The availability of nutrients impacts cell size and growth rate in many organisms. Research in E. coli has traditionally focused on the influence of exogenous nutrient sources on cell size through their effect on growth and cell cycle progression. Utilising a set of mutants where three genes involved in glycogen degradation - glycogen phosphorylase (glgP), glycogen debranching enzyme (glgX) and maltodextrin phosphorylase (malP) - were disrupted, we examined if endogenous polyglucan degradation affects cell size. It was found that mutations to malP increased cell lengths and resulted in substantial heterogeneity of cell size. This was most apparent during exponential growth and the phenotype was unaccompanied by alterations in Z-ring occurrence, cellular FtsZ levels and generation times. ΔmalP mutant cells did, however, accumulate increased DnaA amounts at late growth stages indicating a potential effect on DNA replication. Replication run-out experiments demonstrated that this was indeed the case, and that DNA replication was also affected in the other mutants. Bacteria with a disruption in glgX accumulated glycogen and protein inclusion bodies that coincided with each other at inter-nucleoid and polar regions.

中文翻译：

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糖原代谢的破坏改变了大肠杆菌中的细胞大小

营养物质的可用性会影响许多生物体的细胞大小和生长速率。传统上，对大肠杆菌的研究集中在外源营养源对细胞大小的影响上，即它们对生长和细胞周期进程的影响。利用一组突变体，其中涉及糖原降解的三个基因-糖原磷酸化酶（glgP），糖原脱支酶（glgX）和麦芽糊精磷酸化酶（malP）-被破坏，我们检查了内源性聚葡聚糖降解是否影响细胞大小。发现对malP的突变增加了细胞长度，并导致细胞大小的实质异质性。这在指数增长期间最明显，并且该表型不伴随Z环出现，细胞FtsZ水平和世代时间的改变。但是，ΔmalP突变细胞确实存在 在后期生长阶段积累的DnaA量增加，表明对DNA复制有潜在影响。复制用尽实验证明确实如此，DNA复制在其他突变体中也受到影响。glgX破坏的细菌积累了糖原和蛋白质包涵体，它们在核苷酸间和极性区域彼此重合。