Inhibitory Substances Research Articles

Exploring the Microbial Ecology of Nitrification Denitrification in Wastewater Treatment: Innovations and Future Directions

The nitrification-denitrification process serves as a critical mechanism in the biological removal of nitrogen from wastewater, a necessity for mitigating the environmental impact of nitrogen compounds on aquatic ecosystems. This complex process is orchestrated by diverse microbial communities, whose ecological interactions and functional capabilities are central to the efficiency and stability of nitrogen removal. In recent years, advances in molecular biology and microbial ecology have shed new light on the intricate dynamics within these microbial communities, revealing the roles of lesser known microbial taxa and the importance of microbial community structure and function in optimizing nitrification denitrification processes. This review provides a comprehensive examination of the microbial ecology involved in nitrification and denitrification, exploring the roles of key microbial players, including ammonia oxidizing bacteria (AOB), Nitrite oxidizing Bacteria (NOB), ammonia oxidizing archaea (AOA), and denitrifying bacteria. The review also delves into the environmental factors that influence microbial community dynamics, such as pH, temperature, oxygen availability, and the presence of inhibitory substances. By understanding these factors, the review highlights the challenges of maintaining stable and efficient nitrogen removal processes, particularly in the face of environmental fluctuations and operational disturbances, the review discusses recent innovations in wastewater treatment technologies that leverage microbial ecology to enhance process efficiency. These include bio-augmentation strategies, where specific microbial strains are introduced to bolster nitrification and denitrification, and advanced bioreactor designs, such as moving bed biofilm reactors (MBBRs) and membrane bioreactors (MBRs), which provide optimized environments for microbial growth and activity. The integration of anaerobic ammonium oxidation (anammox) processes, which offer significant energy savings and reduce greenhouse gas emissions, is also explored as a promising alternative to traditional nitrification pathways.

Bacteriocin CM175, a new high molecular weight and phage associated protein produced by Pediococcus pentosaceus CM175

Bacteriocins are proteins with antimicrobial capacity produced by different bacteria. Developing bacteriocin-based technologies could be an effective strategy to address current problems in the pharmaceutical and food industries, including limited therapeutic options against superbug infections, foodborne diseases, and food spoilage microorganisms. The lactic acid bacteria Pediococcus pentosaceus are known producers of bacteriocins. Particularly, Ped. pentosaceus strain CM175 has been reported to produce an uncharacterized bacteriocin-like inhibitory substance (BLIS) with an interesting antibacterial spectrum against Gram-positive and -negative pathogenic bacteria. The objective of the present study was to explore whether the BLIS produced by CM175 contains at least one bacteriocin, and identify it. Our results showed that the CM175 strain produced a non-previously characterized antimicrobial protein of 49 kDa identified by mass spectrometry as a phage-related protein, named bacteriocin CM175. Through fluorescence and transmission electron microscopies, it was demonstrated that bacteriocin CM175 damages the cell membrane integrity of Listeria monocytogenes through a non-lytic mechanism. Bacteriocin CM175 is the first high molecular weight and phage protein-like bacteriocin reported in Ped. pentosaceus. The results of this study open the possibility of exploring various applications directly related to the antimicrobial potential of bacteriocin CM175, including the development of antibiotics, and disinfectants.

Biological Properties of S. warneri KYS-164 Isolated from Kefir Grains.

Staphylococcus worderi KYS-164, isolated from homemade Tibetan kefir grains, produces bacteriocin-like inhibitory substances (BLIS), which are peptides with antimicrobial properties, but have not been fully characterized. The research on BLIS will lay the foundation for mining new bacteriocins. In this study, the optimal culture conditions for the production of highly active BLIS were found to be incubation at 30 °C and 120 rpm, and the most effective extraction method was ammonium sulfate precipitation (ASP) using ammonium sulfate at 80% saturation. The postantibiotic effect (PAE) of BLIS on Staphylococcus aureus CICC 10384 is significant, with a 4 × MIC BLIS concentration able to prolong the PAE to 2.39 h. BLIS has excellent biosafety, with no deleterious effects observed at 8 × MIC concentration. Gas chromatography-ion mobility spectrometry (GC-IMS) was used to analyze the volatile compounds synthesized by Staphylococcus warneri KYS-164 during its growth. Hydroxycitronellal, ethyl pyruvate, and α-pinene were found to be unique substances produced by this strain, which can provide fresh, refreshing floral and fruity aromas as well as strong pine and resinous aromas in the process of kefir grain fermentation of milk. Analysis of the S. warneri KYS-164 genome provided insights into the major metabolic pathways in which genes expressed in this strain are involved. This study represents the first isolation of S. warneri KYS-164 from kefir grains prepared by Tibetan families, and provides a comprehensive analysis of its physicochemical properties. This research provides a solid foundation for better understanding and utilization of S. warneri KYS-164.

Natural Antimicrobial Monoterpenes as Potential Therapeutic Agents in Vaginal Infections: A Review

The recurrence and relapse of vaginal infections in women is a major issue and a challenging pathway to identify and develop new approaches to treatment. In the case of antibiotic therapy, contraceptives, and dietary changes, the recurrence of vaginitis is more common these days. Anaerobic bacteria, Candida spp., and trichomonas in the vaginal microflora cause both symptomatic and asymptomatic vaginitis, which includes vaginal inflammation. It changes the vaginal microbiota and decreases Lactobacilli spp. growth, which is maintaining the vaginal pH (3.5-4.5) through lactic acid production, antimicrobial peptides, bacteriocin, and bacteriocin-like inhibitory substances. The remarkable antimicrobial activity of plant’s producing metabolites like alkaloids, tannins, phenolic compounds, flavonoids and terpenoids for several vaginal infections have been reported in previous studies. Presented review focuses on the pivotal role of monoterpenes, providing a detailed description of thymol, geraniol, limonene, eugenol, eucalyptol, and α-terpineol as antimicrobial molecules in the treatment of vaginal infections. These monoterpenes are very good at killing E. coli, Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus niger, Trichomonas vaginalis and Candida albicans which are the main microbes that cause vaginitis. Future research could explore the latent combinations of such monoterpenes as synergistic antimicrobial agents to treat bacterial and fungal vaginal infections, trichomoniasis, among other conditions.

Production of bacteriocin-like inhibitory substance (BLIS) by Staphylococcus spp. isolates from dogs.

In the present study, 39 canine isolates of Staphylococcus spp. were tested for antimicrobial substance (AMS) production. Seven AMS producers were identified, whose products exhibited a non-acidic character and a proteinaceous nature, therefore being considered bacteriocin-like inhibitory substances (BLIS). The producer strains of BLIS P1, P16 and I3 showed a broad spectrum of antimicrobial activity. Human, veterinary and plant pathogens, such as Listeria monocytogenes, Klebsiella pneumoniae, Staphylococcus spp. and Clavibacter michiganensis, were among the inhibited micro-organisms, suggesting the potential biotechnological application of these peptides. MALDI-TOF mass spectrometry and 16S rDNA sequencing identified the producer strains of BLIS P1, P16 and I3 as Staphylococcus pseudintermedius P1, Staphylococcus schleiferi P16 and Staphylococcus pseudintermedius I3. The plasmid profile of these strains suggests that the BLIS production is linked to biosynthetic genes located on plasmids. PCR analyses revealed that BLIS P1, P16 and I3 are different from 11 staphylococcins already described in the literature and that their genomic DNAs do not carry the most prevalent staphylococcal enterotoxin genes. The highest levels of BLIS production were achieved after 18-24h of growth of the producer strains in TSB medium. Moreover, BLIS P1 and I3 exhibited high resistance to temperature and pH variations, and BLIS P16 maintained 100% of its activity in almost all conditions tested. The characteristics associated with BLIS P1, P16 and I3 described in this work encourage further investigation of these substances, in addition to this study being the first report of BLIS production by a strain of S. schleiferi.

AMH regulates a mosaic population of AMHR2-positive cells in the ovarian surface epithelium

The function and homeostasis of the mammalian ovary depend on complex paracrine interactions between multiple cell types. Using primary mouse tissues and isolated cells, we showed in vitro that ovarian follicles secrete a factor(s) that suppresses growth of ovarian epithelial cells in culture. Most of the growth suppressive activity was accounted for by Anti-Mullerian Hormone/Mullerian Inhibitory Substance (AMH/MIS) secreted by granulosa cells of the follicles, as determined by immune depletion experiments. Additionally, conditioned medium from granulosa cells from wild type control, but not AMH knockout, suppressed epithelial cell growth. Tracing of the AMH regulated cells using AMHR2 (AMH receptor 2)-Cre:ROSA26 mutant mice indicated the presence of populations of AMHR2-positive epithelial cells on the ovarian surface and oviduct epithelia. Cells isolated from the mutant mice indicated that a subpopulation of cells marked by AMHR2-Cre:ROSA26 accounted for most cell growth and expansion in ovarian surface epithelial cells, and the AMHR2 lineage derived cells were regulated by AMH in vitro; whereas, fewer AMHR2-Cre:ROSA26 marked cells accounted for oviduct epithelial cell outgrowth. The results reveal a paracrine pathway in maintaining follicle-epithelial homeostasis in ovary and support a subpopulation of AMHR2 lineage marked epithelial cells as ovarian epithelial stem/progenitor cells with higher proliferative potential regulatable by follicle secreted AMH.

Developmental validation of a multiplex qPCR assay for simultaneous quantification of nuclear and mitochondrial DNA

Quantification of human DNA is key in forensic genetics. A more accurate estimate of the amount of DNA is essential for planning and optimising genotyping assays, as is evaluating the presence of PCR inhibitory substances and DNA degradation status. Multiplex qPCR assays are helpful in forensics because they can quantify different targets simultaneously, thus saving valuable samples, time, and labour. The aim of this study was to highlight the challenges in the developmental validation of a multiplex real-time PCR assay and the drawbacks encountered in translating a previously described and validated assay (SD quants) to a different technology by modifying the dye probes and reagent mix to be used in a different instrument. We developed a TaqMan probe-based multiplex qPCR using reagents and fluorescent probes adapted for the Rotor-Gene 6000 instrument (QIAGEN, Hilden, Germany). The initial assay combined two mitochondrial DNA (mtDNA) and two nuclear DNA (nDNA) targets, with amplification products of different sizes (mtDNA = 69 and 143 bp; nDNA = 71 and 181 bp), to estimate the DNA degradation status and an internal positive control (IPC) to detect potential inhibitors. During the initial testing of the assay, we observed an interaction between the 69 bp mtDNA target and the 71 bp nDNA target probe, and experiments were conducted to resolve this issue without success. We removed the small nDNA target (71 bp) and changed from a 5-plex to a 4-plex qPCR assay (qMIND). The final tetraplex assay was tested on 105 forensic samples and/or small amounts of degraded DNA, such as bones, teeth, fingernails, formalin-fixed paraffin-embedded tissues (FFPE), and hair shaft samples. The quantification results were compared with data acquired from the same samples using another commercially available quantification system commonly used in forensic laboratories. In addition, the short tandem repeat (STR) profiles were investigated to determine their correlation with the quantitative values obtained. Overall, the qPCR assay was robust and reliable for DNA quantification in samples commonly used in forensic practice.

Biological Control of Microbial Pectinolytic Plant Pathogens Causing Soft Rot of Fruits and Vegetables.

It is crucial to implement appropriate measures to prevent the spread of plant pathogens that lead to the decay of fruits and vegetables. From this perspective, we evaluated the biocontrol potential of five Bacillus-plant growth promoting rhizobacteria (PGPR) strains against twenty-one pectinolytic phytopathogens causing soft rot in fruits and vegetables. These phytopathogens had been previously studied. Three in vitro methods were utilized to accomplish this objective: competition, extraction of bioactive substances, and direct confrontation. The inhibitory effect of the direct confrontation method resulted in a slower growth of 11 microbial plant pathogens. In addition, it was noted that 11 strains of plant pathogens generated inhibitory constituents, while 15 plant pathogens produced inducible inhibitory substances. Furthermore, volatile inhibitory compounds were detected in the six tested strains. Overall, strains of PGPR-Bacillus demonstrated strong antifungal and antibacterial properties against phytopathogens. These PGPR can be regarded as potential biocontrol agents for soft microbial rot in fruits and vegetables as well as producers of substances that effectively suppress plant diseases.

Treatment of sludge hydrothermal carbonization wastewater by ferrous/sodium percarbonate system: Effect of wastewater composition and role of coagulation and oxidation

It is crucial to explore the effect of complex wastewater compositions on the ferrous/sodium percarbonate (Fe(Ⅱ)/SPC) system and the role of oxidation-coagulation in designing water treatment processes. This study employed redundancy analysis to investigate the effects of wastewater constituents on oxidation and coagulation. Raman analysis, X-ray Photoelectron Spectroscopy, and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry were used to determine the roles of oxidation and coagulation in the system. The results showed that sulfates and phosphates formed amorphous complexes with iron species via coprecipitation, thereby promoting coagulation to remove organics. Some heavy metals can also be removed by coagulation. The co-activation of SPC by pre-existing transition metals and the added Fe(Ⅱ) facilitated the oxidative removal of organics, while chloride and arsenic were the main inhibitory inorganic substances in the system. Aromatic compounds mainly promoted coagulation, polysaccharides promoted oxidation, humic acid promoted oxidation and coagulation, and C=C/C=O inhibited the Fe(Ⅱ)/SPC system. The oxidation process removed graphitic structures and unsaturated organic matter in the region of (O/C, H/C) = (0.2–0.4, 0.9–2.0) through free radicals and generated amorphous carbon structures and saturated organic matter in the region of (O/C, H/C) = (0.3–0.7, 1.2–1.9). The coagulation process removed aromatic organics with 2–5 rings and unsaturated organics in the region of (O/C, H/C) = (0.2–0.6, 0.7–1.6) with oxygen-containing organics. The combined effects of coagulation and oxidation enhanced the removal efficiency of organic carbon by approximately 40%. This study facilitates the optimization of hydrothermal carbonization wastewater treatment and advanced oxidation processes.

Comparison of Extraction Methods for the Detection of Avian Influenza Virus RNA in Cattle Milk.

Since early 2024, a multistate outbreak of highly pathogenic avian influenza H5N1 has been affecting dairy cattle in the USA. The influenza viral RNA concentrations in milk make it an ideal matrix for surveillance purposes. However, viral RNA detection in multi-component fluids such as milk can be complex, and optimization of influenza detection methods is thus required. Raw bulk tank milk and mastitis milk samples were artificially contaminated with an avian influenza strain and subjected to five extraction methods. HCoV-229E and synthetic RNA were included as exogenous internal process controls. Given the high viral load usually observed in individual raw milk samples, four out of five tested methods would enable influenza detection in milk with normal texture, over a time window of at least 2 weeks post-onset of clinical signs. Nevertheless, sample dilution 1:3 in molecular transport medium prior to RNA extraction provided the best results for dilution of inhibitory substances and a good recovery rate of influenza RNA, that reached 12.5 ± 1.2% and 10.4 ± 3.8% in two independent experiments in bulk milk and 11.2 ± 3.6% and 10.0 ± 2.9% on two cohorts of mastitis milk samples. We have also shown compatibility of an influenza RT-qPCR system with synthetic RNA detection for simultaneous validation of the RNA extraction and RT-qPCR processes.

Efficient metabolic pathway modification in various strains of lactic acid bacteria using CRISPR/Cas9 system for elevated synthesis of antimicrobial compounds

Lactic acid bacteria (LAB) are known to exhibit various beneficial roles in fermentation, serving as probiotics, and producing a plethora of valuable compounds including antimicrobial activity such as bacteriocin-like inhibitory substance (BLIS) that can be used as biopreservative to improve food safety and quality. However, the yield of BLIS is often limited, which poses a challenge to be commercially competitive with the current preservation practice. Therefore, the present work aimed to establish an optimised two-plasmid CRISPR/Cas9 system to redirect the carbon flux away from lactate towards compounds with antimicrobial activity by disrupting lactate dehydrogenase gene (ldh) on various strains of LAB. The lactic acid-deficient (ldhΔ) strains caused a metabolic shift resulting in increased inhibitory activity against selected foodborne pathogens up to 78 % than the wild-type (WT) strain. The most significant effect was depicted by Enterococcus faecalis-ldh∆ which displayed prominent bactericidal effects against all foodborne pathogens as compared to the WT that showed no antimicrobial activity. The present work provided a framework model for economically important LAB and other beneficial bacteria to synthesise and increase the yield of valuable food and industrial compounds. The present work reported for the first time that the metabolism of selected LAB can be manipulated by modifying ldh to attain metabolites with higher antimicrobial activity.

Evaluation of Inhibitory Substance- Producing Bacteria Isolated from Palm Wine (Elaeis Guineenis) Sold in Elele Market, Rivers State, Nigeria

The increase in the number of antimicrobial-resistant food-borne pathogens has become a cause for concern. There is a need to find novel strategies to combat these pathogens, in order to reduce food poisoning and even promote food security. Probiotic bacteria, including lactic acid bacteria, were isolated from palm wine (Elaeis guineensis) to evaluate antimicrobial effects on some selected spoilage and pathogenic microorganisms (Escherichia sp, Pseudomonas sp and Staphylococcus sp). They were identified by gram staining, catalase test, spore staining tests, sugar fermentation test and molecular analysis. These isolates were tested against pathogens to determine if they were capable of inhibiting their growth, and the isolates that exhibited antimicrobial properties were Bacillus cereus, Lactobacillus sp 1 and Lactobacillus sp 2. Bacillus cereus showed 18 mm against both Staphylococcus aureus and Pseudomonas aeruginosa, Lactobacillus sp 1 showed 20 mm against Pseudomonas aeruginosa, while Lactobacillus sp 2 showed 21 mm against Staphylococcus aureus. The quantitative analysis of the molecular results shows the absorbance ratio (A260/A280) for Lactobacillus sp 1 as 1.49, Bacillus cereus as 1.69 and Lactobacillus sp 2 as 1.29. The results indicated that Bacillus cereus, Lactobacillus sp 1 and Lactobacillus sp 2 exhibited probiotic potential.

A Novel C-Terminal Truncated Bacteriocin Found by Comparison between Leuconostoc mesenteroides 406 and 213M0 Isolated from Mongolian Traditional Fermented Milk, Airag.

Bacteriocins produced by lactic acid bacteria are known to be useful tools for food biopreservation and fermentation control. Leuconostoc mesenteroides subsp. mesenteroides 406 and 213M0 isolated from different samples of Mongolian traditional fermented milk, airag, had been reported to produce listericidal bacteriocin-like inhibitory substances with similar but slightly different properties. In this study, the antibacterial properties and the related gene sequences of both strains were compared, and then their bacteriocins were purified and identified. Strain 406 was superior to strain 213M0 in cell growth and antibacterial activity against many strains. However, the activity of 213M0 was stronger than that of 406 against a few strains. DNA sequencing revealed two and three plasmids in 406 and 213M0, respectively, and each one of them harbored an almost identical mesentericin Y105-B105 gene cluster. Removal of these plasmids resulted in a complete loss of activity, indicating that the antibacterial activity of both strains was generated by bacteriocins encoded on the plasmids. Mesentericins Y105 and B105 were purified from both cultures, and another novel bacteriocin, named mesentericin M, was identified from the 213M0 culture only. Its structural gene was coded on a 213M0 plasmid and, surprisingly, its C-terminal three amino acid residues were post-translationally cleaved. To our knowledge, this is the first report of a C-terminal truncated bacteriocin. In conclusion, the novel bacteriocin should be mainly responsible for the difference in antibacterial properties between the two strains.

Production and SERS characterization of bacteriocin-like inhibitory substances by latilactobacillus sakei in whey permeate powder: exploring natural antibacterial potential.

Bacteriocins are antimicrobial compounds that have awakened interest across several industries due to their effectiveness. However, their large-scale production often becomes unfeasible on an industrial scale, primarily because of high process costs. Addressing this challenge, this work analyzes the potential of using low-cost whey permeate powder, without any supplementation, to produce bacteriocin-like inhibitory substances (BLIS) through the fermentation of Latilactobacillus sakei. For this purpose, different concentrations of whey permeate powder (55.15gL-1, 41.3gL-1 and 27.5gL-1) were used. The ability of L. sakei to produce BLIS was evaluated, as well as the potential of crude cell-free supernatant to act as a preservative. Raman spectroscopy and surface-enhanced Raman scattering (SERS) provided detailed insights into the composition and changes occurring during fermentation. SERS, in particular, enhanced peak definition significantly, allowing for the identification of key components, such as lactose, proteins, and phenylalanine, which are crucial in understanding the fermentation process and BLIS characteristics. The results revealed that the concentration of 55.15gL-1 of whey permeate powder, in flasks without agitation and a culture temperature of 32.5°C, presented the highest biological activity of BLIS, reaching 99% of inhibition of Escherichia coli and Staphylococcus aureus with minimum inhibitory concentration of 36-45%, respectively. BLIS production began within 60h of cultivation and was associated with class II bacteriocins. The results demonstrate a promising approach for producing BLIS in an economical and environmentally sustainable manner, with potential implications for various industries.

Rapidly screening of pancreatic lipase inhibitors from Clematis tangutica using affinity ultrafiltration-HPLC-QTOFMS technique combined with targeted separation, in vitro validation, and molecular docking.

Screening of novel pancreatic lipase inhibitors from complex natural products is a meaningful task. Through accurately screening and separating pancreatic lipase inhibitors from Clematis tangutica (C. tangutica), to discover new leading compounds for slimming and accelerate the development and utilization of Tibetan medicine resources. An integrated strategy that combines affinity ultrafiltration and high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (AU-HPLC-QTOFMS), targeted separation, in vitro validation, and molecular docking was developed to screen pancreatic lipase inhibitors from C. tangutica. The AU-HPLC-QTOFMS technique was performed to fish for the potential active substances. Macroporous resin, preparative liquid chromatography, and high-speed countercurrent chromatography were implemented for the accurate and targeted separation of active compounds. The inhibitory activities of target compounds to pancreatic lipase were detected by the inhibition experiments in vitro. The binding affinities and binding sites were analyzed using molecular docking. A total of eleven kinds of pancreatic lipase inhibitory substances were screened from C. tangutica. Seven triterpenoid saponins were screened for the first time as lipase inhibitors and successfully prepared with purities higher than 97%. Tanguticoside B, clematangoticoside J, hederoside H1, and rutin showed stronger inhibitory effects with IC50 values of 1.539 ± 0.048, 1.661 ± 0.092, 1.793 ± 0.069, and 1.792 ± 0.094 mmol/l. Moreover, they have the lowest ΔG values of -10.84, -9.97, -10.87, and -9.39 kcal/mol to pancreatic lipase. The integrated strategy using AU-HPLC-QTOFMS, targeted separation, in vitro validation, and molecular docking was feasible for rapidly screening and directionally isolating pancreatic lipase inhibitors from C. tangutica.

Investigating the acidophilic microbial community's adaptation for enhancement indium bioleaching from high pulp density shredded discarded LCD panels

As part of electronic waste (e-waste), the fastest growing solid waste stream in the world, discarded liquid crystal displays (LCDs) contain substantial amounts of both valuable and potentially harmful metal, offering valuable opportunities for resource extraction but posing environmental threats. The present comprehensive study is an investigation into the bioleaching of indium from discarded LCD panels, with a particular focus on high pulp density shredded (Sh-LCDs) and powdered (P-LCDs) materials. This study involved an acidophilic consortium, with two pathways, namely the mixed sulfur-iron pathways and sulfur pathways, being explored to understand the bioleaching mechanisms. Indium bioleaching efficiencies through the mixed sulfur-iron pathway were approximately 60% and 100% for Sh-LCDs and P-LCDs, respectively. Three mechanisms were involved in the extraction of indium from LCD samples: acidolysis, complexolysis, and redoxolysis. The microbial community adapted to a pulp density of 32.5 g/L was streak-plated and it was revealed that sulfur-oxizing bacteria dominated, resulting in the minimum indium extraction of 10% and 55% for both Sh-LCDs and P-LCDs samples, respectively. It was generally accepted that ferric ions as oxidants were effective for indium bioleaching from both the Sh-LCDs and P-LCDs. This implies that the cooperation or interaction within the microbial community used in the bioleaching process had a beneficial impact, enhancing the overall effectiveness of extracting indium from LCD panels. The adapted consortium utilizes a combination of microbial transformation, efflux systems, and chelation through extracellular substances to detoxify heavy metals. The adapted microbial community demonstrated better indium leaching efficiency (50%) compared to the non-adapted microbial community which achieved a maximum of 29% and 5% respectively from Sh-LCDs and P-LCDs at a pulp density of 32.5 g/L. The advantages of an adapted microbial community for indium leaching efficiency, attributing this advantage to factors such as high metabolic activity and improved tolerance to heavy metals. Additionally, the protective role of the biofilm formed by the adapted microbial community is particularly noteworthy, as it contributes to the community's resilience in the presence of inhibitory substances. This information is valuable for understanding and optimizing bioleaching processes for indium recovery, and by extension to possibly other metals.

Hepatocyte-derived extracellular vesicles regulate liver regeneration after partial hepatectomy.

While significant progress has been made in understanding different aspects of liver regeneration, the molecular mechanisms responsible for the initiation and termination of cell proliferation in the liver after massive loss or injury of liver tissue remain unknown. The loss of liver mass affects tissue-specific mitogenic inhibitors in the blood, which in turn regulate the proliferation of remaining hepatocytes and liver regeneration. Although well described in a number of publications, which inhibitory substances or "sensor molecules" control the regeneration mechanisms to properly maintain liver size remain unknown. Extracellular vesicles (EVs) are nano-sized, membrane-limited structures secreted by cells into the extracellular space. Their proposed role is stable intercellular carriers of proteins and RNAs, mostly micro-RNA, from secreted to recipient cells. Taken up by the recipient cells, EVs can significantly modulate their biological functions. In the present study, using in vivo and in vitro models, we demonstrate that hepatocyte proliferation and liver regeneration are regulated by EVs secreted by hepatocytes into the bloodstream. This regulation is carried out through a negative feedback mechanism, which explains the very precise regeneration of liver tissue after massive damage. We also demonstrate that an essential component of this mechanism is RNA carried by hepatocyte-derived EVs. These findings open up a new and unexplored area of biology regarding the mechanisms involved in the homeostasis regulation of various constantly renewing tissues by maintaining the optimal size and correct ratio between differentiating and proliferating cells.

Effect of Enterococin – Zinc Oxide Nanoparticles on Gene Expression of rsbA Swarming Genes in Proteus mirabilis isolation Catheter urine.

Urinary tract infections linked to catheters are believed to be caused most frequently by Proteus mirabilis. It produces urease, which greatly increases the potency of catheter occlusion caused by swarming. Pathogenic bacteria use swarming as one of their main virulence mechanisms to evade antibiotics; as a result, there is an increasing need to develop novel antibiotic substitutes. Investigating the possible antibiofilm capabilities of artificial zinc oxide nanoparticles (ZnO NPs) made from E. Faecium was the aim of this study. By generating reductive enzymes, bacterial cells are able to catalyze the biosynthesis process. Bacteriocin-like inhibitory substance (BLIS) was used to create the nanoparticles. AFM, TEM, FESEM, and other analytical tools were used to characterize the synthesized zinc nanoparticles and determine the chemical and physical characteristics of the products. Weak swarming is shown by microorganisms that develop strong swarming. After incubation, the ZnO nanoparticles were incubated for 24 or 48 hours at 37°C at a sub-MIC of 32 µg/ml. After these isolates were treated with zinc nanoparticles, downregulation of rsbA expression was detected via real-time PCR compared to that in the untreated isolates. Zinc oxide nanoparticles can serve as antibacterial agents in a concentration-dependent manner, according to all of the study's findings. This was demonstrated by the notable downregulation of rsbA gene expression, which effectively inhibits the production of biofilms and swarming motility. This was demonstrated by their noteworthy downregulation of rsbA gene expression, which effectively promoted swarmed motility.

Real-time triplex loop-mediated isothermal amplification (LAMP) using a turbidimeter for detection of shrimp infectious hypodermal and hematopoietic necrosis virus (IHHNV).

The World Organization for Animal Health still regulates the infectious hypodermal and hematopoietic necrosis virus (IHHNV) in shrimp. The existing disease identification approach is time consuming, necessitates expensive equipment, and requires specialized expertise, thereby limiting the accessibility of shrimp disease screening on farms. Loop-mediated isothermal amplification (LAMP) is recognized for its ability to detect inhibitory substances with high sensitivity and specificity. We developed a real-time triplex LAMP assay that combines the simplicity of point-of-care testing with the accuracy of a turbidimeter. Using a set of three LAMP primers, our technology enables rapid DNA amplification in a single reaction within 45 min and with a low detection limit (10 copies/reaction). We tested 192 shrimp samples from different sources and demonstrated the clinical utility of our method, achieving 100% specificity (95% confidence interval = 93.40-100.00%), 100% sensitivity (97.36-100.00%), and 100% accuracy (98.10-100.00%) in detecting IHHNV DNA, with a high Cohen's kappa value (1) compared to the standard quantitative polymerase chain reaction assay. The high technology readiness level of our method makes it a versatile platform for any real-time LAMP assay, and its low cost and simplicity make it well suited for fast deployment and use in shrimp farming.

Acidogenic gas utilization improves methane production in high-load digestion: Underlying mechanisms

High-load reactors face a significant challenge with fatty acid accumulation. Although injecting acidogenic gas (H2 and CO2) into methanogenic reactors improves biogas production, its mechanisms and stability enhancement remain unclear. Therefore, this study investigated the potential of using acidogenic gas to enhance methane production and system stability in a high substrate-loading co-digestion system with decreasing hydraulic retention time (HRT) and its regulatory role by considering biological pathways. Acidogenic gas injection effectively managed volatile fatty acid accumulation, with a concomitant increase in methane production from 0.042 to 0.066 L/L h as HRT decreased (16–8 days). However, the methane yield decreased from 611 to 460 mL/g volatile solids. Microbial community analysis revealed an increased abundance of hydrogenotrophic methanogens, along with several acidogenic and syntrophic fatty acid oxidizing consortia with decreasing HRT. The HRT10.67 sample exhibited the highest microbial species diversity and richness in the methanogenic reactor. Metabolomics analysis showed acidogenic gas reduced energy synthesis related to the tri-carboxylic acid cycle and oxidative phosphorylation while profoundly regulating the metabolism of amino acids, lipids, fatty acids, membrane transporters and inhibitory substances, thereby strengthening methane metabolism pathways. This study provides valuable insights into the roles of acidogenic gas in regulating energy metabolism to enhance methane production and offers potential opportunities for improving lipid and protein degradation.