1. Isolation and Enrichment of soil bacteria
Regina Gohl, K. Noreen Boyle
02/11/2011
University of Oldenburg - ICBM - Practical course Physiology of bacteria (Group B1) – final presentation

2. Introduction  Aims & Expectations  Course results  Summary
Regina Gohl, K. Noreen Boyle ICBM Uni Oldenburg 2
Introduction
1 soil probe  2 experiments
Isolation
Enrichment ?
37 °C
Pasteurisation
Nitrogen
Nitrogen + yeast
Salt
Salt+yeast
Acidic
Alkaline
Dilution series
Medium variation
Introduction  Aims & Expectations  Course results  Summary

3. Introduction  Aims & Expectations  Course results  Summary
Regina Gohl, K. Noreen Boyle ICBM Uni Oldenburg 3
Aims and expectations
Cultivation of soil bacteria
Determination of abundance
Comparison: fast vs abundant
Influence of different media
Expectations
Direct isolation
Enrichment
Types of bacteria
several
one - few
Colony size
small
large
Growth
slow
fast
Conclusion
abundant
fast growing
Introduction  Aims & Expectations  Course results  Summary

4. Introduction  Aims & Expectations  Course results  Summary
Regina Gohl, K. Noreen Boyle ICBM Uni Oldenburg 4
Direct Isolation
Cells/g soil
3.1 x 10^6
5.4 x 10^6
3.3 x 10^6
1.9 x 10^6
4.7 x 10^6
1.0 x 10^6
0.8 x 10^6
~ 10^9 bacteria/g soil
2.8 x 10^6 cells/g soil
~1 % of bacteria can
be cultured in the lab
Less bacteria than expected
Introduction  Aims & Expectations  Course results  Summary

5. Introduction  Aims & Expectations  Course results  Summary
Regina Gohl, K. Noreen Boyle ICBM Uni Oldenburg 5
Direct Isolation
Introduction  Aims & Expectations  Course results  Summary

6. Introduction  Aims & Expectations  Course results  Summary
Regina Gohl, K. Noreen Boyle ICBM Uni Oldenburg 6
Enrichment
Treatment
Oxidase test
Gram test
Catalase test
Increased temperature + -
Pasteurisation
- nitrogen source
-nitrogen source
+ yeast extract
+ salt
+ salt + yeast extract
acidic
alkaline
tiki-index.php?page=Katalase-Test
Introduction  Aims & Expectations  Course results  Summary

7. Introduction  Aims & Expectations  Course results  Summary
Regina Gohl, K. Noreen Boyle ICBM Uni Oldenburg 7
Enrichment
Treatment
Motility
Growth
Size
Shape
Increased temperature
mobile
fast
large
round, beige
Pasteurisation
immobile
slow
small
- nitrogen source
immobile, rods
white, smooth
+ yeast extract
yellow, smooth
+ salt -
small, round, white
+ salt + yeast extract
large, round, white
acidic
cocci, immobile
beige, bright
alkaline
Introduction  Aims & Expectations  Course results  Summary

8. Introduction  Aims & Expectations  Course results  Summary
Regina Gohl, K. Noreen Boyle ICBM Uni Oldenburg 8
Summary
Results as expected
Variety of bacteria in soil
Different treatment  growth / no growth
- nitrogen source + yeast extract
- nitrogen source
Introduction  Aims & Expectations  Course results  Summary

9. Thank you for your attention