Sorokin Dimitry Y, Elcheninov Alexander G, Khijniak Tatiana V, Kolganova Tatiana V, Kublanov Ilya V
Winogradsky Institute of Microbiology, Federal Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia.
Department of Biotechnology, Delft University of Technology, Delft, Netherlands.
Front Microbiol. 2022 Nov 23;13:1059347. doi: 10.3389/fmicb.2022.1059347. eCollection 2022.
Extremely halophilic archaea (haloarchaea) of the class is a dominant group of aerobic heterotrophic prokaryotic communities in salt-saturated habitats, such as salt lakes and solar salterns. Most of the pure cultures of haloarchaea were enriched, isolated, and cultivated on rich soluble substrates such as amino acids, peptides or simple sugars. So far, the evidences on the capability of haloarchaea to use different polysaccharides as growth substrates remained scarce. However, it is becoming increasingly obvious that these archaea can also actively participate in mineralization of complex biopolymers, in particular cellulose and chitin-two dominant biomass polysaccharides on the planet. Here we used an array of commercially available homo- and heteropolysaccharides to enrich hydrolytic haloarchaea from hypersaline salt lakes with neutral pH and from alkaline soda lakes. This resulted in isolation of a range of halo- and natrono-archaea, respectively, belonging to already described taxa as well as several new genus-level lineages. In some cases, the isolates enriched with different polysaccharides happened to be closely related, thus representing generalistic ecotype, while the others were narrow specialists. In general, soda lakes yielded a broader range of polysaccharide-utilizing specialists in comparison to neutral salt lakes. The results demonstrated a significant diversity of halo(natrono)archaea with a previously unrecognized potential for utilization of a broad range of natural polysaccharides in hypersaline habitats.
嗜盐古菌纲的极端嗜盐古菌（嗜盐古菌）是盐饱和生境（如盐湖和太阳能盐场）中有氧异养原核生物群落的优势群体。大多数嗜盐古菌的纯培养物是在富含可溶性底物（如氨基酸、肽或单糖）上富集、分离和培养的。到目前为止，关于嗜盐古菌利用不同多糖作为生长底物能力的证据仍然很少。然而，越来越明显的是，这些古菌也可以积极参与复杂生物聚合物的矿化，特别是纤维素和几丁质——地球上两种主要的生物质多糖。在这里，我们使用了一系列市售的同多糖和杂多糖，从pH值中性的超盐湖和碱性苏打湖中富集水解嗜盐古菌。这分别导致分离出一系列嗜盐古菌和嗜钠古菌，它们属于已描述的分类群以及几个新的属级谱系。在某些情况下，用不同多糖富集的分离株碰巧密切相关，因此代表泛化生态型，而其他分离株则是狭义的专性菌。一般来说，与中性盐湖相比，苏打湖产生了更广泛的多糖利用专性菌。结果表明，嗜盐（嗜钠）古菌具有显著的多样性，在超盐生境中具有以前未被认识到的利用多种天然多糖的潜力。
