Browsing by Author "Calistru, Claudia."

Now showing 1 - 3 of 3

An investigation of key factors determining innovation delivery in a South African FMCG company.
(2003) Calistru, Claudia.; Salence, Marc.
Organisational theorists and managers have long shown interest in the role of innovation in organisations as innovation plays a crucial role in sustaining competitive advantage. A recent study revealed a gap between what leading corporations say about innovation and what they do. The gap is large: while 80 percent of companies acknowledged the importance of innovation in their business, only four percent were confident that they were good at it. The present study assessed innovation in a local FMCG organisation. An attempt to ascertain the factors determining innovation delivery in the company was made. The current investigation demonstrated that the overall perception on the company's innovation was high, notably the emphasis on the importance of innovation. Positive strong innovation capabilities have been demonstrated: high innovation commitment, a strategy that promotes innovation and that is clearly communicated and understood by all levels, adequate resources and facilities that keep the company competitive and, very important, an effective process. However, to sustain growth through innovation, the organisation needs to address a number of key issues such as unfavourable employee attitudes towards innovation, risk management, management creativity and the company structure.
Some aspects of biological control of seed storage fungi.
(1995) Calistru, Claudia.; Berjak, Patricia.
Under storage conditions of ambient temperature and relative humidity in South Africa, seed-associated mycoflora proliferates. Fusarium moniliforme is ubiquitous in newly-harvested maize, persisting for variable periods in storage, while Aspergillus flavus may represent the final group of species in the succession of aspergilli after grain storage under high temperature and/or high humidity. Many strains of these fungi produce toxigenic secondary metabolites (mycotoxins) under local storage conditions. Since pathogenic fungi may be present within the tissues of stored seeds, these contaminants will not be eradicated by external fungicide treatment, therefore a possible alternative is biological control. The aim of the present investigation was to ascertain whether certain strains and/or species of Trichoderma have potential as biocontrol agents against the seed-associated pathogenic fungi, Aspergillus flavus and Fusarium moniliforme. A study of the fungal growth in dual cultures revealed that from nine isolates of Trichoderma spp. (T harzianum and T viride), four had a noticeable inhibitory effect on the growth of the pathogenic fungi. Scanning electron microscopical investigation of fungal interaction demonstrated no obvious hyphal penetration by - Trichoderma spp. In addition, significant alteration of Fusarium hyphae, with pronounced collapse and loss of turgor, and production of aberrant conidial heads and microheads by A. flavus were observed. Evidence derived from some biochemical studies revealed that antibiosis (by production of extracellular enzymes, volatile compounds and possible antibiotics) is probably the mechanism involved in the antagonistic effect of the four aggressive Trichoderma spp. The in vitro studies demonstrated that the use of Trichoderma spp. as biocontrol agents against A. flavus and F. moniliforme appears promising.
Some implications of associated mycoflora during hydrated storage of recalcitrant seeds of Avicennia marina (Forssk.) Vierh.
(2004) Calistru, Claudia.; Berjak, Patricia.; Pammenter, Norman William.; McClean, Michelle.
Three questions are considered in the context of the possible effects of seedassociated mycoflora, typified by Fusarium moniliforme, during hydrated storage of recalcitrant seeds of the tropical species, Avicennia marina. These are: 1) whether fungal infection reduces storage lifespan; 2) whether seeds become more susceptible to fungal attack during storage and whether they posses defence mechanisms that might suppress fungal proliferation in hydrated storage (production of antifungal compounds and 13-1,3-glucanase (EC 3.2.1.39) and chitinase (EC 3.2.1.14)] and 3) whether it is possible to discriminate ultrastructurally between inherent deteriorative changes and those that are fungally-induced. 1) The data indicate unequivocally that if fungal activity is curtailed, then the hydrated storage lifespan of A. marina seeds can be considerably extended. 2) When inoculated immediately with F. moniliforme, newly harvested seeds were extremely susceptible to the adverse effects of the fungus, while seeds that had been wet-stored for 4 days showed a considerably heightened resilience to the effects of the fungus prior to inoculation. The enhanced resilience, although declining, persisted in seeds stored hydrated for up to 10 days prior to inoculation, being lost after 12 days. This finding was supported by significant increase in 13-1,3-glucanase and chitinase and in antifungal compound production during 10 days of wet storage. After 14 days of wetstorage, seeds become more susceptible to the effects of fungusthanthose in the newly harvested condition. 3) The resilience of seeds that had been stored in the short-term was associated with ultrastructural changes indicative of enhanced metabolic activity associated with the onset of germination (e.g. increase in vacuolation, well-developed mitochondria and endomembrane system [ER and Golgi bodies]). However, with sustained stress associated with wet-storage IV conditions, the seeds became increasingly badly affected by the fungus, showing some ultrastructural fungally-induced abnormalities (e.g. nuclear lobing, presence of lipid bodies and prevalence of Golgi bodies that had many associated vesicles) and a decrease in 13-1,3-glucanase and chitinase activity. It is suggested that the decreased susceptibility of A. marina seeds during short-term storage relies on the ability to create an antifungal environment prior to infection (through synthesis and accumulation of pre-formed and induced antifungal compounds and antifungal enzymes), which would also be an effective strategy during germination in the natural environment.