Poor solubility is the main drawback of the direct industrial exploitation of chitin, the second most abundant biopolymer after cellulose. Chemical methods are conventional to solubilize chitin from natural sources. Enzymatic hydrolysis of soluble chitinous substrates is a promising approach to obtain value-added by-products, such as N-acetylglucosamine units or low molecular weight chito-oligomers. Protein display on the bacterial membrane remains attractive to produce active enzymes anchored to a biological surface. The Lpp-OmpA system, a gene fusion of the Lpp signal sequence with the OmpA transmembrane region, represents the traditional system for targeting enzymes to the E. coli surface. EhCHT1, the amoebic chitinase, exhibits an efficient endochitinolytic activity and significant biochemical features, such as stability over a wide range of pH values. Using an extended Lpp-OmpA system as a protein carrier, we engineered E. coli to express the catalytic domain of EhCHT1 on the surface and assess the endochitinase activity as a trait. Engineered bacteria showed a consistent hydrolytic rate over a typical substrate, suggesting that the displayed enzyme has operational stability. This study supports the potential of biomembrane-associated biocatalysts as a reliable technology for the hydrolysis of soluble chitinous substrates.

溶解性差是直接工业开发甲壳素的主要缺点，甲壳素是仅次于纤维素的第二丰富的生物聚合物。化学方法是从天然来源溶解几丁质的常规方法。可溶性几丁质底物的酶促水解是获得高附加值副产物（如 N-乙酰氨基葡萄糖单元或低分子量壳寡聚体）的一种很有前景的方法。细菌膜上的蛋白质展示对于产生固定在生物表面的活性酶仍然具有吸引力。Lpp-OmpA 系统是 Lpp 信号序列与 OmpA 跨膜区的基因融合，代表了将酶靶向大肠杆菌的传统系统表面。EhCHT1 是一种阿米巴几丁质酶，具有有效的内切几丁质分解活性和显着的生化特征，例如在很宽的 pH 值范围内具有稳定性。使用扩展的 Lpp-OmpA 系统作为蛋白质载体，我们设计了大肠杆菌以在表面表达 EhCHT1 的催化结构域，并评估内切壳多糖酶活性作为特征。工程细菌在典型底物上显示出一致的水解速率，表明展示的酶具有操作稳定性。该研究支持生物膜相关生物催化剂作为可溶性几丁质底物水解的可靠技术的潜力。