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Mahanama R.,University of Sydney | Berenjian A.,University of Sydney | Regtop H.,Agricure Scientific Organics | Talbot A.,Agricure Scientific Organics | And 2 more authors.
ANZIAM Journal | Year: 2011

The fermented Japanese food Natto contains menaquinone 7 which is known to reduce the incidence of bone fractures and cardio vascular diseases. Natto is traditionally produced by the solid state fermentation of soy beans by Bacillus subtilis natto. A mathematical model is developed for describing the production of menaquinone 7 in a static solid substrate bed supported on a tray fermenter using parameters obtained from literature for similar micro-organisms. Two model parameters were fitted to experimental data obtained to predict menaquinone 7 production. The postulated model presented in the form of a sensitivity analysis is likely to yield valuable insights on the dynamic behaviour of bacterial kinetics, including the formation of products such as menaquinone 7 as the first step towards scaling up. © Austral. Mathematical Soc. 2012. Source


Berenjian A.,University of Sydney | Mahanama R.,University of Sydney | Talbot A.,Agricure Scientific Organics | Regtop H.,Agricure Scientific Organics | And 2 more authors.
Applied Biochemistry and Biotechnology | Year: 2014

A nutritional food rich in menaquinone-7 has a potential in preventing osteoporosis and cardiovascular diseases. The static fermentation of Bacillus subtilis natto is widely regarded as an optimum process for menaquinone-7 production. The major issues for the bulk production of menaquinone-7 are the low fermentation yield, biofilm formation and the use of organic solvents for the vitamin extraction. In this study, we demonstrate that the dynamic fermentation involving high stirring and aeration rates enhances the yield of fermentation process significantly compared to static system. The menaquinone-7 concentration of 226 mg/L was produced at 1,000 rpm, 5 vvm, 40°C after 5 days of fermentation. This concentration is 70-fold higher than commercially available food products such as natto. Additionally, it was found that more than 80 % of menaquinone-7 was recovered in situ in the vegetable oil that was gradually added to the system as an anti-foaming agent. The intensification process developed in this study has a capacity to produce an oil rich in menaquinone-7 in one step and eliminate the use of organic solvents for recovery of this compound. This oil can, therefore, be used for the preparation of broad range of supplementary and dietary food products rich in menaquinone-7 to reduce the risk of osteoporotic fractures and cardiovascular diseases. © 2013 Springer Science+Business Media. Source


Mahanama R.,University of Sydney | Berenjian A.,University of Sydney | Valtchev P.,University of Sydney | Talbot A.,Agricure Scientific Organics | And 4 more authors.
International Journal of Food Engineering | Year: 2011

Natto, the richest known source of menaquinone 7 (MK7), is traditionally produced via Solid Substrate Fermentation (SSF) by Bacillus subtilis natto on cooked soy beans. In this work we report a threefold increase in MK7 concentration through the use of a mixture of soy protein granules and nixtamalized corn grits. The effects of fermentation processing factors were investigated and optimized in laboratory scale. These factors include initial moisture content, incubation temperature, incubation time, α-amylase pretreatment and solid substrate medium. Response surface methodology (RSM) was used to develop a mathematical model to identify the optimum values of key process variables to increase MK7 concentration; the model was also validated experimentally. The polynomial model fitted the experimental data well with R2 = 0.89 and R2 (adj) = 0.83. MK7 production was increased from 57.78 ± 1.57 mg/kg to 67.01 ± 0.18 mg/kg when the strain was cultivated at optimum conditions predicted by statistical approach (70% initial moisture, 35°C, 4 days, 10μL/g amylase and equal substrate mix) as compared to basal conditions (60% initial moisture, 40°C, 6 days, 10μL/g amylase and equal substrate mix). © 2011 De Gruyter. All rights reserved. Source


Berenjian A.,University of Sydney | Chan N.L.-C.,University of Sydney | Mahanama R.,University of Sydney | Talbot A.,Agricure Scientific Organics | And 3 more authors.
Molecular Biotechnology | Year: 2013

Bacillus subtilis natto is the key microorganism for the industrial production of menaquinone-7. The fermentation of this bacterium in static culture is associated with biofilm formation. The objective of this study was to determine the effect of biofilm formation on menaquinone-7 production to develop a suitable bio-reactor for the production of menaquinone-7. In the static culture, menaquinone-7 biosynthesis showed a linear correlation with biofilm formation (R 2 = 0.67) and cell density (R 2 = 0.7). The amount of biofilm, cell density and menaquinone-7 formation were a function of nutrient and processing conditions. Glycerol, soy peptone, and yeast extract mixture and 40 C were found to be the optimum nutrients and temperature for accelerating both biofilm and menaquinone-7 biosynthesis in static culture. However, glucose, mixture of soy peptone and yeast extract and 45 C were found to be the optima for cell density. As compared to the static culture, the biofilm formation was significantly inhibited when a shaken fermentation was used. However, shaking caused only a small decrease on menaquinone-7 production. These results demonstrate that the biofilm formation is not essential for menaquinone-7 biosynthesis. This study underlines the feasibility of using large scale stirred fermentation process for menaquinone-7 production. © 2012 Springer Science+Business Media, LLC. Source

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