http://hdl.handle.net/10204/1 2013-05-19T01:31:24Z 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 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 2012-08-01T00:00:00Z http://hdl.handle.net/10204/6693 Title: Fingerprint pores extractor Authors: Mngenge, NA; Nelufule, NN; Nelwamondo, FV; Msimang, M Abstract: Automatic Fingerprint Recognition Systems (AFRSs) rely on minutiae position and orientation within the fingerprint image for matching. Minutiae information is highly accurate provided that the fingerprint image matched is of high quality. However, this is not always the case because of diseases and hash working conditions that affect fingerprints. In order to maintain high level of security independent of varying fingerprint image quality research suggests the use of other fingerprint features to compliment minutiae. These are things like ridge contours, sweat pores, dots, and incipient ridges. Sweat pores have been proven as one of the most distinctive among these feature. Thus in order to improve accuracy of AFRSs pores can be fused with minutiae or used alone. Sweat pores have been less utilized in the past due to constraints imposed by fingerprint scanning devices and resolution standards. Recently, progress has been made on both scanning devices and resolution standards to support the use of pores in AFRSs. However, very few techniques exist for extracting, matching and fusing them with minutiae. Matching and fusion can only be possible if pores are available. Some techniques have been proposed to reliable extract pores. However, existing techniques can only work on one resolution i.e. an algorithm proposed and tested on 500dpi cannot work on 1000dpi without minor modifications because pores size change if resolution changes. In addition, existing pore extraction techniques are computationally expensive. In this paper an algorithm to extract feature level 3 (pores) is proposed. The algorithm uses Laplacian of Gaussian (LoG) in Fourier domain in order to reduce computation. The performance of the proposed algorithm is tested on two distinct databases with different resolutions in order to validate its accuracy. The accuracy of the proposed algorithm is further measured using false detection rate (FDR) and true detection rate (TDR). Results show that FDR ranges from 10-35% while TDR ranges from 65-90%. Description: 2012 National Conference on Computing and Communication Systems, Durgapur, West Bengal, India, 21- 22 November 2012. To be published in IEEE Xplore 2012-11-01T00:00:00Z http://hdl.handle.net/10204/6683 Title: Evaluation of natural products as potential agrochemical agents with insecticide, fungicide and herbicide activities Authors: Dumontet, V; Litaudon, M; Olivon, F; Poullain, C; Rasoanaivo, C; Stien, D; Eparvier, V; Houël, E; Fokialakis, N; Halabalaki, M; Skaltsounis, AL; Espinosa, A; Olmedo, D; Gupta, M; Fouche, G; Hamburger, M; Sorgenfrei, O; Breuninger, D; Guéritte, F Abstract: The present work aims to identify new promising plant sources, which could be exploited for their agrochemical properties. A total of 484 natural products from academic libraries were selected for screening against four fungal pathogens, five insects and two plants. On the basis of the hits founded and a literature survey, the flora of source countries (New Caledonia, French Guiana, Madagascar, Panama, South Africa and Greece) was analysed for plants containing the desired scaffolds. Lists of 1800 plant part samples were thus established. The plant parts collected generated 3600 extracts that are being evaluated. Description: The International Congress on Natural Products Research, New York City, 28 July - 1 August 2012 2012-07-01T00:00:00Z