Process for producing alcohol by using chitin as basic raw material
阅读说明：本技术 一种以几丁质为基础原料生产酒精的工艺 (Process for producing alcohol by using chitin as basic raw material ) 是由 王海东 于 2019-10-09 设计创作，主要内容包括：本发明涉及生物工程技术领域,具体来说是一种以几丁质为基础原料生产酒精的工艺,包括预处理、几丁质的提取、壳聚糖的制备、壳聚糖提取物的降解及发酵过程,本发明以虾或蟹的甲壳为原料,经过一系列方法得到了几丁质、壳聚糖及分子量分布在10KD-20KD范围内的低聚壳聚糖提取物,再将低聚壳聚糖提取物与酵母菌共同发酵,得到了酒精产品,实现了虾或蟹的甲壳的废物利用,降低了虾或蟹的甲壳对环境造成的污染,并且降低了粮食和石油的资源浪费,且具有广泛的应用空间。(The invention relates to the technical field of bioengineering, in particular to a process for producing alcohol by using chitin as a basic raw material, which comprises the steps of pretreatment, chitin extraction, chitosan preparation, chitosan extract degradation and fermentation, wherein the chitin, the chitosan and an oligochitosan extract with the molecular weight distribution within the range of 10KD-20KD are obtained by using shrimp or crab shells as the raw material through a series of methods, and the oligochitosan extract and yeast are fermented together to obtain an alcohol product, so that the waste utilization of the shrimp or crab shells is realized, the pollution of the shrimp or crab shells to the environment is reduced, the waste of grains and petroleum resources is reduced, and the process has wide application space.)
1. A process for producing alcohol by using chitin as a basic raw material is characterized by comprising the following steps:
step 1, pretreatment: selecting shell of shrimp or crab without malodor and rot, shaving residual meat, cleaning, freeze drying, and storing at-20 deg.C to obtain shell for use;
step 2, chitin extraction: extracting chitin in the standby carapace in the step 1 to obtain a chitin extract;
step 3, preparing chitosan: extracting chitosan in the chitin extract in the step 2 to obtain a chitosan extract;
and 4, degrading the chitosan extract: mixing the chitosan extract prepared in the step 3 with cellulase, chitosanase and sterile water according to the ratio of 100: 2-3: 3-5: 100, stirring at 50-70 deg.C for 2-4H, adjusting pH to 3-5, and adding H2O2Reacting the solution at 40-50 deg.C for 2-4 hr, ultrafiltering every 0.5-1 hr during the reaction, and collecting oligochitosan extract with molecular weight distribution of 10KD-20 KD;
step 5, fermentation: and (3) dissolving the chitosan oligosaccharide extract prepared in the step (4) in water to form a chitosan oligosaccharide solution with the volume fraction of 10-20%, inoculating saccharomycetes into the chitosan oligosaccharide solution, adjusting the pH to 5.5-6.5, carrying out sealed anaerobic fermentation for 5-7 days in a dark place under the fermentation conditions that the temperature is 30 +/-5 ℃ and the rotating speed of a shaking table is 50-150r/min, and exhausting air regularly until no carbon dioxide gas is generated to obtain an alcohol product.
2. The process for producing alcohol using chitin as basic raw material according to claim 1, wherein the extraction process of step 2 is: completely immersing the standby carapace in HCl solution with the mass fraction of 3-8%, stirring for 9-14h, cleaning to be neutral, completely immersing the processed carapace in NaOH solution with the mass fraction of 8-10%, heating to 75-100 ℃, stirring for 1.5-3.5h, filtering while hot, adding HCl to adjust to be neutral, and sequentially passing through KMnO with the mass fraction of 1%4And NaHSO4Rinsing the solution for 1 hr, washing with water to neutral, and freeze drying to obtain chitin extract.
3. The process for producing alcohol using chitin as basic raw material according to claim 1, wherein the extraction process of step 3 is: and (3) completely immersing the chitin extract prepared in the step (2) in a NaOH solution with the mass fraction of 40-60%, heating and stirring at the temperature of 100-150 ℃ for 1-1.5h, cooling to room temperature, adjusting the pH value to be neutral by using HCl, washing with water, and drying to obtain the chitosan extract.
4. The process of claim 1, wherein the solution obtained by the step 4 is ultrafiltered with a double-layer ultrafiltration membrane having an upper layer of 20KD and a lower layer of 10KD at 40-50 ℃ each time, the solids between the double-layer ultrafiltration membranes are collected, and the solids collected for several times are combined to obtain the oligochitosan extract having a molecular weight in the range of 10KD-20 KD.
5. The process of claim 1, wherein the step 4 is performed by using H2O2The volume concentration of the solution is 25-30%, and the chitosan extract and H2O2The ratio of the materials to the liquid is 100 g: 2-3 mL.
6. The process of claim 1, wherein step 4 and step 6 are performed by HCl or H2SO4To adjust the pH.
Technical Field
The invention relates to the technical field of bioengineering, in particular to a process for producing alcohol by using chitin as a basic raw material.
Background
Chitin, also called chitin, is edible animal cellulose which is found in nature only with positive charge, is widely present in shells of marine arthropods, shells of crustaceans (such as shrimps and crabs), cell membranes of insects and algae and cell walls of fungi, is a natural polysaccharide compound, has approximately 100 hundred million tons of per year biosynthesis amount, and is the second most renewable resource next to cellulose on the earth; however, because chitin is insoluble in dilute acid, dilute alkali and common organic solvents, the wide application of the chitin is limited, and in some river, lake and sea areas in China, many materials such as shrimp heads, crab shells, fish scales and the like rich in chitin are discarded as garbage, so that not only is the chitin resource wasted, but also the environment is polluted.
Disclosure of Invention
In view of the technical defects, the invention aims to provide a process for producing alcohol by using chitin as a basic raw material, the process takes the chitin as the basic raw material, chitosan is obtained after physical, chemical or biological enzymatic deacetylation, chitosan is subjected to oxidative decomposition or biological enzymatic degradation to obtain oligomeric chitosan, and then the oligomeric chitosan is fermented to obtain an alcohol product; specifically, chitin, chitosan and an oligochitosan extract with the molecular weight distribution within the range of 10KD-20KD are obtained by a series of methods, and the oligochitosan extract and yeast are fermented together to obtain an alcohol product, so that the waste utilization of the shrimp or crab shell is realized, the pollution of the shrimp or crab shell to the environment is reduced, the resource waste of grains and petroleum is avoided, and the alcohol product has wide application space.
In order to solve the technical problems, the invention adopts the following technical scheme:
a process for producing alcohol by using chitin as a basic raw material comprises the following steps:
step 1, pretreatment: selecting shell of shrimp or crab without malodor and rot, shaving residual meat, cleaning, freeze drying, and storing at-20 deg.C to obtain shell for use;
step 2, chitin extraction: extracting chitin in the standby carapace in the step 1 to obtain a chitin extract;
step 3, preparing chitosan: extracting chitosan in the chitin extract in the step 2 to obtain a chitosan extract;
and 4, degrading the chitosan extract: mixing the chitosan extract prepared in the step 3 with cellulase, chitosanase and sterile water according to the ratio of 100: 2-3: 3-5: 100, stirring at 50-70 deg.C for 2-4H, adjusting pH to 3-5, and adding H2O2Reacting the solution at 40-50 deg.C for 2-4 hr, ultrafiltering every 0.5-1 hr during the reaction, and collecting oligochitosan extract with molecular weight distribution of 10KD-20 KD;
step 5, fermentation: and (3) dissolving the chitosan oligosaccharide extract prepared in the step (4) in water to form a chitosan oligosaccharide solution with the volume fraction of 10-20%, inoculating saccharomycetes into the chitosan oligosaccharide solution, adjusting the pH to 5.5-6.5, carrying out sealed anaerobic fermentation for 5-7 days in a dark place under the fermentation conditions that the temperature is 30 +/-5 ℃ and the rotating speed of a shaking table is 50-150r/min, and exhausting air regularly until no carbon dioxide gas is generated to obtain an alcohol product.
Preferably, the extraction process of step 2 is as follows: completely immersing the standby carapace in HCl solution with the mass fraction of 3-8%, stirring for 9-14h, cleaning to be neutral, completely immersing the processed carapace in NaOH solution with the mass fraction of 8-10%, heating to 75-100 ℃, stirring for 1.5-3.5h, filtering while hot, adding HCl to adjust to be neutral, and sequentially passing through KMnO with the mass fraction of 1%4And NaHSO4Rinsing the solution for 1 hr, washing with water to neutral, and freeze drying to obtain chitin extract.
Preferably, the extraction process in step 3 is as follows: and (3) completely immersing the chitin extract prepared in the step (2) in a NaOH solution with the mass fraction of 40-60%, heating and stirring at the temperature of 100-150 ℃ for 1-1.5h, cooling to room temperature, adjusting the pH value to be neutral by using HCl, washing with water, and drying to obtain the chitosan extract.
Preferably, in the step 4, the solution reacted at 40-50 ℃ is ultrafiltered by using a double-layer ultrafiltration membrane with an upper layer of 20KD and a lower layer of 10KD during each ultrafiltration, solids between the double-layer ultrafiltration membranes are collected, and the solids collected for multiple times are combined to obtain the oligochitosan extract with the molecular weight distribution within the range of 10KD-20 KD.
Preferably, H in said step 42O2The volume concentration of the solution is 25-30%, and the chitosan extract and H2O2The ratio of the materials to the liquid is 100 g: 2-3 mL.
Preferably, the step 4 and the step 6 are performed through HCl or H2SO4To adjust the pH.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention takes the shell of shrimp or crab as raw material to produce alcohol, the shell of shrimp or crab is decalcified, deproteinized and decolored to obtain chitin, the chitin is deacetylated to obtain chitosan, the chitosan is firstly enzymolyzed by chitosanase and cellulase, and then H is carried out2O2The solution enables chitosan to be catalytically degraded, the solution which is reacted at the temperature of 40-50 ℃ is subjected to ultrafiltration by adopting an upper-layer 20KD and lower-layer 10KD double-layer ultrafiltration membrane to obtain an oligochitosan extract with the molecular weight distributed in the range of 10KD-20KD, and finally the oligochitosan extract and yeast are fermented together to obtain an alcohol product, so that the waste utilization of the shell of the shrimp or crab is realized, the pollution of the shell of the shrimp or crab to the environment is reduced, the waste of grain and petroleum resources is avoided, and the alcohol product has wide application space.
2. The invention mixes the oligochitosan extract with the molecular weight distribution within the range of 10KD-20KD with yeast for fermentation, and researches prove that the alcohol obtained after fermentation with the molecular weight distribution within 10-20KD is higher in purity compared with the oligochitosan extract with the molecular weight distribution within the range of 20KD-30KD and the molecular weight distribution below 10 KD.
Detailed Description
The following is a detailed description of preferred examples 1-11 and comparative examples 1-4.