Hartford O M, Dowds B C
Department of Biology, St Patrick's College, Maynooth, Co. Kildare, Ireland.
Microbiology (Reading). 1994 Feb;140 ( Pt 2):297-304. doi: 10.1099/13500872-140-2-297.
A mutant of Bacillus subtilis has been isolated by continuous selection in increasing concentrations of H2O2. It grew with a doubling time of 85 min in minimal medium containing 150 mM H2O2, whereas the wild-type parent lysed in 100 mM H2O2. The mutant was also more resistant to organic peroxides than the wild-type. Further resistance to H2O2 could not be induced by pretreatment with low concentrations of the oxidant. The mutant synthesized a number of proteins at a much higher rate than the wild-type, including constitutive synthesis of all of the proteins which were induced by H2O2 in the wild-type. Four of these proteins were sequenced; three were identified as catalase and two subunits of alkyl hydroperoxide reductase. Two proteins whose synthesis was repressed in the mutant were sequenced, and one was identified as flagellin. The mutant grew as non-flagellated, partially septate, filaments of cells, and fragments of flagella were seen in the surrounding medium.
通过在浓度不断增加的过氧化氢中持续筛选，分离出了一株枯草芽孢杆菌突变体。它在含有150 mM过氧化氢的基本培养基中生长，倍增时间为85分钟，而野生型亲本在100 mM过氧化氢中会裂解。该突变体对有机过氧化物的抗性也比野生型更强。低浓度氧化剂预处理无法诱导其对过氧化氢产生进一步抗性。该突变体合成多种蛋白质的速率比野生型高得多，包括野生型中由过氧化氢诱导合成的所有蛋白质的组成型合成。对其中四种蛋白质进行了测序；三种被鉴定为过氧化氢酶，两种为烷基过氧化氢还原酶的亚基。对突变体中合成受抑制的两种蛋白质进行了测序，其中一种被鉴定为鞭毛蛋白。该突变体以无鞭毛、部分分隔的细胞丝形式生长，在周围培养基中可见鞭毛片段。
