近日，来自印度大学的研究者通过对蜂群的遗传多样性进行研究分析，表示蜂群的多样性越高将会导致寄生的致病菌越少，并且有益菌会增多，相关研究成果刊登在了国际杂志PLoS One上。
这项研究开始于2010年，研究者首次在蜜蜂的蜂窝中发现了四种重要的微生物：琥珀酸弧菌属（Succinivibrio，和母牛瘤胃相关）、酒球菌属（Oenococcus，和酒的发酵有关）、Paralactobacillus（和食物发酵有关）、双歧杆菌（Bifidobacterium，和酵母乳相关）。研究者Newton表示，蜜蜂蜂群可以利用这些有益的共生细菌来将不能消化的物质转化成有营养的食物并且增强抵御致病菌的感染能力。当蜂王和许多雄蜂交配后便形成了遗传多样性，这种行为被认为是增强蜜蜂群落的健康程度和生产力。研究者表示，在遗传多样性的蜂群中很少发现有潜在的致病细菌的存在，然后在遗传性单一的蜂群中却存在致病细菌。
研究者对来自10个遗传单一群落的蜂群和12个遗传多样性的蜂群的细菌，总共70，500个遗传序列进行分析，结果发现，在遗传多样性蜂群中的细菌多样性比较高，而遗传单一性蜂群中的细菌多样性却不如遗传多样性的蜂群。在遗传多样性蜂群中的细菌多样性高，而且活力比较旺盛，大多为健康的有益细菌，然而在遗传单一性蜂群中的细菌却是植物和动物消化道中的潜在致病菌，相比遗传多样性的蜂群中比例高出了127%。
研究者Mattila表示，这是一个非常激动人心的结果，因为这可以让遗传单一的蜂群增强其多样性，从而增强整体蜂群的健康度和活力。但是这种遗传多样性的产生以及维持这种多样性和附属的健康细菌群的机制，我们还不是很清楚，蜜蜂可以从寄生的有益细菌中获益，这种细菌同时也可以抵御蜜蜂群感染致病菌，寄生的有益细菌也可以从蜂群中获得营养以生存，这就构成了一个共生的关系。研究者Mattila和Newton又说，他们的研究提供了清晰的解释，不仅仅是在群落规范管理上，而且是在蜜蜂蜂群中一妻多夫制的进化遗传优势的体现。
研究者最后表示，“我们对结果非常感兴趣，相信公众也是，尤其是近几年蜂群遭遇衰竭失调后而引起的蜂群的严重减少，以及这些传粉者在传粉食物安全方面给公众带来的影响。”（生物谷：T.Shen编译）
doi:10.1371/journal.pone.0032962
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Characterization of the Active Microbiotas Associated with Honey Bees Reveals Healthier and Broader Communities when Colonies are Genetically Diverse
Heather R. Mattila1, Daniela Rios1, Victoria E. Walker-Sperling1, Guus Roeselers2, Irene L. G. Newton3*
Recent losses of honey bee colonies have led to increased interest in the microbial communities that are associated with these important pollinators. A critical function that bacteria perform for their honey bee hosts, but one that is poorly understood, is the transformation of worker-collected pollen into bee bread, a nutritious food product that can be stored for long periods in colonies. We used 16S rRNA pyrosequencing to comprehensively characterize in genetically diverse and genetically uniform colonies the active bacterial communities that are found on honey bees, in their digestive tracts, and in bee bread. This method provided insights that have not been revealed by past studies into the content and benefits of honey bee-associated microbial communities. Colony microbiotas differed substantially between sampling environments and were dominated by several anaerobic bacterial genera never before associated with honey bees, but renowned for their use by humans to ferment food. Colonies with genetically diverse populations of workers, a result of the highly promiscuous mating behavior of queens, benefited from greater microbial diversity, reduced pathogen loads, and increased abundance of putatively helpful bacteria, particularly species from the potentially probiotic genus Bifidobacterium. Across all colonies, Bifidobacterium activity was negatively correlated with the activity of genera that include pathogenic microbes; this relationship suggests a possible target for understanding whether microbes provide protective benefits to honey bees. Within-colony diversity shapes microbiotas associated with honey bees in ways that may have important repercussions for colony function and health. Our findings illuminate the importance of honey bee-bacteria symbioses and examine their intersection with nutrition, pathogen load, and genetic diversity, factors that are considered key to understanding honey bee decline.
