Lin L P, Sadoff H L
J Bacteriol. 1968 Jun;95(6):2336-43. doi: 10.1128/jb.95.6.2336-2343.1968.
Cells of Azotobacter vinelandii encysted in Burk's nitrogen-free liquid media which had been supplemented with n-butyl alcohol, beta-hydroxybutyrate, or crotonate. Butyraldehyde and butyrate did not influence the extent of encystment. In the absence of glucose, beta-hydroxybutyrate enhanced the rate and extent of encystment. In the presence of glucose, it promoted abortive encystment, which was manifested by the disorganization of the exine and the release of a highly viscous material into the medium. The soluble, viscous polymer was separated from the medium by a series of ethyl alcohol precipitations and identified as a mucopeptide. It was cleaved by treatment with lysozyme and lysostaphin with a concomitant increase in reducing power. It contained 13.9% N; 56% amino acids, as alanine (alanine, lysine, and glutamic acids); and 42% hexosamines. The polymer appeared to be similar to a noncross-linked peptidoglycan.
在添加了正丁醇、β-羟基丁酸或巴豆酸的伯克无氮液体培养基中，棕色固氮菌细胞会形成孢囊。丁醛和丁酸不影响孢囊形成的程度。在没有葡萄糖的情况下，β-羟基丁酸会提高孢囊形成的速率和程度。在有葡萄糖存在时，它会促进异常孢囊形成，表现为外壁解体并向培养基中释放出一种高粘性物质。通过一系列乙醇沉淀从培养基中分离出这种可溶性粘性聚合物，并鉴定为一种粘肽。用溶菌酶和溶葡萄球菌素处理后，它会被裂解，同时还原能力增加。它含有13.9%的氮；56%的氨基酸，如丙氨酸（丙氨酸、赖氨酸和谷氨酸）；以及42%的己糖胺。这种聚合物似乎类似于一种非交联的肽聚糖。
