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| <p>We intend to design, construct and introduce a synthetic Vitamin B<sub>12</sub> exporter (“Synporter”) into a production organism. Thereby, we aim for facilitated and higher yields in the industrial Vitamin B<sub>12</sub> production without requiring cell lysis. | | <p>We intend to design, construct and introduce a synthetic Vitamin B<sub>12</sub> exporter (“Synporter”) into a production organism. Thereby, we aim for facilitated and higher yields in the industrial Vitamin B<sub>12</sub> production without requiring cell lysis. |
| The B12 Synporter consists of a signal for a Twin Arginine Transporter (Tat) mediated export that is linked to a B<sub>12</sub>-binding domain. This construct will be expressed in <em>S. typhimurium</em> TA100, <em>R. planticola</em> and <em>S. blattae</em>. We will not only test these different production organisms but also different B<sub>12</sub>-binding domains.</p> | | The B12 Synporter consists of a signal for a Twin Arginine Transporter (Tat) mediated export that is linked to a B<sub>12</sub>-binding domain. This construct will be expressed in <em>S. typhimurium</em> TA100, <em>R. planticola</em> and <em>S. blattae</em>. We will not only test these different production organisms but also different B<sub>12</sub>-binding domains.</p> |
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| + | <img src="https://static.igem.org/mediawiki/2016/5/54/T--Goettingen--Synporter.png" style="width:50%; height:50%;"/> |
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| <h3>Background</h3> | | <h3>Background</h3> |
| <p>Vitamin B<sub>12</sub> is involved in metabolic functions in all organisms, and is therefore an essential nutrient. However, it can only be synthesized by some bacteria and archaea, thus, animals have to obtain it through their diet. Thereby, only animal products like meat and dairy contain B<sub>12</sub> in general. This B<sub>12</sub> was synthesized by microorganisms colonizing the gastrointestinal tract of those animals and accumulated in the animals’ tissues. | | <p>Vitamin B<sub>12</sub> is involved in metabolic functions in all organisms, and is therefore an essential nutrient. However, it can only be synthesized by some bacteria and archaea, thus, animals have to obtain it through their diet. Thereby, only animal products like meat and dairy contain B<sub>12</sub> in general. This B<sub>12</sub> was synthesized by microorganisms colonizing the gastrointestinal tract of those animals and accumulated in the animals’ tissues. |
| Vitamin B<sub>12</sub> is one of the most essential biochemicals in the world, and its synthesis is extraordinarily complex. Since the chemical production of Vitamin B<sub>12</sub> requires 70 synthesis steps, it is far too technically challenging and expensive. Therefore, its production is facilitated by genetically engineered microorganisms. These are able to produce Vitamin B<sub>12</sub> in industrial amounts and achieve a high product quality. However, the produced Vitamin B<sub>12</sub> is harvested by cell lysis, which prevents a continuous production. The efficiency of production could be increased by exporting Vitamin B<sub>12</sub> outside the cells. To date, a natural cellular Vitamin B<sub>12</sub> exporter is unknown.</p> | | Vitamin B<sub>12</sub> is one of the most essential biochemicals in the world, and its synthesis is extraordinarily complex. Since the chemical production of Vitamin B<sub>12</sub> requires 70 synthesis steps, it is far too technically challenging and expensive. Therefore, its production is facilitated by genetically engineered microorganisms. These are able to produce Vitamin B<sub>12</sub> in industrial amounts and achieve a high product quality. However, the produced Vitamin B<sub>12</sub> is harvested by cell lysis, which prevents a continuous production. The efficiency of production could be increased by exporting Vitamin B<sub>12</sub> outside the cells. To date, a natural cellular Vitamin B<sub>12</sub> exporter is unknown.</p> |
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| <h3>Relevance</h3> | | <h3>Relevance</h3> |
| <p>An adult needs approximately 3.0 µg Vitamin B<sub>12</sub> per day which is essential for certain functions: it is involved in processes concerning synthesis of DNA, hormones and neurotransmitters and is involved in the formation of the nervous system and blood. Hence, a B<sub>12</sub> deficiency can cause diverse diseases like cancer, dementia, depression, pernicious anemia and polyneuropathy.</p> | | <p>An adult needs approximately 3.0 µg Vitamin B<sub>12</sub> per day which is essential for certain functions: it is involved in processes concerning synthesis of DNA, hormones and neurotransmitters and is involved in the formation of the nervous system and blood. Hence, a B<sub>12</sub> deficiency can cause diverse diseases like cancer, dementia, depression, pernicious anemia and polyneuropathy.</p> |
| <p>Nowadays, many people do not eat meat or animals products at all. Therefore, these people have a high risk to suffer from B<sub>12</sub> deficiency if their diet does not provide enough B<sub>12</sub>.</p> | | <p>Nowadays, many people do not eat meat or animals products at all. Therefore, these people have a high risk to suffer from B<sub>12</sub> deficiency if their diet does not provide enough B<sub>12</sub>.</p> |
| <p>Vitamin B<sub>12</sub> is also used in the industry as it is needed in the biotechnical production of various organic substances. Furthermore, it is added to diverse daily products like toothpaste, fruit gum, non-diary milk or cleaning solution for contact lenses.</p> | | <p>Vitamin B<sub>12</sub> is also used in the industry as it is needed in the biotechnical production of various organic substances. Furthermore, it is added to diverse daily products like toothpaste, fruit gum, non-diary milk or cleaning solution for contact lenses.</p> |
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| <h3>Further Aims</h3> | | <h3>Further Aims</h3> |
| <p>When we have successfully expressed our constructs in our productions organisms, we will try to maximize the Vitamin B<sub>12</sub> yield, and possibly find ways to utilize the periplasmic space to facilitate cytotoxic B<sub>12</sub> dependent reactions.</p> | | <p>When we have successfully expressed our constructs in our productions organisms, we will try to maximize the Vitamin B<sub>12</sub> yield, and possibly find ways to utilize the periplasmic space to facilitate cytotoxic B<sub>12</sub> dependent reactions.</p> |