19 research outputs found
In silico identification of bacteriocin gene clusters in the gastrointestinal tract, based on the Human Microbiome Project’s reference genome database
Storage and thermal stability of biodiesel produced from manketti nut oil of Southern Africa origin with the influence of metal contaminants and antioxidants
Transcription Analysis of a Lantibiotic Gene Cluster from Bifidobacterium longum DJO10A▿
Bifidobacterium longum DJO10A was previously demonstrated to produce a lantibiotic, but only during growth on agar media. To evaluate the feasibility of production of this lantibiotic in broth media, a transcription analysis of the lanA gene was undertaken. Comparative microarray analysis of broth and agar cultures of B. longum DJO10A revealed that the lantibiotic production, modification, transport/peptidase, and immunity genes were significantly upregulated in agar cultures, while the two-component regulatory genes were expressed equally under both conditions. This suggested that the signal transduction regulatory system should function in broth cultures. Real-time PCR and Northern hybridization confirmed that lanA gene expression was significantly repressed in broth cultures. A crude lantibiotic preparation from an agar-grown culture was obtained, and its antimicrobial spectrum analysis revealed a broad inhibition range. Addition of this extract to broth cultures of B. longum DJO10A induced lanA gene expression in a dose-dependent fashion. Subinoculation using >10% of an induced broth culture maintained lanA expression. The expression of lanA was log-phase specific, being significantly downregulated in stationary phase. Transcription start analysis of lanA revealed a 284-bp 5′ untranslated region, which was proposed to be involved in repression of transcription, while an inverted repeat structure located at bp −75 relative to the transcription start was strategically located to likely function as a binding site for the two-component response regulator. Understanding the transcription regulation of this lanA gene is the first step toward enabling production of this novel and potentially interesting lantibiotic in broth cultures
Purification and Partial Characterization of a Novel Bacteriocin Synthesized by Lactobacillus paracasei HD1-7 Isolated from Chinese Sauerkraut Juice
Synthesis of Epoxidized Citrullus lanatus Seed Oil: Experimental Investigation and Statistical Optimization
Comparative in vitro cytotoxic, anti-inflammatory and anti-microbiological activities of two indigenous Venda medicinal plants
Department of MicrobiologyBackground: The Vhembe region of the Limpopo province has a rich tradition of medicinal plants use. Traditionally,
boiled roots of Ziziphus mucronata are used in the treatment of boils, general swelling and other skin infections. A
combination of leaf paste and root infusion treats measles, dysentery, chest complains, and gland swelling. Pterocarpus
angolensis is famous for the treatment of menorrhagia, infertility in women, wounds and pain management. The
purpose of the present study was to compare the cytotoxicity, anti-inflammatory potential and anti-microbial activities
of Ziziphus mucronata and Pterocarpus angolensis from the Vhembe region.
Method: U937, MeWo, Vero and RAW 264.7 cells were treated to various concentrations (50, 100, or 125 or 250 μg/ml
depending on assays) of Ziziphus mucronata and Pterocarpus angolensis. Cytotoxicity assay was done using MTT; Antiinflammatory activity was assessed using NO production; Anti-bacterial activity was done using the Micro-Broth dilution
method and Anti-mycobacteria activity was determined using the Alamar Blue Method while RT activity was measured
by ELISA.
Results: Cytotoxicity results showed that Pterocarpus was more toxic than Ziziphus as observed in the Vero and MeWo
cells; however both displayed toxicity towards a Human cancer cell line. Both extracts did not inhibit nitrate production
but induced significant increase in macrophage activation. The plant extracts have shown anti-tuberculosis activity at
concentrations >500 μg/ml and there was moderation inhibition of HIV replication.
Conclusions: The results obtained indicated that the extracts have pro-inflammatory properties, and the observed
toxicity on malignant cell lines must be investigated further for promising anti-cancer drug therapy.University of Venda, Research and Innovation Directorate(S/15/MBY10