49 research outputs found

    Chlorinated organic compounds produced by Fusarium graminearum

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    Fusarium graminearum, a pathogen of wheat and maize, not only reduces grain yield and degrades quality but also produces mycotoxins in the infected grain. Focus has been on mycotoxins because of the human and animal health hazards associated with them. In addition to work done on mycotoxins, chemical profiling of F. graminearum to identify other compounds produced by this fungus remains critical. With chemical profiling of F. graminearum the entire chemistry of this fungus can be understood. The focus of this work was to identify chlorinated compounds produced by F. graminearum. Various chlorinated compounds were detected and their role in F. graminearum is yet to be understood

    Benzene derivatives produced by Fusarium graminearum — Short communication

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    Using NMR spectroscopy benzene derivatives were detected in mycelia of Fusarium graminearum, a pathogen of wheat and maize. In previous studies F. graminearum was found to cause cancer to humans and benzene derivatives were detected in breath of cancer sufferers. Surprisingly, no study found benzene derivatives to be the cancerous agents in F. graminearum. In this study we detected benzene derivatives in F. graminearum and propose to study their role as cancer agents

    Molecular survey of the Texas Phoenix decline phytoplasma population in Florida, USA

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    A nested polymerase chain reaction (PCR) assay was used to amplify 16S-23S intergenic spacer (IGS) region from DNA samples individually extracted from 25 Sabal palmetto (cabbage palms) showing symptoms of Texas Phoenix decline (TPD) in West Central Florida. The IGS region was also amplified from DNA from other palm species showing symptoms of TPD and lethal yellowing (LY). A subset of the  aforementioned phytoplasma DNA samples (Sabal and other palm species) together with additional samples from various hosts collected from different geographical localities were further studied to compare the collected phytoplasma strains using sequence analysis of the glycoprotease (gcp) genes. Restriction fragment length polymorphisms (RFLP) analysis of the PCR-amplified 16S-23S IGS region and the gcp gene using a three restriction enzymes showed that the population of the phytoplasmas infecting S. palmetto in West Central Florida is probably homogenous. The S. palmetto phytoplasma also appeared similar to all the 16SrIV-D phytoplasmas infecting other palm species and different from all phytoplasmas belonging to the 16SrIV-A subgroup. We recommend more work using genes or genomic regions other than the 16S-23S IGS region and the gcp gene to be done.Keywords: 16S-23S intergenic spacer region, glycoprotease gene, phytoplasma, Texas Phoenix decline, lethal yellowingAfrican Journal of Biotechnology Vol. 12(40), pp. 5814-582

    Differences between the Texas phoenix palm phytoplasma and the coconut lethal yellowing phytoplasma revealed by restriction fragement length polymorphism (RFLP) analysis of the NUSA and HFLB genes

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    A nested polymerase chain reaction (PCR) assay was used to amplify the nusA gene from a DNA sample extracted from a cabbage or sabal (Sabal palmetto) palm showing symptoms of Texas Phoenix decline (TPD) and from three DNA samples from coconut (Cocos nucifera) palms showing symptoms of lethal yellowing (LY). TPD is caused by a 16SrIV-D phytoplasma and LY by a 16SrIV-A strain. From the sabal DNA sample and from one coconut DNA sample two copies of the hflB gene were amplified by nested PCR. Restriction fragment length polymorphisms analysis of the PCR-amplified nusA and the hflB gene copies showed that these genes vary in the phytoplasma strains examined. Four restriction enzymes were used for the nusA gene and 16 were used for the hflB genes.Keywords: nusA, hflB, phytoplasma, Texas Phoenix declineAfrican Journal of Biotechnology Vol. 12(25), pp. 3934-393

    Bacterial species identification getting easier

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    The traditional methods of bacterial identification are based on observation of either the morphology of single cells or colony characteristics. However, the adoption of newer and automated methods offers advantage in terms of rapid and reliable identification of bacterial species. The review provides a comprehensive appreciation of new and improved technologies such fatty acid profiling, sequence analysis of the 16S rRNA gene, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), metabolic finger profiling using BIOLOG, ribotyping, together with the computational tools employed for querying the databases that are associated with these identification tools and high-throughput genomic sequencing in bacterial identification. It is evident that with the increase in the adoption of new technologies bacterial identification is becoming easier.Keywords: Bacteria, Biolog, computational tools, fatty acids, Gram staining, identification, metagenomics, morphology, MALDI-TOF MS, RiboPrinter, 16S rRNA gene.African Journal of Biotechnology Vol. 12(41), pp. 5975-598

    Palm yellows phytoplasmas and their genetic classification

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    Palm yellows phytoplasmas have been a subject of debate because of two recent outbreaks. Firstly, a lethal yellowing-type phytoplasma disease was recorded on a number of palm species of mainly the genus Phoenix in Florida in 2008. Shortly afterwards, Sabal palmetto which has never been threatened by a phytoplasma before, was suddenly attacked by a phytoplasma strain similar to the one that attacked Phoenix in 2008. Both these recent outbreaks have made phytoplasmologists realize the need to characterize palm phytoplasma strains in order to rapidly determine the phytoplasma palm yellows in future disease outbreaks. Various workers have made attempts to genetically characterize palm phytoplasmas but a lot of crucial knowledge is still lacking. This review focuses on the little progress that has been made to characterize palm phytoplasmas and we also recommend further steps to provide more tools for characterization.Keywords: Cocos nucifera, palm yellows phytoplasmas, Sabal palmetto, Phoenix.African Journal of Biotechnology Vol. 12(22), pp. 3376-338

    Effect of Torulaspora delbrueckii Yeast Treatment on Flavanols and Phenolic Acids of Chenin blanc Wines

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    The non-Saccharomyces yeast Torulaspora delbrueckii contributes positively to the sensory properties of wines by affecting aroma and flavour due to changes in alcohols, esters, fatty acids and lactone levels.  One of the less-studied aspects of T. delbrueckii is its effect on phenolic compounds relating to sensory attributes. An HPLC-DAD technique was used for the quantification of phenolic compounds in Chenin blanc wines made with S. cerevisiae and two T. delbrueckii yeasts over three vintages. Chemical andsensory data were subjected to ANOVA and PCA. VIN13, M2/1 and VIN13+M2/1 had a positive effect on the phenolic compound concentrations of Chenin blanc wines. Mouthfeel was highest in VIN13+654 wines and astringency highest in VIN13 wines. An association was evident between flavanols, astringency and mouthfeel for the VIN13, M2/1 and VIN13+M2/1 wines. Chenin blanc wines made with M2/1 and VIN13+M2/1 may result in increased phenolic compound concentrations and astringency, whereas 654 and VIN13+654 may result in wines with increased mouthfeel properties

    Effect of Torulaspora delbrueckii Yeast on the Anthocyanin and Flavanol Concentrations of Cabernet franc and Pinotage Wines

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    Pinotage and Cabernet franc grape must were inoculated with Saccharomyces cerevisiae and Torulasporadelbrueckii yeasts. Differences in colour were observed between Pinotage (S. cerevisiae) and Pinotage (T.delbrueckii) wines, whereas differences in berry and herbaceous character were observed between Cabernetfranc (S. cerevisiae) and Cabernet franc (T. delbrueckii) wines. Mouthfeel properties between treatmentsfor both wines were not significantly different. Overall quality was slightly higher in wines inoculatedwith T. delbrueckii compared to wines inoculated with S. cerevisiae. Anthocyanins and flavanols measuredin Pinotage wines made with T. delbrueckii were higher compared to Pinotage must inoculated with S.cerevisiae. Cabernet franc wines made with S. cerevisiae were higher in anthocyanin glycoside and flavanolconcentrations compared to Cabernet franc wines made with T. delbrueckii. Insignificant differencesin acetylated and coumarylated anthocyanins were evident between Cabernet franc (S. cerevisiae) andCabernet franc (T. delbrueckii) wines. Principal component analysis showed that epigallocatechin gallate,epicatechin gallate, procyanidin B2, peonidin 3-O-glucoside, delphinidin 3-(6-acetyl) glucoside, petunidin3-(6-acetyl) glucoside, malvidin 3-(6-acetyl) glucoside and malvidin 3-O-glucoside concentrationswere highest in Pinotage wines inoculated with T. delbrueckii. Cabernet franc wines inoculated with S.cerevisiae yeasts were highest in malvidin 3-(6-p-coumaroyl) glucoside, petunidin 3-(6-p-coumaroyl)glucoside, petunidin 3-O-glucoside, epicatechin gallate and epigallocatechin gallate concentrations. Totalanthocyanins were highest in Pinotage (S. cerevisiae) wines and Cabernet franc (T. delbrueckii) wines.Flavanols were highest in Pinotage (T. delbrueckii) and Cabernet franc (S. cerevisiae) wines. It is evidentfrom the results that yeast species has an impact on the flavonoid concentrations within a grape variety

    Acetaldehyde suppresses growth, changes conidia morphology and reduces the production of adenosine 3’,5’-cyclic monophosphate in a dose dependent manner in Alternaria alternata

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    One-day-old cultures of the plant pathogenic fungus Alternaria alternata were exposed to 0%, 5% and 10% acetaldehyde mixed with distilled water. Fungal growth data showed that, overall, the 5% and the 10% acetaldehyde treatments significantly inhibited the growth of A. alternata, and that acetyldehyde also facilitated maturity and multicellularity of fungal conidia. The increase of the acetyldehyde dose also caused correlated decrease of adenosine 3’,5’-cyclic monophosphate produced by A. alternata

    Characterisation of Brucella species and biovars in South Africa between 2008 and 2018 using laboratory diagnostic data

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    BACKGROUND: Brucellosis is an infectious zoonotic bacterial disease of humans and other animals. In the Republic of South Africa (RSA), animal brucellosis is widespread and the current available data on the prevalence of this disease rely solely on serological testing. The primary limitation of brucellosis serology is the lack of discriminatory powers to differentiate between Brucella species and biovars as well as the cross-reactivity observed with other Gram-negative bacteria. AIM: The aim of this study was to conduct a retrospective laboratory-based survey on Brucella species and biovars isolated from various animal species in SA between 2008 and 2018. MATERIAL AND METHODS: The isolation of Brucella species and biovar typing was performed using conventional microbiological techniques. Results and Discussion: A total of 963 strains of Brucella species were included in this study with a frequency of detection for B. abortus (n = 883; 91.6%) followed by B. melitensis (n = 42; 4.4%), B. ovis (n = 29; 3.0%) and B. canis (n = 9; 0.9%). Of the 883 strains of B. abortus, 90.1% were typed as B. abortus biovar-1 while 5.7% as B. abortus biovar-2, and 3.3% and 0.5% were B. abortus S19 and B. abortus RB51 vaccine strains, respectively. Among the 42 B. melitensis strains, 71.4% were reported as B. melitensis biovar-1 and 26.2% as B. melitensis biovar-3 while 2.4% was B. melitensis biovar-2. CONCLUSION: A retrospective study, such as this one, provides useful information that can be critical in formulating policies and strategies for the control and eradication of brucellosis in animal populations in RSA.ARC.http://www.wileyonlinelibrary.com/journal/vms3pm2022Veterinary Tropical Disease
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