| 摘要 |
<p>Natural tobacco is extracted with water to produce a soluble extract and an insoluble fibrous residue. The aqueous extract is contacted by microorganisms, such as bacteria or fungi, capable of converting nitrate in the extract to nitrogen. Contacting may be done by adding a microorganism culture to a batch of the extract, or by passing the aqueous extract through a filter carrying a supply of the microorganisms. In either case, the contacting should take place in a substantially anaerobic environment. The culture may be produced by cycling a quantity of tobacco extract through a filtering medium to promote the growth of microorganisms occurring naturally in tobacco. Carbohydrate and/or protein is added to the denitrated extract to replace compounds depleted during the denitrating procedure. Ultimately, the denitrated extract is recombined with the fibrous tobacco residue.</p> |
