Background: Mitochondria play a key role in the regulation of inflammatory processes. It is well established that mitochondria contain their own mitochondrial DNA (mtDNA), which displays a substantially higher frequency of polymorphisms compared to the nuclear genome. To maintain mitochondrial functionality, cells employ a quality control mechanism known as mitophagy, which ensures the selective removal of dysfunctional mitochondria. The aim of this study was to investigate the relationship between mitochondrial polymorphisms, the efficiency of dysfunctional mitochondria clearance, and proinflammatory activation of inflammatory cells. Methods: In this study, we used cybrids derived from the THP-1 (human monocytic leukemia cell line) that differed in their mitochondrial genome. Results: Based on the levels of secreted proinflammatory cytokines (tumor necrosis factor (TNF), interleukin-1β (IL-1β), IL-6, IL-8, and C-C motif chemokine ligand 2 (CCL2)), cybrids were divided into two groups: one exhibiting a low and the other a high proinflammatory response. mtDNA sequencing revealed a higher number of polymorphisms in the high proinflammatory response group. Transcriptome analysis showed that signaling pathways associated with mitophagy were downregulated in cells with a high proinflammatory response. Functional assays confirmed that mitophagy was impaired in this group. Conclusions: Increased proinflammatory activity in cybrids correlated with a greater number of mtDNA polymorphisms and with impaired mitophagy. These observations point to an association between mitochondrial genomic variation, reduced mitochondrial quality control, and heightened proinflammatory activation of inflammatory cells. However, the data are associative and do not establish causality. Further mechanistic studies are required to determine whether and how mtDNA polymorphisms and defective mitophagy directly contribute to proinflammatory activation.
Background: Interest in processing high-tonnage biodiesel production waste (crude glycerol and microalgal biomass after lipid extraction) into commercial products is steadily growing. Moreover, it is attractive to utilize these wastes for the microbiological production of fumaric acid (FA) using immobilized microorganisms, as it combines chemical and biological processes. Methods: The authors developed original approaches to FA production, which immobilize microalgal Chlorella vulgaris cells and the mycelium of the fungus Rhyzopus oryzae. Traditional techniques were employed for cultivating microorganisms, extracting lipids from accumulated microalgal biomass, and producing biomass hydrolysates through thermolysis under acidic conditions. The biochemical composition of C. vulgaris biomass obtained under different growth conditions (autotrophic, heterotrophic, and mixotrophic) was analyzed using standard methods. Results: The maximum accumulation of microalgal biomass was achieved under mixotrophic conditions using an inoculum immobilized in polyvinyl alcohol (PVA) cryogel in Tamiya medium supplemented with crude glycerol and bubbled with air containing 1% vol. CO2. A total of 4.8 ± 0.2 g DW/L of free C. vulgaris biomass was accumulated in five batch cycles. Two types of C. vulgaris hydrolysates were obtained: hydrolysates from whole cell C. vulgaris biomass (ChVH1) and hydrolysates from C. vulgaris biomass waste after lipid extraction (ChVH2), respectively. In combination with crude glycerol (10–50 g/L), microalgal hydrolysates were transformed to FA using fungi R. oryzae immobilized in PVA cryogel. The highest concentration and yield of FA from the converted substrate were obtained when 20 g/L of crude glycerol, in combination with C. vulgaris hydrolysates, was administered alongside the fungi for 40 h. Multiple uses (five cycles, 200 h total) of immobilized fungi added to the medium with 20 g/L of crude glycerol and ChVH2 produced 186 g of FA. The average FA yield was 309 ± 12 mg/g substrate. Conclusion: A combined approach to producing FA by bioconversion of crude glycerol and hydrolysates of lipid-free microalgae biomass waste is of practical importance. These results expand the potential of bioscience in utilizing microorganisms in an immobilized form, contributing to the integration of environmental biotechnology into bioenergy production.
Global energy security and water scarcity are currently two major challenges facing society. Many new strategies and technologies have been developed to address these issues; however, most can only partially solve a single one. Therefore, microbial fuel cells (MFCs) and associated novel technologies have emerged as sustainable, bifunctional solutions for treating various wastewater streams while generating renewable electrical energy through the biochemical oxidation of organic substrates. The basic configuration of an MFC comprises anodic and cathodic chambers, an external electrical circuit, ion-exchange membranes, organic substrates, and electrogenic bacteria. Biological fuel cells are inherently multidisciplinary systems whose performance depends on several biotic and abiotic parameters, with bacterial electrogenic metabolism as the driving force. In this review paper, the most important factors affecting MFC performance and the common equations employed to determine bioelectrochemical efficiency are described. A major highlight is the analysis and comparison of recently proposed MFC-derived hybrid technologies: microbial electrolysis cells (MECs), microbial desalination cells (MDCs), plant microbial fuel cells (PMFCs), and constructed wetland MFCs (CW-MFCs) for treating wastewater and soil pollutants while enhancing the recovery of green energy. Novel configurations, basic biochemistry, and a brief history of bioelectrochemistry are also reported. In addition, this review aims to compare the applications, fundamentals, basic configuration, and limitations of each biological fuel cell. Based on a comprehensive analysis, the challenges, opportunities, economics, and scaling-up possibilities of each MFC-derived technology are reported. Since biological oxidation in the anodic chamber and reduction at the cathode surface are the basis of all fuel cells, there are characteristic challenges that must be addressed: enhancing power output, increasing pollutant degradation and scalability, reducing construction and operational costs, and ensuring long-term stabilization. MFCs and the associated derived systems appear suitable for converting residual organic matter into green energy, even at a pilot scale; however, to improve scalability and reduce power costs, further research is still needed.
Background: This study aimed to investigate the antibacterial and antibiofilm activities of Trifolium purpureum against Escherichia coli. Methods: T. purpureum Loisel. was collected from the mountains of western Lebanon. The plant parts were then extracted by maceration in 70% ethanol and water. The plant fractions were screened for secondary metabolite classes. The antibacterial activity of the extracts was determined using the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Antibiofilm activity was assessed using a colorimetric method, and the effects of T. purpureum extracts on the expression of genes involved in biofilm formation in E. coli were assessed by real-time quantitative polymerase chain reaction (qPCR). Results: Coumarins, tannins, volatile oils, and phenols were absent in T. purpureum; resins were detected only in the flowers, alkaloids were detected in all plant parts except the stems, and saponins, terpenoids, and flavonoids were found in all plant parts. Regarding antibacterial activity, although all extracts had measurable MIC values, only the whole-plant water extract exhibited a bactericidal effect. Furthermore, the water and ethanol extracts exhibited variable biofilm-prevention activity, with minimum biofilm prevention concentration (MBPC) values ranging from 30 to 68.9 mg/mL. Biofilm eradication activity also varied, with minimum biofilm eradication concentration (MBEC) values ranging from 0.13 to 49.65 mg/mL corresponding to 47.3–66.8% eradication. Finally, the whole-plant water extract suppressed the expression of fimA, fimH, and flu in both planktonic cells and cells within established E. coli biofilms. Conclusions: Our results demonstrate that T. purpureum is rich in secondary metabolites and has notable antibacterial and antibiofilm potential against E. coli, especially at the molecular level. These findings suggest that T. purpureum may be a promising candidate for use as an alternative antibacterial and antibiofilm agent.
Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a major global health challenge, particularly in low- and middle-income countries. The Bacillus Calmette–Guérin (BCG) vaccine, developed from attenuated Mycobacterium bovis (M. bovis) and introduced in 1921, is the only licensed vaccine for TB prevention. Although BCG provides strong protection against morbid forms of pediatric TB, its efficacy against adult pulmonary TB is variable. Emerging evidence indicates that BCG exerts broader immunological effects beyond TB prevention, including non-specific immune protection mediated through trained immunity. BCG-induced trained immunity induces epigenetic reprogramming of innate immune cells which enhances host defense against heterologous pathogens. Advances in pharmacological biotechnology, including recombinant BCG platforms, genetic modification, and novel delivery systems, have demonstrated improved antigen presentation, durability of immune memory, and expanded clinical utility. Beyond TB, BCG remains a cornerstone immunotherapy for non–muscle-invasive bladder cancer and shows promising immunomodulatory potential in autoimmune diseases such as type 1 diabetes and multiple sclerosis. While adverse effects are generally mild, they tend to be more pronounced in immunocompromised individuals. This review examines the historical development, biotechnological production, immunological mechanisms, and expanding therapeutic applications of BCG. We synthesized findings on strain variability, manufacturing processes, and immune responses, highlighting the induction of T helper 1 (Th1)–mediated cellular immunity through interferon gamma (IFN-γ) and interleukin-12 (IL-12), macrophage activation, and granuloma formation. Overall, BCG represents both a critical public health intervention and a model system for advancing immune-based therapies.
