Utilization of Sweat Potato Starch Wastewater and Monosodium Glutamate Wastewater for Cultivation of an Anti-Fungal Biocontrol Agent Paenibacillus Polymyxa

Effluents from monosodium glutamate manufacturing plants possess a high strength of COD (10,000--30,000 mg/l), ammonium (15,000--25,000 mg/l), sulphate (15,000--30,000 mg/l) and very low pH (< 2) (Yang et al., 2005). Effluents from sweat potato starch industry contains a high load of protein, pectin, and starchy materials with the COD of 10,000 35,000 mg/l (Mishra et al., 2004). Due to the low pH, high concentration of COD, sufate and NH3N, the treatment of such wastewaters by conventional activated sludge processes consumes a lot of energy, resulting in high treatment costs (Bai et al., 2004). Phyllosphere bacteria often have a positive influence upon plant, where they may be involved in the fixation of nitrogen, promoting the growth of plants, or the control of plant pathogens. However, some high infectivity fungi may damage many economically important crops and trees, and bring a significant risk and safety concerns for the food supplies. Although chemical control agents have been used world widely, the biological control agents have attracted a great R&D interest because of their potential for long-term application as environmental friendly agents (Ten Hoopen and Krauss, 2006). Biocontrol agents have been used to protect plants against foliar diseases in several crops (Yuen and Schoneweis, 2007; Alvindia and Natsuaki, 2008; Perello et al., 2007). However, many of them are poor competitors for leaf surface nutrients compared with indigenous phyllosphere microbes (Zhang et al., 2008). Strains of Paenibacillus polymyxa have been isolated from different soils (Ash et al., 1993), rhizospheres and roots from plants cultivated all over the world, and many of them have been described as effective plant growth promoting rhizobacteria (Pichard et al., 1995; Petersen et al., 1996; Lorentz et al., 2006). Untill now, P. polymyxa has been seldom discovered in the phyllosphere. In the present work, a strain of P. polymyxa EBL06 was isolated from wheat phyllosphere, which could restrain the growth of the filamentous fungi. P. polymyxa strains