This document is about soil microflora and the microorganisms that constitute the soil microbial population. It discusses the four major groups of microorganisms found in soil - bacteria, fungi, algae, and protozoa. Bacteria and fungi are important for decomposition processes and nutrient recycling in soil. The physical and chemical properties of soil influence the growth and activity of soil microflora. The root systems of plants also impact the microorganisms in the rhizosphere.

1. GURU NANAK INSTITUTE OF PHARMACEUTICAL SCIENCE AND
TECHNOLOGY
TOPIC : SOIL MICROFLORA
NAME OF THE STUDENT : ANKIT GHOSH
UNIVERSITY ROLL NUMBER : 31308421036
ACADEMIC SESSION : 2022-2023
PAPER NAME : ENVIRONMENTAL
MICROBIOLOGY
PAPER CODE : CMC 302
Maulana Abul Kalam Azad University of Technology

2. INTRODUCTION
B. Sc./ SEM 3/2022-23/ / ENVIRONMENTAL MICROBIOLOGY / CMC 302 /Presentation_1
• Soil microflora contributes to the biological property of the soil, whose
number and activity has a considerable impact on the soil system. The
physical and chemical factors like pH, temperature, available moisture,
and nutrients influence the growth and activity of the soil microflora.
• The root system in the soil also influences a wide range of
microorganisms, which show intense metabolic activity in
the rhizosphere and known as rhizospheric microorganisms.
• Bacteria, fungi, algae and protozoa constitute the microbial menagerie,
whose number may reach millions to billions per gram of soil. Therefore,
it is difficult to enumerate the number of microorganisms present in the
soil.

3. Soil Microflora
B. Sc./ SEM 3/2022-23/ / ENVIRONMENTAL MICROBIOLOGY / CMC 302 /Presentation_1
Soil microflora refers to a group of soil microorganisms, which primarily
constitute the portion of the soil organic matter and some colloidal
portion of the soil humus. Four major groups of microorganisms (bacteria,
fungi, algae and protozoa) are part of soil microflora.
They constitute the soil microbial population, in which each group has a
significant role in promoting soil and plants health. Microbial
community living within or on the soil system form a soil food web.
Soil Microflora includes bacteria and fungi. Bacteria are numerous, and they
participate in various soil transformation processes like weathering of rocks,
breakdown of organic matter and nutrient recycling. Fungi are also important
for the decomposition process, and they also help in soil aggregation and
restoring nutrients.

4. Soil Microorganisms
B. Sc. / SEM 3/2022-23/ / ENVIRONMENTAL MICROBIOLOGY / CMC 302 /Presentation_1
Bacteria
• Decomposers
• Nitrogen Fixers or
Nitrifying Bacteria
• Denitrifiers
• Mutualists
• Pathogenic Bacteria
• Sulphur oxidizers
• Actinomycetes or
Actinobacteria
Fungi
• Decomposers
• Mycelial fungi
• Disease suppressors
• Mutualists
• Pathogens
Algae
• Cyanophyceae
• Chlorophyceae
• Bacillariaceae
Protozoa
• Flagellates
• Amoebae
• Ciliates

5. CONCLUSION
SUMMARY
B. Sc./ SEM 3/2022-23/ / ENVIRONMENTAL MICROBIOLOGY / CMC 302 /Presentation_1
Soil biology is important for soil health and the soil biological community
encompasses all living things including earthworms, insects, nematodes,
plant roots, animals, and microbes. Beneficial soil microbes perform
fundamental functions such as nutrient cycling, breaking down crop
residues, and stimulating plant growth. While the role of microbes to
maintain soil health and contribute to crop performance is clear, the soil
biological component is extremely difficult to observe and manage.

6. REFERENCE
B. Sc. / SEM 3/2022-23/ / ENVIRONMENTAL MICROBIOLOGY / CMC 302 /Presentation_1
1. Afzal, A.; Ashraf, M.; Asad, S.A. and Farooq, M. (2005). Effect of phosphate solubilizing
microorganisms of
Phosphorus uptake, yield and yield traits of wheat (Triticum aestivum L.) in rain fed area.
International Journal
of Agriculture and Biology, 7(2):207-209.
2. Agnihotrudu, V. (1953). Soil conditions and root diseases VIII. Rhizosphere microflora of some
important
crops of South India. Proceedings Indian Academy of Sciences, 37: 1-13.
3. Alagawadi, A.R. and Gaur, A.C. (1992). Inoculation of Azospirillum brasilense and Phosphate
solubilizing
bacteria on yield of sorghum (Sorghum bicolour (L.) Moech) in dry land. Tropical Agriculture, 69:347-
350.
4. Alagawadi, A.R. and Krishnaraj, P.U. (1998). Field performance of two local rhizobacteria isolates
in sorghum.
37th Annual conference of association of Microbiologists on India, Mangalore, pp 278.