Method for producing L-lactic acid

A technology for lactic acid and lactic acid fermentation, applied in microorganism-based methods, biochemical equipment and methods, separation/purification of carboxylic acid compounds, etc. Simple, continuous effects

Inactive Publication Date: 2010-06-16
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In order to reduce the cost of raw materials for lactic acid production, improve the fermentation intensity, and overcome the shortcomings of the existing lactic acid sepa...

Method used

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  • Method for producing L-lactic acid
  • Method for producing L-lactic acid

Examples

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Embodiment 1

[0029] Attached figure 1 Shown, the operating steps of the present invention are as follows:

[0030] (1) After crushing corn stalks, pass through a 40-mesh sieve, add calcium hydroxide aqueous solution at a ratio of 5L / Kg, heat and stir at 95°C for 25 minutes, add 98% concentrated sulfuric acid to neutralize calcium hydroxide, and separate and remove solids Ingredients and calcium sulfate precipitation, add liquid cellulase with an enzyme activity of 15U / g at a ratio of 1g / L, stir and enzymolyze at 60°C for 60min, and obtain 10L of saccharification solution with a sugar content of 10% by mass;

[0031] (2) The obtained mass percentage is 8-12% saccharification liquid is added in the fermenter, simultaneously adds calcium carbonate 500g, ammonium nitrate 33g, potassium dihydrogen phosphate 4g, sodium dihydrogen phosphate 2.5g, zinc sulfate 3.5g, sulfuric acid Magnesium 3.5g and ferrous sulfate 0.9g, sterilized and cooled to 32°C-34°C, inoculated with spore concentration of 10...

Embodiment 2

[0041] (1) After pulverizing the wheat straw, pass it through a 40-mesh sieve, add calcium hydroxide aqueous solution at a ratio of 5.5L / Kg, heat and stir at 95°C for 20 minutes, add 98% concentrated sulfuric acid to neutralize the calcium hydroxide, and separate the solid Ingredients and calcium sulfate precipitation, add liquid cellulase with an enzyme activity of 15U / g at a ratio of 0.8g / L, stir and enzymolyze at 60°C for 45min, and obtain 10L of saccharification solution with a sugar content of 8% by mass;

[0042] (2) The obtained mass percentage is 8% saccharification liquid and is added in the fermenter, simultaneously adds calcium carbonate 400g, ammonium nitrate 30g, potassium dihydrogen phosphate 3g, sodium dihydrogen phosphate 2g, zinc sulfate 3g, magnesium sulfate 3g and sulfuric acid Ferrous iron 0.8g, sterilized and cooled to 32°C-34°C, inoculated spore concentration of 10 11 500mL of Rhizopus oryzae AS3.819 spore suspension per L, carry out aeration and stirring...

Embodiment 3

[0046] (1) After pulverizing the rice straw, pass it through a 40-mesh sieve, add calcium hydroxide aqueous solution at a ratio of 4.5L / Kg, heat and stir at 95°C for 30 minutes, add 98% concentrated sulfuric acid to neutralize the calcium hydroxide, and separate the solid Ingredients and calcium sulfate precipitation, add liquid cellulase with an enzyme activity of 15U / g at a ratio of 1.2g / L, stir and enzymolyze at 60°C for 70min, and obtain 10L of saccharification solution with a sugar content of 12% by mass;

[0047] (2) Add the 12% saccharified liquid into the fermenter with the obtained mass percentage, and simultaneously add 600 g of calcium carbonate, 35 g of ammonium nitrate, 5 g of potassium dihydrogen phosphate, 3 g of sodium dihydrogen phosphate, 4 g of zinc sulfate, 4 g of magnesium sulfate and sulfuric acid Ferrous iron 1.0g, sterilized and cooled to 32°C-34°C, inoculated spore concentration of 10 11 500mL of rhizopus oryzae AS3.819 spore suspension per L, carry ou...

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Abstract

The invention relates to a method for producing L-lactic acid. In the method, crop straw and Rhizopus oryzae serve as raw materials. The method particularly comprises the following operation steps: A. preparing straw saccharified liquid; B. adding auxiliary material to inoculate Rhizopus oryzae for fermentation; C repeatedly fermenting 25 batches; D. acidizing fermented clear liquid; E. ultrafiltration; F. nanofilteration; G. reverse osmosis; H. ion exchange; I. concentrating in vacuum to obtain the L-lactic acid product with the mass percentage concentration of 85%. The invention takes the straw hydrolysis saccharified liquid as the main raw material to prepare L-lactic acid, which obviously lowers the production cost of L-lactic acid; Rhizopus oryzae is adopted for once inoculation proliferation, thallus can be reused for several times to produce L-lactic acid, thus shortening L-lactic acid fermentation period, and obviously improving the fermentation strength of L-lactic acid; an advanced membrane separation and ion exchange integration technology is adopted to improve the lactic acid product quality; and the invention has simple process and strong continuity.

Description

technical field [0001] The present invention relates to a method for producing L-lactic acid, in particular to Rhizopus oryzae AS3.819 using crop stalks to hydrolyze sugar solution, bacterial cells to repeatedly ferment to produce L-lactic acid and membrane separation and ion exchange integration Method for separating L-lactic acid. Background technique [0002] As an important organic acid, lactic acid has been widely used in food, medicine, medicine and chemical industry. In recent years, in the research to solve the "white pollution" caused by plastic products around the world, it was found that the polymer of L-lactic acid formed by the polymerization of L-lactic acid as a monomer - the plastic film made of poly-L-lactic acid, 100% biodegradable. The human body can only metabolize L-lactic acid. The World Health Organization advocates the use of L-lactic acid instead of DL-lactic acid in the fields of food and medicine. The demand for L-lactic acid continues to expand...

Claims

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Application Information

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IPC IPC(8): C12P7/56C07C59/08C07C51/42C07C51/47C12R1/845
Inventor 姜绍通刘模吴学凤唐晓明潘丽军郑志李兴江罗水忠庞锐陈小举
Owner HEFEI UNIV OF TECH
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