Question: Pumpkin Ale is created by adding pumpkin flesh to what, a vital component in the fermentation process? 

Context paragraphs:
Pyruvate decarboxylase: Pyruvate decarboxylase is a homotetrameric enzyme (EC 4.1.1.1 ) that catalyses the decarboxylation of pyruvic acid to acetaldehyde and carbon dioxide in the cytoplasm of prokaryotes, and in the cytoplasm and mitochondria of eukaryotes.  It is also called 2-oxo-acid carboxylase, alpha-ketoacid carboxylase, and pyruvic decarboxylase.  In anaerobic conditions, this enzyme is part of the fermentation process that occurs in yeast, especially of the "Saccharomyces" genus, to produce ethanol by fermentation.  It is also present in some species of fish (including goldfish and carp) where it permits the fish to perform ethanol fermentation (along with lactic acid fermentation) when oxygen is scarce.  Pyruvate decarboxylase starts this process by converting pyruvate into acetaldehyde and carbon dioxide.  Pyruvate decarboxylase depends on cofactors thiamine pyrophosphate (TPP) and magnesium.  This enzyme should not be mistaken for the unrelated enzyme pyruvate dehydrogenase, an oxidoreductase (EC 1.2.4.1 ), that catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA.

Autolysis (wine): Autolysis in winemaking relates to the complex chemical reactions that take place when a wine spends time in contact with the lees, or dead yeast cells, after fermentation.  While for some wines autolysis is undesirable, it is a vital component in shaping the flavors and mouth feel associated with premium Champagne production.  The practice of leaving a wine to age on its lees (or "sur lie" aging) has a long history in winemaking dating back to Roman winemaking.  The chemical process and details of autolysis were not originally understood but the positive effects of a creamy mouthfeel, breadlike and floral aroma, as well as reduced astringency were noticed early on.

Pumpkin ale: Pumpkin ale is a popular style of beer in the United States.  Pumpkin ale may be produced using pumpkin flesh in combination with malt or other more typical beer grains as a portion of the mash bill, contributing fermentable sugars to the wort.  It may also be produced by adding natural or artificial flavor to a finished beer.  Spice flavor may be added to evoke the flavor of pumpkin pie, a popular American wintertime dessert.

Biosynthesis of doxorubicin: Doxorubicin (DXR) is a 14-hydroxylated version of daunorubicin, the immediate precursor of DXR in its biosynthetic pathway.  Daunorubicin is more abundantly found as a natural product because it is produced by a number of different wild type strains of "streptomyces".  In contrast, only one known non-wild type species, "streptomyces peucetius" subspecies "cesius" ATCC 27952, was initially found to be capable of producing the more widely used doxorubicin.  This strain was created by Arcamone et al. in 1969 by mutating a strain producing daunorubicin, but not DXR, at least in detectable quantities.  Subsequently, Hutchinson's group showed that under special environmental conditions, or by the introduction of genetic modifications, other strains of "streptomyces" can produce doxorubicin.  His group has also cloned many of the genes required for DXR production, although not all of them have been fully characterized.  In 1996, Strohl's group discovered, isolated and characterized dox A, the gene encoding the enzyme that converts daunorubicin into DXR.  By 1999, they produced recombinant Dox A, a Cytochrome P450 oxidase, and found that it catalyzes multiple steps in DXR biosynthesis, including steps leading to daunorubicin.  This was significant because it became clear that all daunorubicin producing strains have the necessary genes to produce DXR, the much more therapeutically important of the two.  Hutchinson's group went on to develop methods to improve the yield of DXR, from the fermentation process used in its commercial production, not only by introducing Dox A encoding plasmids, but also by introducing mutations to deactivate enzymes that shunt DXR precursors to less useful products, for example baumycin-like glycosides.  Some triple mutants, that also over-expressed Dox A, were able to double the yield of DXR.  This is of more than academic interest because at that time DXR cost about $1.37 million per kg and current production in 1999 was 225 kg per annum.  More efficient production techniques have brought the price down to $1.1 million per kg for the non-liposomal formulation.  Although DXR can be produced semi-synthetically from daunorubicin, the process involves electrophilic bromination and multiple steps and the yield is poor.  Since daunorubicin is produced by fermentation, it would be ideal if the bacteria could complete DXR synthesis more effectively.

Stuck fermentation: A stuck fermentation occurs in brewing beer or winemaking when the yeast become dormant before the fermentation has completed.  Unlike an "arrested fermentation" where the winemaker intentionally stops fermentation (such as in the production of fortified wines), a stuck fermentation is an unintentional and unwanted occurrence that can lead to the wine being spoiled by bacteria and oxidation.  There are several potential causes of a stuck fermentation-the most common are excessive temperatures killing off the yeast or a must deficient in the nitrogen food source needed for the yeast to thrive.  Once the fermentation is stuck, it is very difficult to restart due to a chemical compound released by dying yeast cells that inhibit the future growth of yeast cells in the batch.  At the winery winemakers take several steps to limit the possibility of a stuck fermentation occurring, such as adding nitrogen to the must in the form diammonium phosphate or using cultured yeast with a high temperature and alcohol tolerance.  These steps that winemakers may take to prevent a stuck fermentation will each have their own subtle or dramatic effect on the resulting flavors and quality of the wine.

American wild ale: American wild ale generally refers to beers brewed in America using yeast or bacteria in addition to "Saccharomyces cerevisiae" for fermentation.  Such beers may be similar to traditional beers such as Lambic and Oud bruin, and are typically fermented using a strain of "brettanomyces" for part or all of the fermentation.  The use of brettanomyces can result in a "funky" flavor profile.  Examples include Jolly Pumpkin Perseguidor, Avery 15 and Brabant, Ommegang Ommegeddon.

Fermentation starter: A fermentation starter (called simply starter within the corresponding context, sometimes called a mother) is a preparation to assist the beginning of the fermentation process in preparation of various foods and s.  A starter culture is a microbiological culture which actually performs fermentation.  These starters usually consist of a cultivation medium, such as grains, seeds, or nutrient liquids that have been well colonized by the microorganisms used for the fermentation.

Mash ingredients: Mash ingredients, mash bill, mashbill, or grain bill are the materials that brewers use to produce the wort that they then ferment into alcohol.  Mashing is the act of creating and extracting fermentable and non-fermentable sugars and flavor components from grain by steeping it in hot water, and then letting it rest at specific temperature ranges to activate naturally occurring enzymes in the grain that convert starches to sugars.  The sugars separate from the mash ingredients, and then yeast in the brewing process converts them to alcohol and other fermentation products.

Secondary fermentation (wine): Secondary fermentation is a process commonly associated with winemaking, which entails a second period of fermentation in a different vessel than the one used to start the fermentation process.  An example of this would be starting fermentation in a carboy or stainless steel tank and then moving it over to oak barrels.  Rather than being a separate, second fermentation, this is most often one single fermentation period that is conducted in multiple vessels.  However, the term does also apply to procedures that could be described as a second and distinct fermentation period.

Candy pumpkin: A candy pumpkin is a small, pumpkin-shaped, mellowcreme confection primarily made from corn syrup, honey, carnauba wax, and sugar.  Traditionally colored with an orange base and topped with a green stem to make candy pumpkins largely identifiable with Halloween, a candy pumpkin is considered a mellow creme by confectioners since the candy has a marshmallow flavor.  Sometimes called candy corn's first cousin, candy pumpkins are made through a starch casting process similar to that for candy corn.  Brach's candy pumpkin, known by the trademarked name "Mellowcreme Pumpkin ," is the most popular candy pumpkin.  Brach's Confections is now owned by Farley's & Sathers Candy Company.

Supporting paragraphs: Pumpkin ale Mash ingredients
Answer: Mash ingredients