compound to release energy. Examples: . Sulphur bacteria - Thiobacillus thiooxidans . Iron bacteria - Ferrobacillus ferrooxidans .
Hydrogen bacteria - Hydrogenomonas . Nitrifying bacteria - Nitrosomonas and Nitrobacter are due to differences in the structure and composition of the cell wall. The difference between Gram Positive and Gram negative bacteria is given in Table . .
What are Magnetosomes ? Intracellular chains of - magnetite (Fe O ) particles are found in bacterium Aquaspirillum magnetotacticum . and it help the bacterium to locate nutrient rich sediments. .
. Life processes in Bacteria Respiration Two types of respiration are found in Bacteria. They are . Aerobic respiration .
Anaerobic respiration. . Aerobic respiration These bacteria require oxygen as terminal acceptor and will not grow under anaerobic conditions. (i.e.
in the absence of O ) Example: Streptococcus. Obligate aerobes Some Micrococcus species are obligate aerobes (i.e. they must have oxygen to survive). .
Anaerobic respiration These bacteria do not use oxygen for growth and metabolism but obtain their energy from fermentation reactions. Example: Clostridium. Facultative anaerobes There are bacteria that can grow either using oxygen as a terminal electron acceptor or anaerobically using fermentation reaction to obtain energy. When a facultative anaerobe such as E.
coli is present at a site of infection like an abdominal abscess, it can rapidly consume all available O and change to anaerobic metabolism producing an anaerobic environment and thus allow the anaerobic bacteria that are present to grow and cause disease. Example: Escherichia coli and Salmonella. Capnophilic Bacteria Bacteria which require CO for their growth are called as capnophilic bacteria. Example: Campylobacter.
and Clostridium tetani. Endospores are thick walled resting spores. During favourable condition, they germinate and form bacteria. Sexual Reproduction Typical sexual reproduction involving the formation and fusion of gametes is absent in bacteria.
However gene recombination can occur in bacteria by three different methods they are . Conjugation . Transformation . Transduction .
Conjugation J. Lederberg and Edward L. Tatum demonstrated conjugation in E. coli .
in the year . In this method