Department of Industrial Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
Molecules. 2012 Oct 9;17(10):11800-15. doi: 10.3390/molecules171011800.
Streptococcal mutans synthesized under different conditions by growing cultures or by their glucosyltransferases were shown to exhibit a great structural and property diversity. Culturing and environmental factors causing structural differences in mutans were specified. All of the obtained biopolymers (76 samples) were water-insoluble and most of them (72) had a structure with a predominance of α-(1→3)-linked glucose (i.e., the content of α-(1→3)-linkages in the glucan was always higher than 50%, but did not exceed 76%). An exception were four glucans containing more than 50% of α-(1→6)-sequences. In these structurally unique mutans, the ratio of α-(1→3)- to α-(1→6)-bonds ranged from 0.75 to 0.97. Aside from one polymer, all others had a heavily branched structures and differed in the number of α-(1→3), α-(1→6), and α-(1→3,6) linkages and their mutual proportion. The induction of mutanase production in shaken flask cultures of Trichoderma harzianum by the structurally diverse mutans resulted in enzyme activities ranging from 0.144 to 1.051 U/mL. No statistical correlation was found between the total percentage content of α-(1→3)-linkages in the α-glucan and mutanase activity. Thus, despite biosynthetic differences causing structural variation in the mutans, it did not matter which mutan structures were used to induce mutanase production.
在不同条件下生长培养物或通过其葡糖基转移酶合成的变异链球菌表现出很大的结构和性质多样性。指定了导致变异链球菌结构差异的培养和环境因素。所有获得的生物聚合物（76 个样本）均不溶于水，其中大多数（72 个）具有以α-（1→3）-连接的葡萄糖为主的结构（即葡聚糖中的α-（1→3）-键的含量始终高于 50%，但不超过 76%）。四个含有超过 50%α-（1→6）序列的葡聚糖除外。在这些结构独特的变异链球菌中，α-（1→3）-与α-（1→6）-键的比例从 0.75 到 0.97 不等。除了一种聚合物外，所有其他聚合物都具有高度分支的结构，并且在α-（1→3）、α-（1→6）和α-（1→3,6）键的数量及其相互比例上有所不同。结构多样的变异链球菌在摇瓶培养的哈茨木霉中诱导产突变酶，导致酶活范围为 0.144 至 1.051 U/mL。在α-葡聚糖中α-（1→3）-键的总百分比含量与突变酶活性之间未发现统计学相关性。因此，尽管生物合成差异导致变异链球菌的结构发生变化，但使用哪种变异链球菌结构来诱导突变酶的产生并不重要。
