The Response Of Saline Soil In North Jiangsu After Planting3Kinds Of Salt-enduring Plants And Utilization Of Microbial Resources Exploration

The rapid increase of population and economy is making the resources shortage a hot spot with global concern, and the development of China is faced with a hard time of resources shortage. So, it's the key to achieve the sustainable development that how to exploit the new resources to provide the resources guarantee for the rapid economic development in China. To develop new soil resources, germ plasm resources and energy resources from extreme environment is now becoming the focus in the research. The coastal beach is not only one kind of important soil resources, but also precious biological resources, and there are abundant potential drug food and industrial-agricultural products, which haven't been developed yet. Because of the special living conditions of the halobionts, they will, in specific physiological and metabolic ways, produce some secondary metabolites with special physiological functions, such as enzymes, pigments, and antibiotics, etc. So, planting salt tolerant plants in the seaside solonchak, developing the halobiotic agriculture and exploiting the halobionts resources become the hot and bright spot in the new resources development. By studying the change of the nutrient, biochemical activity, and the structure of microbial colonies in the saline soil before and after planting the halophytes, we find the change rule of every element in the planting process of different halophytes, which provides the theoretic basis for the development of the saliniferous agriculture and the planting of salt tolerant plants. Also, we conducted the research on a strain of cyanine-producing and salt tolerant microorganism, which was selected from the solonchak. We studied the identification of strain, the condition of cultivation, the components, stability, and safety of the pigment, and tested whether this strain was useful for the industrial production of microorganism producing natural cyanine. The main studying details and results are as follows:(1) After planting the Ricinus communis L., Kosteletzkya virginica L. and Glycine soja, the physicochemical property, biochemical activity and microbial amount in the saline soil changed. After planting the halophytes, the pH range of the soil increased, the conductivity of a variety of planting soil decreased remarkably, which showed that the saline content decreased, the texture of the soil loosed, thus, the soil was suitable for the living of microbes, and the quantity of many microbes in the saline soil grew. After planting the Kosteletzkya virginica L., the exchange capacity in the soil was up to the highest, while the conductivity was down to the lowest, and the number of halophilic fungi was the largest, that means the Kosteletzkya virginica L. has strong ability to desalinate. The fungi proliferated a lot, such as AM, etc, the soil environment improved, making the exchange capacity in the soil increase and the sum of the microbes rise. The Glycine soja provides the nitrogen element for the plants by nitrogen fixation effect, so, if the intensity of nitrogen fixation of soil is maximized, and the amount of nitrogen-fixing bacteria is the most, the content of total nitrogen and hydrolysable nitrogen will be the highest. After planting the Ricinus communis L, the hydrolysable nitrogen in the soil descended, the ammoniation enhanced, and the number of the ammonifying bacteria was more than that in the soil where other salt tolerant plants grew.(2) The saline soil is improved after planting the Ricinus communis L. It has a significantly decrease on soil conductivity, but the exchange capacity and total nitrogen content increased observably. But along with the sowing time is lengthened, the influence of a large number of phenolic allelochemicals which is secreted by the castor rhizosphere made the soil and fertilizer decrease, the conductivity increase, exchange capacity, organic matter, total nitrogen, available phosphorus and available potassium decrease. Castor has developed root system, planted in the rhizosphere secrete large quantities of organic acids, can secrete the minerals in the soil, microbial growth required to provide mineral elements, to promote the rhizosphere microbial quantity increase, so the soil microbial activity and diversity increased, a variety of bacteria, actinomycetes and the significant increase in the number of functional microorganism.(3) NJYS-02, a cyanine-producing strain, was screened from Gimhae farm. The strain was discovered to be gram-negative, microaerobic, short rhabditiform, aflagellar, sporeless and decapsulated. The colonial morphology on PDA solid media was blue, rounded raised, lustrous and opaque, with a diameter of1-2mm. The bacteria couldn't grow on nutrient agar, Gao's medium and rose Bengal medium. It could grow and produce cyanine on PDA medium at28℃. The strain could grow at the salinity under8%and produce pigment under4%. By16s rDNA cloning and sequencing, a base sequence of about1430bp was obtained. Blast comparison showed that the strain should belong to pseudomonas sp. in taxonomy.(4)The most suitable fermentation conditions of the strain NJYS-02are20%potato juice with2.5%glucose solution, pH6.0,28℃for3days. The best extracting method was to combine supersonicbroken method and neutral salt precipitation and use neutral pH ethanol solution to extract for7hours at the room temperature.In this way,we obtained the highest pigment yield. By separating the crude extraction, it is obvious that the cyanine pigment contains two components whose contents differ largely. Cyanine I accounts for about85%while cyanine II accounts for about15%.(5)The research on the stability of cyanine produced by NJYS-02indicates that the pigment has a relatively strong light resistance and thermotolerance and is stable in sucrose solution of both medium and low concentration. However, reducing agents, sodium citrate and vitamin B1could not damage its structure, but oxidizing agents and preservatives may cause the damage even worse. The cyanine pigment shows no bacterial resistance. The mice study demonstrates that cyanine generated by NJYS-02, is a kind of natural microbial pigment applicable to food, cosmetics, and fodder additives, with a good development prospect and wide applications.