Isolation Of Streptococcus Salvarius Flashcards
What is the process called that converts nitrogen gas (N2) into ammonia?
Nitrogen fixation
This process is crucial for creating organic nitrogen needed for life.
Which group of organisms carries out nitrogen fixation?
Prokaryotes
This includes many soil bacteria such as Azotobacter, Clostridium, and Klebsiella.
What role do soil microorganisms play in the decomposition of organic matter?
They degrade organic matter to produce nutrient-rich topsoil
This process is essential for recycling nutrients in ecosystems.
What is a beneficial practice encouraged for managing yard waste?
Composting
A good compost pile requires a balance of leafy and grassy wastes to support microorganisms.
Name an antibiotic produced by the fungus Penicillium.
Penicillin
This antibiotic was the first widely used and has saved countless lives.
Which genus of bacteria produces streptomycin?
Streptomyces
This genus also synthesizes geosmins, contributing to the earthy smell of soil.
What is the dormant stage formed by Bacillus and Clostridium in response to adverse conditions?
Endospore
Endospores are highly resistant and can survive extreme conditions.
How long does it take for endospore formation to occur?
About eight hours
Mature endospores can remain viable for at least 50 years, potentially thousands.
What distinguishes Clostridium species from Bacillus species?
Oxygen requirements
Clostridium are obligate anaerobes, while Bacillus can be obligate aerobes or facultative anaerobes.
True or False: Most soil microbes are harmful and can cause diseases.
False
While most soil microbes are beneficial, some can cause diseases like tetanus and botulism.
What are the causative agents of tetanus and botulism?
Clostridium tetani and Clostridium botulinum
These bacteria can produce potent toxins under anaerobic conditions.
What technique will be used to estimate the number and diversity of aerobic microorganisms in the soil?
Spread plates
This method avoids the high temperatures that can kill environmental organisms.
How are Bacillus endospores counted in the soil sample?
By heating the sample and then plating it
Heat treatment kills vegetative cells but not endospores, allowing for accurate counting.
Fill in the blank: The characteristic ‘earthy’ odor of soil is produced by _______.
Streptomyces
These bacteria produce geosmins, which contribute to the soil’s smell.
