The mechanism of the effect of the alcohol-biogas double fermentation coupling process on the effect of alcohol fermentation.

In the process of double fermentation coupling of alcohol biogas, the mixture of biogas and alcohol waste is used in the alcohol fermentation process not only to provide nitrogen source for alcohol fermentation to reduce the addition of external nitrogen sources, but also to reduce the production of metabolic by-product glycerin to improve the yield of alcoholAmmonium acetate is the main nitrogen source in mixed waterThe effects of ammonium acetate and ammonium sulfate and ammonium chloride nitrogen source materials on alcohol fermentation were compared to reveal the mechanism of the effect of the double fermentation coupling process of alcohol biogas on the effect of alcohol fermentationThe results showed that the alcohol fermentation time was the shortest, the highest ethanol yield and the lowest by-product glycerin yield compared to the other nitrogen source ammonium acetateThis shows that ammonium acetate in mixed water in the double fermentation coupling process of alcohol biogas is the main reason for increasing the yield of alcoholFurther research shows that the main reason for the positive effect of ammonium acetate as a nitrogen source on alcohol fermentation is the presence of acetic acid roots in ammonium acetateAlcohol is one of china's bulk fermentation products annual output will reach 10,000However, the problem of wastewater pollution has become more serious has become an important factor restricting the development of alcohol industryTake cassava alcohol production process as an example, its waste liquid treatment process is more complex steps, investment in large operation and maintenance costs are high, but also need to enter the urban sewage treatment system to do deep treatmentProfessor Mao Zhonggui of Jiangnan University put forward the "alcohol biogas double fermentation coupling process" in the year, explaining a new way of thinkingIn this process, the starch in the raw materials of cassava is converted into finished alcohol by liquefaction, glycation, fermentation, distillation and other technical means and the distillation process of the waste water produced by anaerobic digestion biogas fermentation into biomass energy - biogas after fermentation of biogas after water purification to reach the resource-based indicators and the main components of liquor waste for cassava raw materials can not be used by yeast, cellulose, pecuoginolal and other biomass winey yeast metabolism products such as organic, organic, Isosterol and the mixture of acetic acid, lactic acid, propylene acid and other liquid re-use as process water to achieve the goal of zero discharge of wastewater, biogas as an alternative to coal as an energy material through "cogeneration" technology to obtain green energy return to the production of various processesThis process has significant advantages over traditional processes: cutting off aerobic digestion treatment with a large footprint and high operating cost, eliminating the cost of deep treatment of sewage, saving a lot of water resources by water reuse, increasing the utilization rate of raw materials, and eliminating the addition of nitrogen sources such as urea in the fermentation process to further reduce the cost of accessoriesThe analysis revealed that ammonium acetate is the main nitrogen source in mixed waterIn this study, the mechanism of the effect of the double fermentation coupling process of alcohol biogas on the effect of alcohol fermentation was revealed by comparing the effects of ammonium acetate and ammonium sulfate and ammonium chloride nitrogen source materials on alcohol fermentationMaterials and Methods Materials Brewing Yeast: Hubei Yichang Angie Yeast Co., Ltd.; Cassava: Wu Jiang Yongxiang Alcohol Manufacturing Co., Ltd.; high temperature alpha amylase and glysase: Wuxi Jenenko Co., LtdMethodS Seed Medium Glucose Yeast PasteNatural osLiquefied liquid preparation and alcohol fermentation by: the proportion of the average particle size of cassava powder mixed with the ingredientwater water added to the high temperature alpha amylase cassava powderThe heating fluid is maintained to the degree CNatural cooling to room temperature uses deionized water to compensate for the loss of water in the liquefaction processDivide into a triangular bottle to sterilize the s.CCooling to room temperature in ultra-clean table added glycose cassava powder, seed culture seed liquid and nitrogen-containing concentration of nitrogen source for alcohol fermentationSet in the medium-degree incubatorThe upper tank alcohol fermentation batch fermentation is carried out in the tank fermentation tank with a working volume of volumeInoculate approximately the pre-cultured seeds into a sterile fermented mediumDuring culture, the change of fermentation temperature is detected by electrodeStir at intervals after vaccinationFirst, the alcohol fermentation process is not regulated by ammonium acetate and ammonium sulfate as the nitrogen source, and then the fermentation process is regulated by ammonium sulfate as the nitrogen source to make it consistent with the trend of change when ammonium acetate is the nitrogen sourceAnalysis Method Total Sugar Determination: Filin Reagent TitratorAlcohol concentration determination: distillation methodGlycerin determination: methodChromatography conditions: chromatin sx x; detectors and detectors; flow phases; column temperatures; flow rates; intake Yeast cell number determination: hematopoic slate counting The use of anova analysis' was considered significant at the time Results and discussion The effects of different nitrogen sources on the effect of cassava alcohol fermentation In the process of alcohol fermentation, each molecular ethanol produced is accompanied by the production of molecules, so that the alcohol fermentation rate can be directly reflected through the weightlessness of the fermentation system of the alcohol fermentation process and can indirectly reflect the alcohol yield From the fermentation weightlessness curve, the graph when ammonium acetate as the nitrogen source when the weightlessness of the fermentation system does not increase indicates that the alcohol fermentation has ended at this time, while ammonium sulfate and ammonium chloride are nitrogen sources when the alcohol fermentation delay to the end This shows that the rate of alcohol fermentation with ammonium acetate as nitrogen is significantly higher than that of alcohol fermentation with ammonium sulfate and ammonium chloride as nitrogen sources respectively In addition, the total weightlessness of alcohol fermentation with ammonium acetate as nitrogen was also significantly higher than that of alcohol fermentation, which was caused by ammonium sulfate and ammonium chloride, respectively, nitrogen-derived indirectly showed that ammonium acetate could improve the alcohol yield of alcohol fermentation In addition, the fermentation solution after fermentation was maintained at a relatively high level compared to ammonium sulfate and ammonium chloride acetate as nitrogen sources In contrast, when ammonium acetate is the source of nitrogen, the total residual sugar concentration is relatively low Because the dry weight of cassava slag yeast contained in the medium is difficult to measure, a blood cell counter is used to count yeast cells to assess the growth of brewery yeast The results of the graph show that the low biomass when using ammonium acetate as a nitrogen source is contrary to the theory that the high fermentation rate is due to high biomass The alcohol volume fraction when ammonium acetate is the nitrogen source as shown is higher than the alcohol volume fraction when ammonium sulfate and ammonium chloride are nitrogen sources, and the result is consistent with the total weightlessness result Different nitrogen sources also affect the production of glycerin, the most important by-product of the alcohol fermentation process The figure shows that the yield of alcohol fermentation with ammonium sulfate and ammonium chloride as nitrogen is similar but higher than that of alcohol fermented with ammonium acetate as nitrogen Based on the above results, it is initially speculated that compared to ammonium sulfate and ammonium chloride ammonium chloride, by reducing the synthesis of the by-product glycerin and the concentration of fermented residual sugar, more carbon sources in the fermentation system into the main product of alcohol So how ammonium acetate reduces the synthesis of glycerin and the concentration of residual sugar is a key scientific problem that needs to be solved further The purpose of yeast glycerin production during alcohol fermentation is to maintain the redox balance and osmotic pressure balance in the cell, and when the culture of the brewery yeast is located changes, it also affects the synthesis of the wine yeast to glycerin When ammonia nitrogen is a nitrogen source, yeast uses ammonia nitrogen to synthesize amino acids at the same time In order to avoid intracellular imbalance of the proportion of wine yeast must be re-oxidized through the glycerin generation pathway However, the nitrogen source used in the experiment is ammonium salt and the concentration is quite similar so it is speculated that the main reason is the difference of glycerin synthesis under the nitrogen-like source In order to prove that this hypothesis first monitored the changes of the alcohol fermentation process when ammonium acetate and ammonium sulfate were the nitrogen source, on this basis, the fermentation system when adjusting ammonium sulfate as the nitrogen source made it consistent with the change trend of ammonium acetate as nitrogen source As shown in the figure, when ammonium sulfate as a nitrogen source, the rate of decline of the fermentation process is significantly higher than when the fermentation of ammonium acetate as the nitrogen source, the minimum value and the minimum value for ammonium acetate fermentation The decrease of fermentation fluid in the process of alcohol fermentation is mainly caused by the process of secretion of protons, absorption of different ions, generation and organic acids by brewery yeast through the process of feeding transmission When ammonium salt as a source of nitrogen, the electrochemical plasma membrane generated by the brewery yeast through the plasma membrane is the potential to absorb ammonia nitrogen from the medium to the intracellular cells in order to maintain the stability of the cell must be the isomos protons discharged to the outer cell, which causes the decline of fermentation fluid Ammonium sulfate and ammonium acetate are alike ammonium salts but sulfate stoe is strong acid and acetate root is weak acid fermentation process acetate will have a strong buffer inglision with acetate near acetic acid caused the fermentation fluid to drop at a relatively low rate and the relatively high degree of the fermentation medium is conducive to the role of the residual total sugar is lower However, when ammonium sulfate is used as a nitrogen source, even if the fermentation system is adjusted to make it consistent with the trend of ammonium acetate as nitrogen source, the yield of glycerin in the fermentation process of alcohol not only did not decrease but increased This shows that the phenomenon that ammonium sulfate is lower than when ammonium acetate is a nitrogen source is not caused by lower fermentation The effect of amacetic acid root on alcohol fermentation of amacetic acid and the eradication of acetic acid rooting in the alcohol fermentation process may also be an influence on the synthesis of yeast glycerin in winemaking Therefore, the effect of acetic acid added on the fermentation process of alcohol under different nitrogen source conditions was studied The results show that the fermentation rate of alcohol is relatively low when ammonium sulfate is the nitrogen source, and adding acetic acid on this basis can increase the fermentation rate of alcohol relative to the former, shortening the fermentation time by about about and being equivalent to the fermentation rate when ammonium acetate is the nitrogen source The addition of acetic acid when ammonium sulfate is a nitrogen source will also improve the end of fermentation and thus lead to the fermentation residual sugar is lower than ammonium sulfate as the sole nitrogen source, but still higher than the alcohol fermentation with ammonium acetate as the nitrogen source which is closely related to fermentation In addition, adding acetic acid to a fermentation system with ammonium sulfate as a nitrogen source can significantly increase alcohol production and reduce glycerin production and is comparable to fermentation levels when ammonium acetate is a source of nitrogen The above results show that adding acetic acid to the fermentation solution can improve the fermentation effect of brewing yeast alcohol and ammonium nitrate as a nitrogen source compared to ammonium nitrate, mainly due to the presence of acetic acid root in amacetic acid Around the effect of acetic acid on brewery yeast and the response mechanism of brewery yeast to acetic acid, scholars at home and abroad have carried out a large number of research work mainly obtained the following conclusions or inferences: under low conditions, most of acetic acid in the undisved state of these acetic acid mainly through a water glycerin transmembrane delivery protein-mediated helped diffusion method stoic cell into yeast cells In intracellular high-proximity neutral environment, acetic acidity dissothing acidification caused by acetic acidification and thus inhibited intracellular metabolic reactions At lethal concentrations of acetic acid can cause cytochrome-released mitochondrial dysfunction in the cell and increase the activity of apoptosis proteins in the cell, and eventually lead to cell death procedural cell death Cytoplasm acidification increases the amount of expression on the cell membrane to pump excess cells out of cells under conditions such as consumption, which will maintain intracellular balance and restore normal cell growth But when the concentration of acetic acid is too high, the yeast cells retain the cells and no longer resume growth and intracellular Low-environment acetic acid activates intracellular kinases so that phosphorylation and subsequent ubiquitinization, internal annexation and eventual degradation by protease in the liquid bubble will prevent acetic acid from entering the cell to reduce damage to the cells It is worth noting that activation is accompanied by a decrease in glycerin concentration From these results, it can be seen that high concentrations of acetic acid inhibit the growth of wine yeast to prolong the fermentation cycle of alcohol and reduce alcohol yield In this study, it was found that low concentration selicacid can improve the alcohol yield and reduce the yield of glycerin during the fermentation process So why low concentrations and high concentrations of acetic acid pressure why yeast cells exhibit different ethanol synthesis amount yeast cell metabolism regulation is how the transition between low concentrations and high concentrations of acetic acid pressure why acetic acid can reduce the production of glycerin is a very worthy of scientific research and we will be going to do in the future Conclusion The application of the double fermentation coupling process of alcohol biogas not only provides sufficient nitrogen source for alcohol fermentation but also improves the yield of alcohol and reduces the production of glycerin, a by-product The results show that ammonium acetate is an effective alcohol fermented nitrogen source substance compared to ammonium sulfate and ammonium chloride, which can shorten the fermentation time of alcohol, improve the yield of alcohol and reduce the synthesis of glycerin, a by-product Therefore, ammonium acetate is the main factor that causes the positive influence of the alcohol biogas double fermentation coupling process on the effect of alcohol fermentation Source: Food and Fermentation Industry Journal.