CN111690588A - Method for preparing culture medium from straw degradation product - Google Patents

Abstract

The invention belongs to the field of bioflocculants, and particularly discloses a method for preparing a culture medium by using straw degradation products, which comprises the following steps of S1: preparation of straw fermentation liquor, S2: preparation of flocculogenic bacteria, S3: so as to obtain straw fermentation liquor as a culture medium of the flocculogenic bacteria. The invention aims to find a proper low-price culture medium to replace the traditional high-price raw materials, utilizes agricultural waste straws as a main carbon source in a fermentation substrate through mixed fermentation, and adopts a cellulose degradation bacteria decomposition technology to degrade the straws to obtain a product, so that a low-cost culture medium is further developed, a symbiotic organic combination of cellulose degradation and microbial flocculation is realized by adopting the fermentation of a cellulose degradation flora and a flocculation flora, a high-efficiency bioflocculation microbial inoculum with low cost is developed, and further a scientific basis is provided for preparing a bioflocculant.

Description

Method for preparing culture medium from straw degradation product

Technical Field

The invention relates to the field of bioflocculants, in particular to a method for preparing a culture medium by using straw degradation products.

Background

The bioflocculant is derived from microbial metabolism, and is a high-efficiency green water purifying agent prepared by separating and screening special macromolecular metabolites which are obtained by coagulating and precipitating substances such as solid suspended particles and the like which are not easy to degrade in the sewage treatment process through a biological technology. The biological flocculant exists in a flocculant system, and has the advantages of secondary pollution avoidance, wide application range, low cost, large specific surface area, high efficiency, no toxicity, high decoloring effect and the like compared with the traditional flocculant.

The treatment effect of the microbial flocculant with a single strain has certain limitation, and the flocculation rate is unstable under different biochemical reaction conditions. The composite bioflocculant can integrate and concentrate the special degradation function of a single bacterial strain and strengthen the coupling of multiple bacterial strains for synergistic reaction, thereby integrally improving the flocculation efficiency.

In summer harvest and autumn and winter every year, a large amount of crop straws have influence on social life, production and other aspects due to the difficult problem of resource utilization. When most of the residual straws are burnt, the harm of reducing the soil fertility, increasing greenhouse gases, reducing the photosynthesis raw materials of the next-stubble crops and the like can be generated. Meanwhile, the straw is also a recyclable resource, if the method is proper, waste can be changed into valuable, and the method has important significance for developing cycle and low-carbon agriculture.

Disclosure of Invention

The invention aims to provide a method for preparing a culture medium by using straw degradation products, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a method for preparing a culture medium by using straw degradation products comprises the following specific steps:

s1: preparing straw fermentation liquor:

s11: putting rotten soil of straw, leaves and other wastes as a strain source into a plastic bag, sealing, and storing in a refrigerator at 3-5 deg.C for later use;

s12: respectively adding 0.5% of corn straws serving as a carbon source into a plurality of 100mL liquid culture media, putting filter paper strips into the culture media, and sterilizing and disinfecting the culture media;

s13: adding 10% of humus soil in S11 into the sterilized culture medium, and performing static culture at normal temperature until the filter paper strips in the culture medium are completely degraded to obtain a culture solution;

s14: transferring 5% culture solution, repeating the process for continuous subculture, eliminating the culture with weak degradation capability to obtain the rest culture with strong degradation capability, repeating the transferring for several generations to obtain 1 group of composite microbial straw degradation microbial inoculum;

s15: taking straws as a fermentation substrate, and fermenting the obtained composite microbial straw degradation microbial inoculum to obtain straw fermentation liquor;

s2: preparing flocculobacteria:

s21: taking 2mL sewage samples from different positions of a sewage pool, respectively adding the sewage samples into 98mL liquid culture media, and culturing for 1d under the conditions that the temperature is 30 ℃ and shaking of a shaking table is 150r/min to obtain an enrichment culture solution;

s22: diluting the above enrichment culture solution to 10% with sterile water^-6Then, respectively coating 0.1mL of the suspension liquid on a solid culture dish, culturing for 48 hours, selecting a single colony with a smooth and sticky surface, and separating the single colony by adopting a plate marking method to obtain a strain;

s23: inoculating the obtained strain into 100mL of standard fermentation medium for culture to obtain fermentation liquor, and carrying out primary selection on the strain in the fermentation liquor;

s24: checking strains: inoculating the strains obtained by primary screening into a 100mL standard fermentation medium, culturing the strains for 72 hours at a screening temperature of 25-30 ℃ and shaking of a shaking table at 150r/min to obtain a bacterial liquid, and screening out the flocculation rate of the bacterial liquid after sewage treatment as an index to obtain flocculation strains with obvious effect and high efficiency;

s3: and (4) centrifuging the straw fermentation liquor obtained in the step (S15) by using a centrifugal machine, and removing residual cellulose degradation thalli in the culture liquor to obtain the straw fermentation liquor as a culture medium of the flocculent bacteria.

Preferably, the peripheral soil in step S11 is selected from one of princess ridge, Jilin and Changchun.

Preferably, in step S23, the specific steps of initially selecting the strain in the fermentation broth are as follows:

s231: mixing 4g of high-mountain soil, 20.2g of CaCl and 1L of distilled water uniformly to prepare 4% kaolin suspension;

s232: adding 98mL of kaolin suspension into the measuring cylinder, adding 2mL of fermentation liquor, turning the measuring cylinder upside down for 5-8 times, and standing and observing;

s233: strains which can cause granular precipitation in the kaolin suspension are selected as initial selection strains.

Preferably, in step S3, the centrifugation condition of the centrifuge is 6000r/min, and the centrifugation time is 10-15 min.

Compared with the prior art, the invention has the beneficial effects that:

the invention aims to find a proper low-price culture medium to replace the traditional high-price raw materials, utilizes agricultural waste straws as a main carbon source in a fermentation substrate through mixed fermentation, and adopts a cellulose degradation bacteria decomposition technology to degrade the straws to obtain a product, so that a low-cost culture medium is further developed, a symbiotic organic combination of cellulose degradation and microbial flocculation is realized by adopting the fermentation of a cellulose degradation flora and a flocculation flora, a high-efficiency bioflocculation microbial inoculum with low cost is developed, and further a scientific basis is provided for preparing a bioflocculant.

Detailed Description

The invention provides a technical scheme that: a method for preparing a culture medium by using straw degradation products comprises the following specific steps:

s1: preparing straw fermentation liquor:

s11: putting rotten soil of straw, leaves and other wastes as a strain source into a plastic bag, sealing, and storing in a refrigerator at 3-5 deg.C for later use;

s12: respectively adding 0.5% of corn straws serving as a carbon source into a plurality of 100mL liquid culture media, putting filter paper strips into the culture media, and sterilizing and disinfecting the culture media;

s13: adding 10% of humus soil in S11 into the sterilized culture medium, and performing static culture at normal temperature until the filter paper strips in the culture medium are completely degraded to obtain a culture solution;

s14: transferring 5% culture solution, repeating the process for continuous subculture, eliminating the culture with weak degradation capability to obtain the rest culture with strong degradation capability, repeating the transferring for several generations to obtain 1 group of composite microbial straw degradation microbial inoculum;

s15: taking straws as a fermentation substrate, and fermenting the obtained composite microbial straw degradation microbial inoculum to obtain straw fermentation liquor;

s2: preparing flocculobacteria:

s21: taking 2mL sewage samples from different positions of a sewage pool, respectively adding the sewage samples into 98mL liquid culture media, and culturing for 1d under the conditions that the temperature is 30 ℃ and shaking of a shaking table is 150r/min to obtain an enrichment culture solution;

s22: diluting the above enrichment culture solution to 10% with sterile water^-6Then, respectively coating 0.1mL of the suspension liquid on a solid culture dish, culturing for 48 hours, selecting a single colony with a smooth and sticky surface, and separating the single colony by adopting a plate marking method to obtain a strain;

s23: inoculating the obtained strain into 100mL of standard fermentation medium for culture to obtain fermentation liquor, and carrying out primary selection on the strain in the fermentation liquor;

s24: checking strains: inoculating the strains obtained by primary screening into a 100mL standard fermentation medium, culturing the strains for 72 hours at a screening temperature of 25-30 ℃ and shaking of a shaking table at 150r/min to obtain a bacterial liquid, and screening out the flocculation rate of the bacterial liquid after sewage treatment as an index to obtain flocculation strains with obvious effect and high efficiency;

s3: and (4) centrifuging the straw fermentation liquor obtained in the step (S15) by using a centrifugal machine, and removing residual cellulose degradation thalli in the culture liquor to obtain the straw fermentation liquor as a culture medium of the flocculent bacteria.

Further, the surrounding soil in step S11 is selected from one of princess ridge, Jilin, and Changchun.

Further, in step S23, the specific steps of performing primary selection on the strains in the fermentation broth are as follows:

s231: mixing 4g of high-mountain soil, 20.2g of CaCl and 1L of distilled water uniformly to prepare 4% kaolin suspension;

s232: adding 98mL of kaolin suspension into the measuring cylinder, adding 2mL of fermentation liquor, turning the measuring cylinder upside down for 5-8 times, and standing and observing;

s233: strains which can cause granular precipitation in the kaolin suspension are selected as initial selection strains.

Further, in step S3, the centrifugation condition of the centrifuge is 6000r/min, and the centrifugation time is 10-15 min.

Compared with the prior art, the invention has the beneficial effects that:

the invention aims to find a proper low-price culture medium to replace the traditional high-price raw materials, utilizes agricultural waste straws as a main carbon source in a fermentation substrate through mixed fermentation, and adopts a cellulose degradation bacteria decomposition technology to degrade the straws to obtain a product, so that a low-cost culture medium is further developed, a symbiotic organic combination of cellulose degradation and microbial flocculation is realized by adopting the fermentation of a cellulose degradation flora and a flocculation flora, a high-efficiency bioflocculation microbial inoculum with low cost is developed, and further a scientific basis is provided for preparing a bioflocculant.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (4)

1. A method for preparing a culture medium by using straw degradation products is characterized by comprising the following specific steps:

s1: preparing straw fermentation liquor:

s11: putting rotten soil of straw, leaves and other wastes as a strain source into a plastic bag, sealing, and storing in a refrigerator at 3-5 deg.C for later use;

s12: respectively adding 0.5% of corn straws serving as a carbon source into a plurality of 100mL liquid culture media, putting filter paper strips into the culture media, and sterilizing and disinfecting the culture media;

s13: adding 10% of humus soil in S11 into the sterilized culture medium, and performing static culture at normal temperature until the filter paper strips in the culture medium are completely degraded to obtain a culture solution;

s14: transferring 5% culture solution, repeating the process for continuous subculture, eliminating the culture with weak degradation capability to obtain the rest culture with strong degradation capability, repeating the transferring for several generations to obtain 1 group of composite microbial straw degradation microbial inoculum;

s15: taking straws as a fermentation substrate, and fermenting the obtained composite microbial straw degradation microbial inoculum to obtain straw fermentation liquor;

s2: preparing flocculobacteria:

s21: taking 2mL sewage samples from different positions of a sewage pool, respectively adding the sewage samples into 98mL liquid culture media, and culturing for 1d under the conditions that the temperature is 30 ℃ and shaking of a shaking table is 150r/min to obtain an enrichment culture solution;

s22: diluting the above enrichment culture solution to 10% with sterile water^-6Then, respectively coating 0.1mL of the suspension liquid on a solid culture dish, culturing for 48 hours, selecting a single colony with a smooth and sticky surface, and separating the single colony by adopting a plate marking method to obtain a strain;

s23: inoculating the obtained strain into 100mL of standard fermentation medium for culture to obtain fermentation liquor, and carrying out primary selection on the strain in the fermentation liquor;

s24: checking strains: inoculating the strains obtained by primary screening into a 100mL standard fermentation medium, culturing the strains for 72 hours at a screening temperature of 25-30 ℃ and shaking of a shaking table at 150r/min to obtain a bacterial liquid, and screening out the flocculation rate of the bacterial liquid after sewage treatment as an index to obtain flocculation strains with obvious effect and high efficiency;

s3: and (4) centrifuging the straw fermentation liquor obtained in the step (S15) by using a centrifugal machine, and removing residual cellulose degradation thalli in the culture liquor to obtain the straw fermentation liquor as a culture medium of the flocculent bacteria.

2. The method for preparing culture medium from straw degradation products as claimed in claim 1, wherein: the peripheral soil in step S11 is selected from one of princess ridge, Jilin, and Changchun.

3. The method for preparing culture medium from straw degradation products as claimed in claim 1, wherein: in step S23, the specific steps of initially selecting the strains in the fermentation broth are:

s231: mixing 4g of high-mountain soil, 20.2g of CaCl and 1L of distilled water uniformly to prepare 4% kaolin suspension;

s232: adding 98mL of kaolin suspension into the measuring cylinder, adding 2mL of fermentation liquor, turning the measuring cylinder upside down for 5-8 times, and standing and observing;

s233: strains which can cause granular precipitation in the kaolin suspension are selected as initial selection strains.

4. The method for preparing culture medium from straw degradation products as claimed in claim 1, wherein: in step S3, the centrifugal condition of the centrifugal machine is 6000r/min, and the centrifugal time is 10-15 min.