The gene gp13 in bacteriophage Phi11 has been annotated as a Single-Stranded DNA binding protein (SSB protein, GenBank accession no. NC_004615.1). SSB proteins protect Single-stranded DNA intermediates generated during replication, recombination, and repair from nuclease degradation by binding to them. This highlights the importance of SSB proteins in the DNA metabolic processes. In this investigation, we have reported a systematic analysis of the structural and functional changes induced in rGp13 (the gene product of gp13) by several factors, such as metal ions and buffers of varying pH. The nature and length of the substrate required for the optimum function of rGp13 has also been investigated. Our results suggest that rGp13 is a robust protein which maintains its structure and function over a wide range of pH, with pH 4 being an exception. The monovalent cations used in this study seemed to have a stabilizing effect on the protein. Interestingly, among the divalent cations studied, only Zn2+ ions were found to completely destabilise rGp13, with a complete loss of the parallel β-sheet and α-helical content of the protein. This, in turn, totally abolished the DNA binding activity of rGp13. Another interesting observation from this study was that rGP13 could also bind to double-stranded DNA molecules. In summary, SSBs bind to dsDNA, ensuring genome integrity, protecting ssDNA, and impacting transcriptional processes. These crucial functions highlight their significance in maintaining cellular stability.
Among all photosynthetic life forms, cyanobacteria exclusively possess a water-soluble, light-sensitive carotenoprotein complex known as orange carotenoid proteins (OCPs), crucial for their photoprotective mechanisms. These protein complexes exhibit both structural and functional modularity, with distinct C-terminal (CTD) and N-terminal domains (NTD) serving as light-responsive sensor and effector regions, respectively. The majority of cyanobacterial genomes contain genes for OCP homologs and related proteins, highlighting their essential role in survival of the organism over time. Cyanobacterial photoprotection primarily involves the translocation of carotenoid entity into the NTD, leading to remarkable conformational changes in both domains and formation of metastable OCPR. Subsequently, OCPR interacts with phycobiliprotein, inducing the quenching of excitation energy and a significant reduction in PS II fluorescence yield. In dark conditions, OCPR detaches from phycobilisomes and reverts to OCPO in the presence of fluorescent recovery proteins (FRP), sustaining a continuous cycle. Research suggests that the modular structure of the OCPs, coupled with its unique light-driven dissociation and re-association capability, opens avenues for exploiting its potential as light-controlled switches, offering various biotechnological applications.
The agricultural productivity and world-wide food security is affected by different phytopathogens, in which Fusarium is more destructive affecting more than 150 crops, now got resistance against many fungicides that possess harmful effects on environment such as soil health, air pollution, and human health. Fusarium fungicide resistance is an increasing concern in agricultural and environmental contexts, requiring a thorough understanding of its causes, implications, and management approaches. The mechanisms of fungicide resistance in Fusarium spp., are reviewed in this article, including increased efflux pump activity, target-site mutations, and metabolic detoxification pathways. Fusarium is naturally resistant to some of the fungicides, on the other hand; it speedily develops resistance against the other fungicides groups. Most of the important plant pathogenic Fusarium species including F. oxysporum, F. psedogramanium, F. graminearium and Fusarium solani, which have shown resistance to major groups of fungicides including triazoles, phenylpyrole and benzimedazoles in various regions of the world. The review also covers a range of management techniques, including fungicide rotation, resistant cultivars, cultural methods, and biological control agents, to lessen fungicide resistance. By shedding light on the current state of knowledge concerning fungicide resistance in Fusarium spp., this review provides valuable information to researchers, policymakers, and practitioners to design long-term effective disease management approaches, as well as fungal menace control to preserve fungicides’ effectiveness in agriculture and conservancy activities.
Researchers have reported that Bacillus megaterium BM18-2 reduces Cd toxicity in Hybrid Pennisetum, but understanding the interaction between plants and associated endophytes is crucial for understanding phytoremediation strategies under heavy metal stress. The current study aims to monitor the colonization patterns of GFP-labeled endophytic bacteria BM18-2 on Hybrid Pennisetum grass. Additionally, it will monitor Cd’s effect on plant bacterial colonization. Confocal laser scanning microscopy of plant roots infected with gfp tagged BM18-2 revealed that the bacterium colonised root hairs and epidermal cells at the early stage of colonization, and over time, the bacteria penetrated to the internal tissues following their colonization of the stem and leaf. The roots, stems, and leaves of H. Pennisetum grown in Cd-contaminated soil contained a higher number of bacteria than those grown in normal soil. The result of Cd translocation indicated the condensation of heavy metals in the root cells and stem, while no Cd was found in the leaf. The study will also look for the enzymatic activity of bacteria BM18-2 and use Leadmium Green AM dye to track how Cd is taken up and moved through the plant. The enzymatic activity results showed that BM18-2 can produce catalase and amylase, but did not record any cellulase or lipase activity. As a result, the pattern of useful endophytic BM18-2 colonization through H. Pennisetum grass will aid in the application and maintenance of these bacteria in farming, and it presents new opportunities for the development of innovative strategies in the fields of agriculture and biotechnology.
Vibrio parahaemolyticus propels itself through liquids using a polar flagellum and efficiently swarms across surfaces or viscous environments with the aid of lateral flagella. H-NS plays a negative role in the swarming motility of V. parahaemolyticus by directly repressing the transcription of the lateral flagellin gene lafA. However, it remains unknown whether H-NS can directly regulate other lateral flagellar genes in V. parahaemolyticus. In this study, we investigated the regulation of fliD, which is responsible for the lateral flagellar filament cap, by H-NS using quantitative real-time PCR, luminescence assay, two-plasmid lacZ fusion assay, electrophoretic mobility shift assay, and DNase I footprinting assay. We found that H-NS represses the transcription of fliD. Overexpression of H-NS in Escherichia coli resulted in the repression of the promoter activity of fliD. Furthermore, His-tagged H-NS was shown to protect a specific DNA region located 11 to 188 base pairs upstream of fliD from DNase I digestion. Therefore, it can be concluded that H-NS directly and negatively regulates the transcription of fliD. This study has contributed to our understanding of the regulatory mechanisms of H-NS on lateral flagella-propelled swarming motility in V. parahaemolyticus.
Infertility can harm a patient in physical, psychological, spiritual, and medical ways. This illness is unusual because it affects the patient's companion and the patient individually. Infertility is a multifactorial disease, and various etiological factors like infection are known to develop this disorder. Recently published studies reported that different bacteria, such as Chlamydia trachomatis, Mycoplasma spp., Ureaplasma urealyticum, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, can lead to infertility by immunopathological effects, oxidative stress, and adverse effects on sperm concentration, motility, morphology, and DNA condensation. Among viruses, Human papillomavirus and Herpes simplex virus reduce sperm progressive motility and sperm concentration. The viruses can lead to the atrophy of the germinal epithelium and degenerative changes in the testes. Candida albicans also harm sperm quality, motility, and chromatin integrity and induce apoptosis in sperm cells. Finally, Trichomonas vaginalis leads to distorted heads, broken necks, and acrosomes exocytosis in sperms. This parasite decreases sperm viability and functional integrity. Noteworthy, oxidative stress could have a role in many pathological changes in the reproductive system. Recent findings show that microorganisms can increase reactive oxygen species concentration inside the host cells, leading to oxidative stress and sperm distress and dysfunction. Therefore, this article explores the potential significance of critical bacteria linked to infertility and their pathogenic mechanisms that can affect sperm function and the female reproductive system.
To explore the mechanistic underpinnings of caffeine as a potent antibacterial against Staphylococcus aureus ATCC 25923 via in vitro functional assays, whole-genome sequencing, and in silico docking studies. In vitro studies established that caffeine’s minimum inhibitory concentration (MIC) against S. aureus ATCC 25923 is 0.01544 mmol/mL. Functional assays along with Scanning Electron Microscopy confirmed that caffeine at 0.030089 mmol/mL (2MIC) released nucleotide constituents (nucleotide leakage assay) and effluxed potassium ions (potassium efflux assay) thereby, further validating caffeine’s role as a membrane-active antimicrobial agent. Whole genome sequencing of control versus caffeine treated samples revealed a significant drop in read mapping percentage from 99.96 to 23.68% and GC content from 30.69 to 6.93%. This massive reduction in the treated sample was a consequence of single nucleotide polymorphisms (SNPs, 50,303), along with insertions and deletions (InDels, 62). Several of these caffeine-induced mutations were found to be harbouring the coding regions of genes involved in processes such as cell membrane organization, bacterial virulence, and DNA repair processes. Thus, implying a caffeine-mediated genomic rearrangement and instability. In silico docking studies revealed a strong binding affinity of caffeine to key cell wall proteins ltaA (-6.9 kcal/mol) and ltaS (-6.5 kcal/mol) respectively. The dynamic simulation studies revealed caffeine’s interaction with receptor ltaS remained stable, with low deviations and minimal fluctuations. Although caffeine has been widely investigated for its antibacterial properties, its specific mechanisms of action, notably its effects on the cell membrane and genomic integrity in S. aureus ATCC 25923, are little understood. This study thus offers a comprehensive functional genomic analysis of caffeine as an antibacterial against S. aureus.
Brine shrimp nauplii are widely used as live food in fish and shellfish aquaculture but they may transmit pathogenic Vibrio to the target species causing significant economic loss. Heavy usage of antibiotics is expensive and environmentally damaging. Use of natural microbes as probiotics for disease management is a more sustainable strategy. In this study the abilities of four marine microbes—Debaryomyces hansenii, Ruegeria mobilis, Lactobacillus plantarum and Bacillus subtilis—to suppress Vibrio spp. and promote growth performance and survival of brine shrimp (Artemia franciscana) were investigated. Nauplii (Instar II) were exposed to 108 CFU mL-1 of one of the four microbes; a control without added microbes was included for comparison. The nauplii were fed daily with the microalga Nannochloropsis oculata. Population change, survival, weight gain, length gain, enzyme activity, microbial retention and body biochemical composition of the brine shrimp were measured. The results showed that B. subtilis and L. plantarum significantly decreased the body loading of Vibrio spp. in A. franciscana. Survival rate, weight gain and length gain of (A) franciscana all increased in L. plantarum and (B) subtilis treatments, but the growth performance in the D. hansenii and R. mobilis treatments was less consistent. Higher lipase and protease activities and lower body ash content in the brine shrimp were observed in the B. subtilis and L. plantarum treatments (P < 0.05). The abundance of B. subtilis in the brine shrimp was relatively stable even after 8 days of starvation. These findings demonstrate that B. subtilis was the most promising probiotic among the tested species, especially for long-term application without the need for repeated inoculation.
An obligate anaerobic, Gram-negative rod-shaped bacterial strain designated AD58T was isolated from the feces of a 3-year-old boy with atopic dermatitis. The closest species is Parabacteroides fecalis with 96.98% 16S rRNA gene identity. The average nucleotide identity value between AD58T and P. fecalis AGMB00274T is 85.0–85.4%. The circular genome sequence is 3.77 Mbp long with 43.5 mol% G + C content. The strain AD58T grows at 32–42 °C, its pH range for growth is 6.0–7.5. No growth is observed in the presence of 1% or higher NaCl concentrations. The major fatty acids are anteiso-C15: 0, iso-C15: 0, and summed feature 11 (iso-C17: 0 3–OH and/or C18: 2 DMA), and the predominant respiratory quinone is MK-9. Conditioned media from AD58T increased expression of IL-8 but decreased expression of TLR-4 in HT29 cells. Based on the described properties, we propose AD58T as the type strain of Parabacteroides absconsus sp. nov. (= VKM B-3630T = JCM 35468T).
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