writer：Yazhi Nong, Min Xu, Bingchuan Liu , Jianfeng Li , Dongye He, Chuanfu Li
keywords：microbial fuel cell
source：期刊
specific source：Water Research
Issue time：2024年
Microbial fuel cell (MFC) sensing is a promising method for real-time detection of water biotoxicity, however, the low sensing sensitivity limits its application. This study adopted low temperature acclimation as a strategy to enhance the toxicity sensing performance of MFC biosensor. Two types of MFC biosensors were started up at low (10°C) or warm (25°C) temperature, denoted as MFC-Ls and MFC-Ws respectively, using Pb2+ as the toxic substance. MFC-Ls exhibited superior sensing sensitivities towards Pb2+ compared with MFC-Ws at both low (10°C) and warm (25°C) operation temperatures. For example, the inhibition rate of voltage of MFC-Ls was 22.81% with 1 mg/L Pb2+ shock at 10°C, while that of MFC-Ws was only 5.9%. The morphological observation showed the anode biofilm of MFC-Ls had appropriate amount of extracellular polymer substances, thinner thickness (28.95 μm for MFC-Ls and 41.58 μm for MFC-Ws) and higher proportion of living cells (90.65% for MFC-Ls and 86.01% for MFC-Ws) compared to that of MFC-Ws. Microbial analysis indicated the enrichment of psychrophilic electroactive microorganisms and cold-active enzymes as well as their sensitivity to Pb2+ shock was the foundation for the effective operation and good performance of MFC-Ls biosensors. In conclusion, low temperature acclimation of electroactive microorganisms enhanced not only the sensitivity but also the temperature adaptability of MFC biosensors.