Jana Olivier

Metagenomic analysis of bacterial diversity of Siloam hot water spring, Limpopo, South Africa

The bacterial diversity of Siloam hot water spring was determined using 454 pyrosequencing of two 16S rRNA variable regions V1-3 and V4-7. Analysis of the community DNA revealed that the phyla Proteobacteria, Cyanobacteria, Bacteriodetes, Planctomycetes, Firmicutes, Chloroflexi and Verrucomicrobia were the most abundant. The bacterial diversity detectable and classifiable was greater when the V4-7 variable region was used compared to the V1-3 region. The most abundant bacteria genera detected with region V1-3 were; Stenotrophomonas (23.3%), Aquaspirillum (5.11%) , Zavarzinella (2.73%), Haliscomenobacteria (1.25%), Rheinheimera (1.14%) and Tepidomonas (1.14%). All the other detectable genera were below 0.6%. Genera detected with region V4-7 from most abundant were; Stenotrophomonas (17.96%), Zavarzinella (5.81%), Aquaspirillum (4.75%), Rheinheimera (3.52%), GPI (1.41%), Gemmata (1.41%) and Syntrophobacter (1.06%). All the other genera detected were below 0.7%. Siloam is one of the hottest thermal springs in South Africa (63°C), the water has a pH of 9.5 and is relatively high in fluoride and bromide; it is possible that the physicochemical properties could have some influence on the diversity of bacteria. This article reports on the first phylogenetic analysis of a South African thermal spring bacterial community. Key words : Thermophilic, hot springs, biodiversity, 454 sequencing, South Africa.

Comparisons of the composition and biogeographic distribution of the bacterial communities occupying South African thermal springs with those inhabiting deep subsurface fracture water.

South Africa has numerous thermal springs that represent topographically driven meteoric water migrating along major fracture zones. The temperature (40–70°C) and pH (8–9) of the thermal springs in the Limpopo Province are very similar to those of the low salinity fracture water encountered in the South African mines at depths ranging from 1.0 to 3.1 km. The major cation and anion composition of these thermal springs are very similar to that of the deep fracture water with the exception of the dissolved inorganic carbon and dissolved O2, both of which are typically higher in the springs than in the deep fracture water. The in situ biological relatedness of such thermal springs and the subsurface fracture fluids that feed them has not previously been evaluated. In this study, we evaluated the microbial diversity of six thermal spring and six subsurface sites in South Africa using high-throughput sequencing of 16S rRNA gene hypervariable regions. Proteobacteria were identified as the dominant phylum within both subsurface and thermal spring environments, but only one genera, Rheinheimera, was identified among all samples. Using Morisita similarity indices as a metric for pairwise comparisons between sites, we found that the communities of thermal springs are highly distinct from subsurface datasets. Although the Limpopo thermal springs do not appear to provide a new window for viewing subsurface bacterial communities, we report that the taxonomic compositions of the subsurface sites studied are more similar than previous results would indicate and provide evidence that the microbial communities sampled at depth are more correlated to subsurface conditions than geographical distance.

Unconventional Water Supply Options in South Africa: A Review of Possible Solutions

Abstract South Africa faces escalating freshwater problems and will experience prolonged water deficits within the next 25 to30 years if current patterns of water use continue unchanged. The level of conventional water resources utilization in the country is very high and new approaches are necessary to stretch the limited water supplies available to meet projected demands for water. Significant research into new technologies and sources of supply has been carried out in South Africa and abroad during the past few decades. This has resulted in the development and evaluation of a number of innovative concepts and methodologies, as well as novel adaptations to existing approaches. These concepts and methodologies include: integration of surface water transfers into a national water grid, transfers of untapped surface water resources from countries located to the north of South Africa, exploitation of deep groundwater and the use of aquifers for storage of surplus water, atmospheric water (fog and cloud) harvesting, iceberg water utilization, desalination and direct use of sea water. Some of these options are still theoretical and unproven, while others have reached different stages of practical testing and implementation. Information on these alternatives for water supply is widely scattered over many different sources. This paper reviews the available information and examines some of these unconventional sources and options for future water supply in terms of their technical aspects, potential applications, likely impacts, approximate costs, and regional relevance in terms of alleviating predicted water shortages.

Mineral contamination from cemetery soils: case study of Zandfontein Cemetery, South Africa.

The burial of coffins may pose an environmental and health hazard since the metals that are used in coffin-making may corrode or degrade into harmful toxins. These may leach into the surrounding soils and groundwater. Very little research has been conducted world-wide on the mineral contamination potential of cemeteries, and virtually none in South Africa. The aim of the study is to determine whether burial practices affect the mineral content of soils in cemeteries. This was done by comparing the mineral concentrations of soils within the Zandfontein Cemetery in Tshwane (Gauteng, South Africa) to those off-site as well as those in zones with high burial loads with those zones with fewer burials. Twenty three soil samples were collected from various sites on- and off-site and analyzed for 31 minerals using ICP-AES. It was found that mineral concentrations of soils within the Zandfontein Cemetery were considerably higher than those off-site. Soil samples in multiple burials blocks also have elevated metal concentrations. These excess metals are probably of anthropogenic origin associated with burial practices and could pose an environmental and human health hazard. Strict monitoring of water quality in boreholes in the vicinity of the cemetery is recommended.

The development path of rooibos tea – a review of patterns and lessons learnt for the commercialisation of other indigenous teas in South Africa

ABSTRACT The commercial value of indigenous South African animal and plant resources can add significantly to the nations socioeconomic development and contribute towards the achievement of the goals of the African Renaissance. However, very few of the countrys many indigenous plants have been successfully commercialised. This article reviews the development phases of one success story: rooibos tea. Its development trajectory offers a useful lesson in the commercialisation of other South African indigenous animal and plant resources. Constraints that hindered the effective commercialisation of the beverage are highlighted, notably the initial over-reliance on a local market and the lack of coordinated broad marketing and quality assurance. These constraints were compounded by international trade restrictions imposed on South Africa prior to the 1994 transition to democracy. While the world moved forward, the rooibos tea sector lagged behind in the development of niche markets. It was only in the late 1990s when a seemingly perfect match between the health-giving properties of rooibos and consumer needs was achieved, thus creating a vibrant niche market for the tea. Since then, production and sales of rooibos tea have increased markedly. Adherence to national and international codes of good manufacturing practice, together with the recognition of the importance of fair trade principles regarding the participation of small-scale cooperatives, are becoming increasingly important parameters for product acceptance.

Traditional Beverages Derived from Wild Food Plant Species in the Vhembe District, Limpopo Province in South Africa

Beverages derived from wild plant species play an important role in local and traditional food systems in rural communities such as in the Vhembe District, South Africa. Conducting research on such foodstuffs may help to prevent loss of indigenous knowledge on potential dietary sources for needy households. Through surveys and focussed group discussions, 41 different beverage-making plant species were identified. Traditional beverage making processes are of three types. Preparing teas involve a boiling process while juices are manually extracted following overnight soaking of the fruit pulp mixture. Brewing traditional beer usually requires a spontaneous fermentation process lasting 2–3 days.