Fermentation microorganisms

In environments lacking a suitable external electron acceptor - such as dioxygen, sulfate, or ferric iron - respiration is not possible. Here, many organic compounds may be metabolized by fermenting microorganisms. Microbes of this class may create ATP by a direct coupling mechanism, using a process known as substrate level phosphorylation, SLP with an ion translocation mechanism like that employed by respirers, as already described or by a combination of SLP and ion translocation.1... 

The fungi (e.g., molds, mildews, rusts, yeasts, or mushrooms) are the third major group of solid phase microorganisms. However, they differ from bacteria and actinomycetes in that they are eukaryotic. They are all heterotrophic, and most are aerobic, with the exception of yeasts, which are fermenting microorganisms. 

There has been considerable research over the past 5-10 yr dedicated to improving microorganisms and separations technologies in order to reduce the overall cost of biobased succinic acid, much of which has been cofunded by DOE. This research has resulted in the development of the fermentation microorganism Escherichia coli strain AFP111, which exhibits greatly improved productivity. Fermentation with AFP111 to produce succinic acid has recently been successfully tested at commercial scale. 

This chapter presents a comprehensive review of previous research on mead production. It will focus on honey characterization and mead production. The first section covers honey composition and the way this affects honey properties, as well as important parameters that are indicators of honey quality. The second section discusses mead production, including fermentative microorganisms, fermentation conditions, and required postfermentation adjustments and maturation conditions. The final section focuses on the problems that must be surpassed and what the future holds for mead production. 

II. Mead production—under this heading are discussed fermentative microorganisms, fermentation conditions, postfermentation adjustments, and maturation conditions. 

Fermentation [16]. Some important pharmaceuticals, including steroids, antibiotics, and certain food additives (such as vitamins) are produced by fermentation. In fermentation, microorganisms (e.g., bacteria, yeast, or fungi) are inoculated in a liquid broth supplemented with nutrients (e.g., temperature, pH, oxygen). These microorganisms produce the desired product (e.g., antibiotic, steroid, vitamin, and so on) as a by-product of normal metabolism. The process of fermentation includes three steps ... 

Although we have considered only lactic acid and alcoholic fermentation, microorganisms are capable of generating a wide array of molecules as end... 

To make natto, soybeans, preferably small seeded, are washed and soaked overnight. The soaked beans are then steamed for 30 min, drained, and cooled to -40°C. Traditionally, the treated soybeans are wrapped with rice straw and set in a warm place for 1-2 days. Rice straw is credited for not only supplying the fermenting microorganism, Bacillus natto, but also absorbing the unpleasant odor of ammonia released from natto and imparting the aroma of straw to the product. 

McFeeters, R.F., Fermentation microorganisms and flavor changes in fermented foods, J. Food Sci., 69, 35, 2004. 

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