JPS6043955B2 - Microbial reaction method using liquid natural medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for carrying out a microbial reaction using a liquid natural medium such as waste molasses, Koenshuger's solution, starch saccharification solution, cellulose saccharification solution, and pulp waste solution.

Conventionally, various methods have been used to produce ethyl alcohol by carrying out metabolic reactions using industrially useful microorganisms such as bacteria, yeast, and mold. Contains suspended solids and colloidal substances consisting of proteins, cellulose (polysaccharides), etc., which can cause clogging of porous materials during the culture process, so a pretreatment process must be performed to remove them. .

For this reason, conventionally, the liquid natural medium is heated, quicklime powder etc. are added, mixed and reacted, and then left to stand to remove the sludge, but this method requires a heating process and additives such as quicklime. However, it had disadvantages such as requiring a long time for mixing, reaction, and standing. The present inventors have conducted extensive research to solve the above drawbacks, and have found that lower alcohols, ketones,
By using a liquid organic solvent such as an organic acid having a boiling point of 100°C or less and which is miscible with water in a wide range of concentrations, it is possible to clarify the liquid natural medium very easily, and also to settle suspended substances and colloidal substances. It was found that the separation efficiency was also good.

The present invention was made based on the above findings, and it is possible to efficiently and economically remove suspended substances and colloidal substances contained in a liquid natural medium by recycling liquid organic solvents such as alcohol produced within the system. The purpose of the present invention is to provide a method for microbial reaction using a liquid natural medium that can be removed in a timely manner.

That is, in the present invention, a liquid organic solvent having a boiling point of 100°C or lower and miscible with water in a wide range of concentrations, such as lower alcohols, ketones, and organic acids, is mixed into a liquid natural medium, and then pretreated to remove insoluble components. After separating, the mixed liquid is sent to a liquid organic solvent separation device to separate the liquid organic solvent from the mixed liquid, and this liquid organic/organic solvent is recycled and reused in the pretreatment device for mixing the liquid natural medium. The method is characterized in that the residual liquid after separating the liquid organic solvent from the mixed liquid is sent to a culture device for cultivation, and then the liquid after culture is sent to a fermentation product separation device to separate the fermentation product and the residual liquid.

Hereinafter, the configuration of the present invention will be explained based on the drawings. FIG. 1 shows an example of an apparatus for carrying out the method of the invention. A liquid natural medium such as waste molasses and a liquid organic solvent such as lower alcohols such as ethyl alcohol and methyl alcohol, ketones such as acetone, and organic acids that have a boiling point of 100°C or less and are miscible with water in a wide range of concentrations. The flocculation precipitation method,
The mixture is supplied to a pretreatment device 1 such as a centrifugal separation method or a filtration method, and mixed to separate insoluble components. Specifically, a liquid organic solvent is added to waste molasses diluted approximately 6 times with water in an amount of at least 3% by weight, preferably 5% by weight or more. 2 is a liquid natural medium supply pipe, and 3 is a sludge extraction pipe.

Then, the mixed liquid from the pretreatment device 1 is introduced into a liquid organic solvent separation device 4 such as a distillation method or a membrane separation method to separate the liquid organic solvent from the mixed liquid, and then this liquid organic solvent is circulated to the pretreatment device 1. The remaining liquid is sent to the culture device 5 together with dilution water as required. 6 is a dilution water supply pipe.

After separating excess bacterial cells from the culture solution, the fermentation product is separated by a fermentation product separation device 7 such as a distillation method or a membrane separation method.
The fermentation product is separated into a product fermentation product, and the remaining liquid is sent to the waste liquid treatment device 8 for treatment. 10 is a tube for extracting excess bacterial cells, and 11 is a tube for extracting fermentation products.

FIG. 2 is a flow sheet for a test in which waste molasses was pretreated by the conventional method and the method using a liquid organic solvent according to the present invention.

In this test, ethyl alcohol was used as the liquid organic solvent. First, 150 ml of waste molasses and 750 ml of water were mixed. 200y of this mixed solution was used as sample 1, and mixed solution 2
00y were used for the conventional pretreatment and for the pretreatment in the method of the present invention. That is, in order to process using the conventional method, 200y of mixed liquid is heated to 90-95°C, and quicklime!
After adding powder 14y and carrying out a mixing reaction for 6 hours while supplying carbon dioxide gas, the mixture was allowed to stand still to remove sludge, and a supernatant was obtained, which was designated as sample 3. On the other hand, in order to process according to the method of the present invention, 200y of mixed liquid and 200y of ethyl alcohol were mixed and allowed to stand, then the sludge was removed, and the supernatant was filtered through P. Next, this supernatant was distilled to separate ethyl alcohol, and water was added to the remaining liquid to make it 150y, which was designated as sample 2. The results of analyzing the sugar content of Samples 1 to 3 were as shown in Table 1. It can be seen from Table 1 that the loss of sugars is extremely small if the pretreatment in the method of the present invention is not performed.

In addition, when adding ethyl alcohol to 6-fold diluted waste molasses, the supernatant glucose concentration and settled suspended solids (SS) were measured by changing the addition amount to 0, 30, 40, 50, and 6 salivary volume%. . The results are shown in Table 2. ．． Note that the values in Table 2 have been corrected for density. From Table 2, it can be seen that the amount of ethyl alcohol added is preferably 5% by weight or more. Sample mixed with 50% by weight of 6-fold diluted waste molasses and 5% by weight of ethyl alcohol, Sample mixed with 4% by weight of 6-fold diluted waste molasses and 6% by weight of ethyl alcohol, 6-fold diluted waste sugar A volume of 10% by weight (without addition of ethyl alcohol) was placed in a measuring cylinder, and the temporal change in the sedimentation distance of the lower surface of the supernatant was measured.

The results were as shown in FIG. From FIG. 3, it can be seen that a supernatant is formed in a short time when ethyl alcohol is added in an amount of 5% or 6%. In the apparatus for carrying out the method of the present invention, the culture apparatus 5 is made of a tubular or flat porous material having numerous micropores through which the microorganisms used or the immobilized enzyme cannot freely pass through to form a plurality of spaces. A reactor is used.

FIG. 4 shows the results of a clogging test for this porous material. The porous material used was sintered stainless steel (SUS3l6) fine particles, with a maximum pore diameter of 3.6 microns, a porosity of 19.5%, and an inner diameter of 10 Wrf.
A tubular one with a t1 length of 20TnIn (leaching area 6.2?) was used.

The leaching pressure was 20Tf$THg. A medium pretreated by a conventional method, a synthetic medium, and a medium pretreated by the method of the present invention are fed into the device having the porous material,
Changes in leachate velocity over time were measured. In Figure 4, curve A is obtained by centrifuging 6-fold diluted waste molasses at 3000r'Pm for 2 minutes, and curve B is obtained by centrifuging 6-fold diluted waste molasses at 5000r'Pm.
Curve C is the 6-fold diluted waste molasses centrifuged at 7000 r'Pm for 2 minutes, Curve D is the 6-fold diluted waste molasses centrifuged at 10000 r'Pm for 2 minutes. , curve E is 6 times diluted waste molasses at 12000r
'Curve F is for synthetic medium.

Curve G shows the case of pretreatment according to the method of the present invention, in which 6-fold diluted waste molasses 5% by volume and 5% by volume of ethyl alcohol were mixed, left to stand, and the supernatant was distilled to separate ethyl alcohol. This is a curve obtained by processing the residual liquid. As is clear from FIG. 4, when the pretreatment is carried out using the method of the present invention, the degree of decrease in the rate of exudate is small even after a long period of time has passed. Next, embodiments of the present invention will be described.

Example This example was carried out using the apparatus shown in FIG.

While diluting 180q/H of waste molasses with 225q/H of water,
After adding 675 Da/H of 0% ethyl alcohol, mixing and pretreatment to separate the sludge content of 4.5 I1/H, the ethyl alcohol is separated using a distillation type separation device.
This ethyl alcohol is circulated and reused in the pretreatment device, and the remaining liquid is sent to a culture device using porous materials for cultivation. After separating the bacterial cells from the cultured liquid, the ethyl alcohol is transferred to a distillation alcohol separation device. Alcohol 30y/H and residual liquid 36
It was separated into 6.5y/H. As explained above, according to the method of the present invention, alcohol can produce suspended matter and colloidal substances in the system, including proteins, cellulose (polysaccharides), etc. contained in liquid natural media such as waste molasses. By recycling liquid organic solvents such as, they can be removed very efficiently, the liquid natural medium can be clarified very easily, and the sedimentation separation efficiency is also good.

In addition, the frequency of backwashing to eliminate clogging between materials in the culture process using porous materials and membranes can be greatly reduced, and the raw materials sent to the culture process can be cleaned of suspended solids and
In the case of contact with highly concentrated organic solvents and distillation separation, a heating process is required, so sterilization and sterilization processes are not necessary. Furthermore, since there are no additives, the sludge discharged from the pretreatment process is small and easy to dry, and the excess bacterial cells discharged from the cultivation process have various excellent effects, such as increasing the product value. be.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an example of an apparatus for carrying out the method of the present invention, Fig. 2 is a system diagram when conducting a test regarding the pretreatment of waste molasses, and Fig. 3 is a system diagram showing the ethyl alcohol of waste molasses. A curve diagram showing the results of the pretreatment test, and Figure 4 shows the results of the clogging test for porous materials! The curve diagram shown in FIG. 5 is a system diagram showing the apparatus used in the example. 1... Pretreatment device, 2... Liquid natural medium supply pipe, 3... Sludge extraction pipe, 4...
...Liquid organic solvent separation device, 5...Culture device,
6... Dilution water supply pipe, 7... Fermentation product separation device, 8... Waste liquid treatment device, 10...
. . . Surplus bacterial body extraction tube, 11 . . . Fermentation product extraction tube.

Claims (1)

[Claims] 1. Mix lower alcohols, ketones, organic acids, etc. with a liquid organic solvent that has a boiling point of 100°C or less and is miscible with water in a wide range of concentrations into a liquid natural medium, pre-process to separate insoluble components, and then mix. The liquid is sent to a liquid organic solvent separation device to separate the liquid organic solvent from the mixed liquid, and this liquid organic solvent is circulated and reused to the pretreatment device for mixing the liquid natural medium to separate the liquid organic solvent from the mixed liquid. A reaction method for microorganisms using a liquid natural medium, characterized in that the residual liquid is sent to a culture device for cultivation, and then the liquid after culture is sent to a fermentation product separation device to separate the fermentation product and the residual liquid. .