| Bacillus megaterium is a Gram-positive bacterium with a wide distribution.It can industrially produce isomerase,decompose organic phosphorus,and is used to produce bio-fertilizer.It is often used to manufacture bio-fertilizer and water treatment agent.It has a good economic effect.In this paper,a plant fermentation process amplification and optimization study on a Bacillus megaterium BM2.Rejuvenate and expand the cultivated seeds in the laboratory to cascade fermentation in the production workshop,continuously adjust the medium to determine the optimal fermentation formula,use the flask,seed tank,fermentation tank and other stages for liquid aerobic fermentation,and use crystal violet for leather Lan's staining is used for microscopic examination,using spectrophotometry for quantitative detection in the wavelength range of 600 nm,and finally using plate counting method for qualitative and quantitative detection.This thesis mainly studies the BM2 Bacillus megaterium in the laboratory two-stage shake flask culture formula,culture conditions,culture time,inoculation volume,logarithmic phase and other related parameters,looking for the three-stage fermentation tank culture formula,inoculation volume,culture temperature,Ventilation,rotation speed,p H and other indicators,according to the obtained experimental data,to find a set of high content of Bacillus megaterium spores of the best experimental method and process.The main conclusions are as follows:1.Research on laboratory(seed)cultivation technology: Through comparison and optimization experiments,the optimal first-level cultivation formula of BM2 Bacillus megaterium was determined,and through a single factor test,the cultivation time was determined to be 10 h,and the OD value could reach 17-19,Possess the condition of inoculating the lower-level flaskThrough comparison and optimization experiments,the optimal experimental formula of the second-level shake flask was determined,and the cultivation period was about 10-11 h,which reached the logarithmic growth period,and the number of effective viable bacteria reached about 560 million,which reached the best potting period.2.Fermentation tank cultivation experiment: The optimal fermentation formula ofthe first-level tank(100 L)is determined through a comparative experiment.The cultivation temperature is 35-37?,the p H adjustment range is controlled at 6.0-6.5,and the early ventilation of the cultivation is 4 m3/h 1.When the rotation speed is 100r/min and the OD value reaches about 20,adjust the ventilation volume to 6 m3/h and the rotation speed to 200 r/min.The cultivation takes about 12 h to reach the logarithmic growth phase,and the effective viable bacteria count is about 1.1billion/m L.At this time,it is used as the best strain for inoculating the secondary tank(1000 L).The secondary tank cultivation experiment is basically the same as the primary tank process,and the adjustment of related parameters is basically the same.The tertiary tank was cultivated under the conditions of the best inoculation amount,the best formula,and the best p H range.Some spores appeared around 19 h,and the spore rate was more than 98% in 24-28 h.Counting and testing the bacterial liquid,the result is 8.1-8.5×10? cfu/m L,which is 4 times higher than other species of Bacillusmegaterium.3.Bacterial liquid storage and application related research:(1)The comparison experiment found that sodium benzoate has the best antiseptic effect,and the optimal concentration is about 1.5%.The BM2 Bacillus megaterium bacterial liquid can be stored for 7 days under the pressure of 0.03-0.05 MPa under the condition of airtight sealed storage.(2)The bio-fertilizer produced by BM2 Bacillus megaterium(the effective number of bacteria is ?50 million/g).The effective number of bacteria in the finished product can meet the index requirements within the valid period of 6 months specified in the standard.At the same time,the number of effective viable bacteria showed a gradual downward trend with time,the longer the storage time,the higher the loss rate.In addition,the bio-organic fertilizer produced by BM2 Bacillus megaterium in this process can improve the crop quality while increasing the yield of crops on wheat and peanut cultivation,and increase the yield by 8-15% year-on-year,achieving the goal of win-win for enterprise farmers. |
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