Biology subjects

Mur, L.

Publications and source records attributed to Mur, L..

8 recordsLinked to original sources

bioRxiv2026

One-Entry Golden Seamless Cloning with a Reusable Donor Streamlines Plant Gene Functional Analysis

Molecular cloning underpins functional genomics, yet current toolboxes force a trade-off. Golden Gate frameworks handle one-pot multi-fragment assembly but overcomplicate routine single-gene cloning, whereas Gibson, In-Fusion, and Gateway systems need backbone linearization, resequencing, or proprietary recombinases that leave scars. Here we present Golden Seamless (GS), a one-entry, many-destination system in which a single PCR captures a gene once into a reusable Entry-and-Expression Clone that is never re-cloned. Circle-to-circle Golden Gate moves the same validated clone into plant, yeast, or bacterial vectors without linearization, and a ccdB counter-selection with orthogonal antibiotic markers drives background near zero. Bacterial destinations embed superfolder GFP, enabling naked-eye monitoring of recombinant proteins and an antibody-free dual-modality EMSA that resolves protein and DNA channels across a >150-nm spectral gap. GS thus consolidates capture, distribution, and validation into one low-background workflow with built-in quality control, cutting the time and cost of screening many candidates across functional assays.

molecular biology↗

bioRxiv2024

2,3-bis (phenylamino) quinoxaline - containing compounds display potent activity against Methicillin-resistant Staphylococcus aureus, Enterococcus faecalis and their biofilms

Antimicrobial resistance remains a global challenge threatening the ability to control diseases caused by bacterial infections. Here, we explored the antimicrobial activity of 2,3-N,N-diphenyl quinoxaline derivatives against representative Gram-positive, Gram-negative and Mycobacterium species. Two quinoxaline derivatives (compounds 25 and 31) demonstrated particularly potent activity against most Staphylococcus aureus, Enterococcus faecium and Enterococcus faecalis strains tested (MIC values between 0.25 to 1 mg/l). These compounds also demonstrated potent antibacterial activity against methicillin-resistant S. aureus (MRSA) and vancomycin-resistant E. faecium/E. faecalis (VRE) strains. Against an extensive panel of clinically relevant isolates, they further showed comparable or better activity to four currently used antibiotics (vancomycin, teicoplanin, daptomycin and linezolid). Finally, they performed better in preventing S. aureus and E. faecalis biofilm formation when compared to several other antibiotics. In conclusion, these two quinoxaline derivatives have promising activities that could be further explored as part of efforts to identify urgently needed new antibacterial agents.

microbiology↗

bioRxiv2023

Identifying the fungal diseases of African Yam Bean ( Sphenostylis stenocarpa Harms) and their occurrence in South- West Nigeria

Sphenostylis stenocarpa, commonly known as African yam bean (AYB), is an orphan crop with high nutritional properties but low yield production due to diseases. Hence, this study accessed the diversity and pathogenicity of fungi associated with AYB in Southwest (SW) Nigeria as a model area of cultivation. The incidence of fungi infecting AYB were surveyed in Oyo, Ondo, Ekiti, Osun, and Ogun states within SW Nigeria during 2018 planting season. The common field symptoms across all sites were tiny spot, brown spot, leaf blight, brown spot with yellow halo, necrotic lesion, and brown spot on pods. A total of 1005 fungi were isolated from leaf and pod samples, and identified morphologically on pure cultures as Aspergillus sp, Botrytis sp, Colletotrichum gloeosporioides, Curvularia lunata, Trichoderma harzianum, Macrophomina phaseolina, Pestalotia sp, Phoma sp, Fusarium verticillioides, F. oxysporum, F. solani, Botryodiplodia theobromae, and Choanephora curcubitarium and Nigrospora spp. Phoma sp and C. gleosporoides had highest frequency of occurrence 69.9% and 51.9% at early and mature stages, respectively. To conform to Kochs postulates, the pathogenicities of 12 exemplar strains of the most abundant fungal species were confirmed in controlled glasshouse tests. The identities of Colletotrichum sp., Aspergillus sp., Didymella sp., Pestalopsis sp, Lasiodiplodia theobromae, F. solani and F. oxysporum were confirmed based on internal transcribed spacer (ITS) sequencing and comparisons with the Genbank database. AYB germplasm from curated seed banks and farmer donated landraces were grown at the same site in 2020 and identical fungi were isolated. Further, genotypes with reduced disease incidences and incidences were identified. This first study to reveal the diversity of fungi associated with AYB in SW Nigeria that could inform disease management practices.

plant biology↗

bioRxiv2022

Identification and characterisation of potent anti-MRSA phloroglucinol derivatives of Dryopteris crassirhizoma Nakai

Traditional Chinese Medicine (TCM) has been used to treat infectious diseases and could offer potential drug leads. This study evaluates the in vitro antimicrobial activities commercially sourced Dryopteris crassirhizoma Nakai whose authenticity was confirmed by DNA barcoding based on the ribulose bisphosphate carboxylase (rbcL) gene. Powdered rhizomes were sequentially extracted using n-hexane, dichloromethane, ethyl acetate and methanol at ambient temperature. The dried extracts at different concentrations were tested for antimicrobial activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA), and Mycobacterium smegmatis. D. crassirhizoma extracts exhibited significant antimicrobial activities only against MRSA. Activity-led fractionations of D. crassirhizoma and characterisation by Ultra performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS) identified two potent anti-MRSA phloroglucinol derivatives: Norflavaspidic acid AB and flavaspidic acid AB. The impact of norflavaspidic acid AB on MRSA cells was examined using untargeted metabolomic analysis and compared to that of other established antibiotics (all treatments normalized to MIC50 at 6 h). This suggested that norflavaspidic acid AB had a distinctive effect which involved targeting bioenergetic transformation, metabolism, and particularly acetyl CoA, in MRSA cells. No cytotoxicity was observed for norflavaspidic acid AB against murine HepG2 cells. This study requires further experimental validation but can have indicated a naturally available compound that could help counter the threat of clinically relevant strains with antibiotic resistance.

microbiology↗

bioRxiv2022

The faecal microbiome of the wild European badger Meles meles; a comparison against other wild omnivorous mammals from across the globe

Here we investigate the faecal microbiome of wild European badgers Meles meles using samples collected at post-mortem as part of the All Wales Badger Found Dead study based on sequencing the V3-V4 region of the 16S rRNA gene. This is the first published characterisation of the badger microbiome. We initially undertook a sex-matched age comparison between the adult and cub microbiomes. Analysis used the QIIME 2 pipeline utilising DADA2 and the Silva database for taxonomy assignment. Fusobacteria appeared to be more abundant in the microbiomes of the cubs than the adults although no significant difference was seen in alpha or beta diversity between the adult and cub badger microbiomes. Comparisons were also made against other wild, omnivorous, mammals faecal microbiomes using publicly available data. Significant differences were seen in both alpha and beta diversity between the microbiomes from different species. As a wildlife species of interest to the disease bovine tuberculosis, knowledge of the faecal microbiome could assist in identification of infected badgers. Our work here suggests that if comparisons were made between the faeces of bTB infected and non-infected badgers, its possible age may not have a significant impact on the microbiome.

microbiology↗

bioRxiv2021

Isolation and characterisation of quercitrin as a potent anti-sickle cell anaemia agent from Alchornea cordifolia.

Alchornea cordifolia Mull. Arg. (commonly known as Christmas Bush) has been used traditionally in Africa to treat sickle cell anaemia (a recessive disease, arising from the S haemoglobin [Hb] allele) but the active compounds are yet to be characterised. Herein we describe the use of sequential fractionation coupled with in vitro anti-sickling assays to purify the active component. Sickling was induced in HbSS genotype blood samples using sodium metabisulphite (Na2S2O5) or incubation in 100 % N2. Methanol extracts of A. cordifolia leaves and its sub-fractions showed >70 % suppression of HbSS erythrocyte sickling. Purified compound demonstrated 87.2 {+/-} 2.39 % significant anti-sickling activity and 93.1 {+/-} 2.69 % erythrocyte sickling-inhibition at 0.4 mg/mL. Nuclear magnetic resonance (NMR) spectra and high-resolution mass spectroscopy identified it as quercitrin (quercetin 3-rhamnoside). Purified quercitrin also inhibited the polymerisation of isolated HbS and stabilized sickle erythrocytes membranes. Metabolomic comparisons of blood samples using flow-infusion electrospray-high resolution mass spectrometry indicated that quercitrin could convert HbSS erythrocyte metabolomes to be similar to HbAA. Sickling was associated with changes in anti-oxidants, anaerobic bioenergy and arachidonic acid metabolism, all of which were reversed by quercitrin. The findings described could inform efforts directed to the development of an anti-sickling drug or quality control assessments of A. cordifolia preparations.

pharmacology and toxicology↗

bioRxiv2020

The anti-mycobacterial activity of Artemisia annua L is based on deoxyartemisinin and artemisinic acid

The discovery of antimalarial artemisinin from Artemisia annua L. is an example of how Traditional Chinese Medicine (TCM) may be exploited to meet a recognized need. In this study, we systemically investigated A. annua L. for its antimicrobial activity and assessed it as a source of bioactive natural products for anti-mycobacterial activity. We used a silica gel column to perform antimicrobial activity-guided purification of the A. annua leaf, whose identity was confirmed by rbcL DNA barcoding, and used UHPLC-HRMS and NMR to elucidate the structure of purified active compounds. The antimicrobial activity of crude extracts, isolated compounds and the control artemisinin (Apollo Scientific Ltd) was assessed against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Mycobacterium smegmatis strains by serial micro dilution method (31.25-1000 g/mL). The isolated compounds were tested for synergistic effects against mycobacterium. Bioactive compounds were purified and identified as deoxyartemisinin and artemisinic acid. Artemisinic acid (MIC 250 g/mL) was more effective in comparison to deoxyartemisinin (MIC 500 g/mL) and artemisinin (MIC 1000 g/mL) against M. smegmatis. We used a molecular docking approach to investigate the interactions between selected anti-mycobacterial compounds and proteins involved in vital physiological functions in M. tuberculosis, namely MtPks13, MtPknB, MtPanK, MtKasA, MtInhA and MtDprE1 and found artemisinic acid showed docking scores superior to the control inhibiters for MtKasA, suggesting it to be a potential nick for further in vitro biological evaluation and anti-TB drug design.

pharmacology and toxicology↗

bioRxiv2019

Illuminating the functional rare biosphere of the Greenland Ice Sheet’s Dark Zone

The Dark Zone of the western Greenland Ice Sheet is the most expansive region of contiguous bare terrestrial ice in the Northern Hemisphere. Microbial processes within the Dark Zone play an important role in driving extensive albedo reduction and amplified melting, yet the composition and function of those consortia have not been fully identified. Here we present the first results from joint 16S rRNA gene and 16S rRNA (cDNA) analysis for the comparison of input (snow), storage (cryoconite), and output (supraglacial stream water) habitats across the Dark Zone over the melt season. Our analysis reveals that all three Dark Zone communities are characterized by a preponderance of rare taxa exhibiting high protein synthesis potential (PSP). Furthermore, taxa with high PSP represent highly connected \"bottlenecks\" within community structure, consistent with roles as metabolic hubs within their communities. Finally, the detection of low abundance-high PSP taxa affiliated with Methylobacterium within snow and stream water indicates a potential role for Methylobacterium in the carbon cycle of Greenlandic snowpacks, and importantly, the export of potentially active methylotrophs to the bed of the Greenland Ice Sheet. By comparing the dynamics of bulk and potentially active microbial communities in the Dark Zone of the Greenland Ice Sheet our study provides insight into the mechanisms and impacts of the microbial colonization of this critical region of our melting planet.

microbiology↗