The fish cultivation MG132 supplier industry has various problems to overcome, such as food safety issues. Antibiotics are routinely used to prevent fish disease, and human consumption of the residual antibiotics remaining in the food is a major concern. To increase fish farm efficiency, large quantities of fish are often bred within a limited area. The overcrowded breeding environment leads to a rapid decrease in the water quality and exposure of the cultivated fish to excessive stress, which reduces the resistance of the fish to disease.In an overcrowded breeding environment, a single sick individual can quickly spread disease throughout the entire fish culture. Such disease outbreaks can produce enormous economic damage.
As antibiotics are used to treat sick fish, drugs may remain in the body of the treated fish, which leads to widespread concern that residual antibiotics will have negative effects on consumer health.Maita et al. reported that the health of cultivated fish can be effectively monitored using a blood test to measure blood components such as glucose, cholesterol, and l-lactic acid [1,2]. Stress, such as transport stress, pesticide exposure, and oxygen deficiency, increases blood l-lactic acid levels [3�C5]. Kamalaveni et al. reported that blood l-lactic acid levels increase in fish exposed to nerve poison [3]. Ramikrishna et al. also reported increases in blood l-lactic acid levels in carp exposed to sublethal concentrations of waste residues from distillation processes [4].In addition, Hur et al. reported that transportation stress increases l-lactic acid levels in the blood of flatfish [5].
l-Lactic acid, which is the final product of sugar metabolism and the glycolytic pathway, is caused by the reduction of pyruvic acid by the catalysis of lactic acid dehydrogenase. Lactic acid is produced from muscle cells under anaerobic conditions, and is then converted to energy after being used for glucose-resynthesis in the liver [6]. Because both blood glucose and l-lactic acid levels are increased by excessive stress, blood levels of these compounds are Carfilzomib good indicators of stress in fish. Therefore, studies on the management of fish health by inspecting the blood constituents revealed that l-lactic acid levels can be used as an indicator of stress levels in fish [3�C5].
Measuring blood l-lactic acid levels, however, requires difficult procedures such as preprocessing blood to obtain blood plasma, which decreases the practical applicability of this process.We reported the development of a needle-type biosensor for monitoring blood glucose in fish in 2006 [7]. Using this technique, long-term measurements were difficult to selleck chemicals achieve because the sensor output current was decreased by blood coagulation and protein (e.g., albumin, ��-globulin) coalescing on the sensor.