Signal Peptide-Guided Delivery of a Mucin-Like Collagen Analogue for Periplasmic Barrier Reinforcement: A Platform for Enhancing Microbial Survival

The environmental resistance exhibited by microorganisms is concerned with their ability to withstand and adapt to an array of detrimental environmental conditions, with their survival and reproductive success being threatened. Within the realm of biotechnology, which emphasizes stress resistance, a critical role in bacterial adaptive strategies to environmental fluctuations is assumed to be in the periplasmic space. An innovative methodology to augment bacterial tolerance to stress by employing a mucin-mimetic collagen analogue, designated as S1552 (which is secreted into the periplasmic compartment), is introduced by this investigation. Exceptional protective barrier attributes are highly regarded in S1552. An appropriate signal peptide for the periplasmic expression of S1552 in <i>Escherichia coli</i> was identified by employing computational analysis (<i>in silico</i>). The fusion protein of S1552 and the DsbA signal peptide (DS1552) is efficiently translocated into the periplasmic space of <i>E. coli</i>. This approach not only fortifies the cellular barrier but also significantly enhances the bacterium's resistance to a variety of stressors, including elevated salinity, high osmotic stress, extreme pH values, antibiotics, toxicants, and heavy metal ions. Meanwhile, this pioneering application has the potential to be extended to other bacteria with a periplasmic space, enhancing their viability and proliferation in harsh environments.