Development Of A Bio-fertilizer And Their Effect On The Soil-cerasus Pseudocerasus System

The aim of the present study was to provide the excellent strain resources for theproduction of Cerasus pseudocerasus bio-fertilizer. Bacterial isolates were isolated and screenedfrom the rhizosphere soil of Cerasus pseudocerasus using the methods of remaining green andradish cotyledon bioassay. And then, plant hormones produced by the bacterial isolates werequantitatively detected. Additionally, a pot experiment was conducted to determine whether theuse of the bacterial isolates benefits the growth of Cerasus pseudocerasus. At last, the bacterialisolate YT3that exert beneficial effects were identified based on the results of morphologiccharacteristics, physiological biochemical properties and phylogenetic analysis of16S rRNAgenes. YT3was identified as Pseudomonas sp..The current study was conducted to determine whether different agricultural organic waste,namely, chicken manure, vermicompost, mushroom residue, and peat, could be used as carrierfor microbial fertilizer by inoculating plant growth-promoting rhizobacteria （PGPR）. PGPR arethe rhizosphere bacteria that can enhance plant growth through a wide variety of mechanisms.The potential of PGPR in agriculture is gradually increasing because it offers an attractive wayto replace chemical fertilizer use. Therefore, a bacterial strain with known positive effects onplant growth, named YT3, was selected in the present investigation. Considering the resourceutilization of agricultural organic wastes, the physico-chemical properties, bacterial strainrelease rate, effective live bacteria, and germination index in the40th day were investigated.The result showed that the water absorption rate of chicken manure was the lowest, whereas theYT3release rate, measured at93.08%, was the highest among all the four organic wastes. Inaddition, the water absorption rate of mushroom residue was highest, whereas the bacterialstrain release rate was the lowest. The phytotoxicity of different organic wastes was measuredwith the germination index of alfalfa seeds cultured in the microbial fertilizer solution. Theresults indicated that, The numbers of these strains on chicken manure, vermicompost, and peathad a significantly increased. On the30th day after inoculating YT3, the numbers of the strainwere highest at8.9×10⁸,7.5×10⁸, and5.9×10⁸CFU/g, which were increased by560%,326%, and187%from their initial amounts, respectively. On the180th day after inoculating the strain,the numbers of YT3were lower than their initial amounts. Although mushroom residue hadhigher initial inoculation amount, the numbers of YT3continually decreased with increasinginoculation time. All of the germination indices, except for the mushroom residue, were above80%, and the solution can be beneficial to plant seed development, but with nophytotoxicity.Therefore, chicken manure and vermicompost, especially chicken manure, wasbetter as a carrier for YT3than peat.The flask-shaking fermentation conditions （ie. culture temperature, initial pH, rotationspeed, and inoculation amount） of YT3was studied through the single factor experiments. Theresults showed that the fermentation conditions were obtained as culture temperature of theshaking34°C, initial pH of the medium6.5, rotation speed180rpm, as well as the inoculationamount of10%. The strain amounts dynamic amounts of YT3could be well described byLogistic equation. The correlation coefficient between the predicted and observed values of thestrain amounts was very high and ensured the statistical integrity of the logistic equation. Theamount of YT3exhibited rapid change between3and12hours. The optimal seed age was12hours after YT3inoculation. Additionally, the maximum growth rate was at7hours afterinoculation. The optimum liquid fermentation of YT3was studied by the single factorexperiments and orthogonal experiments. Results showed that the effect order of each factorfrom weak to strong was peptone, lactose, MgSO₄, and K₂HPO₄. The optimum culture mediumfor the strain YT3were determined as lactose2%, peptone2%, K₂HPO₄0.15%, MgSO₄·7H2O0.02%, and CaCl₂0.01%.YT3was labeled with GFP via Green Fluorescent Protein Gene Label technique. The testof plasmid stability showed that plasmid could keep stable inheritance in YT3, and the loss rateof plasmid was very low in the absence of selection pressure. So YT3（G） could used in a potexperiment to investigate colonization dynamics. The result of pot experiment showed thatYT3（G） could colonize in Cerasus pseudocerasus rhizosphere in120days.A pot experiment was conducted. Purpose of the study was to examine the effects oforganic fertilizer （OF） and bio-fertilizer （BF） on bacterial community structure, soil enzymeactivities, Cerasus pseudocerasus growth and nutrient uptake. Three treatments were installed,no fertilizer （CK）, OF, and BF, respectively. Comparing with CK, OF and BF improved the bacterial community structure, but there were no significant difference between them, what’smore, OF increased the activities of soil urease, sucrase, BF increased the activities of soilurease, phosphatase, sucrase and polyhenoloxidase. Comparing with OF, BF significantlyincreased the activities of soil urease, phosphatase, sucrase and polyhenoloxidase. Comparingwith CK, OF, which had no effect on aerial part biomass of Cerasus pseudocerasus, couldincrease root biomass of Cerasus pseudocerasus and promote the absorption of nitrogen andphosphorus. BF not only promoted the absorption of nitrogen, phosphorus and potassium, butaslo increased the biomass of root and aerial part of Cerasus pseudocerasus compared with CK.Comparing with OF, the biomass of root, stem and leaf in treatment BF were increased by9.55%,9.98%and11.16%, N, P and K nutrient uptake in treatment BF were increased by15.35%,21.06%and32.09%, respectively. Thus it could be seen, both OF and BF couldimprove the ecological environment of Cerasus pseudocerasus rhizosphere soil and promoteCerasus pseudocerasus growth and nutrient absorption under the condition of potted, but theeffect of BF was better than OF. BF exhibited broad application prospects in Cerasuspseudocerasus production.