Publications by authors named "Heerden E"

Background: Effective palliative care is an urgent humanitarian need, particularly in less developed countries, including South Africa (SA). People can be palliated within their communities, motivating the integration of palliative care into primary healthcare systems. While community health workers (CHWs) play a vital role in health coverage at the primary care level, literature on their roles in palliation is limited.

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Keystone species or ecological engineers are vital to the health of an ecosystem; however, often, their low abundance or biomass present challenges for their discovery, identification, visualization and selection. We report the development of fluorescent in situ hybridization of transcript-annealing molecular beacons (FISH-TAMB), a fixation-free protocol that is applicable to archaea and bacteria. The FISH-TAMB method differs from existing FISH methods by the absence of fixatives or surfactants in buffers, the fast hybridization time of as short as 15 min at target cells' growth temperature, and the omission of washing steps.

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Sulfate-reducing bacteria Candidatus Desulforudis audaxviator (CDA) were originally discovered in deep fracture fluids accessed via South African gold mines and have since been found in geographically widespread deep subsurface locations. In order to constrain models for subsurface microbial evolution, we compared CDA genomes from Africa, North America and Eurasia using single cell genomics. Unexpectedly, 126 partial single amplified genomes from the three continents, a complete genome from of an isolate from Eurasia, and metagenome-assembled genomes from Africa and Eurasia shared >99.

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The interaction of a single-chain variable fragment (scFv) directed against human tissue factor (TF) was predicted using an in silico approach with the aim to establish a most likely mechanism of inhibition. The structure of the TF inhibiting scFv (TFI-scFv) was predicted using homology modeling, and complementarity-determining regions (CDRs) were identified. The CDR was utilized to direct molecular docking between the homology model of TFI-scFv and the crystal structure of the extracellular domains of human tissue factor.

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The nematode Halicephalobus mephisto was originally discovered inhabiting a deep terrestrial aquifer 1.3 km underground. H.

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The biorecovery of europium (Eu) from primary (mineral deposits) and secondary (mining wastes) resources is of interest due to its remarkable luminescence properties, important for modern technological applications. In this study, we explored the tolerance levels, reduction and intracellular bioaccumulation of Eu by a site-specific bacterium, Clostridium sp. 2611 isolated from Phalaborwa carbonatite complex.

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This study evaluated the potential of a biopolymeric flocculant produced by sp. isolated from Sterkfontein Dam, South Africa. Microbial flocculants aid the aggregation of suspended solutes in solutions, thus, suggesting its alternative application to inorganic and synthetic organic flocculants, which are associated with health-related problems.

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Eukarya have been discovered in the deep subsurface at several locations in South Africa, but how organisms reach the subsurface remains unknown. We studied river-subsurface fissure water systems and identified Eukarya from a river that are genetically identical for 18S rDNA. To further confirm that these are identical species one metazoan species recovered from the overlying river interbred successfully with specimen recovered from an underlying mine at -1.

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Rare earth metals are widely used in the production of many modern technologies. However, there is concern that supply cannot meet the growing demand in the near future. The extraction from low-grade sources such as geothermal fluids could contribute to address the increasing demand for these compounds.

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Aliphatic and aromatic hydrocarbons are ubiquitous in the environment due to natural and anthropogenic processes. Under aerobic conditions hydrocarbons can be rapidly biodegraded but oxygenated environments often quickly become anaerobic when microbial respiration is coupled to contaminant oxidation. Most studies in literature usually focus on the initial microbial diversity of the hydrocarbon impacted environment and examine either aerobic or anaerobic conditions for enrichment.

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Metagenomic sequencing of fracture fluid from South Africa recovered a nearly complete " Bathyarchaeota" archaeon genome. The metagenome-assembled genome of BE326-BA-RLH contains genes involved in methane metabolism and dissimilatory nitrate reduction. This study presents the first genomic evidence for potential anaerobic methane oxidation in the phylum " Bathyarchaeota.

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Halophilic archaea are known to produce a diverse array of pigments for phototrophy and photoprotection. The aim of this paper was to determine the role of a gene encoding the predicted cytochrome P450 monooxygenase (CYP174A1) in pigment synthesis through a combined genetic, phenotypic, and transcriptomic approach. We report on the observed phenotype changes [increased bacterioruberin levels and the loss of purple membrane (PM)] between the R1 and its -deletion mutant.

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The development of therapeutic antibodies in their various forms has been a constant challenge since the development of the first monoclonal antibodies in 1975. This is especially true for the development of therapeutic single chain variable (scFv) fragments in Escherichia coli. In a previous study the selection of a tissue factor inhibiting single chain variable fragment (TFI-scFv) isolated from the Thomlinson I + J phage libraries was described.

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The concentrations of electron donors and acceptors in the terrestrial subsurface biosphere fluctuate due to migration and mixing of subsurface fluids, but the mechanisms and rates at which microbial communities respond to these changes are largely unknown. Subsurface microbial communities exhibit long cellular turnover times and are often considered relatively static-generating just enough ATP for cellular maintenance. Here, we investigated how subsurface populations of CH4 oxidizers respond to changes in electron acceptor availability by monitoring the biological and geochemical composition in a 1339 m-below-land-surface (mbls) fluid-filled fracture over the course of both longer (2.

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Background: The discharge of poorly treated effluents into the environment has far reaching, consequential impacts on human and aquatic life forms. Thus, we evaluated the flocculating efficiency of our test bioflocculant and we report for the first time the ability of the biopolymeric flocculant produced by Arthrobacter humicola in the treatment of sewage wastewater. This strain was isolated from sediment soil sample at Sterkfontein dam in the Eastern Free State province of South Africa.

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Most of the power generation globally is by coal-fired power plants resulting in large stockpiles of fly ash. The trace elements associated with the ash particles are subjected to the leaching effects of precipitation which may lead to the subsequent contamination of surface and groundwater systems. In this study, we successfully demonstrate an efficient and sustainable dual treatment remediation strategy for the removal of high levels of Cr and SO introduced by fly ash leachate generated by a power station situation in Mpumalanga, South Africa.

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A novel strictly anaerobic, thermotolerant, moderately halophilic, organotrophic bacterium, strain MRo-4T, was isolated from a sample of a microbial mat, developed under the flow of subsurface water in TauTona gold mine, South Africa. Cells of the novel isolate stained Gram-positive and were motile, spore-forming rods, 0.2-0.

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Article Synopsis
  • SLiMEs (subsurface lithoautotrophic microbial ecosystems) thrive under oligotrophic conditions, primarily supported by energetic processes from sulfate reducers rather than the expected methanogens.
  • Recent studies in South Africa's Witwatersrand Basin revealed that methane production from methanogens is minimal (<5% of DNA), challenging previous assumptions about their role in these ecosystems.
  • The active community is dominated by sulfur-oxidizing β-proteobacterial genera, which engage in previously unrecognized metabolism allowing diverse reactions to flourish despite harsh subsurface conditions.
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A novel aerotolerant anaerobic, moderately thermophilic, organotrophic bacterium, strain MBL-TLPT, was isolated from a sample of microbial mat, developed under the flow of subsurface water in TauTona gold mine, South Africa. Cells of the new isolate were flagellated, spore-forming rods, 0.25-0.

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Dectin-1 is a C-type lectin receptor critical in anti-fungal immunity, but Dectin-1 has not been linked to regulation of sterile inflammation or oncogenesis. We found that Dectin-1 expression is upregulated in hepatic fibrosis and liver cancer. However, Dectin-1 deletion exacerbates liver fibro-inflammatory disease and accelerates hepatocarcinogenesis.

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Following the discovery of the first Eukarya in the deep subsurface, intense interest has developed to understand the diversity of eukaryotes living in these extreme environments. We identified that Platyhelminthes, Rotifera, Annelida and Arthropoda are thriving at 1.4 km depths in palaeometeoric fissure water up to 12,300 yr old in South African mines.

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Stalactites (CaCO3 and salt) from water seeps are frequently encountered in ceilings of mine tunnels whenever they intersect water-bearing faults or fractures. To determine whether stalactites could be mineralized traps for indigenous fracture water microorganisms, we analyzed stalactites collected from three different mines ranging in depth from 1.3 to 3.

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Subsurface microbial communities comprise a significant fraction of the global prokaryotic biomass; however, the carbon metabolisms that support the deep biosphere have been relatively unexplored. In order to determine the predominant carbon metabolisms within a 3-km deep fracture fluid system accessed via the Tau Tona gold mine (Witwatersrand Basin, South Africa), metagenomic and thermodynamic analyses were combined. Within our system of study, the energy-conserving reductive acetyl-CoA (Wood-Ljungdahl) pathway was found to be the most abundant carbon fixation pathway identified in the metagenome.

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