Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Vermicomposts (VCs) are the solid excreta of earthworms, known to contain plant available nutrients, large amounts of microbial life and diversity, and plant growth regulating hormones. VCs may play an integral role in the nitrogen nutrition of Lupinus angustifolius and function to reduce the reliance of legume crops on chemical fertilizers. Furthermore, the effects of the combination of VC solids and VC teas on legume growth and N nutrition, is unknown. The aim of the present study was to determine the role of varying concentrations of chicken manure VC, with and without the additions of varying VC tea concentrations, on the substrate bacterial functional diversity, plant biomass and N nutrition of the legume, L. angustifolius. In the first experiment the plants were grown in pots under glasshouse conditions and VC was substituted into the quartz sand growth media at rates of 5%, 10% and 100%. Furthermore, rhizobia inoculated and non-inoculated groups were established within the VC treatments. The plants were harvested after 30 days and analysed for tissue nutrient concentrations and biomass production. The VC-containing substrates were assessed for wide-spectrum soil analyses, nematode diversity and microbial diversity via Biolog EcoPlates. In the second experiment the plants were grown under similar conditions for 50 days and amended with 5% VC in the growth media as well as 50ml of aerated VC teas. The teas were brewed for 24 hours in concentrations of 4%, 10% and 20% (v/v), with molasses and kelp extract added as sugar sources. The combined treatments of 5% VC and rhizobia inoculation yielded the greatest biomass response. Furthermore the addition of VC allowed for bacterial nitrogen fixation within non-rhizobia treatments. However, changes in VC concentration had no effect on bacterial guild structure but were found to effect nematode funtional diversity. The additions of VC teas to soil media containing 5% VC had no effect on biomass production but were found to influence bacterial nitrogen fixation. Lower concentration teas increased BNF while the 20% tea reduced this parameter significantly over 50 days. The 20% tea also contained significantly greater bacterial functional diversity than the 5% and 10% teas. The findings of study indicate that the combined treatment of VC solids and teas do not increase the plant biomass of L. angustifolius, but that the additions of 20% teas result in greater microbial diversity in the soil. This in turn may lead to increases in soil fertility. Furthermore, additions of high concentration vermicompost teas (20%) shift the dependence of the plant from atmospheric N sources to soil N sources. / AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar

[Truncated abstract] Obesity is now a major public health problem worldwide. More than half the Australian population is now overweight. This is an important public health concern primarily because of the impact of overweight and obesity on risk of diabetes, hypertension and cardiovascular disease. Many strategies have been proposed to fight the obesity epidemic. One possible strategy involves understanding of the role of dietary components in the control of food intake. In this regard, dietary protein and fibre appear to be the most satiating nutrients. Foods enriched in protein, replacing energy from carbohydrate, or dietary fibre can increase satiety and reduce energy intake in the short-term. Longer-term trials suggest benefits of increasing protein or fibre intake on weight loss and features of the metabolic syndrome. The effects of dietary approaches which increase both protein and fibre at the expense of refined carbohydrate are uncertain. A practical approach to increasing both protein and fibre content of processed foods is to incorporate high protein and fibre ingredients into high carbohydrate foods. Lupin kernel flour is a novel food ingredient derived from the endosperm of lupin. It contains 40 to 45% protein, 25 to 30% fibre, and negligible sugar and starch. Lupin kernel flour can be incorporated into refined carbohydrate rich foods such as bread to increase protein and fibre content at the expense of refined carbohydrate. ... Body weight was measured every 2 weeks throughout the 16 week intervention, and these data were analysed to determine whether there was any between group difference in the rate of change in weight over 16 weeks. Over 16 weeks, lupin bread compared to white bread resulted in a significant increase in protein (13.7 (2.3, 25.0) g/d) and fibre (12.5 (8.8, 16.2) g/d) intakes, and a decrease in carbohydrate intake (-19.9 (-45.2, 5.5) g/d). There was a significant difference between groups in the rate of weight change over the 16 weeks (P=0.05). However, at 16 weeks there was no significant effect on body weight (-0.4 (-1.3, 0.6) kg), fat mass (-0.5 (-1.2, 0.2) kg) or fat free mass (0.2 (-0.5, 0.8) kg). Plasma adiponectin and leptin were not altered. Mean 24 hour systolic blood pressure (-2.4 (-3.4, -1.3) mm Hg) and pulse pressure (-3.1 (-3.9, -2.3) mm Hg) were lower for lupin relative to white bread, but diastolic blood pressure was not significantly different between groups. Apart from a lower HDL cholesterol for lupin relative to white bread (-0.09 (-0.17, -0.01) mmol/L), there were no significant differences in other blood lipids and glucose and insulin concentrations. Interpretation of the results was not influenced after adjustment for potential confounding factors. These studies assessed effects of bread enriched in lupin kernel flour relative to white bread, resulting in a higher protein and fibre intake and lower refined carbohydrate intake. This increased satiety and reduced energy intake acutely, but did not significantly influence body weight over 16 weeks. Systolic blood pressure and pulse pressure were significantly reduced. There were no significant improvements in blood lipids or glucose and insulin concentrations. Therefore, increasing protein and fibre intake at the expense of refined carbohydrate using lupin kernel flour may benefit satiety and blood pressure. Longer-term trials incorporating weight loss may be needed to observe benefits on body weight.