Basic dyes such as malachite green and methylene blue have been used as disinfectants to control water fungal infections since the 1930s. However, after succeeding reports of carcinogenicity and bioaccumulation of the dye, their use was forbidden in lieu of public health. This study undertook to evaluate the therapeutic effect of sulfur solution processed by effective microorganisms (EM-PSS) against Saprolegnia parasitica infection, and its safety in fish. In vitro antifungal evaluation of EM-PSS inhibited the growth of S. parasitica mycelia at concentrations of 50 ppm or higher. The acute toxicity test of EM-PSS to the mud fish (Misgurnus mizolepis) measured a no effect concentration (NOEC) at 100 ppm, the lowest effect concentration (LOEC) at 125 ppm, and the half-lethal concentration (LC50) at 125 ppm in juvenile and 250 ppm in the immature stage. In addition, the ecotoxicity test of EM-PSS using Daphnia magna inhibited swimming of D. magna at concentrations of 100 ppm or less. Lastly, the EM-PSS prevented infection of S. parasitica to mud fish, at concentrations of 50 ppm. Furthermore, at 100 ppm concentration, the EM-PSS showed no acute toxicity on mud fish, nor any eco-toxic effects on D. magnano. Therefore, we conclude that carcinogenic disinfectants such as malachite green and methylene blue could be replaced by EM-PSS to remove S. parasitica in mud fish farming, and might be a potential eco-friendly disinfectant in aquaculture.

In this study, we present a more electrochemically enhanced electrode using activated carbon (AC)-sulfur (S) composite materials, which have high current density. The morphological and micro-structure properties were investigated by transmission electron microscopy. Quantity of sulfur was measured by thermogravimetric analysis analysis. The electrochemical behaviors were investigated by cyclic voltammetry. As a trapping carbon structure, AC could provide a porous structure for containing sulfur. We were able to confirm that the AC-S composite electrode had superior electrochemical activity.

To control the disease of root rot in ginseng nursery, inorganic sulfur solution of 0.1%, 1.0%, and 2.0% were irrigated by amount of 10ℓ per 3.3m2 before sowing. On the last ten days of July, Fusarium solani and F. oxysporum were similarly detected by 44.8% and 43.8%, respectively, while Cylindrocarpon destructans was low detected by 4.4% in the diseased seedling. The more sulfur's concentration was increased, the more soil pH was decreased. Soil pH was decreased from 5.87 to 4.59 by the irrigation of sulfur solution of 1.0%. The more sulfur's concentration was increased, the more electrical conductivity (EC) of soil was increased. EC was increased from 0.27 dS/m to 1.28 dS/m by the irrigation of sulfur solution of 1.0%. Irrigation of sulfur solution was effective on the inhibition of damping-off caused by Rhizoctonia solani in ginseng seedling. Control value for damping-off by the irrigation of sulfur solution of 1.0% and 2.0% were 75.7%, and 78.5%, respectively. Growth of leaf was inhibited by the irrigation of sulfur solution of 2.0%. Root weight per 3.3m2 showed the peak in sulfur solution of 1.0%, while survived-root ratio and root weight per plant were decreased in the level of 2.0%. Survived-root ratio of seedling in sulfur solution of 1.0% was distinctly increased by 4.7 times compare to the control, but control value for root rot was relatively low as 49.2%. Mycelium growth of C. destructans, F. solani, and R. solani were distinctly inhibited by the increase of sulfur's concentration in vitro culture using PDA medium.