Method for producing L-lactic acid by continuous fermentation of lignocellulose

A technology of lignocellulose and cellulase, applied in the direction of microorganism-based methods, biochemical equipment and methods, fermentation, etc., can solve the problem that the efficiency of fermentation and the utilization rate of bacteria cannot meet the needs of industrial production, and the utilization rate of medium is still to be determined. Improvement, high equipment precision requirements, etc., to achieve the effect of promoting lactic acid production, improving the utilization rate of bacteria, and simplifying the production process

Active Publication Date: 2021-04-16
上海汉禾生物新材料科技有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

4. High requirements for equipment precision, medium utilization rate needs to be improved
This method has less pollution, less emissions, and high utilization rate of raw materials, but using grain as raw material is too wasteful o

Method used

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  • Method for producing L-lactic acid by continuous fermentation of lignocellulose
  • Method for producing L-lactic acid by continuous fermentation of lignocellulose
  • Method for producing L-lactic acid by continuous fermentation of lignocellulose

Examples

Experimental program
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Effect test

Embodiment 1

[0041] Example 1 The amount of cellulase solution required for biomass materials

[0042] After pretreatment, the main components of biomass materials are cellulose and lignin, and cellulase can be used to enzymatically decompose cellulose into monosaccharides and disaccharides. The cellulase liquid is the fermentation supernatant produced by the fermentation of Trichoderma reesei. Adding a suitable cellulase liquid can save the cost of enzymatic hydrolysis of biomass materials. Add the cellulase liquid according to the quality of the pretreated biomass material. 8, 10, 12, 14, 16, 18, 20 FPU / g respectively, the pretreated biomass material accounted for 15% of the total enzymatic hydrolysis system mass ratio, and the rest was water. The enzymolysis temperature is 50° C., the enzymolysis time is 24 hours, and the stirring speed is 120-150 rpm. The contents of cellobiose, xylose and glucose in the supernatant after enzymolysis were measured, and the results are shown in Table...

Embodiment 2

[0046] Example 2 Effect of speed

[0047] The continuous fermentation of the present invention can be divided into three stages, which are the enzymolysis stage at the initial stage of production, which lasts from the beginning to 12-15 hours; the middle stage of production is the stable growth stage of bacteria, which starts after the enzymolysis stage ends and lasts for 20-30 hours; Finally comes the later stage of production, the continuous fermentation stage. The present invention adopts different stepped rotating speeds at different stages, which can maximize production efficiency and increase production capacity.

[0048] In the same fermenter, first carry out enzymatic hydrolysis of waste straw for 12-15 hours, then inoculate the seed culture solution of Bacillus coagulans (B. coagulans) and cultivate for 21 hours, and start to continuously feed and separate the fermentation solution. In this process, the early stage of production is the enzymatic hydrolysis stage, a...

Embodiment 3

[0051] Example 3 The rate of feeding liquid and separating fermentation liquid in lactic acid continuous fermentation

[0052] After the first 21 hours of continuous lactic acid fermentation, feed feeding and separation of fermentation broth are started. Different separation rates determine the quality of the separated products. Choosing the most suitable separation rate can make the biomass materials fully utilized. The thermophilic Bacillus coagulans grows and reproduces in the fermenter while using the fermentable sugar in the enzymolysis liquid to produce lactic acid. The fermentation feed liquid is added from the top of the fermenter, and the fermented liquid is separated from the bottom. The fermentation system maintains a dynamic balance. Feeding and separating too fast will lead to insufficient utilization of the biomass material in the feeding liquid, insufficient concentration of lactic acid produced, and cellulose mixed in the solid product; too slow separation wil...

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Abstract

The invention provides a method for producing Llactic acid by continuous fermentation of lignocellulose, which comprises the following steps: adding a biomass material subjected to steam explosion treatment and cellulase into a fermentation tank, carrying out enzymolysis for 12-15 hours, inoculating a bacillus coagulans strain seed solution into a fermentation tank containing a base material after the enzymolysis is finished, fermenting at 45-50 DEG C for 20-30 hours, separating a small amount of feed liquid in the fermentation tank every other 1-2 hours, supplementing continuous fermentation feed supplementing liquid containing a biomass material and cellulase, enabling the volume of the supplemented feed supplementing liquid to be slightly smaller than that of the separated feed liquid, reducing the total feed liquid volume of the fermentation system by 2-5% after 40-60 hours of separation, and supplementing bacillus coagulans seed liquid at one time. The condition is that the total feed liquid volume in the system is recovered to an initial level after the bacillus coagulans seed liquid is replenished each time, a separation and feeding process is completed, and feed liquid separation and feeding in the fermentation tank are repeatedly performed until the content of the produced lactic acid is reduced to be below 80g/L.

Description

technical field [0001] The invention relates to the technical field of fermentative preparation of lactic acid engineering, in particular to a method for producing L-lactic acid by continuous fermentation of lignocellulose. Background technique [0002] There is a huge amount of biomass stored on the earth, and a large amount of new biomass is produced every day under the photosynthesis of plants. Biomass is divided into two categories, one can be fully utilized by humans, such as food, wood, etc., and the other One type is biomass that has not been fully utilized by humans at present, such as discarded straw, rice straw, etc. Waste biomass is produced along with agricultural production, and its main components are cellulose, hemicellulose, lignin, etc. Cellulose is formed by the polymerization of glucose through β-glucosidic bonds, and hemicellulose is formed by the polymerization of xylose, arabinose, mannose, and galactose. Sugars and disaccharides can be used as raw ma...

Claims

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Application Information

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IPC IPC(8): C12P7/56C12P19/14C12P19/12C12P19/02C12R1/07
CPCY02E50/10
Inventor 韩琴涂濂波钟清陶程程
Owner 上海汉禾生物新材料科技有限公司
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