Exercise 11 Part 1: Microbial Production of Sauerkraut

The final acid concentration of sauerkraut fermentation often reaches ______ to ______ percent before Lactobacillus ceases to grow

1.5 to 2

The salt concentrations should be between ___ and ___ percent by weight

2 and 3

Among the facultative anaerobic microorganisms that ferment plant sugars in the early stage of sauerkraut fermentation are _______________ and __________________ ____________, both of which are Gram-______________

Enterobacter, Erwinia herbicola, and negative

In the final stage of sauerkraut fermentation, _______________ species become that predominant microbial forms about 4-6 days of incubation

Lactobacillus

In the intermediate stage of sauerkraut fermentation, _________________ species become the numerically predominant microbial forms in the culture by the second or third day of fermentation

Leuconostoc

In the intermediate stage of sauerkraut fermentation, __________________ __________________ is an organism that is seen most often during this stage of fermentation and can bring the acid concentration for the brine up to about 0.8%, after which further growth of the organism is inhibited by the acid

Leuconostoc mesenteroides

The fluid that is extracted from the plant tissues by the salt is known as ________

brine

Salt ________ the flavor of the final product

enhances

An ___________ _________ favors the growth of a certain bacteria

enrichment culture

_____________ microorganisms are organisms that can grow with or without oxygen

facultative

Leuconostoc species are called _______________ fermenters because they produce a mixture of almost equal parts of lactic acid, carbon dioxide, and ethanol when they ferment the plant sugars in the brine

heterolactic

Lactobacillus is a ________________ fermenter, which means that it produces mostly lactic acid when it ferments sugars in the fermentation brine

homolactic

Many types of microorganisms occur naturally on cabbage plants. Among these are several species of __________ _______ bacteria that can ferment carbohydrates to act and other kinds of organic acids

lactic acid

In the early stage of sauerkraut fermentation, the pH is ___________ when facultative anaerobic microorganisms ferment the plant sugars in the brine to various acids

lowered

The sauerkraut fermentation is an example of _________________ ____________, a situation in which different types of microorganisms grow up and then die off one after another as the conditions in the environment change over time

microbial succession

The salts serves to extract __________-____________ fluids from the leaf tissues, thereby making it easier for the microorganisms to get at the nutrients

nutrient-containing

Lactobacillus species are Gram-__________________ and can tolerate very ___________ acid concentrations than most other types of lactic acid bacteria

positive and higher

Leuconostoc species are Gram-____________, can tolerate ______ salt concentrations, and _____ pH

positive, high, and low

The salt suppresses the growth of unwanted microorganisms that cannot tolerate high _______ concentrations

salt

Salt specifically favors the growth of _______-__________ lactic acid bacteria

salt-tolerant

Enrichment conditions to favor the growth of lactic acid bacteria in sauerkraut fermentation are created by adding _____________ _________ to the cabbage leaves and removing _____________ in order to maintain an anaerobic environment

sodium chloride and oxygen

A __________ is placed on top of the cabbage-salt mixture in the fermentation container, in order to keep the mixture beneath the surface of the brine

weight