CN115161354A - Method for improving anaerobic acid production of kitchen waste through enzymolysis and microorganism reinforced coupling - Google Patents

Method for improving anaerobic acid production of kitchen waste through enzymolysis and microorganism reinforced coupling Download PDF

Info

Publication number
CN115161354A
CN115161354A CN202210768799.3A CN202210768799A CN115161354A CN 115161354 A CN115161354 A CN 115161354A CN 202210768799 A CN202210768799 A CN 202210768799A CN 115161354 A CN115161354 A CN 115161354A
Authority
CN
China
Prior art keywords
kitchen waste
enzymolysis
propionibacterium
kitchen
anaerobic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210768799.3A
Other languages
Chinese (zh)
Inventor
王攀
任连海
郑义
赵丽雅
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Technology and Business University
Original Assignee
Beijing Technology and Business University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing Technology and Business University filed Critical Beijing Technology and Business University
Priority to CN202210768799.3A priority Critical patent/CN115161354A/en
Publication of CN115161354A publication Critical patent/CN115161354A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P7/00—Preparation of oxygen-containing organic compounds
    • C12P7/40—Preparation of oxygen-containing organic compounds containing a carboxyl group including Peroxycarboxylic acids
    • C12P7/52—Propionic acid; Butyric acids
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P7/00—Preparation of oxygen-containing organic compounds
    • C12P7/40—Preparation of oxygen-containing organic compounds containing a carboxyl group including Peroxycarboxylic acids
    • C12P7/54—Acetic acid
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12R—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES C12C - C12Q, RELATING TO MICROORGANISMS
    • C12R2001/00—Microorganisms ; Processes using microorganisms
    • C12R2001/01—Bacteria or Actinomycetales ; using bacteria or Actinomycetales

Landscapes

  • Organic Chemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Zoology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Microbiology (AREA)
  • General Chemical & Material Sciences (AREA)
  • Biotechnology (AREA)
  • Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Health & Medical Sciences (AREA)
  • Genetics & Genomics (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

The invention discloses a method for improving anaerobic acid production of kitchen garbage by enzymolysis and microorganism reinforced coupling, belonging to the technical field of solid waste resource utilization and comprising the following steps: (1) Firstly, performing enzymolysis by combining cellulase and hemicellulase, and simultaneously adding the cellulase and the hemicellulase into the kitchen waste for enzymolysis; then carrying out alkali-heat pretreatment to obtain pretreated kitchen garbage; (2) The process for enhancing the production of propionic acid from kitchen waste by adding propionibacterium comprises the following steps: firstly, propionibacterium inoculum culture is carried out, and then propionibacterium inoculation bacterial liquid with the inoculation sludge mass of 20-70% is added to strengthen the kitchen waste to produce propionic acid at the initial stage of anaerobic fermentation acid production reaction. The method utilizes cellulase and hemicellulase to carry out enzymolysis on the kitchen waste in a synergistic manner so as to degrade cellulose refractory organic matters and increase the yield of even-carbon volatile fatty acid acetic acid and butyric acid; the propionibacterium is used as an exogenous microorganism to strengthen the anaerobic fermentation of the kitchen waste to generate the odd-carbon volatile fatty acid propionic acid.

Description

Method for improving anaerobic acid production of kitchen waste through enzymolysis and microorganism reinforced coupling
Technical Field
The invention relates to a method for improving anaerobic acid production of kitchen waste by coupling enzymolysis and microorganism reinforcement, which is mainly a method for improving the yield of volatile fatty acid generated by anaerobic fermentation of the kitchen waste by coupling the enzymolysis and the microorganism reinforcement; belongs to the technical field of solid waste resource utilization.
Background
Volatile Fatty Acids (VFAs) are a class of carboxylic acids consisting of 2 to 6 carbon atoms; has wide application value in various fields, such as synthesis of industrial chemicals (ester, ketone, aldehyde and alcohol) as precursors, production of biodegradable plastics (polyhydroxyalkanoate) and the like.
At present, the process flow of synthesizing volatile fatty acid is mainly divided into a chemical method and a biological method; in industrial production, volatile fatty acids are mainly produced by oxidation or carboxylation of chemical precursors (such as aldehydes and olefins) produced in the conventional petroleum processing process, which will cause the consumption of non-renewable petroleum resources and discharge carbon dioxide, exacerbating greenhouse effect; the process of biologically synthesizing volatile fatty acid can relieve the consumption of petrochemical resources, but at present, pure carbon sources such as glucose or sucrose are used as main raw materials, which can also cause the question whether the technology has green development prospect. Therefore, in order to meet the requirements of green chemical synthesis and sustainable development, the search for the production of volatile fatty acid by using organic waste as a raw material becomes a research hotspot.
With the continuous promotion of the garbage classification policy in China, the kitchen garbage yield shows an increasing trend; the kitchen garbage in China accounts for 59 percent of the urban domestic garbage, and the yield reaches 1.2 to 1.3 hundred million tons per year. Kitchen waste is a cheap and easily available municipal organic solid waste, and has attracted attention as a raw material for biosynthesis of volatile fatty acids due to its advantages such as excellent biodegradability and rich organic content. The kitchen waste refers to perishable waste such as vegetable leaves on the vegetable sides, melon and fruit peels and kernels, leftovers, waste food and the like generated in families; food residues, food processing wastes and waste edible oil and fat generated in food processing, food service, unit catering and other activities of enterprises and institutions engaged in catering management activities, troops, schools, enterprise careers and other unit collective canteens; vegetable, fruit and vegetable garbage, rotten meat, broken meat and bones, aquatic products, livestock and poultry viscera and the like generated in farmer markets and agricultural product wholesale markets; the main components are carbohydrate, protein, cellulose substances and a small amount of lipid. The method utilizes the volatile fatty acid with high synthetic value and wide application of the kitchen waste, can realize the reduction of the kitchen waste, and can synthesize the volatile fatty acid chemical with high utilization value so as to reduce the consumption of petroleum-based raw materials. However, the fruit and vegetable wastes in the kitchen wastes contain a large amount of cellulose substances which are main components of plant cell walls, the crystallization structure is firm, the degradation is difficult in the treatment process, the yield of synthesized volatile fatty acid is low, and the like.
At present, aiming at the problems of low degradation efficiency of kitchen waste and low yield of volatile fatty acid, some process technologies are developed to improve the degradation efficiency and acid production performance, such as carrying out thermal hydrolysis and enzymolysis pretreatment on kitchen waste raw materials, or promoting the anaerobic fermentation of the kitchen waste to produce acid by changing reaction conditions and other means in the anaerobic fermentation process. These methods all adopt a single means, the acid yield is improved to a lower extent, and how to comprehensively improve the yield of the volatile fatty acids with even number of carbons and odd number of carbons is not comprehensively considered.
Therefore, it is urgent to explore a method for improving anaerobic fermentation and acid production of kitchen waste by coupling enzymolysis and microorganism reinforcement and comprehensively increasing the yield of volatile fatty acids with odd and even carbon numbers.
Disclosure of Invention
The invention aims to provide a method for producing volatile fatty acid by performing coupled addition of propionibacterium after the kitchen waste is subjected to enzymolysis cooperatively with cellulase and hemicellulase and then is subjected to anaerobic fermentation, hydrolysis and acidification. Aiming at kitchen waste raw materials, cellulose refractory organic matters are degraded by utilizing the synergistic effect of cellulase and hemicellulase, and the yield of volatile fatty acid acetic acid and butyric acid with even number of carbon atoms in the subsequent anaerobic fermentation acid production process is increased; in the anaerobic fermentation acid production process of the kitchen waste, propionibacterium is added as an exogenous microorganism to increase the yield of the odd-carbon volatile fatty acid propionic acid in the anaerobic fermentation acid production process, and the method for stably and effectively enhancing the production of the volatile fatty acid by the anaerobic fermentation of the kitchen waste is convenient to operate and environment-friendly.
The above object of the present invention is achieved by the following technical solutions:
a method for improving anaerobic acidogenesis of kitchen waste by coupling enzymolysis and microorganism reinforcement comprises the following steps:
(1) Cellulase and hemicellulase synergistic enzymolysis pretreatment process step
(1) Cellulase and hemicellulase for synergistic enzymolysis
Cellulase and hemicellulase are used as enzymolysis additives and added into kitchen garbage with a solid content of 5-40 wt%, and the addition amount of the cellulase is 100-150U/g VS Kitchen waste (U: 1 minute amount of enzyme capable of converting 1. Mu. Mol of substrate, VS Kitchen waste : volatile solid in kitchen garbage), the addition amount of the hemicellulase is 200-800U/g VS Kitchen waste (ii) a Performing synergistic enzymolysis for 12-48 h at 35-55 ℃ to complete the enzymolysis process;
(2) alkali thermal pretreatment
Adjusting the pH value of the kitchen garbage after enzymolysis to 7-9, and carrying out alkali treatment for 4-8 h; carrying out heat treatment at 80-120 ℃ for 1-3 h to obtain a pretreated kitchen waste raw material;
(2) The process for producing propionic acid by adding propionibacterium to strengthen anaerobic fermentation of kitchen waste comprises the following steps:
(1) propionibacterium inoculum culture method
Inoculating Propionibacterium to a stoppered serum bottle filled with a sterilized culture medium, filling high-purity nitrogen to ensure the anaerobic environment in the bottle, sealing with a rubber stopper, culturing, and then using sterile water to adjust the OD of the Propionibacterium liquid 600 Adjusting the value to 1.0-2.0 as an inoculation bacterial liquid;
(2) method for producing propionic acid from kitchen garbage by strengthening propionibacterium
Preparing an anaerobic fermentation acid production substrate from the kitchen waste raw material pretreated in the step (1) and anaerobic inoculation sludge according to a volatile solid mass ratio of (2-9).
Preferably, in step (1) of (1), the kitchen waste includes kitchen waste or perishable organic waste generated by waste classification.
Preferably, in step (1) of step (1), the solid content of the kitchen waste is 5 to 15 wt%.
Preferably, in step (1), the cellulase is added in an amount of 110 to 130U/g VS Kitchen waste The addition amount of the hemicellulase is 400-600U/g VS Kitchen waste (ii) a The enzymolysis temperature is 40-50 ℃, and the enzymolysis time is 18-36 h. Cellulases and hemicellulases are commercially available products.
Preferably, in the step (2) of the step (1), the pH value of the alkali treatment of the kitchen garbage after enzymolysis is 7.5-8.5, and the alkali treatment time is 5-7 hours; the heat treatment temperature is 90-110 ℃, and the heat treatment time is 1.5-2.5 h.
Preferably, in the step (1) of the step (2), the Propionibacterium has the Latin name of Propionibacterium acidipropionici and the preservation number of CGMCC 1.2232, the preservation unit is China center for culture Collection of microorganisms, and the isolated source is Swiss cheese.
Preferably, in the step (1) of the step (2), the OD of the Propionibacterium inoculated solution 600 The range is 1.3 to 1.8.
Preferably, in the step (1) of the step (2), the OD of the Propionibacterium inoculated solution 600 Is 1.5.
Preferably, in the step (2) and the step (2), the mixture ratio of the pretreated kitchen waste raw material to the anaerobic inoculation sludge is that the volatile solid mass ratio is 3 to 1.
The method for calculating the volatile solid content in the kitchen garbage raw material and the anaerobic inoculation sludge comprises the following steps: the solid content (% by weight) and the ash content (% by weight) were measured according to GB 5009.3-2016 and GB 5009.4-2016, respectively, and the difference between the solid content and the ash content indicates the volatile solid content (% by weight).
Wherein, anaerobic inoculation sludge is taken from an IC reactor (internal circulation anaerobic reactor) in sewage treatment.
Preferably, in step (2) (1), the sterilized culture medium has the following composition: 10g/L of tryptic casein, 5g/L of yeast extract and 10g/L of sodium lactate; the pH value is 7.0-7.2; the propionibacterium is cultured for 1.5 to 2.5 days at the temperature of between 29 and 32 ℃.
Has the beneficial effects that:
the invention has the advantages that: 1. cellulose and hemicellulase are used for carrying out synergistic enzymolysis on kitchen garbage to degrade cellulose organic matters and increase the yield of even-numbered carbon volatile fatty acids in the subsequent anaerobic fermentation acid production process, wherein the cellulose and hemicellulose degradation rates after enzymolysis respectively reach 40.03% and 32.91%; the yield of acetic acid in the volatile fatty acid with even number of carbon atoms in the acid production process of anaerobic fermentation can be improved by 56.17 percent, and the yield of butyric acid can be improved by 108.30 percent. 2. Compared with the method without strengthening of propionibacterium, the yield of the odd-numbered volatile fatty acid propionic acid in the volatile fatty acid generated by strengthening the kitchen garbage by using the propionibacterium as an exogenous microorganism is improved by 79.57 percent.
Drawings
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is an SEM photograph of enzymatic digestion of kitchen waste in examples 1 to 5 of the present invention;
FIG. 3 is a graph showing the effect of different enzymatic conditions of the present invention on the production of total VFAs from kitchen waste;
FIG. 4 shows the effect of different enzymatic conditions of the present invention on the production of acetic acid and butyric acid from kitchen waste;
FIG. 5 is the effect of the addition of Propionibacterium on the production of total VFAs from kitchen waste in accordance with the invention;
FIG. 6 shows the effect of the addition of Propionibacterium on the production of propionic acid from kitchen waste according to the invention;
FIG. 7 is the effect of the time of addition of Propionibacterium on the production of total VFAs from kitchen waste according to the invention;
FIG. 8 shows the effect of the addition time of Propionibacterium on the production of propionic acid from kitchen waste.
Detailed Description
The invention is further described below with reference to specific examples.
The advantages and features of the present invention will become more apparent as the description proceeds. These examples are illustrative only and do not limit the scope of the present invention in any way. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that such changes and substitutions are intended to be within the scope of the invention.
The methods used in the examples are conventional methods unless otherwise specified, all the percentage concentrations are mass percentage concentrations, and all the solvents in the medium are distilled water.
As shown in fig. 1, the kitchen waste is crushed and dehydrated to obtain kitchen waste with a solid content of 5-15 wt%, enzymatic hydrolysis is completed by adopting the cellulase and hemicellulase synergistic enzymatic hydrolysis process, and then alkaline heat treatment is performed to obtain pretreated kitchen waste; then the pretreated kitchen garbage is subjected to microorganism enhanced anaerobic fermentation hydrolysis to produce acid, and volatile fatty acid is obtained.
The method for optimizing the cellulase and hemicellulase collaborative enzymolysis process comprises the following steps: firstly, cellulase and hemicellulase are used as enzymolysis additives and are simultaneously added into kitchen garbage with a solid content of 5-40 wt%, and the addition amount of the cellulase is 100-150U/g VS Kitchen waste The addition amount of the hemicellulase is 200-800U/g VS Kitchen waste (ii) a Carrying out synergistic enzymolysis for 12-48 h at 35-55 ℃; after the enzymolysis, the cellulose content in the kitchen garbage is degraded from 29.25 +/-0.53 percent to 17.55 +/-1.47 percent, and the hemicellulose content is degraded from 15.80 +/-0.77 percent to 10.60 +/-0.38 percent; then adjusting the pH value of the kitchen waste to 7-9 for alkali treatment for 4-8 h; heat treatment is carried out for 1 to 3 hours at the temperature of between 80 and 120 ℃; the acid production effect of the kitchen garbage is detected after anaerobic fermentation, hydrolysis and acidification, the yield of volatile fatty acid generated by the kitchen garbage after enzymolysis can be improved by 61.61% compared with the kitchen garbage without enzymolysis, the yield of acetic acid is improved by 56.17% compared with the kitchen garbage without enzymolysis, and the yield of butyric acid is improved by 108.30% compared with the kitchen garbage without enzymolysis;
the enzymolysis process of the invention is a method for the synergistic treatment of cellulase and hemicellulase, and the cellulase and the hemicellulase are added simultaneouslyThe solid content of the kitchen waste is preferably 5 to 15 weight percent, and the kitchen waste is uniformly mixed; the contents of the better cellulase and hemicellulase are respectively 110-130U/g VS during enzymolysis Kitchen waste And 400-600U/g VS Kitchen waste (ii) a The preferred enzymolysis temperature is 40-50 ℃, and the preferred enzymolysis time is 18-36 h; the pH value of the better kitchen waste alkali treatment is 7.5-8.5, and the time is 5-7 h; the heat treatment temperature is preferably 90-110 ℃, and the time is preferably 1.5-2.5 h.
The method for optimizing the process mode of adding the propionibacterium to strengthen the anaerobic fermentation of the kitchen waste to generate the propionic acid comprises the following steps: firstly, culturing propionibacterium, inoculating propionibacterium into a serum bottle with a plug and a sterilized culture medium (10 g/L of tryptic casein, 5g/L of yeast extract, 10g/L of sodium lactate and pH of 7.0-7.2), filling high-purity nitrogen to ensure the anaerobic environment in the bottle, sealing by using a rubber plug, and culturing for 2 days at the temperature of 30 ℃; OD of bacterial suspension with sterile Water 600 The value is adjusted to be 1.0-2.0 to serve as an inoculation bacterial liquid, then an anaerobic fermentation acid production substrate is prepared from the pretreated kitchen waste raw material and anaerobic inoculation sludge according to the mass ratio of volatile solids to solids of 1-9, propionibacterium acidipropionici (CGMCC 1.2232) is used as an exogenous microorganism, propionibacterium acidipropionici (CGMCC 1.2232) with the mass of 20-70% of the mass of the inoculation sludge is respectively added at the initial reaction time to perform anaerobic hydrolytic acidification on the kitchen waste, and the generation of propionic acid is enhanced, after the microorganism enhancement of the invention, the yield of volatile fatty acid generated by anaerobic hydrolytic acidification on the kitchen waste can reach 41.16 +/-1.49 g/L, and the yield of propionic acid can reach 8.79 +/-0.29 g/L, compared with the yield of propionic acid which is not enhanced by Propionibacterium acidipropionici, the yield of propionic acid is improved by 79.57%.
After the propionibacterium is cultured, the better propionibacterium inoculation bacterial liquid OD 600 The range is between 1.3 and 1.8; when the kitchen waste is hydrolyzed to produce acid to generate volatile fatty acid, the better pretreated kitchen waste raw material and the anaerobic inoculated sludge are prepared into an anaerobic fermentation acid production substrate according to the mass ratio of volatile solids of 3.
Example 1
Kitchen waste (kitchen waste generated by a certain community) with the solid content of 11.2 percent is not subjected to enzymolysis.
Example 2
The method for enzymolysis of kitchen garbage by cellulase comprises the following steps:
cellulase (commercially available) was added to kitchen waste (kitchen waste produced in a certain community in example 1) with a solid content of 11.2% as an enzymatic additive, and the amount of cellulase added was 120U/g VS Kitchen waste (ii) a Carrying out enzymolysis for 24h at 45 ℃ to finish the enzymolysis process.
Example 3
The method for enzymolysis of kitchen garbage by hemicellulase comprises the following steps:
hemicellulase (commercially available) was added as an enzymatic additive to kitchen waste (kitchen waste produced in a certain community in example 1) having a solid content of 11.2%, wherein the amount of hemicellulase added was 500U/g VS Kitchen waste (ii) a Carrying out enzymolysis for 24h at the temperature of 45 ℃ to finish the enzymolysis process.
Example 4
The method comprises the following steps of sequentially carrying out enzymolysis on kitchen garbage by cellulase and hemicellulase (in turn):
(1) Cellulase (commercially available) was added to kitchen waste (kitchen waste from a community in example 1) with a solid content of 11.2% as an enzymatic additive, and the amount of cellulase added was 120U/g VS Kitchen waste (ii) a Carrying out enzymolysis for 24h at 45 ℃ to obtain semi-enzymatic hydrolysis kitchen waste;
(2) Adding hemicellulase (commercially available) as enzymolysis additive into the above semi-enzymolysis kitchen garbage, wherein the addition amount of hemicellulase is 500U/g VS Kitchen waste (ii) a Carrying out enzymolysis for 24h at 45 ℃ to finish the enzymolysis process.
Example 5
The method for enzymolysis of kitchen waste by cellulase and hemicellulase in a synergistic manner comprises the following steps:
cellulase (commercially available) and hemicellulase (commercially available) were added simultaneously as enzymatic additives to kitchen waste (kitchen waste from a community in example 1) having a solids content of 11.2%Residual garbage), the addition amount of cellulase is 120U/g VS Kitchen waste The addition amount of the hemicellulase is 500U/g VS Kitchen waste (ii) a And (4) performing enzymolysis for 24 hours at the temperature of 45 ℃ in a synergistic manner to finish the enzymolysis process.
Examples 1 to 5 set up a non-enzymatic hydrolysis (example 1) and 4 different enzymatic hydrolysis modes for kitchen waste, which are a single cellulase enzymatic hydrolysis (example 2), a single hemicellulase enzymatic hydrolysis (example 3), a cellulase and a hemicellulase sequentially enzymatic hydrolysis (example 4), and a cellulase and a hemicellulase simultaneously enzymatic hydrolysis (example 5).
In the experiment of the invention, a Van Soest (Van Soest) fiber washing analysis method is adopted for measuring the content of the cellulose and the hemicellulose. As shown in fig. 2, is an SEM image of the kitchen waste after enzymolysis in examples 1-5 of the present invention, wherein: a is example 1; b is example 2; c is example 3; d is example 4; e is example 5.
In the embodiment 1 (a), fine granular substances exist on the surface of the kitchen waste, the structure is complete and compact, and organic matters are not easily utilized by microorganisms; in the embodiment 2 (b), the cell wall part on the surface of the kitchen waste is broken, the structure is obviously changed, the porosity is increased, and organic matter hydrolysis is facilitated; in the embodiment 3 (c), the kitchen waste has smooth surface and no damage to the structure, and the hydrolysis effect is not ideal by using the hemicellulase; in the embodiment 4 (d), large-area cell walls on the surface of the kitchen waste are broken, holes are generated inside the kitchen waste, the specific surface area is increased, and organic matter hydrolysis is facilitated; in the embodiment 5 (e), on the basis of large-area breakage of the surface layer of the kitchen waste, part of the organic matter is hydrolyzed, and crystalline fiber substances are exposed, so that the structure is more favorable for the utilization of microorganisms in the anaerobic fermentation process.
The cellulose and hemicellulose contents of the kitchen garbage are still higher than 26% and 14% after the kitchen garbage is subjected to enzymolysis by using single cellulase and hemicellulase; after the cellulase and the hemicellulase are subjected to enzymolysis at the same time, compared with the condition that the enzymolysis is not carried out, the cellulose is hydrolyzed by 40.03 percent, and the hemicellulose is hydrolyzed by 32.91 percent; compared with the enzymolysis in the embodiments 2, 3 and 4, the degradation rate of the organic matters which are difficult to degrade is improved.
TABLE 1 degradation of cellulose and hemicellulose by enzymatic hydrolysis of kitchen waste
Figure BDA0003723154970000071
Then respectively adjusting the pH value of the kitchen garbage subjected to enzymolysis in the embodiments 1 to 5 to 8 for alkali treatment for 6 hours; heat treatment is carried out for 2 hours at 100 ℃ to obtain the pretreated kitchen waste raw material. Preparing an anaerobic fermentation acid production substrate by using the pretreated kitchen waste as a raw material and anaerobic inoculated sludge (sold in the market) according to a volatile solid mass ratio of 4:
respectively measuring the solid content and the ash content of the kitchen garbage and the anaerobic inoculated sludge according to methods GB 5009.3-2016 and GB 5009.4-2016, wherein the difference value of the solid content and the ash content represents the volatile solid content; the volatile solid content of the kitchen waste was 10.20 wt%, and the volatile solid content of the anaerobic inoculated sludge was 3.19 wt%.
Example 1: the yield of the volatile fatty acid generated by the kitchen garbage without enzymolysis is 22.47 +/-1.18 g/L, wherein the yield of the acetic acid is 9.77 +/-0.20 g/L, and the yield of the butyric acid is 7.27 +/-0.19 g/L.
Example 2: the yield of the volatile fatty acid generated by the kitchen waste after being treated by the cellulase is improved by 34.23 percent compared with the yield of the volatile fatty acid generated by the kitchen waste without being treated by enzymolysis (example 1), wherein the yield of the acetic acid is improved by 36.40 percent, and the yield of the butyric acid is improved by 77.70 percent.
Example 3: the yield of the volatile fatty acid generated by the kitchen waste after only being treated by the hemicellulase is increased by 29.43 percent compared with the yield of the volatile fatty acid generated by the kitchen waste without being treated by enzymolysis (example 1), wherein the yield of acetic acid is increased by 29.44 percent, and the yield of butyric acid is increased by 34.52 percent.
Example 4: the kitchen waste is firstly subjected to cellulase treatment and then subjected to hemicellulase treatment, so that the yield of generated volatile fatty acid is increased by 42.45 percent compared with that of the kitchen waste which is not subjected to enzymolysis treatment (embodiment 1), wherein the yield of acetic acid is increased by 52.83 percent, and the yield of butyric acid is increased by 55.17 percent.
Example 5: the kitchen waste is treated by cellulase and hemicellulase simultaneously, and the yield of generated volatile fatty acid is improved by 61.61 percent compared with that of the kitchen waste which is not treated by enzymolysis (embodiment 1), wherein the yield of acetic acid is improved by 56.17 percent, and the yield of butyric acid is improved by 108.30 percent.
As shown in FIG. 3, the influence of different enzymolysis conditions of the present invention on the anaerobic fermentation of kitchen waste to produce volatile fatty acid; as shown in fig. 4, it is the influence of different enzymolysis conditions of the invention on the anaerobic fermentation of kitchen waste to generate even-numbered volatile fatty acids acetic acid and butyric acid; it can be seen that, compared with example 1, the effect of simultaneously performing cellulase and hemicellulase treatments on the promotion of the yield of volatile fatty acids, the yield of acetic acid and the yield of butyric acid generated by kitchen waste is optimal, and the yield of volatile fatty acids is improved to a certain extent compared with the yield of volatile fatty acids generated by other enzymolysis modes in examples 2, 3 and 4.
Examples 6 to 10
Adjusting the pH value of the kitchen waste subjected to enzymolysis prepared in the embodiment 5 to 8, and performing alkali treatment for 6h; heat treatment is carried out for 2 hours at 100 ℃ to obtain the pretreated kitchen waste raw material. Preparing an anaerobic fermentation acid-producing substrate by using the pretreated kitchen waste as a raw material and anaerobic inoculated sludge (sold in the market) according to the mass ratio of volatile solids of 4; and propionibacterium inoculation bacterial liquids (OD) which are not reinforced by propionibacterium and are respectively added with 10 percent, 30 percent, 50 percent and 70 percent of anaerobic inoculation sludge by mass at the initial stage of reaction 600 = 1.5) propionibacterium enrichment experiments.
The method for culturing the propionibacterium inoculum comprises the following steps: inoculating Propionibacterium (China center for culture of microorganisms, the Latin science of Propionibacterium acidipronici, CGMCC 1.2232, original number is DSM20272, strain source DSMZ, direct source country is Germany, preservation time is 7 months and 14 days in 1998, other preservation number = ATCC4875= NCIMB8070, non-mode strain, culture temperature is 30 ℃, culture medium 0286, other culture conditions are anaerobic, separation source is Swiss cheese) into a bottle with a plug containing sterilized culture medium, filling high-purity nitrogen to ensure the anaerobic environment in the bottle, sealing with a rubber plug, culturing at 30 ℃ for 2 days, and using sterile water to ensure OD of the Propionibacterium liquid 600 Adjusting the value to 1.5, and performing a microorganism strengthening experiment as an inoculation bacterial liquid; the sterilized medium consisted of: 10g/L of tryptic casein and 5g/L of yeast extractSodium lactate 10g/L; the pH value is 7.0-7.2.
Example 6: the yield of volatile fatty acid generated by kitchen waste which is not subjected to propionibacterium reinforcement is 37.68 +/-2.16 g/L; the yield of propionic acid was 4.89. + -. 0.16g/L.
As shown in FIG. 5, the influence of the addition amount of Propionibacterium in the present invention on the production of total VFAs from kitchen waste is shown, and the volatile fatty acid yields after the strengthening of the Propionibacterium-inoculated liquid solutions in examples 7, 8, 9, and 10, in which the sludge mass was 10%, 30%, 50%, and 70%, were 36.12. + -. 1.36, 41.16. + -. 1.49, 34.09. + -. 2.88, and 32.93. + -. 1.47g/L, respectively; as shown in FIG. 6, the effect of the addition amount of Propionibacterium of the present invention on the production of propionic acid from kitchen waste was demonstrated, and the yields of propionic acid were 5.81. + -. 0.04, 8.79. + -. 0.29, 7.96. + -. 0.59 and 7.41. + -. 0.07g/L, respectively. In example 8, the yield of volatile fatty acid is improved to the maximum after the propionibacterium inoculation bacterial liquid with 30% of anaerobic inoculation sludge mass is added, and compared with example 6, the yield of volatile fatty acid is improved by 9.21% without microbial reinforcement and is higher than the adding conditions of other propionibacterium; the propionic acid yield was improved by 79.57% compared to example 6, and the addition of propionibacterium exceeding 30% by mass of anaerobically inoculated sludge did not further significantly improve propionic acid yield.
Examples 11 to 12
Carrying out anaerobic fermentation hydrolysis acid production reaction on the pretreated kitchen waste, as shown in figures 7 and 8, wherein the influence of the addition time of the propionibacterium on the generation of total VFAs and propionic acid in the kitchen waste is shown respectively; examples 11 and 12 are strengthening experiments with propionibacterium added with 30% of the mass of anaerobically inoculated sludge only at 3 days and 6 days of reaction, respectively, and the volatile fatty acid yields are 41.16 + -2.04 and 35.05 + -1.24 g/L, respectively; the propionic acid yields were 4.90. + -. 0.15 and 5.28. + -. 0.32g/L. In combination with example 8, it can be seen that the addition of propionibacterium at the initial stage of acidogenesis by hydrolysis of kitchen waste (day 0) is most effective in increasing the yield of volatile fatty acids and the yield of propionic acid.
According to the method, the cellulase and the hemicellulase are added simultaneously in an enzymolysis mode, so that the two enzymes generate a synergistic treatment effect to improve the degradation efficiency of the kitchen waste and increase the yield of even-number carbon volatile fatty acid acetic acid and butyric acid; further, during the anaerobic fermentation and acid production process of the kitchen waste, propionibacterium is added to increase the yield of the odd-carbon volatile fatty acid propionic acid during the anaerobic fermentation and acid production process of the kitchen waste, and finally, the yield of the volatile fatty acid generated by the anaerobic fermentation of the kitchen waste is comprehensively increased by the enzymolysis and microorganism reinforced coupling method.
The above-mentioned embodiments are further detailed to explain the objects, technical solutions and advantages of the present invention, but the present invention is not limited thereto, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A method for improving anaerobic acidogenesis of kitchen waste by coupling enzymolysis and microorganism reinforcement comprises the following steps:
(1) Cellulase and hemicellulase synergistic enzymolysis pretreatment process step
(1) Cellulase and hemicellulase for synergistic enzymolysis
Cellulase and hemicellulase are used as enzymolysis additives and added into kitchen garbage with a solid content of 5-40 wt%, and the addition amount of the cellulase is 100-150U/g VS Kitchen waste The addition amount of the hemicellulose is 200-800U/g VS Kitchen waste (ii) a Performing synergistic enzymolysis for 12-48 h at 35-55 ℃ to complete the enzymolysis process;
(2) alkali thermal pretreatment
Adjusting the pH value of the kitchen garbage after enzymolysis to 7-9, and carrying out alkali treatment for 4-8 h; carrying out heat treatment at 80-120 ℃ for 1-3 h to obtain a pretreated kitchen waste raw material;
(2) The process for producing propionic acid by adding propionibacterium to strengthen anaerobic fermentation of kitchen waste comprises the following steps:
(1) propionibacterium inoculum culture method
Inoculating Propionibacterium to a serum bottle with a plug and containing a sterilized culture medium, introducing high-purity nitrogen to ensure the anaerobic environment in the bottle, sealing with a rubber plug, culturing, and then using sterile water to make OD of the Propionibacterium liquid 600 Adjusting the value to 1.0-2.0 as an inoculation bacterial liquid;
(2) method for producing propionic acid from kitchen garbage by strengthening propionibacterium
Preparing an anaerobic fermentation acid production substrate from the kitchen waste raw material pretreated in the step (1) and anaerobic inoculated sludge according to a volatile solid mass ratio of 2-9, taking Propionibacterium acidipronici as an exogenous microorganism, adding Propionibacterium acidipronici inoculation bacterial liquid with the mass of 20-70% of that of the anaerobic inoculated sludge at the initial reaction, performing anaerobic fermentation hydrolysis acidification reaction on the kitchen waste for 6-10 days at 25-35 ℃, and strengthening the generation of propionic acid and the generation of volatile fatty acid from the kitchen waste.
2. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymolysis and microbial strengthening according to claim 1, wherein the method comprises the following steps: in the step (1) of the step (1), the kitchen waste includes kitchen waste or perishable organic waste generated by waste classification.
3. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymatic hydrolysis and microbial strengthening according to claim 2, wherein the method comprises the following steps: in the step (1) of the step (1), the solid content of the kitchen waste is 5-15 wt%.
4. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymatic hydrolysis and microbial strengthening according to claim 1, wherein the method comprises the following steps: in the step (1) of the step (1), the addition amount of the cellulase is 110-130U/g VS Kitchen waste The addition amount of the hemicellulase is 400-600U/g VS Kitchen waste (ii) a The enzymolysis temperature is 40-50 ℃, and the enzymolysis time is 18-36 h.
5. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymatic hydrolysis and microbial strengthening according to claim 1, wherein the method comprises the following steps: in the step (1) and the step (2), the pH value of alkali treatment of the kitchen garbage after enzymolysis is 7.5-8.5, and the alkali treatment time is 5-7 h; the heat treatment temperature is 90-110 ℃, and the heat treatment time is 1.5-2.5 h.
6. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymatic hydrolysis and microbial strengthening according to claim 1, wherein the method comprises the following steps: in the step (2) (1), the Propionibacterium latin name is Propionibacterium acidipropionici, the preservation number is CGMCC 1.2232, and the preservation unit is China center for culture Collection of microorganisms.
7. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymolysis and microbial strengthening according to claim 1, wherein the method comprises the following steps: in the step (2) (1), the OD of the Propionibacterium inoculated liquid 600 The range is 1.3 to 1.8.
8. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymatic hydrolysis and microbial strengthening according to claim 6, wherein the method comprises the following steps: in the step (2) (1), the OD of the Propionibacterium inoculated liquid 600 ＝1.5。
9. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymatic hydrolysis and microbial strengthening according to claim 1, wherein the method comprises the following steps: in the step (2) and the step (2), the mixture ratio of the pretreated kitchen waste raw material to the anaerobic inoculation sludge is (volatile solid mass ratio) 3-5.
10. The method for improving anaerobic acidogenesis of kitchen waste by coupling enzymatic hydrolysis and microbial strengthening according to claim 1, wherein the method comprises the following steps: in step (2) (1), the sterilized culture medium comprises: 10g/L of tryptic casein, 5g/L of yeast extract and 10g/L of sodium lactate; the pH value is 7.0-7.2; the propionibacterium is cultured for 1.5 to 2.5 days at the temperature of between 29 and 32 ℃.
CN202210768799.3A 2022-06-30 2022-06-30 Method for improving anaerobic acid production of kitchen waste through enzymolysis and microorganism reinforced coupling Pending CN115161354A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210768799.3A CN115161354A (en) 2022-06-30 2022-06-30 Method for improving anaerobic acid production of kitchen waste through enzymolysis and microorganism reinforced coupling

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210768799.3A CN115161354A (en) 2022-06-30 2022-06-30 Method for improving anaerobic acid production of kitchen waste through enzymolysis and microorganism reinforced coupling

Publications (1)

Publication Number Publication Date
CN115161354A true CN115161354A (en) 2022-10-11

Family

ID=83489992

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210768799.3A Pending CN115161354A (en) 2022-06-30 2022-06-30 Method for improving anaerobic acid production of kitchen waste through enzymolysis and microorganism reinforced coupling

Country Status (1)

Country Link
CN (1) CN115161354A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117025713A (en) * 2023-09-21 2023-11-10 北京工商大学 Method for preparing ethanol by composite bacterial system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117025713A (en) * 2023-09-21 2023-11-10 北京工商大学 Method for preparing ethanol by composite bacterial system
CN117025713B (en) * 2023-09-21 2024-02-13 北京工商大学 Method for preparing ethanol by composite bacterial system

Similar Documents

Publication Publication Date Title
Hitit et al. Increased hydrogen yield and COD removal from starch/glucose based medium by sequential dark and photo-fermentation using Clostridium butyricum and Rhodopseudomonas palustris
Sun et al. Feasibility of dry anaerobic digestion of beer lees for methane production and biochar enhanced performance at mesophilic and thermophilic temperature
Yasin et al. Food waste and food processing waste for biohydrogen production: a review
Song et al. Microbial production of lactic acid from food waste: latest advances, limits, and perspectives
Srivastava et al. Biohydrogen production using kitchen waste as the potential substrate: A sustainable approach
Ma et al. The utilization of acid-tolerant bacteria on ethanol production from kitchen garbage
Taifor et al. Elucidating substrate utilization in biohydrogen production from palm oil mill effluent by Escherichia coli
Waqas et al. Conversion of food waste to fermentation products
US20240102058A1 (en) Caproate-producing bacterium with multiple substrate utilization capabilities and its applications
JP2011514806A5 (en)
CN102533609B (en) Methane dry fermentation compound bacteria
Tsapekos et al. Fermentative production of lactic acid as a sustainable approach to valorize household bio-waste
CN111117937A (en) Novel acid-resistant salt-resistant composite bacterium for degrading kitchen waste and preparation method and application thereof
CN106811438B (en) Straw degradation acidification microbial inoculum and preparation method thereof
US10301652B2 (en) Process for hydrogen production from glycerol
CN110791533A (en) Method for improving acid production of kitchen waste saccharified residue through fermentation by using rumen microorganisms
CN113174416A (en) Method for producing bacterial cellulose by fermenting kitchen waste with black tea fungus
CN115161354A (en) Method for improving anaerobic acid production of kitchen waste through enzymolysis and microorganism reinforced coupling
Rawoof et al. Enhancement of lactic acid production from food waste through simultaneous saccharification and fermentation using selective microbial strains
WO2018088884A1 (en) Method for obtaining a microbial consortium in order to produce hydrogen and hydrolysates using complex substrates
Reddy et al. Production of biofuel precursor molecules (monocarboxylic acids, biohydrogen) from apple and pumpkin waste through an anaerobic fermentation process
US10801043B2 (en) Process for hydrogen production from glycerol
CN103952447A (en) Method for producing succinic acid by virtue of fermentation under anaerobic conditions
Hegde et al. Sustainable waste-to-energy technologies: fermentation
Sinbuathong et al. Preparation of active hydrogen-producing cultures from palm oil mill sludge for biohydrogen production system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination