Le vallon du pont, 29410 Pleyber-Christ, France.
FEMS Microbiol Ecol. 2023 Mar 23;99(4). doi: 10.1093/femsec/fiad026.
Efforts to isolate uncultured microorganisms over the last century and a half, as well as the advanced 'omics' technologies developed over the last three decades, have greatly increased the knowledge and resources of microbiology. However, many cellular functions such as growth remain unknown in most of the microbial diversity identified through genomic sequences from environmental samples, as evidenced by the increasingly precise observations of the phenomenon known as the 'great plate count anomaly'. Faced with the many microbial cells recalcitrant to cultivation present in environmental samples, Epstein proposed the 'scout' model, characterised by a dominance of dormant cells whose awakening would be strictly stochastic. Unfortunately, this hypothesis leaves few exploitable possibilities for microbial cultivation. This review proposes that many microorganisms follow the 'comfort timing' strategy, characterised by an exit from dormancy responding to a set of environmental conditions close to optimal for growth. This 'comfort timing' strategy offers the possibility of designing culture processes that could isolate a larger proportion of uncultured microorganisms. Two methods are briefly proposed in this article. In addition, the advantages of dormancy, of the 'scout' model and of the 'comfort timing' strategy for survival under difficult conditions, but also for colonisation of environments, are discussed.
在过去的一个半世纪中，人们一直努力分离未培养的微生物，而在过去三十年中，先进的“组学”技术也得到了发展，这极大地增加了微生物学的知识和资源。然而，正如“大平板计数异常”现象的日益精确观察所证明的那样，通过从环境样本中获得的基因组序列所鉴定的大部分微生物多样性中，许多细胞功能（如生长）仍然未知。面对环境样本中存在的许多对培养具有抗性的微生物细胞，Epstein 提出了“侦察兵”模型，其特征是休眠细胞占主导地位，其唤醒将是严格随机的。不幸的是，该假设几乎没有为微生物培养提供可利用的可能性。本综述提出，许多微生物遵循“舒适时机”策略，其特征是从休眠状态退出，以响应一组接近最佳生长的环境条件。这种“舒适时机”策略为设计培养过程提供了可能性，从而可以分离出更大比例的未培养微生物。本文简要提出了两种方法。此外，还讨论了休眠、“侦察兵”模型和“舒适时机”策略在困难条件下生存的优势，以及在环境中定植的优势。
