase from the transformant A412-3 was partially purified, achieving a purification factor of 10.6. SDS-PAGE analysis of partially purified tyrosinase revealed three bands of 40, 53, and 130 kDa. These bands were sequenced by LC–MS/MS, revealing eight peptides that showed similarity to tyrosinases from different fungi. It was determined that purified tyrosinase exhibited higher diphenolase activity than monophenolase activity, in line with previous studies on fungal tyrosinases.

Antibiotic resistance has become a global issue. The most significant risk is the acquisition of these mechanisms by pathogenic bacteria, which can have a severe clinical impact and pose a public health risk. This problem assumes that bacterial fitness is a constant phenomenon and should be approached from an evolutionary perspective to develop the most appropriate and effective strategies to contain the emergence of strains with pathogenic potential. Resistance mechanisms can be understood as adaptive processes to stressful conditions. This review examines the relevance of homeostatic regulatory mechanisms in antimicrobial resistance mechanisms. We focus on the interactions in the cellular physiology of pathogenic bacteria, particularly Gram-negative bacteria, and specifically Klebsiella pneumoniae. From a clinical research perspective, understanding these interactions is crucial for comprehensively understanding the phenomenon of resistance and developing more effective drugs and treatments to limit or attenuate bacterial sepsis, since the most conserved adjuvant phenomena in bacterial physiology has turned out to be more optimized and, therefore, more susceptible to alterations due to pharmacological action.