Q. Show the important groups of bacteria?

The important groups of bacteria are:

a) Bacillus: rod-shaped.

b) Coccus: spherical.

c) Coccobacillus: oval-shaped.

d) Aerobes: require atmospheric oxygen for growth, e.g., Acetobacter aceti.

e) Facultative anaerobes: can grow with or without atmospheric oxygen.

f) Obligate anaerobes: do not grow in atmospheric oxygen.

g) Mesophiles: require a temperature below 38°C for growth.

h) Obligate thermophiles: grow between 38°C and 82°C.

i) Facultative thermophiles: grow over a wide range of temperatures covered by mesophiles and obligate thermophiles and below.

j) Psychrophiles: grow fairly well at refrigeration temperatures and some can even grow slowly at temperatures below freezing.