The document discusses the challenges of culturing unculturable soil microbes, which make up over 99% of soil species and thrive only in their natural habitats. It highlights various techniques to isolate these organisms, such as adjusting atmospheric conditions, temperature, pH, and utilizing co-culture and community culture methods. Additionally, it emphasizes the importance of metagenomics as a culture-independent approach to explore these microbes for sustainable agricultural practices.

1. UNCULTURABLE SOIL BIOTA
Presentor
MADHU BHARATH K
M.Sc (Agri)
SOIL SCIENCE AND AGRL. CHEMISTRY
NM CA, NAU.

2. INTRODUCTION
Some microbes cannot be grown under artificial
medium condition, they only grow in their natural
conditions.
• More than 99% of these species cannot be cultured
by traditional techniques
Uncultivable bacteria
• Bacteria that can not be grown on any artificial non
living conditions

3. REASONS FOR PROBLEMS IN CULTIVATION
• The chemistry of microbe’s natural habitat
• Change in climatic factors
• Difficulty in mimicking the microbes habitat
• Absense of signals
• Absense of interactions
• Still unknown reasons

4. • Cellular interactions happens in many soil flora
which is not still unknown
• Ex : bacteria like organisms lives as endosymbionts
in cytoplasm of Gigaspora sp. This BLO’s are
closely related to the burkholderia sp of bacteria

5. HOW TO CULTURE THE UNCULTURABLE
MICROBES
Air conditions
• Incubation in the presence of air and hypoxic and
anoxic atmosphere was used to isolate various
bacteria that live in different microhabitats in soil
• An elevated concentration of CO2 can be added for
some bacteria

6. Temperature
• Because lower temperature decreases metabolic rate,
the productivity of growth-inhibiting materials
decreases, inducing more colonies for more isolates.
• In particular, if samples are obtained from cold
regions, then the incubation temperature should be
lowered
• ex: Proteobacteria, Cytophaga-Flavobacteria-
Bacteroides

7. pH
• Adjusting the pH to acidic, extreme acidic and
alkaline as like the microbes natural habitat
Community culture and co-culture
• Mixed cellular assemblages can perform multistep
degradation of cellulose and the intermediates can be
utilized as carbon sources
• Community culture is an effective way to cultivate
facultative or syntrophic organisms and other
community members

8. Incubation time
• Increased incubation periods are one of the most
important factors when attempting to identify lower-
growth and fastidious isolates
Modifications to growth media
• The design of media for the growth of different
microorganisms is a difficult task and a real challenge
for microbiologists.
• This requires in-depth insight into the nature and
characterization of samples, including all factors that
are directly related to and mediate growth..
• Ex: Acidobacteria, Actinobacteria

9. • The Metagenomics - emerging field in which the
power of genomic analysis (the analysis of all the
DNA in an organism) is applied to entire
communities of microbes,
• Bypassing the need to isolate and culture individual
microbial species.

11. • The metaproteomics is the technique used to study
the proteins
• By studying the proteins of the environment
interactions, possible genes can be known
• Used to prepare the culture media

12. • The Metatranscriptomics used to study and
characterize the RNA molecules

13. Research paper
 Goel, R., Kumar, V., Suyal, D. C., Narayan & Soni, R
(2018).Toward the Unculturable Microbes for Sustainable
Agricultural Production
Abstract
As per the information available from published researches, a
big portion of microbial wealth is unculturable which may contain
several beneficial traits, including the plant growth-promoting
activities for sustainable agricultural production. Exploitation of
these unculturable microbes can enhance our understanding of
present practices of organic agriculture. The only way to exploit this
unculturable wealth is the “metagenomics,” the culture-independent
approach where we are analyzing microbial DNA extracted directly
from an environmental sample.

14. Conclusion
• We all believe that microbes are very precious and, if
explored judiciously, can contribute to the sustainable
agricultural development.
• Advance approaches like metagenomics are revealing
interactions between plant and their microbial partner in
exceptionally detail.
• However, without a suitable methodology for confirming
the reliability of metagenomic analyses, assessing
whether the presence and activity of microorganisms are
correctly evaluated is not possible

15. References
 Pham, V. H. T. & Kim, K. (2004). Cultivation of
unculturable soil bacteria. Microbiology Ecology. 48,
1–13.
 Goel, R., Kumar, V., Suyal, D. C., Narayan & Soni, R
(2018).Toward the Unculturable Microbes
for Sustainable Agricultural Production. Role of
Rhizospheric Microbes in Soil. 107