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Carboxymethyl cellulose (CMC) has been broadly used in various fields ranging from pharmacy to lithium batteries because of its excellent properties such as the environmental friendliness, the good solubility, its low cost and biocompatibility. Herein, we present a direct electrodeposition method for carboxymethyl cellulose based on the coordination deposition. Using this method we can conveniently build smooth and homogeneous CMC films on the surface of copper and silver electrodes (or substrates). On the other hand, the deposited CMC film has sufficient strength to be completely detached from the electrodes (or substrates), which enables a novel and controllable method to prepare CMC films that can be used as independent film materials. In particular, the deposited CMC film shows favorable antibacterial activities, which are promising for applications in bioactive antibacterial coatings on metal substrates. More interestingly, the CMC electrodeposition provides the possibility to directly build sensors and detectors for electrochemical detection. Therefore, the CMC electrodeposition developed in this study can be potentially applied in surface coatings, functional films, and sensors.

The succession of bacterial microbiota in tilapia fillets during cold storage at 4 °C was investigated employing PCR-DGGE method. Results showed that Pseudomonas was the most dominant genus during entire storage period. Shewanella and Psychrobacter were also always present, but became dominant only after 3 days of storage. Acinetobacter, Brevibacterium, Flavobacterium, Dietzia and Janthinobacterium were always the minor genera, among which Acinetobacter and Brevibacterium disappeared 6 days later, and Dietzia and Janthinobacterium only appeared at the end of storage. Further, the potential spoiler(s) of tilapia fillets at 4 °C were investigated in situ. The spoilage ability of a specific group of bacteria was evaluated as follows: Certain preservatives were selectively added to fillets to inhibit a specific group of bacteria, and then the changes in spoilage degree of fillets were determined. In this way the spoilage ability of the inhibited bacteria was evaluated. Our experiments showed that protamine strongly inhibited Pseudomonas but rarely inhibited Psychrobacter, Acinetobacter and Brevibacterium, but garlic juice, on the contrary, strongly inhibited the latter three but rarely inhibited the former. The mixed preservative, which consisted of protamine and garlic juice, didn't play better than protamine alone in preventing the spoilage of fillets. This indicated that Psychrobacter, Acinetobacter and Brevibacterium contribute little to the spoilage of tilapia fillets.