Directly inoculated fermentation

Wine. The earliest known wiaes were made ia Iran about 5400—5000 BC (25). The species of grape used is unknown and may have been either the wild grape Fitis viniferus sjJvestris or a cultivated precursor of the modem wine grape F. viniferus viniferus. The source of the yeast used, and the procedures used are completely unknown. In modem times, grapes (about 21—23% sugar) are pressed the Hquid must is either separated and allowed to settle for 1—2 days (for white win.es) before inoculation with yeast, or the whole mass is directly inoculated with yeast (for red wines). In either case, while the initial fermentation takes place, the carbon dioxide formed by fermentation excludes air and prevents oxidation. White wines are transferred to a second fermentor (racked) near the end of fermentation and kept isolated from the air while soHds, including yeast, settle out, a process that requires about six... 

Nielsen, J.C., Prahl, C., and Lonvaud-Funel, A. 1996. Malolactic fermentation in wine by direct inoculation with freeze-dried Leuconostoc oenos cultures. Am. J. Enol. Vitic. 47, 42—48. 

Commercial starter cultures are available in both frozen and freeze-dried formats and can be used to directly inoculate the material to be fermented. The use of these types of cultures, referred to as direct vat set (DVS) cultures, has many advantages over the... 

In the production of fermented food, starter cultures are used to prevent fermentation failure and to ensure high-product quality. Starter cultures are cultures with well-defined properties that ensure a fast, safe, and defined fermentation and lead to fermented food products with high and constant product quality. The use of defined starter cultures is state-of-the-art in the dairy industry, and replaces traditional procedures in the production of meat and bakery products and other fermented commodities. Starter cultures are mostly produced by specialized companies that distribute the cultures worldwide, and are being used increasingly in concentrated forms for direct inoculation into the food matrix (direct-to-vat-set cultures, DVS Hansen, 2002). 

With one recent exception (Vinflora oenos), rehydration of freeze-dried cultures is usually recommended in sterile distilled or deionized water followed by transfer to expansion media. Most LAB cultures prepared from either laboratory cultures, concentrates, or rehydrated from freeze-dried preparations must be propagated and expanded under winelike conditions prior to inoculation into the total volume of fermentation or wine. This acclimation period is necessary to prevent the significant population crashes observed upon direct inoculation into wine. 

Gavazza, a., E. Poznanski, and G. Trioli. 2004. Restart of fermentation of simulated stuck wines by direct inoculation of active dry yeasts. Am.J. Enol. Vitic. 55 160-167. 

The yeast must be so finely dispersed throughout the wort that a quick yeast growth is assured, which leaves no possibiUty for other microorganisms, if any, to develop. The inoculation of yeast occurs through injection directly into the wort pipe. To be used in the next batch of wort, the yeast that is harvested after the end of fermentation must be protected against contamination. 

The SF-837 strain, namely Streptomyces mycarofaciens identified as ATCC No. 21454 was inoculated to 60 liters of a liquid culture medium containing 2.5% seccharified starch, 4% soluble vegetable protein, 0.3% potassium chloride and 0.3% calcium carbonate at pH 7.0, and then stir-cultured in a jar-fermenter at 28°C for 35 hours under aeration. The resulting culture was filtered directly and the filter cake comprising the mycelium cake was washed with dilute hydrochloric acid. 

Short-chain acids accumulate.under anoxic conditions/-which favor fermentative metabolism of bacteria. Such phytotoxins nay damage the plant directly or predispose plants to infection by pathogens. However plant residues nay also be used as substrates for beneficial micro-organisms to produce plant nutrients, soil conditioners, and plant protection chemicals. There is scope to promote the beneficial microbial effects against the harmful by soil management and by inoculation. 

Practical and fundamental aspects of malo-lactic fermentation are given. Conditions which winemakers can use for better control of the fermentation, including detailed procedures for inoculation with Leuconostoc oenos ML 34 and for inhibition with fumaric acid, are presented. New information on the role of malic acid decarboxylation in bacterial metabolism and on the enzymatics of malic acid decarboxylation are reviewed. The malic acid decarboxylation seems to involve two pathways a direct decarboxylation of malic to lactic acid with NAD as a coenzyme and a concurrent but small oxidative decarboxylation to pyruvic acid and NADH. How these pathways can bring about the marked stimulation of bacterial growth rate by the malo-lactic reaction and their negligible effect on growth yield are discussed. 

Fermentation. The juice should be inoculated with an actively fermenting culture of one of the selected strains of S. fermentati. Such yeasts may be obtained from winery supply houses as pure cultures which must be multiplied to obtain enough inoculum for the large fermentation or as dried yeast which may be added directly to the juice. Alternatively, the juice may be fermented dry with one of the standard, non-film-forming yeasts, and then the dry white wine may be inoculated... 

In the next part of our research on EBI-fungicides, we restricted ourselves to Pyricularia oryzae since from our point of view the In vitro results with that organism are representative and the test procedure is rather simple. The test chemical is applied in a suitable concentration to the culture medium which is then inoculated from an untreated pre-culture. After a 24-hour fermentation, the cells are separated from the culture filtrate by centrifugation, resuspended in a chloroform/methanol-mixture and homogenized using an ultraturrax treatment. After this extraction procedure, the sterol-conjugates are split to free sterols by a potassium-hydroxide treatment. Adsorption of the sterols to a Sep-pak column and step-wise desorption leads to a sterol fraction which can be analyzed directly by gas chromatography on a SE-30 capillary column. 

A glycerol stock of cells was used directly as an inoculum in all experiments. It was first inoculated into 5 mL of LB broth in universal bottles. One percent inoculum was added to a 1-L conical flask containing 200 mL of flask fermentation medium that was grown on a rotary shaker at 250 rpm and 37°C. Antibiotic ampicillin was added in a final concentration of 80 pg/mL. 

Pilone, G.J. 1995. A New Zealand experience in direct-vat inoculation for malolactic fermentation. Aust. NZ. Wine Ind. J. 10, 169-173. 

Shallow stainless steel containers are filled with already inoculated medium. Humid air is blown over the surface of the solution for 5 to 6 d, after which dry air is used. As the fermentation progresses, thick mats of mycelium (a few cm in thickness) form on the surface. Citric acid is formed mainly from the bottom layer of cells that have direct contact with the medium. Normally it takes 8 to 10 d to reduce the sugar concentration to 10 to 30 g/1 from an original concentration of 200 g/1. The pH of the solution is lowered from the 5-6 range to... 

Batch fermentations were inoculated by transferring around 10% (v/v) of the overnight flask culture directly to the stirred-tank bioreactor (BioFlo 3000, New Brunswick Scientific, Edison, NJ). For the fermentations, the initial cell density was monitored spectrophotometrically to give an optical density at 6(X) nm in the range 0.4 to 0.5 corresponding to growth in the midexponential phase. 

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