Although Agaricus bisporus mushroom is a popular mushroom consumed world-widely, the application of common bio-elements to verify its geographical origin remains highly limited. Therefore, this study aimed to verify whether the six cultivation regions in Korea of A. bisporus could be determined by the stable isotope composition analysis of bio-elements, which are unique and abundant in most living creatures. δ13C, δ15N, δ18O, and δ34S in A. bisporus were influenced by the region, cultivar, and the interactions between these two factors (P < 0.05). In particular, the effect of cultivation region was more significant to the isotope ratio profiles as compared to the mushroom cultivar effect. During the cultivation period of A. bisporus, the C, N, O, and S isotopic fractionation was observed between the mushroom and cultivation medium, note higher in the mushroom (P < 0.05). Two dimensional plot of δ15N, δ18O, or δ34S effectively distinguished the cultivation regions, Nonsan, Buyeo, Boryung, Daegu, and/or Gyeongju examined in this study. Further, these isotope ratio profiles measured in this study would be statistically analyzed with various chemometrics to provide isotope markers for the authenticity of geographical origin. Our preliminary case study improves our understanding of how the isotope composition of A. bisporus varies with respect to cultivation regions and cultivars. In conclusion, the analysis of stable isotope ratios is a suitable potential tool for discrimination between the cultivation origins of A. bisporus collected from Korea, with potential application to other countries after certain validation steps required.

Concerns about water quality in the Nakdong River have been raised because the Nakdong River will change from a lotic environment to a lentic environmental due to the installation of eight weirs to be constructed as part of the Four Major Rivers Restoration Project. The rapid urbanization and industrialization of the middle and the lower reaches of Nakdong River causes the indiscreet discharge of uncleanly living sewage and industrial wastewater. And the water quality of lower reaches of Nakdong River is getting seriously worse. Owing to the water shortage of Nakdong River and the closing of reaches because of the estuary dyke in the dry season, the velocity of a moving fluid is almost accumulated under 0.03m/sec. Then a pollutant is piled up on the bottom of the river. Polluted sediment is formed and nutrition level of water is increased more and more. The eutrophication state propagated to dark brown or green from eutrophication often comes out. Therefore in this study, we measured Chl. a of chlorophyll sensor (YSI6600V2) and aceton extraction through field observation in the Nakdong River and Samrangjin. And we evaluated the reliability of chlorophyll sensor. In correlation analysis between chlorophyll sensor and aceton extraction, it shows high relation in general. And it also shows high relation among the chlorophyll sensor and aceton extraction of the dominant diatom (Skeletonema costatum), Dinophyta (Prorocentrum minimum) in the Nakdong River estuary by laboratory analysis results.