INTRODUCTION to SOIL MICROBIOLOGY

Question 1

It is the study of microorganisms that
live in the soil; their metabolic activity;
their roles in energy flow; and their roles
in nutrient cycling.

Answer 1

Soil Microbiology

Question 2

“the branch of soil science concerned with soil-inhabiting microorganisms, their functions and activities”

Answer 2

Soil Microbiology

Question 3

It is a dynamic natural body formed 
from weathering of rocks and minerals 
composed of mineral matter, organic 
matter, air and water, and possesses 
distinct characteristics and properties 
which in turn influence plant growth.

Answer 3

Soil

Question 4

Importance of Soil Microbiology:

Answer 4

Soil as a living system
-Soil microbes and plant growth
-Soil microbes and soil structure
*soil aggregation or soil binding properties order:
fungi > actinomycetes > gum producing bacteria > yeasts
-Soil microbes and organic matter decomposition
*organic matter/substances include cellulose, lignins and
proteins (in cell wall of plants), glycogen (animal tissues),
proteins and fats (plants, animals).
- Soil microbes and humus formation

Question 5

Importance of Soil Microbiology:

Answer 5

Soil microbes and cycling of elements
~ Soil Microbes and biological N, fixation
~* Soil microbes as bio-control agents
*eco-friendly bio formulations of microbial origin: Trichoderma
sp and Gleocladium sp for seed and soil-borne diseases,
fungal genera as insect pest or bacteria like Bacillus
thuringeinsis for leaf spot and worm diseases.
~Degradation of pesticides in soil by microorganisms
Biodegradation of hydrocarbons

Question 6

Focus in the study of the biota
living in soil and concerned itself with the cycling of nutrients and their availability to agricultural
plants

Answer 6

Early years

Question 7

More of an interdisciplinary study, 
involving agricultural production, 
aquatic and biogeochemical 
sciences, bioremediation, 
environmental quality, 
biodiversity, and global climate 
change

Answer 7

today

Question 8

Approach 2
To study the chemical, geological and biological
processes and reactions that governs the
composition of the natural environment.

Answer 8

a. Biogeochemistry - how they affect our environment
chemically
b. Nutrient cycling - how they recycle compounds in soil
c. Global change - how they affect global properties
such as temperature and atmospheric chemistry
d. Ecology — how they interact with their environment
and with other microorganisms

Question 9

To study the mechanical, physical, and biochemical

functions of living organisms.

Answer 9

a. Physiology - how they grow and metabolize
b. Taxonomy - what they look like and how they are
related to one another
c. Pathology - how they cause disease of plants,
animals and humans
d. Symbioses - how they interact with more complex
organisms

Question 10

first written history of soil and soil biota originated
in the East where scholars were recognized in the
__________.

Answer 10

early Chinese royal courts

Question 11

ancient Chinese regarded earthworms as

Answer 11

“angels of the earth.”

Question 12

Romans, such as Aristotle, considered earth worms

as

Answer 12

“intestines of the earth’.

Question 13

Inscriptions on ____________ show
that the production of beer and bread involved the
use of a starter (fungi) and required an incubation
time.

Answer 13

Egyptian walls from 2400 BCE

Question 14

soil microbiology emerges as a distint branch of soil science during__________

Answer 14

first half of 19th century.

Question 15

Recognized as being the first to see [giaealanae

bacteria in his self-designed microscopes.

Answer 15

Antonie van Leeuwenhoek

1632 — 1723

Question 16

He observed minute, moving objects which he
called “animalcules’ (small animals) which are
now known as protozoa, fungi and bacteria.

Answer 16

Antonie van Leeuwenhoek

1632 — 1723

Question 17

He for the first time made the authentic drawings 
of microorganisms (protozoa, bacteria, fungi).

Answer 17

Antonie van Leeuwenhoek

1632 — 1723

Question 18

Robert Hooke (1635 — 1703)

Answer 18

Developed a compound microscope with
multiple lenses and described the fascinating
world of the microbes.

Question 19

Robert Hooke (1635 — 1703)

Answer 19

Micrographia, was
published in 1665 and considered the first
microbiology textbook

Question 20

Responsible for the process of heating liquids

to partially sterilize them (Pasteurization).

Answer 20

Louis Pasteur (1822 — 1895)

Question 21

Can be said to have pioneered microbial

culture technique.

Answer 21

Robert Koch (1843 — 1910)

Question 22

Investigated microbial activities directly
related to the soil and often called the “Father
of Soil Microbiology”.

• He studied nitrification, sulfur oxidation,
  microbial oxidation of ferrous iron and
  microbial growth on CO, and inorganic ions, a
  process called chemoautotrophy.
• Developed the Winogradsky column, a
  self-contained ecosystem for studying the sulfur cycle.

Answer 22

Serge Winogradsky (1856-1953)

Question 23

1. A specific microorganism can = 
always be found with a given disease. 
2.The microorganism can be isolated 
and grown in a pure culture in the 
laboratory. 
3.The pure culture will produce the 
disease when inoculated into a 
susceptible host. 
4. The microorganism can be 
tecovered from the infected host and 
grown again in a pure culture.

Answer 23

Koch’s postulate:

Question 24

cultured the first nitrogen-fixing bacteria
that grew symbiotically in association with
legumes and the first aerobic nitrogen-fixing
bacteria that grew asymbiotically as free-living
soil organisms. These were Rhizobium and
Azotobacter, respectively.

Answer 24

Martinus Beijerinck (1851-1931)

Question 25

he is Considered the pioneer of antibiotics and

discovered evidence of the first antibiotic; penicillin

Answer 25

Sir Alexander Fleming (1881-1955)

Question 26

he is Interested in the effects of soil organisms
on soil fertility and plant growth. Lipman’s
textbook “Bacteria in Relation to Country Life”
(Lipman 1908) was the first attempt to
popularize the science of soil microbiology.

Answer 26

Jacob Lipman (1874-1939)

Question 27

who isolated a soil actinomycete called
Streptomyces. Streptomyces has _ antibiotic
properties much like those Fleming found with penecillum

Answer 27

Selman Waksman (1888-1973)