Dr Gwynneth Matcher
Manager Rhodes University GS Sequencing Facility
- Microbial ecology in the soil and meltwater environments of continental Antarctica
- Anthropogenic impacts in pristine Antarctic environments
Manager of the Rhodes University High Throughput Sequencing Facility and Research Fellow (January 2012 – Present)
Post Doctoral Fellow, Rhodes University (July 2009 – Present)
Post Doctoral Fellow, Stellenbosch University (July 2006- June 2009)
Lecturer (Contract): Department of Biochemistry, Microbiology and Biotechnology, Rhodes University (June 2004 - June 2006)
1) Soil microbial ecology in Western Dornning Maud Land (Antarctica)
Microbes are critical to soil ecological functioning and this is particularly true in Antarctica where in many instances microbes are the sole soil biota present. It is generally accepted that due to the extreme abiotic conditions in Antarctica, the trophic component of ecosystems is constrained and in many instances is limited to microbial biota. Despite the harsh environment, molecular studies have revealed surprisingly high bacterial diversity profiles in Antarctic soils. Most of these studies are of soils from the McMurdo Dry Valleys in southern Victoria Land or on the Antarctic Peninsula. The only molecular based bacterial study on soil microorganisms done to date on the eastern Antarctic was carried out at Schirmacher Oasis where they used denaturing gradient electrophoresis to assess diversity profiles and sequenced a limited (i.e. 79) number of bands in order to identify the dominant microbes present (Teo & Wong 2014). Using quantitative analysis of distribution data in combination with expert-defined bioregions, Terauds et al. (2012) generated a map of Antarctica delineating several Antarctic Conservation Biogeographic regions. From this analysis, nunataks in the Western Dronning Maud Land form a biogeographic region unique to the rest of Antarctica (Terauds et al., 2012). Analysis of the microbial community in soils from Dronning Maud Land thus needs to be addressed in order to provide a holistic depiction of the distribution of microbes in the Antarctic continent. This study aims to fill this knowledge gap and to correlate diversity patterns to geographical location and/or abiotic factors.
2) Anthropogenic impacts in Antarctica
Sensitive Antarctic ecosystems are under threat from two major sources, namely global climate change and direct human impacts. Of these two, the extent and implications of human anthropogenic impacts have not being clearly ascertained and as a result, the necessary regulatory mechanisms cannot be put in place in order to protect Antarctic ecosystems.
While wastes are an obvious source of pollution in Antarctica, the mere presence of humans may present an alternative input of non-indigenous bacteria (albeit at a much reduced degree). The surface of the human skin is typically home to a natural assemblage of over a trillion microorganisms which are continuously released into the environment via skin sloughing, hair loss, coughing, sneezing, etc. While the number of human symbiotic bacteria released into the environment is likely to be somewhat lower in Antarctica (due to the several layers of clothes worn to combat the low temperatures) the number of non-indigenous bacteria entering the Antarctic system is likely to remain substantial.
The majority of the non-indigenous microorganism seeded into the Antarctic environment are mesophilic (grow in temperate conditions) and are unlikely to survive the extreme Antarctic environment but they could significantly contribute to the available pool of DNA which may be incorporated into the genomes of indigenous bacteria via horizontal gene transfer. Horizontal gene transfer is widespread among bacteria and while this phenomenon is well established in bacteria from a wide variety of environments, due to limited research, very few reports of gene transfer in cold environments have been documented.
While the potential negative impacts of non-indigenous bacteria/DNA into the Antarctic environment have been highlighted, minimal research has been carried out on the extent to which these bacteria impact the natural microbiota, the location of substantially impacted areas or the long term viability and /or effects of the non-indigenous bacteria in Antarctica. These questions need to be addressed in order for adequate regulatory protocols to be implemented.
Wasserman R.J., Matcher G.F., Vink T.J.F., Froneman P.W. (2015) “Preliminary evidence for the organization of a bacterial community by zooplanktivores at the top of an estuarine planktonic food web.” Microbial Ecology. DOI 10.1007/s00248-014-0505-3
Perissinotto R, Bornman T.G., Steyn P, Miranda NAF, Dorrington R.A., Matcher G.F., Strydom N, Peer N (2014) “Tufa stromatolite ecosystems on the South African south coast.” S. Afr. J. Sci. 110(9/10), doi.org/10/1590/sajs.2014/20140011
Matcher G.F., Jiwaji M., de la Mare J., Dorrington R.A. (2013) “Complex pathways for regulation of pyrimidine metabolism by carbon catabolite repression and quorum sensing in Pseudomonas putida RU-KM3S.”Appl. Microbiol. Biotechnol. 97:5993-6007
Walmsley, T.A., Matcher, G.F., Zhang F., Hill, R.T., Davies-Coleman, M.T. and Dorrington, R.A. (2012) “Diversity of bacterial communities associated with the Indian Ocean sponge Tsitsikamma favus that contains the bioactive pyrroloiminoquinones, Tsitsikammamine A and B.” Marine Biotechnol. 14(6): 681-691. DOI 10.1007/s10126-012-9430-y
Matcher, G.F., Dorrington, R.A., Henninger, T.O. and Froneman, P.W. (2011) “Insights into the bacterial diversity in a freshwater-deprived permanently open Eastern Cape estuary, using 16S rRNA pyrosequencing analysis” WaterSA, 37, 381-390
Matcher, G.F. and Rawlings, D.E. (2009) “The effect of the location of the proteic post-segregational stability system within the replicon of plasmid pTF-FC2 on the fine regulation of plasmid replication” Plasmid, 62, 98-107
Jiwaji, M., Matcher, G.F., and Dorrington, R.A. (2008) “A broad host range reporter plasmid for the analysis of divergent promoter regions” SAJS, 104, 305-307
Matcher, G.F., Dorrington, R.A., and Burton, S. (2004) “Mutational analysis of the hydantoin hydrolysis pathway in Pseudomonas putida RU-KM3S” Applied Microbiology and Biotechnology, 65, 391-400
Buchanan, K., Burton, S.G., Dorrington, R.A., Matcher, G.F. and Skepu, Z. (2001) “A novel Pseudomonas putida strain with high levels of hydantoin-converting activity producing L-amino acids” Journal of Molecular Catalysis B: Enzymatic, 11, 397-406
Burton, S.G., Dorrington, R.A., Hartley, C., Kirchmann, S., Matcher, G., and Phehane, V. (1998) “Production of enantiometically pure amino acids: Characterization of South African hydantoinases and hydantoinase-producing bacteria” Journal of Molecular Catalysis B: Enzymatic, 5, pg 301-305
Published Book Chapters
Jiwaji M, Matcher G.F. and Dorrington R.A. (2014) “Understanding the unseen majority around us: An overview of microbiological techniques” in “Bioinformatics and data analysis in microbiology” Ed. Tastan Bishop, O, Caister Academic Press, pg 1-24
Matcher, G.F., Dorrington, R.A. and Burton .S.G (2012) “Enzymatic production of enantiospecific amino acids from mono-substituted hydantoin substrates” in “Unnatural Amino Acids, Methods in Molecular Biology” Eds. Pollegioni, L. and Servi, S., 794, pg 37-54
Matcher G.F., Froneman P.W. and Dorrington R.A. (2014) “Aquatic microbial diversity: a sensitive and robust tool for assessing ecosystem health and functioning” Water Research Commission Report, No K5/2038
Last Modified :Fri, 11 Dec 2015 14:41:28 SAST