The Modeling Of Safety Assessment And Early Warning System Based On The Microorganism Migration Laws On Stored Grain

The research modeled the safety assessment and early warning system of stored grain,based on illustrating the microorganism migration laws. First, the microorganisms on thesurface of barley and wheat were isolated, purified, and identified, using conventional andmolecular biology methodologies. Microbial communities were also assessed andidentified. Results indicated that the changes of microbial communities were closelyrelated to the quality of tested barley and wheat. The correlation between the quality ofmalt and grain was used to generate microorganisms as an indicator for the quality ofrelated grain freshness. Corresponding safety evaluation system was then establishedbased on such correlation. Furthermore, the growth of negative-going indicator bacteriaPantoea agglomerans on barleyand and its positive-going indicator fungus was analyzedby DPS data analysis program. A statistic model for their growth was then generated uponGompertz and Boltmann models. Lastly, the effect of negative-going indicator bacteriaPantoea agglomerans (M-4) on PYF with respect to various fermentation conditions waselaborated.1. The distribution of microbial communities on fresh grains in the early period ofstorage was assessed. Conventional and molecular biology methodologies were used forthe isolation, purification, and identification of those microbial communities.8bacteriastrains and7fungus strains were isolated from barley samples, while four bacteria strainsand four fungus strains were isolated from wheat samples.2. In this study, the activities of microorganisms on grains were analyzed in relationto storage duration, temperature, and moisture. A safety assessment and early-warningsystem was established based on a standard germination rate (95%) as below:1) Safety assessment system for wheat: less than10%of fungus strains were positive-goingindicator Aspergillus flavus, and more than10%of bacteria strains were negative-goingKlebsiella ornithinolytica;2) Safety assessment system for barley: more than40%ofbacteria strains were positive-going Escherichia hermannii, and less than60%of bacteriastrains were negative-going Pantoea agglomerans.3. The dynamic changes of microbial indicators for the quality of barley and wheatwere analyzed, in accordance with various storage time, temperature, and moisture. DPSdata analysis program and Minitab analysis software were used for data analysis.Gompertz models and ‘Fail-safe’ aviliable boltzmann square root statistics model for theprediction of ecological activities of microbial communities were then generated. Thosemodels were verified by both theoretical and experimental studies.4. Results indicated that PYF of the negative-going strain Pantoea agglomerans.（M-4）was in the supernatant of malt sugar standard culture medium. It is noted that EPS(extracellular polysaccharide) indicated stronger flocculating activity than Pantoeaagglomerans perse. In addition, the EPS from Pantoea agglomerans reached maximumflocculating activity towards standard yeast suspension at0.9g/L,20℃and pH4.