Abstract

A new, highly efficient xanthan-producing strain, Xanthomonas campestris M 28, was obtained. It produces up to 28 g/L of the polysaccharide on a molasses medium, which is almost two times higher than the productivity of the NRRL B-1459 strain. Whole-genome sequencing of the strain was performed with the Illumina method and nanopore sequencing. The genome of X. campestris M 28 contained one chromosome of 5 102 828 nucleotides with an average G + C content of 65.03%. The structure and physicochemical and rheological properties of the obtained xanthan were studied. It was found that the addition of xanthan to the bentonite dispersion led to the formation of primary clay particles (70 nm) and aggregates of ~190 nm without the formation of a precipitate. This indicated the interaction of macromolecules with particles and aggregates with the formation of polymer-clay bridging structures. This ensures the stability of clay dispersions and makes it possible to achieve the required rheological properties of drilling fluids based on xanthan obtained in a molasses medium, thereby reducing its cost.

中文翻译：

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新产黄原胶菌株野油菜黄单胞菌 М 28 的特性：多糖的基因组、培养条件以及理化和流变特性研究

摘要

获得了一种新的高效产黄原胶菌株Xanthomonas campestris M 28。它在糖蜜培养基上产生高达 28 g/L 的多糖，几乎是 NRRL B-1459 菌株生产力的两倍。菌株的全基因组测序采用 Illumina 方法和纳米孔测序。X. campestris的基因组M 28包含一条5 102 828个核苷酸的染色体，平均G+C含量为65.03%。对所得黄原胶的结构、理化和流变特性进行了研究。发现将黄原胶添加到膨润土分散体中导致形成初级粘土颗粒 (70 nm) 和约 190 nm 的聚集体，而没有形成沉淀物。这表明大分子与颗粒和聚集体的相互作用与聚合物-粘土桥接结构的形成。这确保了粘土分散体的稳定性，并使基于在糖蜜介质中获得的黄原胶的钻井液获得所需的流变特性成为可能，从而降低其成本。