Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be'er Sheva 84105, Israel.
The Ilse Katz Center for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Be'er Sheva 84105, Israel.
Biosensors (Basel). 2024 Aug 8;14(8):383. doi: 10.3390/bios14080383.
is an opportunistic Gram-negative bacterium that remains a prevalent clinical and environmental challenge. Quorum-sensing (QS) molecules are effective biomarkers in pinpointing the presence of . This study aimed to develop a convenient-to-use, whole-cell biosensor using reporters individually encapsulated within alginate-poly-L-lysine (alginate-PLL) microbeads to specifically detect the presence of bacterial autoinducers. The PLL-reinforced microbeads were prepared using a two-step method involving ionic cross-linking and subsequent coating with thin layers of PLL. The alginate-PLL beads showed good stability in the presence of a known cation scavenger (sodium citrate), which typically limits the widespread applications of calcium alginate. In media containing synthetic autoinducers-such as N-(3-oxo dodecanoyl) homoserine lactone (3-oxo-C-HSL) and -butanoyl-L-homoserine lactone (C-HSL), or the cell-free supernatants of planktonic or the flow-cell biofilm effluent of wild (PAO1)-the encapsulated bacteria enabled a dose-dependent detection of the presence of these QS molecules. The prepared bioreporter beads remained stable during prolonged storage at 4 and -80 °C and were ready for on-the-spot sensing without the need for recovery. The proof-of-concept, optical fiber-based, and whole-cell biosensor developed here demonstrates the practicality of the encapsulated bioreporter for bacterial detection based on specific QS molecules.
铜绿假单胞菌是一种机会性革兰氏阴性菌，仍然是临床上和环境中的一个普遍挑战。群体感应 (QS) 分子是确定 存在的有效生物标志物。本研究旨在开发一种方便使用的全细胞生物传感器，使用单独封装在藻酸盐-聚-L-赖氨酸 (alginate-PLL) 微珠内的报告基因来特异性检测细菌自诱导物的存在。使用两步法制备 PLL 增强型微珠，该方法涉及离子交联和随后用 PLL 的薄层进行涂层。藻酸盐-PLL 珠在存在已知阳离子清除剂（柠檬酸钠）时表现出良好的稳定性，这通常限制了海藻酸钙的广泛应用。在含有合成自诱导物的培养基中 - 例如 N-(3-氧代十二酰基)高丝氨酸内酯 (3-oxo-C-HSL) 和 -丁酰基-L-高丝氨酸内酯 (C-HSL)，或浮游生物的无细胞上清液或野生型 （PAO1）的流动池生物膜流出物 - 封装的细菌能够对这些 QS 分子的存在进行剂量依赖性检测。制备的生物报告珠在 4 和 -80°C 下长时间储存时保持稳定，并且无需回收即可随时进行现场感测。这里开发的基于光纤的概念验证和全细胞生物传感器证明了基于特定 QS 分子的封装生物报告器用于细菌检测的实用性。
