Schmit J C, Edson C M, Brody S
J Bacteriol. 1975 Jun;122(3):1062-70. doi: 10.1128/jb.122.3.1062-1070.1975.
The levels of glucosamine and galactosamine were determined in conidia, germinating conidia, and vegetative mycelia of Neurospora crassa. In the vegetative mycelia about 90% of the amino sugars were shown to be components of the cell wall. The remaining 10% of the amino sugars were tentatively identified as the nucleotide sugars uridine diphospho-2-acetamido-2-deoxy-D-glucose and uridine diphospho-2-acetamido-2-deoxy-D-galactose. Conidia and vegetative mycelia contained about the same levels of glucosamine. During the first 9 h after the initiation of germination, the total glucosamine content had increased 3.1-fold, whereas the residual dry weight of the culture had increased 7.7-fold. This led to a drop in the glucosamine concentration from 100 mumol/g of residual dry weight to 42 mumol/g. During this time, all of the conidia had germinated and the surface area of the new germ tubes had increased to 10 times that of the conidia. Either germ tubes were initially produced without glucosamine-containing polymers, or these polymers (probably chitin) were deposited only at low densities in the germ tube cell walls. The chitin precursor uridine diphospho-2-acetamido-2-deoxy-D-glucose was present at all times during conidial germination. Conida contained very low levels of galactosamine. During germination, galactosamine could not be detected until the culture had reached a cell density of about 0.6 mg of residual dry weight per ml of growth medium. This was observed regardless of the time required to reach this cell density or the fold increase in dry weight. The accumulation of galactosamine-containing polymers does not appear to be necessary for germ tube formation. The levels of soluble galactosamine (uridine diphospho-2-actamido-2-deoxy-D-galatose) were very low in conidia and increased during germination at the same time that galactosamine appeared in the cellular polymers. In addition, under certain culture conditions, the appearance of galactosamine and the increase in the glucosamine concentration occurred simultaneously.
测定了粗糙脉孢菌分生孢子、萌发的分生孢子和营养菌丝体中氨基葡萄糖和半乳糖胺的含量。在营养菌丝体中，约90%的氨基糖被证明是细胞壁的成分。其余10%的氨基糖初步鉴定为核苷酸糖尿苷二磷酸-2-乙酰氨基-2-脱氧-D-葡萄糖和尿苷二磷酸-2-乙酰氨基-2-脱氧-D-半乳糖。分生孢子和营养菌丝体中氨基葡萄糖的含量大致相同。在萌发开始后的前9小时内，总氨基葡萄糖含量增加了3.1倍，而培养物的残余干重增加了7.7倍。这导致氨基葡萄糖浓度从每克残余干重100μmol降至42μmol。在此期间，所有分生孢子都已萌发，新萌发的芽管表面积增加到分生孢子的10倍。要么芽管最初产生时不含含氨基葡萄糖的聚合物，要么这些聚合物（可能是几丁质）仅以低密度沉积在芽管细胞壁中。几丁质前体尿苷二磷酸-2-乙酰氨基-2-脱氧-D-葡萄糖在分生孢子萌发的全过程中均有存在。分生孢子中半乳糖胺的含量非常低。在萌发过程中，直到培养物达到每毫升生长培养基约0.6毫克残余干重的细胞密度时才能检测到半乳糖胺。无论达到该细胞密度所需的时间或干重增加的倍数如何，均观察到这种情况。含半乳糖胺聚合物的积累似乎不是芽管形成所必需的。分生孢子中可溶性半乳糖胺（尿苷二磷酸-2-乙酰氨基-2-脱氧-D-半乳糖）的含量非常低，在萌发过程中随着半乳糖胺出现在细胞聚合物中而增加。此外，在某些培养条件下，半乳糖胺的出现和氨基葡萄糖浓度的增加同时发生。
