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CN-121976409-A - Method for pretreatment of lignocellulose by rumen microorganism dry method

CN121976409ACN 121976409 ACN121976409 ACN 121976409ACN-121976409-A

Abstract

The invention discloses a method for pretreating lignocellulose by using a rumen microorganism dry method, which relates to the technical field of resources and environment. The method comprises the steps of crushing lignocellulose to 1-5cm, then filling the crushed lignocellulose into a sealed space, spraying microorganisms according to the mass ratio of rumen microorganisms to lignocellulose volatile components of 0.015-0.03:1 under an anaerobic condition, controlling the water content of a system to be 30% -60%, regulating and controlling the pretreatment temperature to be 35-42 ℃, the pH value to be 6.0-7.5 and the time to be 10-14 days, enabling the total abundance of functional microorganisms Pseudacidovorax, hallella, prevotellamassilia to be more than or equal to 55%, enabling the three types of microorganisms to form strong interaction with specific companion bacteria respectively, and carrying out process regulation and control according to the crystallinity and the yield of reducing sugar when the relative crystallinity of the lignocellulose is reduced by more than 15% and the volatile components are reduced by 10% after pretreatment is completed for 10 days. The invention adopts a dry process and combines a bionic principle and a solid state fermentation technology, realizes the full-component cascade utilization of lignocellulose, provides a green solution for the industrialized and high-valued conversion of lignocellulose, and has remarkable economic, social and environmental protection benefits.

Inventors

  • XU XIAOCHEN
  • Zhao Huancui
  • JIN WENYAO
  • GAO LINGYUN

Assignees

  • 大连理工大学
  • 大连大学

Dates

Publication Date
20260505
Application Date
20260107

Claims (10)

  1. 1. A method for dry pretreatment of lignocellulose using rumen microorganisms, comprising: pulverizing lignocellulose, and filling into a sealed space; Uniformly spraying rumen microorganisms on the surface of the crushed lignocellulose under the anaerobic condition, and controlling the mass ratio of the rumen microorganisms to the lignocellulose volatile matters and the water content of a reaction system; Regulating and controlling the temperature, the pH value and the reaction time parameters in the pretreatment process to ensure that the total abundance of functional microorganisms in a reaction system reaches a preset standard; judging whether the pretreatment reaches a terminal point or not according to the relative crystallinity degradation of lignocellulose and the volatile component degradation; when pretreatment is carried out to a preset time node, the crystallization degree standard reaching condition of lignocellulose and the accumulated yield of reducing sugar are combined, and the pretreatment process is regulated and controlled in a targeted mode.
  2. 2. The method for dry pretreatment of lignocellulose by utilizing rumen microorganisms according to claim 1, wherein the mass ratio of the rumen microorganisms to lignocellulose volatile matters is 0.015-0.03:1, and the water content of a reaction system is controlled to be 30% -60%.
  3. 3. The method for dry pretreatment of lignocellulose by rumen microorganisms according to claim 1, wherein the pretreatment temperature is 35-42 ℃, the pH is 6.0-7.5, and the reaction time is 10-14 days.
  4. 4. The method for dry pretreatment of lignocellulose by rumen microorganisms according to claim 1, wherein the total abundance of functional microorganisms is not less than 55%, the functional microorganisms comprise Pseudacidovorax, hallella and Prevotellamassilia, the specific control Pseudacidovorax gene abundance is more than 30%, hallella abundance is more than 20% and Prevotellamassilia abundance is more than 5%.
  5. 5. The method for dry pretreatment of lignocellulose by using rumen microorganisms according to claim 4, wherein the control Pseudacidovorax forms a strong interaction relationship with LENTISPHAERAE BACTERIUM adurb.
  6. 6. The method for dry pretreatment of lignocellulose using a rumen microorganism according to claim 4, wherein the control Hallella forms a strong interaction relationship with Methanobrevibacter、Lentisphaerae bacterium ADurb.Bin242、Bacteroidetes bacterium ADurb.BinA104、Bacteroidetes bacterium ADurb.Bin037.
  7. 7. The method for dry pretreatment of lignocellulose using a rumen microorganism according to claim 4, wherein the control Prevotellamassilia forms a strong interaction relationship with Pseudacidovorax、Bacteroidetes bacterium ADurb.BinA104、Lentisphaerae bacterium ADurb.Bin242、Bacteroidetes bacterium ADurb.Bin123.
  8. 8. The method for dry pretreatment of lignocellulose by using rumen microorganisms according to claim 1, wherein the pretreatment endpoint determination criteria is a reduction in relative crystallinity of 15% or more and a reduction in volatiles of 10% or more.
  9. 9. The method for dry pretreatment of lignocellulose by using rumen microorganisms according to claim 1, wherein the preset time node is 10 days, the pretreatment is judged to be failed when the crystallinity is not up to the standard and the cumulative yield of reducing sugar is lower than 4mg/g, and the rumen microorganisms are supplemented to continue the pretreatment when the crystallinity is up to the standard and the cumulative yield of reducing sugar is lower than 4 mg/g.
  10. 10. The method for dry pretreatment of lignocellulose using rumen microorganisms according to claim 1, wherein the crushed particle size of lignocellulose is 1-5cm.

Description

Method for pretreatment of lignocellulose by rumen microorganism dry method Technical Field The invention relates to the technical field of resources and environment, in particular to a method for pretreating lignocellulose by using a rumen microorganism dry method. Background The straw is a solid waste resource with huge yield in rural areas in China, and the recycling and high-valued comprehensive utilization of the straw has important strategic significance for developing circular economy, relieving energy shortage, improving ecological environment and solving the problem of helping power-assisted 'three farmers'. However, the current straw utilization modes are widely and widely spread, direct returning and the like are concentrated, the added value of products is extremely low, the core sign is that the special structure of lignocellulose in the straw is formed by interweaving cellulose, hemicellulose and lignin, and the special structure is compact three-dimensional binding structure, the cellulose, the hemicellulose and the lignin are tightly connected and have strong stability, so that effective contact of degrading enzyme and a substrate is greatly hindered, and the obvious problems of high investment cost, high pretreatment difficulty, low conversion efficiency and the like are caused in the recycling of lignocellulose, so that the large-scale development of straw resources is severely restricted. To solve the technical bottleneck, three lignocellulose pretreatment technologies, namely a physical method, a chemical method and a biological method, are developed at home and abroad. The physical method breaks the material structure through mechanical crushing, high-temperature steaming and boiling, and the like, but has high energy consumption, large equipment investment and limited treatment effect, and the chemical method breaks lignin-carbohydrate complex by means of acid, alkali, oxidant, and the like, so that the subsequent degradation efficiency can be improved, but the problems of large consumption of chemical reagents, difficult recovery, easy generation of toxic byproducts, high environmental pollution risk, and the like exist, and the two are difficult to meet the requirements of green and large-scale application. In contrast, the biological pretreatment method has the advantages of environmental friendliness, low energy consumption, simple equipment requirement, no secondary pollution and the like, and becomes a research hotspot and a development direction. Among many biological systems, rumen microorganisms have been widely used in anaerobic digestion research due to their natural ability to efficiently degrade lignocellulose. The rumen of ruminant is a natural high-efficiency degradation in-situ system, and inhabits a large number of complex microbial communities, wherein anaerobic bacteria and anaerobic fungi are core functional flora, the rumen fungi can penetrate lignin barriers to create action sites for other microorganisms, and the rumen bacteria can secrete various cellulases and hemicellulases, so that the lignocellulose is efficiently hydrolyzed through physical penetration, enzymolysis and microorganism synergistic interaction. Although the rumen microorganism pretreatment straw has huge potential, the prior related researches are deficient, and the reported technology is mostly in a wet pretreatment mode, so that the problems of difficult precise regulation and control of the hydrolysis process, complex subsequent solid-liquid separation, higher operation cost and the like exist, and the industrialized popularization is severely limited. Disclosure of Invention The invention aims to provide a method for preprocessing lignocellulose by using rumen microorganism dry method, which damages the compact structure of lignocellulose by regulating and controlling the abundance of functional microorganisms and the interaction relationship thereof, reduces the crystallinity of lignocellulose, and further realizes the efficient and green preprocessing of lignocellulose. In order to achieve the aim, the technical scheme of the application is that the method for pretreating lignocellulose by using rumen microorganism dry method comprises the following steps: pulverizing lignocellulose, and filling into a sealed space; Uniformly spraying rumen microorganisms on the surface of the crushed lignocellulose under the anaerobic condition, and controlling the mass ratio of the rumen microorganisms to the lignocellulose volatile matters and the water content of a reaction system; Regulating and controlling the temperature, the pH value and the reaction time parameters in the pretreatment process to ensure that the total abundance of functional microorganisms in a reaction system reaches a preset standard; judging whether the pretreatment reaches a terminal point or not according to the relative crystallinity degradation of lignocellulose and the volatile component degradation; when pretreatment is c