CN106916749B

CN106916749B - Nostoc sphaeroids kutz culture method and device

Info

Publication number: CN106916749B
Application number: CN201511001142.0A
Authority: CN
Inventors: 胡强; 汪丰海
Original assignee: Sdic Biotechnology Investment Co ltd
Current assignee: Sdic Biotechnology Investment Co ltd
Priority date: 2015-12-28
Filing date: 2015-12-28
Publication date: 2021-03-09
Anticipated expiration: 2035-12-28
Also published as: CN106916749A

Abstract

The invention provides a nostoc sphaeroides cultivation method and a nostoc sphaeroides cultivation device, and belongs to the technical field of microalgae cultivation industry. The culture method is to put nostoc sphaeroides in a thin layer culture solution for standing culture so that the microalgae can directly utilize CO absorbed on the surface of the thin layer culture solution₂. The culture device is a stacked microalgae thin-layer culture device. The method and the device can increase the biomass yield of the unit area light source. Through thin-layer and static culture, energy consumption such as carbon supply, stirring and the like can be saved, and the unit cost is effectively reduced.

Description

Nostoc sphaeroids kutz culture method and device

Technical Field

The invention belongs to the field of algae biological culture, and relates to a nostoc sphaeroides culture method and a nostoc sphaeroides culture device.

Background

Nostoc sphaeroides Kutzing is a multicellular blue-green algae belonging to Nostoc sphaeroides, and is known as Nostoc sphaeroides. Nostoc sphaeroides is a kind of edible blue-green algae, named for the names and experiences of the Jinchao theorists, doctors and Danjia Kudzuvine flood in the promotion direction, and the compendium of materia Medica also records the efficacy of treating diseases such as nyctalopia and rectocele. The wild nostoc sphaeroides is also rich in protein, extracellular polysaccharide and various trace elements, the protein content is up to 52 percent, the amino acid types are complete, and the total sugar content is about 20 percent (wherein the content of the polysaccharide with biological activity is up to 8 to 12 percent), so the wild nostoc sphaeroides can be widely applied to the fields of food, medicine, health care and the like; at present, many scholars research the polysaccharide and the fatty acid, and find that the polysaccharide has the effects of antioxidant activity, antiviral activity, antibacterial activity, organism immunity enhancement and the like, and the fatty acid also has a certain treatment effect on heart diseases. Because of its special growing environment, wild nostoc sphaeroides exists only in the paddy fields of a few mountainous areas in China. However, due to the abuse of chemical fertilizers and pesticides brought by the development of modern agriculture, the yield of wild nostoc sphaeroides is reduced sharply, and the application requirements of people cannot be met, so that artificial culture is a necessary trend. For the artificial cultivation of nostoc sphaeroides, how to increase the biomass of nostoc sphaeroides and how to reduce the cultivation cost is a main barrier for future industrialization and marketization of nostoc sphaeroides.

At present, the cultivation method of nostoc sphaeroides is mainly a liquid immersion methodThe photobioreactor is of an open raceway pond and a glass plate type bioreactor. The immersion method comprises immersing algae in a large amount of culture solution, and making the culture solution continuously in circulation state by stirring device, circulation device or aeration device to make each nostoc cells uniformly receive light and absorb CO₂And preventing the nostoc sphaeroides cells from depositing at the bottom of the reactor. However, the culture method and apparatus have a common disadvantage of high energy consumption, low biomass (the dry cell weight of nostoc sphaeroides is only 0.4g/L), low light utilization efficiency, low space utilization rate, high water consumption, and easy damage of cell structures by the shearing force of a mechanical stirring member (in high-speed stirring), wherein the major disadvantages of high energy consumption, low light utilization efficiency, high water consumption, low space utilization rate, and easy damage of cell structures by stirring blades are high energy consumption, low light utilization efficiency, high water consumption, and low space utilization rate.

Therefore, the high unit cost of the traditional immersion method for culturing microalgae is a recognized problem in the industry and is also a problem to be solved urgently in industrialization.

Disclosure of Invention

The first purpose of the invention is to provide a nostoc sphaeroides cultivation method, which is used for solving the problem of high unit cost in nostoc sphaeroides cultivation at present.

It is a second object of the present invention to provide a culture apparatus suitable for the culture method.

In order to achieve the above object, the present invention provides a method for culturing microalgae, which comprises the step of performing stationary culture on the microalgae in a thin layer culture solution to make the microalgae directly utilize CO absorbed on the surface of the thin layer culture solution₂。

The thickness of the culture medium may be 1mm to 20mm, and preferably 2mm to 10 mm.

Based on the above, the invention further provides a nostoc sphaeroides cultivation method, which is to perform static cultivation on nostoc sphaeroides in a thin layer culture solution to ensure that the nostoc sphaeroides can directly utilize CO absorbed on the surface of the thin layer culture solution₂. Wherein the thickness of the culture solution is 1-4 times of the particle size range of nostoc sphaeroides, the particle size of the dried nostoc sphaeroides is about 0.4mm, and the diameter of the fresh nostoc sphaeroides is about 1.0-5 mm.The thickness of the culture solution may be 1mm to 20mm, and preferably the thickness of the culture solution is 2mm to 10 mm.

Wherein the ambient temperature of the static culture may be 20-28 ℃.

Wherein the light intensity of the static culture can be 2-526 mu mol.m^-2·s^-1More preferably 16.9 to 274.6. mu. mol. m^-2·s^-1。

Wherein, the culture medium of the static culture can be BG11 liquid culture medium without nitrogen element.

Wherein the ambient humidity range of the static culture can be 80-99%.

Wherein the inoculation amount of nostoc can be 0.1-0.9 g/L.

Further, the invention provides a stacked microalgae thin-layer culture device suitable for standing culture of microalgae, which comprises a plurality of culture flat plates distributed in a stacked manner, wherein each culture flat plate comprises a bottom plate and a cofferdam tightly connected with the bottom plate around the bottom plate, the height of the lowest part of the cofferdam is 1-20mm, and a preset distance is reserved between every two adjacent culture flat plates.

Wherein, a support part is arranged between the two adjacent culture plates, and the support part enables the predetermined distance to be formed between the two adjacent culture plates.

Wherein, the supporting component can be respectively connected with the cofferdams or the bottom plates of two adjacent culture flat plates.

The support members may be a set of stationary support systems, such as support racks or support posts, that connect the growth plates into a matrix of growth plates, or a suspension system that connects the growth plates into a matrix of growth plates. For example, in one embodiment of the invention the support member is a support post.

Wherein, the distance between the bottom plate and the bottom plate of two adjacent culture flat plates is 5-30 mm.

Wherein the material of the bottom plate and/or the cofferdam of the culture plate is preferably a transparent material, including but not limited to the following transparent materials: glass, GPPS, ABS, styrene acrylonitrile, PVC, PMMA, polycarbonate or polystyrene.

Wherein the material of the support member is preferably a transparent or light-transmitting material.

Wherein the culture plate may be integrally formed.

Wherein the culture plate and the support member may be integrally formed.

Wherein, the bottom plate material of the culture plate can be plate glass, and the cofferdam material of the culture plate can be transparent adhesive tape.

Wherein, at least one side of the thin layer culture device can be provided with a light source.

The invention adopts a thin layer static culture method, and does not need homogenization operations such as stirring and mixing and the like and CO introduction into the culture solution because the thickness of the culture solution is small enough₂Can ensure that the algae cells in the culture solution can be uniformly illuminated, can exchange gas, and can obtain CO required by photosynthesis of the algae cells from the liquid level of the culture solution₂And discharging O inhibiting photosynthesis₂. Therefore, the culture method has the advantages of saving energy consumption and reducing culture cost. The invention provides a processing mode of introducing thin-layer and static culture for the first time, and the essence of the invention is a novel culture method between an immersion method and a semi-dry method.

The culture apparatus of the present invention can realize high density lamination, and has gaps between layers for light to propagate to a long distance, so that nostoc can be cultured in a light-accessible range. This directly increases the biomass production per area of the light source. And because of thin-layer and static culture, energy consumption such as carbon supply and stirring is saved.

Drawings

FIG. 1 is a schematic view (front view) of a culture apparatus of the present invention.

FIG. 2 is a schematic view of a culture plate of the culture apparatus of the present invention.

FIG. 3 is another schematic view (side view) of the culture apparatus of the present invention.

Figure 4A is a top view of an embodiment of the present invention using a culture plate having an area of 120mm x 60mm cultured in a light source of 1 square meter, the light source having a height of 1m and a width of 1m, and 7 rows of culture plates perpendicular to the light source.

FIG. 4B is a schematic view (plan view) of a raceway pond in a conventional culture method, the raceway pond having a surface area of 2.5m²。

FIG. 4C is a schematic view (perspective view) of a fish pond reactor in a conventional culture mode, which has a length, width and height of 55cm, 20cm and 45cm, respectively.

FIG. 5 shows the light intensity values and the dry cell weight of Nostoc sphaeroids Kutz measured at different distances from the light source during Nostoc sphaeroids Kutz cultivation according to the present invention.

In the figure: 1 culture plate, 11 bottom plates, 12 cofferdams, 2 supporting parts and 3 light sources.

Detailed Description

The present invention will now be described in detail with reference to the drawings, but the invention is not to be construed as being limited thereto.

The nostoc sphaeroides culture method provided by the invention is to perform static culture on nostoc sphaeroides in a thin-layer culture solution, so that the nostoc sphaeroides can directly utilize CO absorbed on the surface of the thin-layer culture solution₂。

The thickness of the culture medium is preferably not more than 20mm, more preferably 1.5-10mm, still more preferably 2-10 mm, and may be about 1mm, about 2mm, about 3mm, about 4mm, about 5mm, 7mm, 10mm or a range between any of these values. The thickness of the culture solution is too large, and CO obtained by the interaction of the surface of the culture solution and air₂It is not enough to support the continuous culture of nostoc sphaeroides, and the light energy loss is large, so that the algae seeds below the liquid surface can not absorb enough light intensity. In addition, the thickness of the culture medium is too small, for example, less than 0.3mm, on one hand, the culture medium is too thin, so that the local part of some of the grown fresh nostoc sphaeroides with large particle size may be exposed outside the culture medium to influence the growth, and the volatilization of water is not favorable for the culture, and the culture amount is reduced, which is not economical.

Of course, the above is based on conventional culture conditions. If by increasing CO₂The thickness of the culture solution can be increased by taking measures such as concentration, improvement of illumination conditions and the like.

Since the culture medium in the method of the present inventionIs small enough to allow nostoc cells to directly obtain the CO required for photosynthesis from the liquid surface of the culture solution through gas exchange₂And discharging O inhibiting photosynthesis₂Therefore, it is not necessary to perform aeration operation to the culture solution. In addition, homogenization operations such as stirring and mixing are not required, and the nostoc sphaeroides cells in the culture solution can be ensured to be uniformly illuminated.

The harvesting and drying of algae are important steps for algae cultivation, and the energy consumption is high and the efficiency is low. However, according to the method of the present invention, nostoc sphaeroides is statically cultured using a thin layer liquid medium, and most of the medium is generally consumed when algae grow to maturity (generally about 8-12 days). At this time, the dry weight of the cells reaches a higher ratio, which is very beneficial to harvest and dry the algae. In the thickness range (1mm-10mm) of the culture solution, the thickness of the culture medium can be adjusted according to factors such as the inoculation amount of nostoc sphaeroides, light intensity, humidity, temperature and the like, so that the amount of the culture medium is just suitable for the algae to grow to the mature period without excessive surplus. In addition, because the algae are always in the thin-layer culture solution, the algae are less prone to mildew.

In some embodiments, the temperature used in the nostoc sphaeroides culture method is 20-28 ℃. In some embodiments, the light intensity used in the nostoc sphaeroides culture is 2-526 μmol · m^-2·s^-1. In some embodiments, the medium used in the nostoc sphaeroides culture is BG11 liquid medium without nitrogen element. In some embodiments, the ambient humidity range in the nostoc sphaeroides culture is 80-99%. In some embodiments, the amount of inoculated nostoc may be 0.1-0.9g/L in the nostoc culture.

The nostoc sphaeroides culture method adopts a thin-layer static culture mode, is a novel nostoc sphaeroides culture method between an immersion method and a semi-dry method, and has the advantages of saving energy consumption, reducing culture cost, reducing mold and effectively controlling explosive pollution risks of other enemy phytoplankton.

The laminated nostoc sphaeroides thin layer culture device suitable for nostoc sphaeroides static culture comprises a plurality of culture flat plates distributed in a laminated mode, wherein each culture flat plate comprises a bottom plate and a cofferdam which is tightly connected with the bottom plate around the bottom plate, the height of the lowest position of each cofferdam is 1-20mm, and a preset distance is reserved between every two adjacent culture flat plates.

Because thin-layer culture is adopted, the weight born by the culture plate is relatively low, and the culture plate can be lighter and thinner, so that the transparency of the culture plate can be improved, and the light penetration is facilitated. Moreover, because gaps are reserved between each layer of culture plate, and the cofferdam is also made of transparent materials, light can enter the upper surface and the bottom surface of the culture plate from the side surface, so that the nostoc sphaeroides cultured in the culture plate can receive light more sufficiently and uniformly, and the utilization efficiency of a light source is greatly improved.

The length of the culture plate may be, for example, 10cm to 10m, and the width may be, for example, 5cm to 1 m. The thickness can be 0.5 mm-2.0 mm, and can be adjusted according to different materials. Each cultivation plain white is in the range upon range of arrangement in vertical direction, makes the structure integrate, and the effective cultivation area maximize of unit occupation of land space.

The cofferdam may be perpendicular to the floor or at a certain inclination to the floor. For example, to facilitate the harvesting of nostoc sphaeroides, at least one side or a portion of the cofferdam may be inclined at an angle greater than 90 ° to the bottom plate (i.e., the cofferdam is inclined outwardly), such as at an angle of 135 °. In addition, the joint part of the cofferdam and the bottom plate can be a round angle, so that dead corners for harvesting or cleaning can be prevented.

The heights of the cofferdams can be the same or different. The distance of the cofferdam above the floor may be 1-20mm, preferably 2-10 mm, and may be about 1mm, about 2mm, about 3mm, about 4mm, about 5mm, 7mm, 10mm, or a range between any of these values.

The cofferdam and the bottom plate can be made separately and then combined together or formed integrally. These can be adjusted appropriately according to the difficulty of preparation and cost factors.

The bottom plate and the cofferdam material forming the culture plate can be glass or plastic with high light transmittance, such AS GPPS, transparent ABS, AS (styrene acrylonitrile), PVC, PMMA (polymethyl methacrylate), PC (polycarbonate), PS (polystyrene) and the like. The materials of the cofferdam and the bottom plate can be the same or different, for example, other transparent materials such as adhesive tape, glass cement and the like can be used.

The distance between the culture plates is determined according to the light source arrangement, the culture and harvest requirements of nostoc sphaeroides. For example, it may be 5mm to 30 mm.

A support member is provided between the upper and lower adjacent culture plates to allow the predetermined distance to be formed between the upper and lower adjacent culture plates. The supporting component can be respectively connected with the cofferdams or the bottom plates of two adjacent culture flat plates. The support members may be a set of stationary support systems, such as support racks or support posts, that connect the growth plates into a matrix of growth plates, or a suspension system that connects the growth plates into a matrix of growth plates. For example, in some embodiments of the invention the support member is a support post. In other embodiments, instead of the support member, a holder having a plurality of grids is used, and a plurality of culture plates made of sheet glass are respectively placed on the holders with a certain distance therebetween. The support is provided with a leveling system, can stably stand on the ground, and each grid is also provided with a leveling structure, so that the problem that the surface of the culture plate is not level due to error can be counteracted.

The culture plate and the support member may be integrally formed, or may be separately prepared and combined together. For example, the support member is a support column, and the support member may be fixedly mounted on the bottom of the corresponding culture plate, or may be integrally formed to form a unit including the culture plate and the support member, and then constitute a stacked culture apparatus.

In addition, the culture device can also comprise a plurality of rows of the stacked culture plates to form a culture array, thereby realizing large-scale culture.

In addition, the nostoc sphaeroides culture device can further comprise a culture solution instillation system, wherein the culture solution instillation system comprises a instillation head, a culture solution box, a pipeline for connecting the instillation head and the culture solution box, a control circuit for controlling the instillation to be opened or closed, a sensor for sensing the liquid level of the culture solution in the culture flat plate and the like, the sensor sends a liquid level signal to the control circuit, and the control circuit controls the instillation system to be opened or closed according to the liquid level signal. Of course, the drip system may not be used, as is typical, with the initial set of culture thicknesses and associated culture conditions of the present invention.

When the nostoc sphaeroides culture device is used for culturing nostoc sphaeroides, the culture device can be placed in a greenhouse with a temperature adjusting system, a humidity adjusting system and a lighting system, relatively constant temperature, humidity, lighting conditions and the like are provided through the greenhouse, the culture medium is prevented from volatilizing too fast, and the nostoc sphaeroides is always in a proper growth environment.

The invention is a thin-layer, static and high-density laminated culture mode between the traditional immersion type and the semi-dry type, wherein the thickness of the culture medium can be calculated and estimated in advance according to the type and life habit of the cultured algae, environmental factors and the like and empirical values, and the environmental humidity can be controlled manually, so that the specific gravity of the dry weight of cells is in a relatively high range when the nostoc sphaeroides reaches the harvest, and the energy consumption is saved for the later harvest. In addition, the algae in the culture device is still in a thin culture solution, so that the algae is less prone to generate mould, and harmful pollution can be controlled in a local range.

Assuming that the thickness of each flat plate layer is 1.5mm, the height of the support column is about 5-20 mm, and the liquid thickness is 2.5 mm; 45-153 layers can be stacked in a 1M height space, if nostoc commune is cultured in the cofferdam of each layer of flat plate, the biomass capable of being cultured in the 1M height range is considerable, and the dry cell weight can reach 1608g/M through experimental calculation³The productivity of the illumination area is as high as 10.7 g.m^-2·d^-1(dry matter), the energy consumption of per unit mass of nostoc sphaeroides is about 560 kJ/g.

Example 1 stacked Nostoc commune thin layer culture apparatus

As shown in FIG. 1, the culture apparatus in this embodiment comprises a plurality of culture plates 1 arranged in a stacked manner, wherein each culture plate 1 (FIG. 2) comprises a bottom plate 11 and a cofferdam 12 closely connected to the bottom plate 11 around the bottom plate 11, the cofferdam 12 is higher than the bottom plate 11 by about 1-20mm, the bottom plate 11 and the cofferdam 12 form a culture space for nostoc sphaeroides, and a predetermined distance is provided between two adjacent culture plates 1.

A support member 2 is provided between two adjacent culture plates 1, and the support member 2 allows the culture plates 1 to be spaced apart from each other by the predetermined distance. The support member 2 is a support column in this example. The upper and lower adjacent culture plates 1 are supported by a plurality of support columns, and the top end and the bottom end of each support column are respectively connected with the bottom plates 11 of the two culture plates 1.

The shape, material, number, spacing and arrangement of the support posts may be unlimited, and only the support posts need have a strength sufficient to support the growth plates stacked thereon and the culture fluid in the growth plates. The support column is made of transparent materials, such as glass, acrylic, PC and the like. The support column may have any suitable shape including, but not limited to, cylindrical, tubular, square, elongated, and the like.

As shown in FIG. 3, the light source 3 is provided on one side of the culture apparatus, and the light source 3 is provided on the side of the culture apparatus and is perpendicular to the culture plate 1, unlike a general light source provided on the upper side or the top of the culture system.

Because the invention adopts thin layer culture, the weight born by the culture plate is relatively lower, and the culture plate can be lighter and thinner, thereby improving the transparency of the culture plate and being beneficial to the penetration of light. Moreover, because gaps are reserved between each layer of culture plate, and the cofferdam is also made of transparent materials, light can enter the upper surface and the bottom surface of the culture plate from the side surface, so that the nostoc sphaeroides cultured in the culture plate can receive light more sufficiently and uniformly, and the utilization efficiency of a light source is greatly improved.

Example 2 Nostoc commune thin layer static culture and comparison with conventional culture method

In order to show the beneficial technical effects of the culture method and the culture device, four factors directly related to the industrial benefit, namely 'light source yield per unit area', 'algae powder energy consumption per unit mass', 'cost' and 'water consumption per unit light source area' are considered and verified through experiments.

Experimental groups:

as shown in FIG. 4A, the same as in example 1 was usedThe thin layer culture device and the culture method are characterized in that the left side is a light source 3 with the length of 1m and the height of 1m, and the light intensity is 274.6 mu mol.m^-2·s^-1. The right side is culture plate array, and culture plate is glass material, and specification is 120mm 60mm, and glass thickness is 1.5 mm. The height of the cofferdam was 2.5mm (thickness of culture broth). The amount of algae that can be accommodated by each plate was 18ml (120mm by 60mm by 2.5 mm). The height of the supporting column is 10 mm. Laminated to 1m in the vertical direction. The environmental temperature is controlled to be about 25 ℃, and the relative humidity is 80-99%. The culture solution is BG11 liquid culture medium without nitrogen element, and the initial inoculation dry weight is 0.3 g/L. The whole environment is tested under the condition of completely shielding natural light, and the interference of the natural light is eliminated.

At the beginning of the culture, the light intensity detector detects that the light source is close to the 1 st row to the 7 th row, and the light intensity on the surface of the culture medium is shown in figure 5. As can be seen from fig. 5, because the support columns are arranged between the stacked flat plates, a large number of fine spaces exist between the layers, light can always continuously pass to the right through the gaps between the layers, and the light intensity is weaker at farther positions. (the lower graph shows the intensity values of the culture medium surface in row 7, row 6, and row 1 of … … from left to right)

And the glass sheet in the 1 st row is observed to be close to the light source, so that the growth condition is the best, the growth condition is worse as the glass sheet is farther away from the light source lamp panel, and the growth conditions of the 7 th and 6 th rows are the worst. Harvesting after culturing for 11 days, and counting the total amount of algae according to different rows during harvesting, wherein the growth condition is shown as a bar chart in figure 5. It can be seen that although the dry weight of the algae in rows 6 and 7 is small, since the light can reach the place, nostoc sphaeroides in the place can still obtain the light source and grow. (the biomass collected in row 7, row 6, row … …, row 1 (ordinate) from left to right in the upper plot.)

The harvested algae were summed together for a total of 145.2g for all plate layers in the model described above. The total volume V of the culture broth was (1000/100) × 7 × 18ml × (1000/11.5) ═ 90.3L, and the average harvested algae dry weight density was calculated to be 1.608 g/L.

Control group 1:

indoor culture (fig. 4C) was performed in a goldfish bowl culture room. The culture conditions were as follows: culture lightThe strength is 120-^-2·s^-1The culture temperature is 25 ℃, air is pumped by an air pump, the ventilation quantity is 0.1-1L/min, and the inoculation density is 0.1g/L (dry weight).

Control group 2:

the culture was carried out outdoors using a goldfish bowl (FIG. 4C). The culture conditions were as follows: the culture temperature is outdoor environment temperature, the culture light intensity is natural light, air is pumped by an air pump, the ventilation quantity is 0.1-1L/min, and the inoculation density is 0.02g/L (dry weight).

Control group 3:

outdoor culture was performed using an open raceway pond (fig. 4B). The culture conditions were as follows: the culture temperature is outdoor environment temperature, the culture light intensity is natural light, a 0.75KW stirrer is used for electrically stirring, and the inoculation density is 0.05-0.13g/L (dry weight).

In the case of a raceway pond, the culture liquid level is high, and light is attenuated in water very quickly, so that light is difficult to penetrate to the bottom of the raceway pond, and a stirring pump is continuously used for stirring circulation when the light goes to the pond.

For the glass cylinder, the energy consumption is also needed to drive the stirring device, and simultaneously, the strength of 1 square meter is 274.6 mu mol m^-2·s^-1The light emitted from the right side of the light source can only be used for the growth of nostoc sphaeroides in one goldfish bowl (also under the condition of not considering natural light), and the goldfish bowl arranged towards the right side cannot obtain an effective light source, so that the utilization rate of the light energy of the two reactors is low. Namely, the whole environment is tested under the condition of completely shielding natural light, and the interference of the natural light is eliminated. A light source of 1 square meter irradiates one side surface of a traditional flat plate container type reactor, the side surface of a flat plate container is 1 square meter and has the width of 20cm, the light intensity of light rays passing through 20cm of algae liquid is weakened violently (the measured light energy loss rate reaches more than 95 percent), the light intensity can not be supplied for the normal growth of algae, and the light source of 1 square meter can only directly irradiate the nearest first row of golden fish tank culture container. (see fig. 4C).

Test results and conclusions:

according to the models of the experimental group and the control group, the thin-layer and high-density stacked culture device of the invention is compared with the traditional flat-plate type container (the strength of each square meter is 274.6 mu per square meter)mol·m^-2·s^-1Light source as reference object):

from the above, the thin layer culture method of the invention is obviously superior to the traditional culture method in terms of light source yield per unit area, energy consumption cost, water consumption and the like.

In addition, since the culture method and apparatus of the present invention are cultured in a static manner, there is no need to supply high-pressure CO during the culture₂The air-floating type stirring is realized, energy consumption equipment such as a circulating pump, a stirring paddle and the like for homogenization are not needed, and the algae harvested by the method is in a semi-wet state, so that the energy consumption for concentration after harvesting is reduced.

Furthermore, according to the culture mode and conditions of the experimental group, the light source yield per unit area of the present invention was 6.8 g.m.^-2·d^-1，10.7g·m^-2·d^-1，8.05g·m^-2·d^-1、8.3g·m^-2·d^-1. From the results, it was found that the light source yield per unit area was the highest at the seeding density of 0.3g/L, but the yield per unit area was still much higher at other seeding densities than in the conventional flat plate type container. Therefore, the result obtained at present is that the utilization efficiency of energy consumption is higher when the inoculation density is 0.1-0.9 g/L.

Further, when the inoculation density was 0.3g/L and the thickness of the culture medium was 1mm, 1.5mm, 2mm, 3mm, 5mm, 7mm, 10mm, 15mm, 20mm according to the culture method and conditions of the experimental group, the light source yield per unit area of the present invention was 4.47 g.m.^-2·d^-1、4.86g·m^-2·d^-1、5.21g·m^-2·d^-1、7.79g·m^-2·d^-1、9.60g·m^-2·d^-1、8.33g·m^-2·d^-1、5.85g·m^-2·d^-1、5.09g·m^-2·d^-1、3.87g·m^-2·d^-1(ii) a Wherein when the thickness of the culture solution is 2mm to 10mm, the utilization efficiency of nostoc sphaeroides to light is high.

Claims

1. The nostoc sphaeroides cultivation method is characterized in that a stacked microalgae thin-layer culture device nostoc sphaeroides is adopted, nostoc sphaeroides is placed in a thin-layer BG11 culture solution for standing cultivation, the inoculation amount of the nostoc sphaeroides is 0.1-0.9g/L, the thickness of the culture solution is 1-4 times of the diameter range of the cultivated fresh nostoc sphaeroides, and the nostoc sphaeroides can directly utilize CO absorbed on the surface of the thin-layer culture solution₂(ii) a The environmental temperature of the static culture is 20-28 ℃; the light intensity of the static culture is 2-526 mu mol.m^-2·s^-1。

2. The culture method according to claim 1, wherein the thickness of the culture medium is 1mm to 20 mm.

3. The culture method according to claim 2, wherein the thickness of the culture medium is 2mm to 10 mm.

4. The culture method according to claim 1, wherein the light intensity of the static culture is 16.9 to 274.6. mu. mol. m^-2·s^-1。

5. The culture method according to any one of claims 2 to 4, wherein the ambient humidity range of the static culture is 80 to 99%.