Andrea Talbot

Efficient media for high menaquinone-7 production: response surface methodology approach

The aim of this study was to assess the effect of nutrients on the production of menaquinone-7 and determine the optimum conditions to achieve a high concentration of this product. Bacillus subtilis natto was fermented at 40°C for a period of six days. Design of experiments was used for screening the most effective nutrients, and central composite face design was employed for the optimization. The optimum media consisted of 5% (w/v) yeast extract; 18.9% (w/v) soy peptone; 5% (w/v) glycerol and 0.06% (w/v) K(2)HPO(4). The pH, bacterial growth, concentrations of amino acids, glycerol and menaquinone-7 were measured at the optimum fermentation media each day. Total free amino acids concentration increased 1.7-fold during the fermentation. Lysine and glutamic acid were the most abundant whereas arginine, asparagine and serine were the limiting amino acids at the end of fermentation period. The menaquinone-7 concentration approached 86% of the final value in the third day of fermentation, where the bacteria growth was at exponential phase. At this condition the concentration of glycerol as carbon source and asparagine, serine and arginine as the amino acid sources were dramatically diminished in the fermentation media. The optimum menaquinone-7 concentration was in good agreement with the predicted value by the model (96% validity). The maximum menaquinone-7 concentration of 62.32 ± 0.34 mg/L was achieved after six days of fermentation; this value is the highest concentration reported in the literature.

Enhanced Production of Menaquinone 7 via Solid Substrate Fermentation from Bacillus subtilis

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, 10 µL/g amylase and equal substrate mix) as compared to basal conditions (60% initial moisture, 40°C, 6 days, 10 µL/g amylase and equal substrate mix).

A potential biotechnological process for the sustainable production of vitamin K1

Abstract The primary objective of this review is to propose an approach for the biosynthesis of phylloquinone (vitamin K1) based upon its known sources, its role in photosynthesis and its biosynthetic pathway. The chemistry, health benefits, market, and industrial production of vitamin K are also summarized. Vitamin K compounds (K vitamers) are required for the normal function of at least 15 proteins involved in diverse physiological processes such as coagulation, tissue mineralization, inflammation, and neuroprotection. Vitamin K is essential for the prevention of Vitamin K Deficiency Bleeding (VKDB), especially in neonates. Increased vitamin K intake may also reduce the severity and/or risk of bone fracture, arterial calcification, inflammatory diseases, and cognitive decline. Consumers are increasingly favoring natural food and therapeutic products. However, the bulk of vitamin K products employed for both human and animal use are chemically synthesized. Biosynthesis of the menaquinones (vitamin K2) has been extensively researched. However, published research on the biotechnological production of phylloquinone is restricted to a handful of available articles and patents. We have found that microalgae are more suitable than plant cell cultures for the biosynthesis of phylloquinone. Many algae are richer in vitamin K1 than terrestrial plants, and algal cells are easier to manipulate. Vitamin K1 can be efficiently recovered from the biomass using supercritical carbon dioxide extraction.