CN117229979B - Extended microbubble strain for producing algin lyase and application thereof - Google Patents

Abstract

The invention belongs to the field of microorganisms, and discloses an extended microbubble strain for producing algin lyase and application thereof; the extended microbubble HZ11 strain for producing algin lyase is classified and named as extended microbubbleMicrobulbifer elongatusThe strain is preserved in China general microbiological culture collection center (CGMCC) at the date 08 and 03 of 2023, and the preservation number is CGMCC No.28090; the strain can produce algin lyase and degrade brown algae; the activity of the algin lyase can reach 87.108 U.mL ^‑1 The method comprises the steps of carrying out a first treatment on the surface of the The invention also provides application of the extended microbubble strain in the production of algin lysate. Compared with the prior art, the strain provided by the invention can be used for preparing the algin oligosaccharide, and has important significance for improving the algin utilization efficiency and promoting the development and preparation of the functional algin oligosaccharide.

Description

Extended microbubble strain for producing algin lyase and application thereof

Technical Field

The invention relates to the field of microorganisms, in particular to an extended microbubble strain for producing algin lyase and application thereof.

Background

Algin is an important structural component of the cell wall of brown algae, accounting for about 18% -40% of the dry weight of the algae, and is composed of (1-4) glycosidically linked beta-D-mannuronic acid (M) and alpha-L-guluronic acid (G). Algin has gel property, stability and viscosity, and plays an important role in the production of foods, medicines, cosmetics, fertilizers and textiles as a stabilizer, a humectant, a thickener and an emulsifier. In addition, the algin also has the biological activities of reducing blood fat, resisting tumor, resisting bacteria and the like.

The molecular weight of the commercial algin is 33000-400000Da, the dissolution speed is low, the solution viscosity is high, and the algin is difficult to penetrate through biological membranes and be absorbed and utilized by organisms. And alginate oligosaccharides (Alginate oligosaccharide, AOS) with the polymerization degree of 2-25 after degradation often show better physicochemical properties and higher biological activity. The biological activity of AOS is affected by the degree of polymerization and the M/G composition ratio. Therefore, how to efficiently and directionally prepare the AOS becomes an important problem for research and utilization of the AOS, and a biodegradation method is one of potential means for solving the problem.

The biodegradation method generally refers to the steps of degrading the algin by adding algin lyase or producing the algin lyase by microbial fermentation, so as to obtain the AOS, and the method has the advantages of mild reaction conditions, specific biological enzyme action sites, high yield and the like, and can effectively avoid the problems of high energy consumption, long reaction time, poor repeatability, environmental pollution and the like in the physical and chemical degradation process. The identified algin-lysing bacteria are mainly from Pseudomonas genusPseudomonas sp.) Bacillus genusBacillus sp.) Genus VibrioVibrio sp.) Sphingomonas spSphingomonas sp.). However, most algin-cracking bacteria have low enzyme production capacity, so industrial mass production of AOS prepared by microbial fermentation is not realized. Based on the method, the development and screening of the efficient and safe algin splitting bacteria have important significance and practical production value.

Patent application CN116606769A discloses a Vibrio freundii mutant strain for producing algin lyase and application thereof, and provides a Vibrio freundii C3-2 for producing algin lyaseVibrio furnissii C3-2) The enzyme activity of the algin lyase produced by the strain is improved by more than 40% compared with that of a wild strain, the algin lyase has stronger tolerance to alkaline environment, and meanwhile, the genetic characteristic is stable, so that the algin lyase has good industrial development prospect. However, the efficiency of producing algin lyase by using the strain is still difficult to meet the industrial production requirement.

Providing a strain that efficiently produces algin lyase is one of the important problems to be solved in the art.

Disclosure of Invention

The invention provides an extended microbubble strain for producing alginate lyase and application thereof, wherein the strain can degrade the alginate into alginate oligosaccharides by using self-synthesized extracellular enzyme under mild external conditions (the temperature is about 25-32 ℃ and the pH is about 7.0).

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

prolonged microbubble strain HZ11 for producing algin lyase and classified and named prolonged microbubble strainMicrobulbifer elongatusThe microbial strain is preserved in China general microbiological culture collection center (CGMCC) at the date 08 and 03 of 2023, and the preservation number is CGMCC No.28090 and the preservation address is Beijing of China.

The extended microbubble HZ11 is separated from seawater near Zhejiang Zhoushan islands and is obtained by utilizing flat-plate directional screening with algin as a unique carbon source.

The physiological and biochemical characteristics of the extended microbubble strain HZ11 are as follows:

at a culture temperature of 25 ℃, the strain can grow to a pH value of 6.5-8.5, and the concentration of the growable sodium chloride is 20-90g/L.

Inoculating HZ11 seed liquid into 1L 2216E and enzyme-producing culture medium respectively according to the inoculation amount of 2%, culturing at 25 ℃ at 120 r/min, sampling every 2 hours, detecting the change condition of the absorbance value of the culture medium OD600, and drawing a HZ11 growth curve. It was found that HZ11 was grown in the logarithmic phase approximately 8 hours after inoculation and in the slow phase 26 hours after inoculation in 2216E medium, and the culture began to decay after 36 hours. In the enzyme-producing medium, HZ11 enters the logarithmic phase after 10 hours of inoculation, enters the slow phase after 24 hours, and begins to decay after 38 hours of culture.

The culture medium adopted by the invention comprises the following components:

2216E solid medium: 5g of peptone, 1g of yeast extract, 0.01g of ferric phosphate, 20g of agar, 1L of seawater and sterilizing at high temperature and high pressure for 20min at 121 ℃.

2216E liquid medium: 5g of peptone, 1g of yeast extract, 0.01g of ferric phosphate, 1L of seawater and high-temperature and high-pressure sterilization at 121 ℃ for 20min.

Enzyme-producing medium: 5g of algin, 5g of ammonium sulfate, 2g of dipotassium hydrogen phosphate, 30g of sodium chloride, 1g of magnesium sulfate heptahydrate, 0.01g of ferrous sulfate heptahydrate, 1L of deionized water, and high-temperature and high-pressure sterilization at 121 ℃ for 20min.

The invention also provides a method for prolonging the HZ11 of the microbubble bacteriaMicrobulbifer elongatus) A method for preparing alginate lyase, comprising the steps of:

(1) The prolonged microbubble bacteria HZ11 with the preservation number of CGMCC No.28090Microbulbifer elongatus) Activating to obtain activated colonies;

(2) Inoculating the activated colony obtained in the step (1), and culturing to obtain strain seed liquid;

(3) Inoculating the strain seed liquid obtained in the step (2), culturing, centrifuging to remove precipitate, and extracting.

Preferably, the activation in step (1) is: the extended microbubble was placed on 2216E solid medium to activate the strain.

Further preferably, the process of activating the strain is: streaking the frozen bacterial liquid on 2216E solid culture medium, and culturing in an inverted mode.

Still more preferably, the temperature of the inversion culture is 28-32℃for 22-26 hours.

Preferably, the inoculation in step (2) is: inoculated in 2216E liquid culture medium.

Preferably, the culturing in step (2) is: culturing until OD600 = 0.6-0.8.

Further preferably, the culturing conditions are: the temperature is 25-28 ℃, the rotating speed is 100-140rpm, and the time is 22-26 hours.

Preferably, the inoculation in step (3) is: inoculating in enzyme-producing culture medium.

Further preferably, the inoculation amount of the inoculation is 2% (v/v).

Preferably, the culturing conditions in step (3) are: the temperature is 25-28 ℃, the rotating speed is 100-140rpm, and the time is 22-26 hours.

The invention also provides the algin lyase prepared by the method.

The invention also provides application of the extended microbubble strain HZ11 in preparation of algin degradation products.

The invention also provides application of the algin lyase in preparing algin degradation products.

The invention also provides a method for preparing the algin degradation product by adopting the algin lyase, which comprises the following steps:

s1, prolonging the microbubble strain HZ11 with the preservation number of CGMCC No.28090Microbulbifer elongatus) Activating to obtain activated colonies;

s2, inoculating the activated colony obtained in the step S1, and culturing to obtain strain seed liquid;

s3, inoculating the strain seed solution obtained in the step S2 into an enzyme production culture medium containing algin according to the inoculation amount of 2%, and culturing for 40 hours at 25-28 ℃ at 120 r/min;

or (b)

S1, prolonging the microbubble strain HZ11 with the preservation number of CGMCC No.28090Microbulbifer elongatus) Activating to obtain activated colonies;

s2, inoculating the activated colony obtained in the step S1, and culturing to obtain strain seed liquid;

s3, inoculating the strain seed solution obtained in the step S2, culturing, centrifuging to remove sediment, taking supernatant, adding the supernatant into a buffer solution containing algin according to the addition amount of 8%, and degrading the algin.

Preferably, the buffer solution comprises the following components:

algin, sodium monohydrogen phosphate, sodium dihydrogen phosphate and sodium chloride.

Still more preferably, the pH of the buffer solution=7.5.

Most preferably, the buffer solution comprises the following concentrations of components:

alginate 0.05kg/L, sodium monohydrogen phosphate and sodium dihydrogen phosphate total 50mM and sodium chloride 300mM.

The beneficial effects of the invention are as follows:

the invention provides an extended microbubble bacterium with a preservation number of CGMCC No.28090Microbulbifer elongatusHZ11 strain has high-efficiency degradation effect on algin. The strain can degrade algin into algin oligosaccharide by using self-synthesized extracellular enzyme under mild external conditions (about 25-32 ℃ and pH 7.0).

The strain provided by the invention can be used for preparing alginate oligosaccharides, and has important significance for improving the utilization efficiency of the algins and promoting the development and preparation of functional alginate oligosaccharides.

Preservation description

Preserving the strain: prolonging the microbubble bacteria HZ11;

classification naming: prolonged microbubble bacteriaMicrobulbifer elongatus；

Preservation number: CGMCC No.28090;

preservation date: 2023, 08, 03;

preservation unit: china general microbiological culture Collection center (China Committee for culture Collection);

preservation address: beijing, china.

Drawings

FIG. 1 is a colony morphology of strain HZ11 plate;

FIG. 2 is a view (1000X) of strain HZ11 in microscopic morphology;

FIG. 3 is an agarose gel electrophoresis of HZ11 PCR products;

FIG. 4 is a HZ11 16S rDNA phylogenetic tree;

FIG. 5 is a HZ11 growth graph;

FIG. 6 is a glucose standard graph;

FIG. 7 is a thin layer chromatography analysis of the enzymatic hydrolysate;

FIG. 8 is a graph showing the growth of HZ11 on agar plates;

FIG. 9 is a graph showing the growth of HZ11 on starch plates;

FIG. 10 is a graph showing the growth of HZ11 on sodium carboxymethylcellulose plates;

FIG. 11 is a morphology of the kelp 3 days after the HZ11 inoculation (a is a control group; b, c are two experimental groups) without HZ11 inoculation;

FIG. 12 is a morphology of the inoculated HZ11 and the inoculated HZ 11-degraded Sargassum for 5 days (a is control group, b, c, d are three experimental groups);

FIG. 13 is a graph of the supernatant of the degraded Sargassum horneri of FIG. 12 (a is a control group, and b, c, and d are three experimental groups).

Detailed Description

The present invention will be described in detail with reference to examples. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials being described herein.

The raw materials used in the invention are all common commercial products, and the sources thereof are not particularly limited.

The following raw material sources are exemplary illustrations:

the equipment and the instrument adopted by the invention are as follows:

the culture medium adopted by the invention comprises the following components:

2216E solid medium: 5g of peptone, 1g of yeast extract, 0.01g of ferric phosphate, 20g of agar, 1L of seawater and sterilizing at high temperature and high pressure for 20min at 121 ℃.

2216E liquid medium: 5g of peptone, 1g of yeast extract, 0.01g of ferric phosphate, 1L of seawater and high-temperature and high-pressure sterilization at 121 ℃ for 20min.

Enzyme-producing medium: 5g of algin, 5g of ammonium sulfate, 2g of dipotassium hydrogen phosphate, 30g of sodium chloride, 1g of magnesium sulfate heptahydrate, 0.01g of ferrous sulfate heptahydrate, 1L of deionized water, and high-temperature and high-pressure sterilization at 121 ℃ for 20min.

EXAMPLE 1 HZ11 bacteria form observation and 16S rDNA identification

The strain is cultured for 24 hours in an inverted way at 30 ℃ on 2216E solid culture medium, and a milky white circular colony with smooth and neat edges is grown (figure 1); the strain was gram-negative and observed as an elongated rod by microscopic examination (FIG. 2).

The strain was cultivated to od600=0.6-0.8 using 2216E liquid medium, and bacterial total DNA was extracted, which was used as template to amplify the 16S rDNA sequence using primers 27F (SEQ ID No. 1) and 1492R (SEQ ID No. 2). The resulting PCR product was detected by 1% agarose gel electrophoresis as a bright single band with a length of about 1500 bp (FIG. 3). The PCR product was sent to the Beijing Rui Biotechnology Co., ltd for sequencing (the sequencing result is shown as SEQ ID No. 3). Sequencing results BLAST alignment was performed on the NCBI (National Center for Biotechnology Information) database, and the sequence was aligned toMicrobulbiferThe 16S rDNA sequence of the genus microorganism has higher similarity, and the phylogenetic tree is shown in figure 4. HZ11Microbulbifer elongatusThe highest similarity of the 16S rDNA sequences is 99.93 percent, and the strain is identified as the prolonged microbubble strain by combining the observation result of the bacterial form of the strainMicrobulbifer elongatus）。

EXAMPLE 2 HZ11 physiological Biochemical characterization

At a culture temperature of 25 ℃, the HZ11 strain can grow to have a pH value of 6.5-8.5 and a concentration of 20-90g/L of sodium chloride.

Preparing HZ11 seed liquid:

200mL 2216E liquid culture medium is inoculated with 100 mu L of HZ11 frozen glycerol bacterial liquid, and shake culture is carried out at 25 ℃ and 120rpm until OD=0.6 is reached, and the liquid is used as HZ11 seed liquid for standby.

According to the inoculation amount of 2 percent, the HZ11 seed liquid is respectively inoculated into 1L 2216E liquid culture medium and 1L enzyme production culture medium, the culture is carried out at 25 ℃ and 120rpm, sampling is carried out every 2 hours, the change condition of the absorbance value of the culture medium OD600 is detected, and the HZ11 growth curve is drawn. It was found that HZ11 was grown in the logarithmic phase approximately 8 hours after inoculation and in the gentle phase after 26 hours in 2216E liquid medium, and the culture began to decay after 36 hours. In the enzyme-producing medium, HZ11 was grown in the logarithmic phase 10 hours after inoculation, in the slow phase 24 hours after inoculation, and the cells were grown to 38 hours to begin to decay (FIG. 5).

Example 3 enzyme Activity detection of extracellular algin-producing lyase by HZ11

(1) Preparing crude enzyme solution of algin lyase.

HZ11 seed solution was inoculated into the enzyme-producing medium in an inoculum size of 2%, the enzyme-producing medium loading amount was 50mL/300mL (medium volume/Erlenmeyer flask container volume), and the culture was carried out at 28℃and 120rpm for 40 hours. After the culture is finished, removing bacterial precipitate by centrifugation, and obtaining supernatant fluid which is crude enzyme liquid of algin lyase.

(2) And drawing a glucose standard curve.

Accurately preparing 1mg/mL of D-anhydrous glucose standard solution, and respectively sucking 0, 20, 40, 60, 80, 100, 120, 140, 160, 180 and 200 mu L of standard solution into a clean centrifuge tube, and supplementing sterile water to a final volume of 200 mu L. 150 μl of DNS reagent was added to each tube and mixed well, boiled for 10min, cooled, 1mL of sterile water was added and mixed well, the absorbance of OD540 was measured, and a standard curve was drawn with glucose content (mg) on the abscissa and OD540 on the ordinate (fig. 6).

(3) HZ11 algin lyase enzyme activity detection

80. Mu.L of crude enzyme solution and 920. Mu.L of algin substrate solution (algin 0.5% (m/v), naH ₂ PO ₄ -Na ₂ HPO ₄ 50mM, 300mM sodium chloride, ph=7.5), in a 30 ℃ water bath for 30min; under the condition that other conditions are unchanged, the crude enzyme liquid is boiled for 10min for inactivation to be used as a control group. After the reaction is finished, uniformly mixing reaction solution obtained by reacting 200 mu L of crude enzyme solution with an algin substrate solution with 150 mu L of DNS solution, boiling for reaction for 10min, cooling, adding 1mL of sterile water, uniformly mixing, and detecting the change condition of an OD540 absorbance value; 3 sets of parallel experiments were set up.

Definition of enzyme activity unit: under the above reaction conditions, the content of alginate lyase required for producing 1. Mu.g of reducing sugar in 1min was one enzyme activity unit (U.mL ^-1 ). The specific calculation formula is as follows:

enzyme activity (U.mL) ^-1 ）=（m×N×1000）/（T×V）

m-the content (mg) of reducing sugar produced by the enzymatic reaction of the crude enzyme solution, calculated from the glucose standard curve and OD 540;

n—dilution of fermentation supernatant (undiluted to 1);

t-enzymatic reaction time;

v-enzyme solution (fermentation supernatant) volume;

according to the formula, the enzyme activity of extracellular algin lyase produced by HZ11 is 87.108 U.mL under the culture condition ^-1 。

(4) Thin layer chromatography analysis of enzymatic hydrolysis products

80 mu L of HZ11 algin lyase crude enzyme solution and 920 mu L of 1% algin substrate (algin 1% (m/v), naH ₂ PO ₄ -Na ₂ HPO ₄ 50mM, 300mM sodium chloride, pH 7.5) was mixed well and digested at 30℃for 24h.

And carrying out thin layer chromatography identification on the enzymolysis product. N-butanol: acetic acid: water (3:2:3, v/v/v) is used as developing agent, and the enzymolysis product is spotted on a silica gel plate and placed in a chromatographic cylinder for developing. After the chromatography is finished, the silica gel plate is taken out, dried, sprayed with a color-developing agent (sulfuric acid: ethanol=1:9, v/v) and baked in an electric furnace for color development. The experimental results show that the product of the enzymolysis of the algin by HZ11 is mainly the algin disaccharide (figure 7).

In fig. 7: a: d-mannuronic acid monosaccharide standard, B: d-mannuronic acid disaccharide standard, C: enzymolysis product, D: the algin substrate was not enzymatically hydrolyzed.

Example 4 identification of HZ11 to produce other exopolysaccharide degrading enzymes

Preparing solid plate culture medium with starch, sodium carboxymethyl cellulose and agar as carbon source. The media content included: 5g/L of ammonium sulfate, 1g/L of magnesium sulfate heptahydrate, 2g/L of dipotassium hydrogen phosphate, 0.01g/L of ferrous sulfate heptahydrate, 30g/L of sodium chloride and 1.2% -1.5% (m/v) of agar. 1% (m/v) of starch or sodium carboxymethyl cellulose is added to a medium containing starch or sodium carboxymethyl cellulose as a carbon source, based on the above content.

mu.L of HZ11 seed solution was added dropwise to the corresponding solid plate medium in 4 aliquots and the incubator was inverted at 30℃for 48h.

After the end of the culture, a hydrolysis ring appeared around the colonies of the plates with agar (FIG. 8) and starch (FIG. 9) as carbon sources. 15mL Congo red dye liquor (1 mg/mL) is used for covering the surface of the sodium carboxymethylcellulose flat plate, and dyeing is carried out for 15min; the dye solution was discarded, 15mL of sodium chloride solution (1M) was added, decolorized for 10min, and the sodium chloride solution was discarded. After staining, transparent hydrolysis circles appeared around the growing colonies of sodium carboxymethylcellulose plates (fig. 10). The experimental results show that HZ11 can also secrete extracellular amylase, agarase and cellulase, and the extracellular amylase, the agarase and the cellulase grow by taking starch, agar or sodium carboxymethyl cellulose as carbon sources.

EXAMPLE 5 HZ11 degradation of kelp and Sargassum horneri

(1) HZ11 degradation kelp:

the kelp is washed on the surface of the kelp by sterile water for a plurality of times and cut into small fragments for standby.

A group of control groups was set: adding 6g kelp pieces and 20mL of enzyme-producing medium into a conical flask;

two experimental groups were set up: to both Erlenmeyer flasks 6g of kelp pieces and 19mL of enzyme-producing medium were added, respectively, followed by 1mL of HZ11 seed solution. The conical flask was placed in a shaking table at 180rpm at 23℃for shaking culture, and the morphological changes of the kelp pieces were observed periodically.

The kelp pieces of the three experiments all had different degrees of hydrolysis after 3 days. The control group (not inoculated with HZ11 bacteria solution) had slightly poorer hydrolysis degree of kelp fragments, and more kelp fragments were adhered to the bottle wall (FIG. 11 a); kelp pieces from both groups (inoculated with HZ11 bacteria solution) were almost completely hydrolyzed after 3 days, with less kelp pieces remaining on the bottle wall (fig. 11 b, c). The result shows that HZ11 has better hydrolysis effect on kelp, and can hydrolyze kelp thoroughly when acting alone.

(2) HZ11 degradation of Sargassum horneri:

the method comprises the steps of thoroughly cleaning Sargassum horneri with water to remove surface impurities, then sucking water with filter paper, thoroughly cleaning with sterile water in an ultra-clean workbench, and then cleaning with sterile seawater for later use.

A group of control groups was set: 12g of Sargassum horneri was added to 50mL of sterile seawater;

three experimental groups were set up: adding 12g of Sargassum horneri into 49mL of sterile seawater, and adding 1mL of HZ11 seed solution respectively; the flask was placed in a shaking table at 25℃and 120rpm for shaking culture, and the morphology change of Sargassum horneri was observed periodically.

After 7 days, the Sargassum horneri has different degrees of hydrolysis, and the hydrolyzed Sargassum horneri liquid is centrifuged to collect supernatant. The control group (not inoculated with HZ11 bacteria solution) had poor degree of Sargassum hydrolysis (FIG. 12 a), and the hydrolyzed supernatant was clear (FIG. 13 a); the degrees of hydrolysis of the Sargassum horneri in the three groups of experimental groups (inoculated with HZ11 bacteria liquid) are slightly different, the degree of hydrolysis of the first group of experimental groups (b in fig. 12) is better, and the hydrolyzed liquid is the most turbid (b in fig. 13); the degree of hydrolysis was relatively low for groups two and three (c, d in FIG. 12) and the hydrolyzed supernatants were cloudy (c, d in FIG. 13). The result shows that HZ11 has better hydrolysis effect on Sargassum horneri.

Comparative example

Since the comparative example is different from the enzyme activity detection method adopted in the present experiment and the comparative example does not provide the original experimental data, the enzyme activities of the two cannot be compared. However, the present invention demonstrates that HZ11 can produce amylase, agarase and cellulase in addition to algin lyase (fig. 8-10), which can demonstrate the advantageous effects of the present invention compared to the comparative examples.

The invention has been further described with reference to specific embodiments, which are exemplary only and do not limit the scope of the invention in any way. It will be understood by those skilled in the art that various changes and substitutions in the details and form of the present invention may be made without departing from the spirit and scope of the invention.

Claims (8)

1. Prolonged microbubble strain HZ11 for producing algin lyase and classified named prolonged microbubble strainMicrobulbifer elongatus) The microbial strain is preserved in China general microbiological culture collection center (CGMCC) at the date 08 and 03 of 2023, and the preservation number is CGMCC No.28090 and the preservation address is Beijing of China.

2. The method for preparing algin lyase by using the extended microbubble strain according to claim 1, which is characterized in that: the method comprises the following steps:

(1) Activating the extended microbubble strain HZ11 to obtain an activated colony;

(2) Inoculating the activated colony obtained in the step (1), and culturing to obtain strain seed liquid;

(3) Inoculating the strain seed liquid obtained in the step (2), culturing, centrifuging to remove precipitate, and extracting to obtain the strain seed liquid;

the inoculation in the step (3) is as follows: inoculating in an enzyme-producing culture medium;

the enzyme-producing culture medium comprises the following components:

algin, ammonium sulfate, dipotassium hydrogen phosphate, sodium chloride, magnesium sulfate heptahydrate, ferrous sulfate heptahydrate and deionized water.

3. The method according to claim 2, characterized in that: the activation in step (1) is: placing the extended microbubble on 2216E solid medium to activate the strain; the 2216E solid culture medium comprises the following components:

peptone, yeast extract, ferric phosphate, agar and seawater.

4. A method according to claim 3, characterized in that: the process of activating the strain is as follows: streaking the frozen bacterial liquid in 2216E solid culture medium, and culturing in an inverted manner; the temperature of the inversion culture is 28-32 ℃ and the time is 22-26 hours.

5. The method according to claim 2, characterized in that: the inoculation in the step (2) is as follows: inoculating into 2216E liquid culture medium; the culturing in the step (2) is as follows: culturing until the OD600 = 0.6-0.8;

the temperature is 25-28 ℃, the rotating speed is 100-140rpm, and the time is 22-26h;

the 2216E liquid culture medium comprises the following components:

peptone, yeast extract, ferric phosphate and seawater.

6. The method according to claim 2, characterized in that: the inoculation amount of the inoculation in the step (3) is 2%.

7. The use of the extended microbubble of claim 1 for the preparation of alginate degradants.

8. A method for preparing alginate degradation products is characterized in that: the method comprises the following steps:

s1, activating the extended microbubble strain HZ11 of claim 1 to obtain an activated colony;

s2, inoculating the activated colony obtained in the step S1, and culturing to obtain strain seed liquid;

s3, inoculating the strain seed solution obtained in the step S2 into an enzyme-producing culture medium containing algin according to the inoculation amount of 2%, and culturing for 40 hours at 25-28 ℃ and 120 rpm;

or (b)

S1, activating the extended microbubble strain HZ11 of claim 1 to obtain an activated colony;

s2, inoculating the activated colony obtained in the step S1, and culturing to obtain strain seed liquid;

s3, inoculating the strain seed solution obtained in the step S2, culturing, centrifuging to remove sediment, taking supernatant, adding the supernatant into a buffer solution containing algin according to the addition amount of 8%, and degrading the algin.