We present a numerical model of electroporation in a gram-positive bacterium, which accounts for the presence of a negatively charged soft polyelectrolyte layer (which may include a periplasmic space, peptidoglycan layer, cilia, flagella, and other surface appendages) surrounding its plasma membrane. We model the ion transport within and outside the soft layer using the soft layer electrokinetics-based Poisson-Nernst-Planck formalism. Additionally, we model the electroporation dynamics on the plasma membrane using the pore nucleation-based electroporation formalism developed by Krassowska and Filev. We find that ion transport within the soft layer (surface conduction), which depends on the relative importance of the soft layer charged group concentration compared to the buffer concentration, significantly alters the transmembrane voltage across the plasma membrane and hence the pore characteristics. Our numerical simulations suggest that surface conduction significantly lowers the pore number in the plasma membrane. This observation is consistent with experimental studies that show that gram-positive bacteria, in general, have lower transformation efficiencies compared to gram-negative bacteria. Our studies highlight a strong dependence of bacterial electroporation on cell envelope properties and buffer conditions, which need to be taken into consideration when designing electroporation protocols.

我们提出了革兰氏阳性细菌中电穿孔的数值模型，该模型解释了围绕其质膜存在带负电的软聚电解质层（可能包括周质空间，肽聚糖层，纤毛，鞭毛和其他表面附件） 。我们使用基于软层动力学的泊松－能斯特－普朗克形式主义对软层内部和外部的离子传输进行建模。此外，我们使用Krassowska和Filev开发的基于孔核化的电穿孔形式主义对质膜上的电穿孔动力学进行建模。我们发现软层内的离子传输（表面传导）取决于软层带电基团浓度与缓冲液浓度的相对重要性，大大改变了质膜上的跨膜电压，从而改变了孔的特性。我们的数值模拟表明表面传导显着降低了质膜中的孔数。该观察结果与实验研究一致，后者表明革兰氏阳性菌通常比革兰氏阴性菌具有较低的转化效率。我们的研究突出了细菌电穿孔对细胞包膜特性和缓冲液条件的强烈依赖性，在设计电穿孔方案时需要将其考虑在内。该观察结果与实验研究一致，后者表明革兰氏阳性菌通常比革兰氏阴性菌具有较低的转化效率。我们的研究突出了细菌电穿孔对细胞包膜特性和缓冲液条件的强烈依赖性，在设计电穿孔方案时需要将其考虑在内。该观察结果与实验研究一致，后者表明革兰氏阳性菌通常比革兰氏阴性菌具有较低的转化效率。我们的研究突出了细菌电穿孔对细胞包膜特性和缓冲液条件的强烈依赖性，在设计电穿孔方案时需要将其考虑在内。