http://hdl.handle.net/10204/892 Wed, 19 Jun 2013 09:38:07 GMT 2013-06-19T09:38:07Z http://hdl.handle.net/10204/6709 Title: Development of a novel rDNA based plasmid for enhanced cell surface display on Yarrowia lipolytica Authors: Bulani, S; Moleleki, L; Albertyn, J; Moleleki, J Abstract: In this study, a novel rDNA based plasmid was developed for display of heterologous proteins on the cell surface of Yarrowia lipolytica using the C- terminal end of the glycosylphosphatidylinositol (GPI) anchored Y. lipolytica cell wall protein 1 (YlCWP1). mCherry was used as a model protein to assess the efficiency of the constructed plasmid. Y. lipolytica transformants harbouring the expression cassettes showed a purple colour phenotype on selective YNB-casamino plates as compared to control cells indicating that mCherry was displayed on the cells. Expression of mCherry on cells of Y. lipolytica was confirmed by both fluorescent microscopy and flow cytometry. Furthermore, SDS-PAGE analysis and matrix-assisted laser desorption/ionization (MALDI)-time-of (TOF)-mass spectrometry (MS) peptide mass fingerprinting (PMF) confirmed that the protein cleaved from the yeast cells using enterokinase was mCherry. Efficient cleavage of mCherry reported in this work offers an alternative purification method for displayed heterologous proteins on Y. lipolytica cells using the plasmid constructed in this study. The developed displaying system offers great potential for industrial production and purification of heterologous proteins at low cost. Description: Copyright: 2012 BioMed Central. This is an Open Access journal. This journal authorizes the publication of the information herewith contained. Published in AMB Express, vol. 2(27), pp 1-8 Tue, 01 May 2012 00:00:00 GMT http://hdl.handle.net/10204/6709 2012-05-01T00:00:00Z http://hdl.handle.net/10204/6697 Title: The soil and plant determinants of community structures of the dominant actinobacteria in Marion Island terrestrial habitats, Sub-Antarctica Authors: Sanyika, TW; Stafford, W; Cowan, DA Abstract: Marion Island is a Sub-Antarctic island made up of distinct ecological habitats based on soil physiochemical, plant cover and physical characteristics. The microbial diversity and ecological determinants in this harsh Sub-Antarctic environment are largely uncharacterized. Actinobacteria have diverse ecological functions related to soil and plant functioning. This study was aimed at characterizing the diversity and community structures of the dominant actinobacteria in the distinct habitats and to identify their determinant soil and plant characteristics. Using the 16S rRNA gene, the denaturing gradient gel electrophoresis patterns and clone library diversity were correlated with the soil and plant characteristics. Multivariate statistical methods were also used to identify determinant soil and plant characteristics. Salinity and pH were the most important soil determinants, and a number of important site-specific plant species may have been important. The Coastal Fellfield Habitat was dominated by sequences of the suborders Micrococcineae (44%) and Propionibacterineae (18%), with salinity identified as the principal determinant. The Cotula Herbfield Habitat was dominated by Frankineae (37%) and Streptosporangineae (38%), which were correlated with organic nutrient concentrations. The Wet Mire Habitat was dominated by Acidimicrobineae (61%), with moisture and organic carbon content as principal components. Culture-dependent studies were complementary to culture-independent studies with the majority of actinobacteria isolated not identified in 16S rRNA gene clone libraries. This study demonstrates how the soil physiochemical characteristics and plant species independently determine the community structures of the dominant actinobacteria in distinct ecological habitats. These factors subsequently influence their ecological adaptation, roles and functions. Description: Copyright: 2012 Springer Verlag. This is an ABSTRACT ONLY. The definitive version is published in Polar Biology, vol. 35(8), pp 1129-1141 Wed, 01 Aug 2012 00:00:00 GMT http://hdl.handle.net/10204/6697 2012-08-01T00:00:00Z http://hdl.handle.net/10204/6676 Title: Recombinant hepatitis B surface antigen production in Aspergillus niger: evaluating the strategy of gene fusion to native glucoamylase Authors: James, ER; Van Zyl, WH; Van Zyl, PJ; Görgens, JF Abstract: This study demonstrates the potential of Aspergillus niger as a candidate expression system for virus-like particle production using gene fusion. Description: Copyright: 2012 Springer-Verlag. This is an ABSTRACT ONLY. The definitive version is published in Applied Microbiology and Biotechnology, vol. 96 (2), pp 385-394 Mon, 01 Oct 2012 00:00:00 GMT http://hdl.handle.net/10204/6676 2012-10-01T00:00:00Z http://hdl.handle.net/10204/5913 Title: Energy-aware path selection metric for IEEE 802.11s wireless mesh networking Authors: Mhlanga, MM; Nyandeni, TC; Olwal, TO; Ntlatlapa, N; Adigun, MO Abstract: The IEEE 802.11s working group has commenced activities, which would lead to the development of a standard for wireless mesh networks (WMNs). The draft of 802.11s introduces a new path selection metric called airtime link metric. However, there are various types of restrictions. The biggest restriction is the confined energy of the batteries. Thus, energy consumption is crucial in the design of new mesh routing protocols. This paper presents a new energy-aware routing metric for HWMP to balance the energy consumption among the nodes of the network. This work will be simulated using NS-2 and a test-bed implementation using the MERAKA test-bed. Description: Southern Africa Telecommunication Networks and Applications Conference (SATNAC 2009), Swaziland, 30 August-2 September 2009 Sat, 01 Aug 2009 00:00:00 GMT http://hdl.handle.net/10204/5913 2009-08-01T00:00:00Z