Browsing by Author "Mokoena, Mduduzi Paulos."

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Bacterial degradation of 2,4-dichlorophenol : catabolic genes detection and enzyme characterization.
(2017) Setlhare, Boitumelo.; Mokoena, Mduduzi Paulos.; Olaniran, Ademola Olufolahan.
Abstract available in PDF file.
Biodegradation of pentachlorophenol by Bacillus tropicus isolated from activated sludge of a wastewater treatment plant in Durban, South Africa.
(2021) Aregebesola, Oladipupo Abiodun.; Olaniran, Ademola Olufolahan.; Mokoena, Mduduzi Paulos.
Abstract available in PDF.
The fate of mycotoxins in non-alcoholic lactic acid maize meal fermentation.
(2003) Mokoena, Mduduzi Paulos.; Gqaleni, Nceba.
This study was aimed at investigating the potential of lactic acid fermentation in reducing myco toxin concentration in maize meal products. Maize meal was spiked separately with aflatoxin Bi, fumonism Bi, and zearalenone, and fermented for four days. During this period the concentration of each toxin and the pH of the fermented maize meal were monitored. There was a significant (p= 0.000) decrease in the concentration of all the mycotoxins, with a percentage reduction of 55-69 by the third day and 68-75 by the fourth day, respectively. Commercial amahewu samples were also screened for the presence of these three mycotoxins, and the results indicated that the samples were not contaminated with detectable levels of these toxins. An attempt was made to characterise the metabolic derivatives (by-products) of each mycotoxin following lactic acid maize meal fermentation. To achieve this maize meal samples were separately spiked with each of mycotoxin, fermented for four days and screened for specific mycotoxin derivatives (by-products) using GC/MS, HPLC and relevant standards (i.e. partially hydrolysed fumonisin Bi, aflatoxin B2a, a- and Pzearalenol). None of the targeted derivatives could be detected in the fermented maize meal samples. The potential cytotoxicity of the mycotoxin-spiked fermented samples was investigated using an SNO cell line. The fermented toxin-spiked maize meal samples with a starter culture were comparatively less toxic (29 - 36%) to SNO oesophageal cells than samples spiked with toxin without a starter culture (24 - 30%). However, this observed difference was not statistically significant (p = 0.295 - 0.681). Furthermore, cells that were only inoculated with the cell culture medium had significantly (p = 0.000) high percentage cell viability. This study indicates that it is possible to significantly reduce the concentration of mycotoxins using lactic acid maize fermentation to trace levels. However, such a reduction will not significantly alter the possible chronic toxic effects of such toxins in the diet, particularly a maize based diet containing poor quality protein. The trace amounts of these toxins in fermented and unfermented maize meal should continue to be a cause for concern.
Study on Fusarium toxins contamination of cereal grains in Jiangsu Province, China.
(2018) Fang, Ji.; Mokoena, Mduduzi Paulos.; Olaniran, Ademola Olufolahan.; Shi, J.
Jiangsu Province is located in the transition zone from subtropical to warm temperate zone, with the characteristics of monsoon climate. The province's natural ecological conditions are suitable for the production of winter wheat and rice. In this region, the warm and humid climate is very suitable for the plant epidemics such as Fusarium head blight (FHB). Fusarium mycotoxins are secondary metabolites produced by Fusarium species; and can cause acute and chronic toxic effects on the body and are a threat to humans and animal health. Therefore, knowledge about the prevalence of FHB-producing Fusarium species, incidence of deoxynivalenol, zearalenone and fumonisins as well as possible influencing factors is imperative for preventing influx of contaminated grains into food supply chain. The present study focuses on the occurrence of Fusarium species coupled with contamination levels of Fusarium mycotoxins from different Jiangsu Province, China for three years, and the influences of rainfall and temperature on accumulation of DON. In addition, Fusarium strains were isolated from rice and assessed for the potential to produce fumonisins and beauvericin. The findings of this study increase the knowledge on important rice fungal pathogens and provide relevant information on the high variability of these pathogens, as well as their implications for the development of further diseases. The ICS test developed in our study has advantages, such as rapid and efficient screening of samples. The data obtained from the ICS test shows good agreement with LC-MS/MS data. These results showed that the ICS test is suitable for on-site monitoring of ZEN.