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Related Experiment Video

Updated: May 21, 2025

High Throughput Co-culture Assays for the Investigation of Microbial Interactions

High Throughput Co-culture Assays for the Investigation of Microbial Interactions

Published on: October 15, 2019

Microbes display broad diversity in cobamide preferences.

Kenny C Mok¹, Olga M Sokolovskaya¹, Adam M Deutschbauer^1,2

¹Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA.

|March 21, 2025

Summary

Microbes show diverse preferences for vitamin B12 (cobamide) forms, impacting their growth and community roles. This study characterized bacterial cobamide preferences using purified, rare cobamides.

Keywords:

cobalamin cobamide cobamide preference corrinoid vitamin B12

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Last Updated: May 21, 2025

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Area of Science:

Microbiology
Biochemistry
Nutritional Science

Background:

Cobamides (vitamin B12 family) are essential cofactors for many organisms, but produced by few prokaryotes.
Cobamides exhibit significant structural diversity, with various forms found in microbial communities.
Existing research on cobamide preferences is limited by the commercial unavailability of most cobamide forms.

Purpose of the Study:

To characterize bacterial preferences for diverse, commercially unavailable cobamides.
To investigate how different cobamide forms affect bacterial growth and metabolic processes.
To understand the ecological implications of cobamide diversity in microbial communities.

Main Methods:

Extraction and purification of seven commercially unavailable cobamides.
Growth experiments with engineered *Escherichia coli*, *Sinorhizobium meliloti*, and *Bacillus subtilis* strains.
Functional isolation of specific cobamide-dependent pathways, such as methionine synthesis.

Main Results:

Significant variation in cobamide preferences was observed across different bacterial species and even between metabolic pathways within the same organism.
Microbes differed in their most efficiently utilized cobamides, those that did not support growth, and minimum required concentrations.
Growth efficiency varied by up to four orders of magnitude across organisms and up to 20-fold between enzymes within an organism.

Conclusions:

Bacterial cobamide preferences are highly diverse, influencing growth and metabolic function.
These preferences likely play a critical role in shaping microbial community structure and function.
Further research into cobamide biology is essential for understanding microbial ecology and nutrient cycling.