Project No.2250
Primary Supervisor
Dr Andrew Simkin – University of Kent
Co-Supervisor(s)
Dr Eleftheria Stavridou – NIAB EMR
Dr Andrew Lawrence – University of Kent
Summary
The work will be broken down into three packages representing short (WP1), medium (WP2) and long-term (WP3) approaches to boosting B12 availability in green tissue for human consumption.
The work will be broken down into three packages representing short (WP1), medium (WP2) and long-term (WP3) approaches to boosting B12 availability in green tissue for human consumption. B12 is made exclusively by a small group of prokaryotes (bacteria and archaea)1. Some of these bacteria are found in the flora of ruminant mammals where they proliferate in the stomach and continue to form B12.
This source of B12 therefor accumulates in animal product including meat, eggs, milk and is the key dietary source of B12 in the population. B12 is absent from fruits and vegetables2. B12 is an essential nutrient for animals and B12 deficiency can result in a range of symptoms including depression, loss of memory (reduced cognitive performance), fatigue, lethargy and headaches and in some people mania and psychosis. Research has shown that as much as 40% of the world’s population are deficient in B12. Biofortification of plants via feeding mechanisms has demonstrated that Lepidium sativum (garden cress) can take up B12 if grown in B12 enriched media, where it accumulates in the vacuole of the cotyledons. Work Packages WP1 Will study feeding of B12 to pea and lettuce in Aquaponics systems to evaluate the mechanism of uptake and bioavailability. WP2 Will express bacterial B12 binding proteins in pea and lettuce to improve the stockage and bioavailability. Conduct feeding experiments (as WP1). WP3 As a first step in engineering Vitamin B12 biosynthesis into tomato fruit, we will look to produce the first 9 steps of the aerobic pathway for cobalamin biosynthesis into tomato fruit plastids, where the B12 pathway can syphon from the haem and chlorophyll pathways. This will involve the cloning of cobA-I-G-J-M-F-K-L-H genes and will result in the production of a stable intermediate called hydrogenobyrinic acid.