Electrospun PEO nanofibers containing the bacteria2009) described the use of poly (ethylene oxide) poly (propylene oxide)—poly (ethylene oxide) triblock polymers to entrap Pseudomonas, Zymomonas, and Escherichia via electrospinning. Biohybrid materials are produced through immo- bilization techniques such as physical entrapment, encapsulation, and covalent binding are commonly used to immobilize bacteria (Liu et al. 2009; Lopez et al. 2009; Homaeigohar and Elbahri 2014). Figure 6.2 shows the safe encapsulation of bacteria in PEO nanofiber. Bacteria have been encapsulated in matrices varied from silica gels to alginate microcapsules or grafted on substrates varied from glass beads to polymer microparticles, depending on the bacteria properties, process parame- ters, and ultimate uses (Agarwal et al. 2009; Xie et al. 2016). For the purpose of using bacteria safely, bacteria immobilization has been explored aiming at limiting the active area of bacteria.