Inducible and constitutive formation of fructanase in batch and continuous cultures of Streptococcus mutans.
Inducible and constitutive formation of fructanase in batch and continuous cultures of Streptococcus mutans.
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变形链球菌分批和连续培养物中果聚糖酶的诱导和组成型形成。
DOI：
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
G. J. Walker
中科院分区：
文献类型：
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作者：
N. J. Jacques;J. G. Morrey;G. J. Walker
研究了几株变形链球菌在连续培养条件下产胞外β-D-果聚糖酶的情况。当葡萄糖为限制性营养时，S.变形杆菌K1-R和OMZ 176在低生长速率（稀释速率0.05 - 0.10 h-1）下积累果聚糖酶至最大水平，这是由于在这些条件下细菌在培养容器中的停留时间较长。胞外果聚糖酶活性大于先前报道的分批培养。两株S.当葡萄糖限制时，变形菌株K1-R和OMZ 176随着生长速率的增加而增加。在葡萄糖充足的条件下，无论生长速率如何，果聚糖酶的产生速率总是低于葡萄糖限制的培养物。鼠伤寒沙门氏变形杆菌Ingbritt（血清型c）与山梨糖醇或葡萄糖限制性合成果聚糖酶一起以非常低的基础速率生长。当果糖是限制性碳水化合物时，酶被诱导，在0.40 h-1的稀释率下产生最大速率。链球菌菌株来自其它血清型（A、D、D/g）的变形菌或者不受限制糖从葡萄糖变为果糖的影响，或者在果糖限制培养基中果聚糖酶活性略微降低。不同菌株的果聚糖酶。变形菌容易水解（2----6）-β-D-果聚糖，但所有变形菌都具有不同程度水解（2----1）-β-D-果聚糖的能力。
The production of extracellular beta-D-fructanase by several strains of Streptococcus mutans was studied in continuous culture. When glucose was the limiting nutrient, S. mutans K1-R and OMZ176 accumulated fructanase to maximum levels at low growth rates (dilution rate 0.05-0.10 h-1), due to the longer residence times of the bacteria in the culture vessel under these conditions. Extracellular fructanase activity was greater than has been previously reported for batch cultures. The rate of fructanase production for both S. mutans strains K1-R and OMZ176 increased with increasing growth rate when glucose was limiting. Under conditions of glucose sufficiency, the rate of fructanase production was always lower than in cultures where glucose was limiting, irrespective of the growth rate. Cultures of S. mutans Ingbritt (serotype c) grown with sorbitol- or glucose-limitation synthesized fructanase at a very low basal rate. When fructose was the limiting carbohydrate the enzyme was induced with a maximum rate of production occurring at a dilution rate of 0.40 h-1. Strains of S. mutans from other serotypes (a, d, d/g) were either not affected by changing the limiting sugar from glucose to fructose or else fructanase activity was slightly decreased in the fructose-limited medium. Fructanases from various strains of S. mutans readily hydrolysed (2----6)-beta-D-fructans, but all possessed the ability to hydrolyse (2----1)-beta-D-fructans to varying degrees.
来自变形链球菌分批培养物的内葡聚糖酶抑制剂。
DOI：
10.1016/0006-291x(82)91792-2
发表时间：
1982
影响因子：
3.1
作者：
Hamelik,RM;McCabe,MM
通讯作者：
McCabe,MM