The crystalline region of cellulose is the main barrier to the utilization of crystalline cellulose. Cytophaga hutchinsonii actively digests the crystalline region of cellulose by an unknown mechanism. Transposon mutagenesis was done to identify a novel gene locus chu_1557, which is required for efficient disruption of the crystalline region of cellulose, and the absence of CHU_1557 resulted in decreased glucose assimilation efficiency. The defect of the mutant in the disruption of the crystalline region of cellulose was partially retained by additional glucose or pre-culturing the mutant in a low glucose concentration medium which could improve its glucose absorption efficiency. These results suggested that extracellular glucose has important roles in the disruption of crystalline cellulose by C. hutchinsonii. Further study showed that the expression of an outer membrane protein CHU_3732 was downregulated by the absence of CHU_1557 in a low glucose concentration medium. CHU_3732 was involved in uptake of glucose and its expression was induced by a low concentration of glucose. CHU_3732 was predicted to be a porin, so we inferred that it may work as a glucose transport channel in the outer membrane. Based on these results, we deduced that CHU_1557 played a role in the process of glucose assimilation and its disruption affected the expression of other proteins related to glucose transportation such as CHU_3732, and then affected the cell growth in a low glucose concentration medium and disruption of the crystalline region of cellulose.

中文翻译：

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鉴定细胞表面蛋白与葡萄糖同化作用和细胞分裂的纤维素结晶区的破坏。

纤维素的结晶区域是利用结晶纤维素的主要障碍。Cytophaga hutchinsonii通过未知机制积极消化纤维素的结晶区域。进行了转座子诱变以鉴定新基因座chu_1557，这是有效破坏纤维素晶体区域所必需的，而CHU_1557的缺失导致葡萄糖同化效率降低。突变体在纤维素的晶体区域破坏中的缺陷通过额外的葡萄糖或在低葡萄糖浓度的培养基中预培养该突变体而得以部分保留，这可以提高其葡萄糖吸收效率。这些结果表明，细胞外葡萄糖在哈氏梭菌对晶体纤维素的破坏中具有重要作用。进一步的研究表明，由于在低葡萄糖浓度培养基中不存在CHU_1557，外膜蛋白CHU_3732的表达被下调。CHU_3732与葡萄糖的摄取有关，其表达是由低浓度的葡萄糖诱导的。预计CHU_3732是孔蛋白，因此我们推断它可能充当外膜中的葡萄糖转运通道。根据这些结果，我们推断出CHU_1557在葡萄糖同化过程中发挥了作用，其破坏影响了与葡萄糖转运相关的其他蛋白质（例如CHU_3732）的表达，进而影响了在低葡萄糖浓度培养基中的细胞生长以及对葡萄糖的破坏。纤维素的结晶区域。