Microbacterium and application of microbacterium in conversion of reed straw hydrolysate to prepare microbial flocculant

Abstract

The invention discloses a microbacterium and an application of microbacterium in conversion of a reed straw hydrolysate to prepare a microbial flocculant. The microbacterium is classified as Microbacterium trichothecenolyticum BWL1091, and a preservation number is CGMCC No. 14436. A method of preparing the microbial flocculant comprises the following steps: inoculating the strain in a seed liquidmedium, and preparing the seed liquid by shaking table culture at 37 DEG C; transferring the seed liquid to a ratio of 1% to a fermentation medium taking the 650 mL / L reed straw hydrolysate as a solecarbon source, and performing shaking table culture at a constant temperature of 30 DEG C; centrifuging a fermentation broth, and collecting a supernatant for use as a liquid microbial flocculant; adding 2-time volumes of pre-cooled anhydrous ethanol to the liquid microbial flocculant, and collecting the precipitate by centrifugation, and performing freeze drying to obtain the solid microbial flocculant. The microbacterium of the invention can tolerate a high concentration of reed straw hydrolysate, and can utilize the rich reducing sugar in the reed straw hydrolysate as the sole carbon sourceto ferment and produce the microbial flocculant, the output can reach up to 7.53g / L, the production process is simple, and the cost is low.

Description

technical field

[0001] The invention relates to the field of microbial flocculants, in particular to a strain of microbacteria and its application in transforming reed straw hydrolyzate to prepare microbial flocculants. Background technique

[0002] In the process of agricultural production in my country, the amount of agricultural waste produced is huge. The annual production of various straw and other agricultural wastes is about 600-700 million tons, which are mainly used as agricultural waste returning to the field, rural living fuel, or as animal feed Most of the rest are piled up in the field as agricultural waste, causing serious environmental pollution and waste of biomass resources. These agricultural wastes are rich in lignocellulosic substances, and reducing sugars can be obtained through thermal acid hydrolysis, and then used as fermentation carbon sources for microorganisms to produce high value-added microbial metabolic products, turning waste into treasure. ...

Examples

Embodiment 1

[0023] Screening, identification of embodiment 1 bacterial strain

[0024] Samples were collected from the sediment of the Nemoer River in Nehe City, Heilongjiang Province, packed into sterile ziplock bags and sealed, and brought back to the laboratory for bacterial strain isolation in time. Use the enrichment culture method and the gradient dilution method to isolate and screen functional strains. The enrichment medium components are: 500mL / L rice husk hydrolyzate, yeast powder 2g / L, magnesium sulfate heptahydrate 0.2g / L, dihydrogen phosphate Potassium 1.2g / L, tryptone 2g / L, acid hydrolyzed casein 2g / L. The separation and purification medium is: glucose 4g / L, starch 2g / L, yeast powder 2g / L, magnesium sulfate heptahydrate 0.2g / L, dipotassium hydrogen phosphate 1.2g / L, tryptone 2g / L, acid Hydrolyzed casein 2g / L.

[0025] Morphological identification of strains: inoculate the strains on LB solid plate, culture at 30 degrees for 24 hours, observe the colony shape, the colony is...

Embodiment 2

[0028] Example 2 Application of strain Microbacterium trichothecenolyticum BWL1091 in the preparation of microbial flocculant by transforming reed straw hydrolyzate

[0029] Specific steps are as follows:

[0030]Step 1, the reed stalks are pulverized, and after screening with a 60-mesh sieve, the reed stalk powder is added to 1.7% (W / W) H 2 SO 4 In the solution, hydrolyze at 121°C for 120min, after cooling, centrifuge at 8000-10000rpm for 10min, collect the supernatant, and use Ca(OH) 2 Adjust the pH to 7.0, centrifuge again at 8000-10000rpm for 10min, collect the supernatant, and obtain the reed straw hydrolyzate to be used as the carbon source of the subsequent fermentation medium;

[0031] Step 2. Inoculate the strain Microbacterium trichothecenolyticum BWL1091 into the seed liquid medium, culture at 180 rpm, 37° C. on a shaker for 18-20 h, and prepare the seed liquid; the components of the seed liquid medium are as follows: glucose 4 g / L, yeast powder 2 g / L, magnesium...

technical field

[0001] The invention relates to the field of microbial flocculants, in particular to a strain of microbacteria and its application in transforming reed straw hydrolyzate to prepare microbial flocculants. Background technique

[0002] In the process of agricultural production in my country, the amount of agricultural waste produced is huge. The annual production of various straw and other agricultural wastes is about 600-700 million tons, which are mainly used as agricultural waste returning to the field, rural living fuel, or as animal feed Most of the rest are piled up in the field as agricultural waste, causing serious environmental pollution and waste of biomass resources. These agricultural wastes are rich in lignocellulosic substances, and reducing sugars can be obtained through thermal acid hydrolysis, and then used as fermentation carbon sources for microorganisms to produce high value-added microbial metabolic products, turning waste into treasure. ...

Examples

Embodiment 1

[0023] Screening, identification of embodiment 1 bacterial strain

[0024] Samples were collected from the sediment of the Nemoer River in Nehe City, Heilongjiang Province, packed into sterile ziplock bags and sealed, and brought back to the laboratory for bacterial strain isolation in time. Use the enrichment culture method and the gradient dilution method to isolate and screen functional strains. The enrichment medium components are: 500mL / L rice husk hydrolyzate, yeast powder 2g / L, magnesium sulfate heptahydrate 0.2g / L, dihydrogen phosphate Potassium 1.2g / L, tryptone 2g / L, acid hydrolyzed casein 2g / L. The separation and purification medium is: glucose 4g / L, starch 2g / L, yeast powder 2g / L, magnesium sulfate heptahydrate 0.2g / L, dipotassium hydrogen phosphate 1.2g / L, tryptone 2g / L, acid Hydrolyzed casein 2g / L.

[0025] Morphological identification of strains: inoculate the strains on LB solid plate, culture at 30 degrees for 24 hours, observe the colony shape, the colony is...

Embodiment 2

[0028] Example 2 Application of strain Microbacterium trichothecenolyticum BWL1091 in the preparation of microbial flocculant by transforming reed straw hydrolyzate

[0029] Specific steps are as follows:

[0030]Step 1, the reed stalks are pulverized, and after screening with a 60-mesh sieve, the reed stalk powder is added to 1.7% (W / W) H 2 SO 4 In the solution, hydrolyze at 121°C for 120min, after cooling, centrifuge at 8000-10000rpm for 10min, collect the supernatant, and use Ca(OH) 2 Adjust the pH to 7.0, centrifuge again at 8000-10000rpm for 10min, collect the supernatant, and obtain the reed straw hydrolyzate to be used as the carbon source of the subsequent fermentation medium;

[0031] Step 2. Inoculate the strain Microbacterium trichothecenolyticum BWL1091 into the seed liquid medium, culture at 180 rpm, 37° C. on a shaker for 18-20 h, and prepare the seed liquid; the components of the seed liquid medium are as follows: glucose 4 g / L, yeast powder 2 g / L, magnesium...