Coenzyme B12 synthesis as a baseline to study metabolite contribution of animal microbiota

Abstract

SummaryMicrobial communities thrive in a number of environments. Exploration of their microbiomes – their global genome – may reveal metabolic features that contribute to the development and welfare of their hosts, or chemical cleansing of environments. Yet we often lack final demonstration of their causal role in features of interest. The reason is that we do not have proper baselines that we could use to monitor how microbiota cope with key metabolites in the hosting environment. Here, focusing on animal gut microbiota, we describe the fate of cobalamins – metabolites of the B12 coenzyme family – that are essential for animals but synthesized only by prokaryotes. Microbiota produce the vitamin used in a variety of animals (and in algae). Coprophagy plays a role in its management. For coprophobic man, preliminary observations suggest that the gut microbial production of vitamin B12 plays only a limited role. By contrast, the vitamin is key for structuring microbiota. This implies that it is freely available in the environment. This can only result from lysis of the microbes that make it. A consequence for biotechnology applications is that, if valuable for their host, B12‐producing microbes should be sensitive to bacteriophages and colicins, or make spores.

Beneficial Endophytic Bacteria-Serendipita indica Interaction for Crop Enhancement and Resistance to Phytopathogens

“…Analysis of the genomes revealed the four Mycolicibacterium strains contain numerous genes predicted to be involved in the stimulation of S. indica growth. Some vitamins and cofactors are indispensable for fungal growth (van Overbeek and Saikkonen, 2016), and since some vitamins like cobalamin (B12) can only be synthesized by bacteria (Ghignone et al, 2012;Danchin and Braham, 2017), we hypothesized that production of vitamins could be one of the key factors in the stimulation of fungal growth. We identified several genes involved in the synthesis of six vitamins of the vitamin B complex: cobalamin (B12), biotin (B7), thiamin (B1), riboflavin (B2), pyridoxin (B6), and folate (B9), as well as menaquinone and phylloquinone of the vitamin K complex in all the four genomes.…”

The effect of the algal microbiome on industrial production of microalgae

“…Second, bacteria synthesize important compounds for algal growth stimulation, spore germination, morphogenesis and pathogen resistance (Amin et al, 2012(Amin et al, , 2015Ramanan et al, 2016). These compounds include micronutrients, siderophores, growth stimulants and antibiotics (Bruhn et al, 2007;Amin et al, 2009;Seyedsayamdost et al, 2011;Wahl et al, 2012;Natrah et al, 2013;Danchin and Braham, 2017). In addition, symbiotic microorganisms help their algal hosts to cope with changing environmental conditions (Xie et al, 2013a;Dittami et al, 2016).…”

Bacteria in the ageing gut: did the taming of fire promote a long human lifespan?

“…This implies that, beside the contribution of the host microbiota, the indirect contribution of foreign microbiota in food should always be taken into account in animal metabolic studies (Korpela, ). As a case in point, vitamin B12 can only be produced by bacteria and not by plants, while it is not supplied, or supplied to a very limited extent, by the human microbiota (Danchin and Braham, ). In an equally important way, menaquinones and their derivatives (vitamin K forms) display a concentration in the human gut that appears highly variable and is associated with gut microbiota composition.…”