Black truffles are prized delicacies that are cultivated by inoculating seedlings with truffle fungus in specialized nurseries. This research tested whether beneficial bacteria and fungi found naturally in truffles could improve the inoculation success in oak seedling nurseries. One bacterial strain, Agrobacterium tumefaciens, significantly improved how well truffles colonized the seedling roots, suggesting that carefully selected microbial co-inoculants could enhance truffle farm productivity.