CN109438773B - Method for degrading sodium alginate and agar composite membrane by using flavobacterium obesum galactomannan - Google Patents

Abstract

The invention provides a method for degrading sodium alginate and agar composite membrane by using chrysophanol tebexae, which comprises the steps of putting a prepared sodium alginate and agar composite membrane wafer into a culture solution containing the chrysophanol tebexae for degradation, taking out the degraded membrane after a period of time, then weighing by using an analytical balance after filtering, washing and freeze drying, and comparing with the membrane before degradation, wherein the result shows that the method has better degradation effect. The method is safe, environment-friendly and convenient, can effectively avoid environmental pollution caused by degrading the membrane by the traditional chemical method, and has very wide application prospect.

Description

Method for degrading sodium alginate and agar composite membrane by using flavobacterium obesum galactomannan

Technical Field

The invention belongs to the technical field of membrane degradation, and particularly relates to a method for degrading a sodium alginate and agar composite membrane by using flavobacterium obelisae.

Background

Flavobacterium lactofermentum (Zobellia galactanovorans) is a marine bacterium and is present in a wide range in nature. The strain grows fast and is not easy to inactivate, thereby having higher application prospect. And the special agar degradation effect is also contained, so that the industrial application potential is further increased.

Among the factors causing environmental pollution, public hazards caused by plastic wastes have attracted a great deal of attention from society. In the beginning of the 21 st century, the consumption of plastic packaging materials in China is large, the annual consumption can reach 5000 ten thousand tons, and if 30 percent of the plastic packaging materials are disposable foamed plastics, the annual waste plastics in China can reach more than 1500 ten thousand tons; it follows that the development and production of biodegradable membranes to mitigate environmental pollution has become prohibitive.

The biodegradable film is generally split and degraded in natural environment through the action of microorganisms in soil and water or the action of ultraviolet rays in sunlight, although the biodegradable film can be degraded, the degradation speed is slow, and the biodegradable film cannot be degraded in common bacteria in the air, so that the development of a new film degradation technology for improving the degradation speed becomes an urgent need.

Disclosure of Invention

The invention aims to provide a method for degrading a sodium alginate and agar composite membrane by using flavobacterium obelismortis, which is safe, environment-friendly and pollution-free and accelerates the degradation rate.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for degrading a sodium alginate and agar composite membrane by using Flavobacterium parvum galactovorum comprises the following steps:

1) culturing Flavobacterium parvum with galactan at 35 deg.C for 2-3 days, and adjusting absorbance to 0.3 to obtain Flavobacterium parvum culture solution with galactan;

2) mixing 75mL of 1% sodium alginate solution and 75mL of 1% agar solution, uniformly stirring at 55 ℃, pouring into a culture dish with the diameter of 190mm, putting into an oven, drying at 50 ℃ for 12h, taking out, adding a mixed solution containing 0.5wt.% of calcium chloride and 20vt.% of absolute ethyl alcohol, immersing the solution in a membrane, crosslinking for 30min, and putting into the oven to dry to prepare a small wafer for later use;

3) and (3) putting the small round piece obtained in the step 2) into the galactomannan-free yellow-bacillus rabbeter culture solution obtained in the step 1) for degradation, standing in a shaking table at 35 ℃ for 5 days, taking out, filtering out the membrane by using a 200-mesh sieve, washing for 3-5 times by using distilled water, and freeze-drying by using a freeze dryer to obtain a dry membrane, thus obtaining the degraded sodium alginate and agar composite membrane.

The culture solution in the step 1) comprises the following raw materials in parts by weight: 5 parts of peptone, 1 part of yeast extract, 0.1 part of ferric phosphate, 30 parts of NaCl and 1000 parts of distilled water.

The invention has the following remarkable advantages:

(1) the flavobacterium chrysophanol obenzi grows fast and is not easy to inactivate, and has excellent characteristics. The invention utilizes the effect of degrading the agar membrane by utilizing the galactomannan-jejuni flavobacterium, degrades the sodium alginate and agar composite membrane, does not use a reagent which can cause pollution to the environment in the process, can effectively avoid the problem of environmental pollution caused by degrading the membrane by the traditional chemical method, and is an environment-friendly membrane degradation method.

(2) The degradation time of the treatment membrane is short, the method is convenient and fast, and the method has no pollution to the environment.

(3) The method has mild reaction conditions, does not need high temperature and high pressure, and does not need a special reactor.

Detailed Description

In order to make the present invention more comprehensible, the technical solutions of the present invention are further described below with reference to specific embodiments, but the present invention is not limited thereto.

Example 1

A method for degrading a sodium alginate and agar composite membrane by using Flavobacterium parvum galactovorum comprises the following steps:

1) 5 parts by weight of peptone, 1 part by weight of yeast extract, 0.1 part by weight of phosphoric acid ferric iron, 30 parts by weight of NaCl and 1000 parts by weight of distilled water. Preparing a culture solution, culturing the Flavobacterium lactofermentum in the culture solution at the pH of 7.5 and the temperature of 35 ℃ for 3 days, and adjusting the absorbance to 0.3 to obtain the Flavobacterium galactofermentum culture solution for later use.

2) Mixing 75mL of 1wt.% sodium alginate solution and 75mL of 1wt.% agar solution, stirring uniformly at 55 ℃, pouring into a culture dish with the diameter of 190mm, putting into an oven, drying for 12h at 50 ℃, taking out, adding a mixed solution containing 0.5wt.% calcium chloride and 20vt% absolute ethyl alcohol, immersing the solution in a membrane, crosslinking for 30min, putting into the oven, drying to prepare a small disc with a proper size, weighing by using an analytical balance, and keeping the weight of 0.1104g for later use.

3) And (3) putting the small round piece obtained in the step 2) into the galactomannan-free yellow-bacillus rabbeter culture solution obtained in the step 1) for degradation, standing in a shaking table at 35 ℃ for 5 days, taking out, filtering out the membrane by using a 200-mesh sieve, washing for 5 times by using distilled water, and freeze-drying by using a freeze dryer to obtain a dry membrane. The degraded sodium alginate and agar composite membrane is obtained and weighed by an analytical balance, the weight is 0.0553, the degradation rate is 49.91%, and the membrane degradation effect is good.

Example 2

A method for degrading a sodium alginate and agar composite membrane by using Flavobacterium parvum galactovorum comprises the following steps:

1) 5 parts by weight of peptone, 1 part by weight of yeast extract, 0.1 part by weight of phosphoric acid ferric iron, 30 parts by weight of NaCl and 1000 parts by weight of distilled water. Preparing a culture solution, culturing the Flavobacterium lactofermentum in the culture solution at the pH of 7.5 and the temperature of 35 ℃ for 2 days, and adjusting the absorbance to 0.3 to obtain the Flavobacterium galactofermentum culture solution for later use.

2) The preparation method comprises the steps of uniformly stirring 75mL of 1 wt% sodium alginate solution and 75mL of 1% agar solution at 55 ℃, then pouring the mixture into a culture dish with the diameter of 190mm, then putting the culture dish into an oven to be dried at 50 ℃ for 12 hours, taking the culture dish out, then adding a mixed solution containing 0.5% by weight of calcium chloride and 20vt% of absolute ethyl alcohol, immersing the solution into a membrane, crosslinking the membrane for 30 minutes, putting the membrane into the oven to be dried into small disks with proper sizes, weighing the disks by using an analytical balance, and using the disks with the weight of 0.1034g for later use.

3) And (3) putting the small round piece obtained in the step 2) into the galactomannan-free yellow-bacillus rabbeter culture solution obtained in the step 1) for degradation, standing in a shaking table at 35 ℃ for 5 days, taking out, filtering out the membrane by using a 200-mesh sieve, washing for 4 times by using distilled water, and freeze-drying by using a freeze dryer to obtain a dry membrane. The degraded sodium alginate and agar composite membrane is obtained and weighed by an analytical balance, the weight is 0.0554, the degradation rate is 46.42 percent, and the membrane degradation effect is good.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.

Claims (2)

1. The application of the flavobacterium obelisae for galactan in degrading the sodium alginate and agar composite membrane is characterized in that: the method comprises the following steps:

1) culturing Flavobacterium parvum with galactan at 35 deg.C for 2-3 days, adjusting absorbance to 0.3 to obtain Flavobacterium parvum culture fluid

2) Mixing 75mL of 1wt.% sodium alginate solution and 75mL of 1wt.% agar solution, stirring uniformly at 55 ℃, pouring into a culture dish with the diameter of 190mm, putting into an oven, drying for 12h at 50 ℃, taking out, adding a mixed solution containing 0.5wt.% calcium chloride and 20vt.% absolute ethyl alcohol, immersing the solution in a membrane, crosslinking for 30min, putting into the oven, drying, and preparing a small disc for later use

3) And (3) putting the small round piece obtained in the step 2) into the galactomannan-free yellow-bacillus rabbeter culture solution obtained in the step 1) for degradation, standing in a shaking table at 35 ℃ for 5 days, taking out, filtering out the membrane by using a 200-mesh sieve, washing for 3-5 times by using distilled water, and freeze-drying by using a freeze dryer to obtain a dry membrane, thus obtaining the degraded sodium alginate and agar composite membrane.

2. Use according to claim 1, characterized in that: the culture solution in the step 1) comprises the following raw materials in parts by weight: 5 parts of peptone, 1 part of yeast extract, 0.1 part of ferric phosphate, 30 parts of NaCl and 1000 parts of distilled water.