Film type aseptic bioreactor for heterotrophic and polyculture culture of microalgae
Technical Field
The utility model relates to a microalgae film bioreactor, in particular to a film type aseptic bioreactor for heterotrophic and polyculture culture of microalgae.
Background
The microalgae is rich in various nutritional ingredients such as protein, carotenoid, unsaturated fatty acid, vitamin, mineral elements and the like, and is widely applied to the fields of biomedicine, nutritional functional food, food and food additives, feed and animal health care, aquaculture and the like. In addition to the development of photosynthetic synthetic organic matter and growth of microalgae using sunlight, carbon dioxide and water, microalgae can also be grown under light conditions using organic carbon sources (e.g., glucose, glycerol, acetic acid), which is called heterotrophic growth, and some microalgae can also be grown under dark conditions using only organic carbon sources, like microorganisms, which is called heterotrophic growth. Compared with the photoautotrophic microalgae, the organic carbon source is added in the process of the mixed culture and the heterotrophic culture of the microalgae, and the microalgae can quickly utilize the organic carbon source for growth, because the high growth rate and the high concentration of the algae cells can be realized. For example, the photoautotrophic growth rate of chlorella is generally 0.1-0.2 g/L/d, and the maximum algae cell concentration is about 0.5-2 g/L; the growth rate of the chlorella polyculture and heterotrophy can reach 1-3 g/L/d generally, and the maximum concentration of the chlorella cells can reach more than 100 g/L. Therefore, the microalgae mixed culture and heterotrophic culture can obtain extremely high concentration and growth rate of the algae cells, remarkably improve the yield of the algae cells and reduce the production period, and have great technical advantages. In recent years, chlorella and euglena based on heterotrophic culture techniques and haematococcus pluvialis based on mixed culture techniques have been industrialized. As such, the microalgae industry is transitioning from a "facility agriculture" mode, centered on traditional photoautotrophic culture, to an "industrial" mode, centered on microalgae heterotrophic and heterotrophic technology.
Because heterotrophic culture and mixotrophic culture of microalgae need to be carried out in a sterile environment, at present, heterotrophic culture of microalgae is mainly carried out in a traditional stainless steel fermentation tank, and mixotrophic culture of microalgae is mainly carried out in a stainless steel fermentation tank provided with an internal light source. Therefore, heterotrophic culture and mixed culture of microalgae are carried out based on the traditional fermentation tank system, however, the investment of fermentation equipment is very large, the matching system is complex (a matching boiler and the like is needed), and the operation and maintenance cost is high, so that the cost of the microalgae produced based on the heterotrophic culture and mixed culture technology is high, and the cost of the microalgae produced based on the photoautotrophic culture technology of microalgae has no obvious advantages compared with the microalgae produced based on the photoautotrophic culture technology of microalgae. In addition, since the fermentation tank needs to be sterilized at high temperature and high pressure before culturing microalgae, the method of installing a light source (such as an LED lamp) inside the fermentation tank or installing a transparent viewing mirror (installing a light source outside a glass viewing mirror to provide illumination) on the cylinder of the fermentation tank can significantly damage the structure of the fermentation tank, reduce the pressure bearing capacity of the fermentation tank, and significantly reduce the safety of the fermentation tank. Therefore, in order to ensure the use safety of the fermentation tank, the number of the light sources arranged inside the fermentation tank or the sight glasses arranged on the cylinder body of the fermentation tank through the holes is very limited, and the requirement of microalgae mixed culture on illumination cannot be met.
SUMMERY OF THE UTILITY MODEL
The purpose of the invention is as follows: an object of the utility model is to provide a can repeat the sterilization and use and can improve little algae heterotrophic and the aseptic bioreactor of mixed culture of membrane formula of illumination area.
The technical scheme is as follows: the invention relates to a film type aseptic bioreactor for heterotrophic and polyculture culture of microalgae, which comprises a cover plate, a backing plate ring, a film bag and a sealing hoop; the base plate ring is positioned at the lower end of the cover plate, the opening of the film bag is arranged between the cover plate and the base plate ring, the cover plate and the base plate ring are fixed by the sealing hoop along the circumferential direction, and the cover plate, the base plate ring and the film bag form a closed inner cavity through the sealing hoop; a speed reducer is arranged in the center of the cover plate, one end of the speed reducer is connected with a stirring shaft, and the stirring shaft penetrates through the cover plate and extends into the film bag; the cover plate is also provided with a vent pipe for providing sterile air for the film bag, an air outlet pipe for exhausting air, a feed pipe for providing a sterile liquid culture medium for the film bag and a sampling pipe for taking materials; the vent pipe and the sampling pipe extend into the bottom of the film bag, and the air outlet pipe and the feed pipe extend into the film bag.
Further, a support for supporting the reactor is arranged at the lower end of the backing plate ring, a galvanized mesh ring for supporting the film bag is arranged on the outer side of the film bag, and a heat exchange jacket for controlling the temperature of the film bag is arranged at the bottom of the film bag; the heat exchange jacket is connected with the bracket through a support sheet. The zinc-plated net circle plays the outside supporting role of film bag, prevent that the film bag from inserting liquid medium and algae kind after outwards expanding and breaking, heat transfer jacket adopts stainless steel, wrapping up the plastic bag bottom, be used for controlling the temperature to the culture solution in the plastic bag, it is connected and realizes with constant temperature circulating water machine to press from both sides the cover through the heat transfer, wherein, the both sides that the heat transfer jacketed are equipped with circulating water entry and circulating water export respectively, the circulating water gets into from the water inlet that presss from both sides the cover, discharge from the delivery port, thereby realize the temperature of control culture solution.
Furthermore, in order to monitor and regulate relevant parameters in the culture process, a temperature electrode for monitoring the environmental temperature, a pH electrode for monitoring the environmental pH and a dissolved oxygen electrode for monitoring the oxygen content are arranged on the cover plate; the temperature electrode, the pH electrode and the dissolved oxygen electrode penetrate through the cover plate and extend into the film bag.
Furthermore, the bottom of the cover plate is provided with a groove, the top surface of the backing plate ring is provided with an embedded groove corresponding to the groove, and a cavity formed by the groove and the embedded groove is internally provided with a silica gel strip for sealing.
Furthermore, the cover plate, the backing plate ring and the film bag are made of transparent materials. The cover plate and the backing plate ring are made of transparent organic glass, the vent pipe, the feeding pipe, the air outlet pipe and the discharging pipe are made of silica gel, the stirring shaft and the stirring paddle are made of tetrafluoroethylene, the sealing hoop is made of stainless steel or aluminum alloy, and the film bag is made of one or more composite transparent materials of food-grade nylon, polyester resin, polycarbonate and polyethylene. Because the transparent material is adopted, the whole reactor is basically transparent, so that the illumination area of the reactor is close to 100 percent, and the illumination area is greatly increased.
Further, an LED lamp for providing a light source is arranged outside the film bag. When microalgae are cultured in the bioreactor in a mixed culture mode, the bioreactor needs to be placed in an environment with illumination or a light source is arranged outside a film bag, the reactor can use outdoor sunlight, for example, the reactor is placed in a glass room or a plastic greenhouse or an artificial light source, for example, an LED lamp is used.
Furthermore, the stirring shaft is provided with a stirring paddle for mixing the culture solution.
Furthermore, the air outlet pipe is communicated with the outside air through an air filter or a fermentation tank respirator, so that the inner cavity of the plastic bag is prevented from being polluted by the outside air; the interfaces of the vent pipe, the feed pipe and the discharge pipe are all provided with a luer valve and a quick connector, and the luer valve and the quick connector can be conveniently connected with an external ventilation system, a feed system and a discharge system.
The working principle is as follows: the utility model discloses by the apron, the backing plate ring, the closed inner chamber that film bag and sealed hoop formed is sterile environment, remove through sealed hoop, can detach apron and film bag, inner chamber after cultivateing little algae carries out rinse thoroughly, then can be once more to the apron, the backing plate ring, the film bag, sealed hoop equipment forms film formula inner chamber, through radiation, one kind or multiple mode combined use of electron beam and ultraviolet sterilization technique disinfects and sterilizes, realize the sterile environment of film bag inner chamber, reactor repeatedly usable once more after through the sterilization treatment, realize the heterotrophic or the mixed culture of little algae.
Has the advantages that: compared with the prior art, the utility model, have following advantage: the utility model adopts transparent and cheap plastic film material as the main body of biological reaction, greatly increases the illumination area of the reactor, and meets the requirements of microalgae mixed culture on illumination area and intensity; the aseptic environment of the inner cavity of the film bag is realized by one or more combined use of radiation, electron beam and ultraviolet sterilization technologies, and the complete cleaning and the repeated use of the inner cavity of the film bag are realized by detaching the sealing hoop, so that the investment cost, the operation cost and the maintenance cost of heterotrophic and mixed culture of microalgae are greatly reduced.
Drawings
FIG. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 is a schematic view of the cover plate structure of the present invention;
FIG. 3 is a top view of FIG. 2;
FIG. 4 is a schematic view of the structure of the backing plate of the present invention;
FIG. 5 is a top view of FIG. 4;
fig. 6 is a schematic view of the sealing hoop structure of the present invention.
Detailed Description
The present invention will be further explained with reference to the drawings and examples.
The membrane-type sterile bioreactor shown in fig. 1-6 comprises a cover plate 1, a gasket ring 2, a membrane bag 3 and a sealing hoop 4; the bioreactor comprises a main body, a thin film bag 3, a backing plate ring 2, a groove 118, an embedded groove 202, a silica gel strip 201, a sealing hoop 4 and a backing plate ring 2, wherein the main body of the bioreactor is the thin film bag 3, the backing plate ring 2 is positioned at the lower end of a cover plate 1, an opening of the thin film bag 3 is arranged between the cover plate 1 and the backing plate ring 2, the bottom of the cover plate 1 is provided with the groove 118, the top surface of the backing plate ring 2 is provided with the embedded groove 202 corresponding to the groove 118, a cavity formed by the groove 118 and the embedded groove 202 is internally provided with the silica gel strip 201, the opening of the thin film bag 3 is sealed by the cover plate 1 and the backing plate 2 through the elastic silica gel strip 201 to form a closed inner cavity, the sealing hoop 4 is in a circular ring shape and is arranged at the outer sides of the cover plate 1 and the backing plate ring 2, and the cover plate 1 and the thin film bag 3 can be detached by removing the sealing hoop 4; the cover plate 1 is provided with a speed reducer 101 which is connected with a stirring shaft 109, the stirring shaft 109 is provided with a stirring paddle 110, and the speed reducer is connected with a motor M and then can drive the stirring shaft 109 to rotate, so that the stirring paddle is driven to rotate, the culture solution is mixed, algae cells are prevented from settling, bubbles are broken, the gas-liquid mass transfer coefficient is improved, the oxygen in the bubbles (air) is promoted to be transferred to the culture solution, and the effect of improving the dissolved oxygen of the culture solution is improved; the cover plate 1 is also provided with an air pipe 105 for supplying sterile air to the film bag 3, an air outlet pipe 107 for exhausting air, a feed pipe 106 for supplying sterile liquid culture medium to the film bag 3 and a sampling pipe 108 for taking materials; the vent pipe 105 penetrates through a hole 111 for mounting the vent pipe on the cover plate in a sealing manner to enter the bottom of the film bag, and one end of the vent pipe 105 is provided with a luer valve and a quick connector which can be quickly connected with a pipeline of an air supply system in a butt joint manner, so that sterile air is delivered to the culture solution in the film bag to provide oxygen for the growth of microalgae; the feed pipe 106 penetrates through a hole 112, used for installing the feed pipe, in the cover plate 1 in a sealing mode and enters the thin film bag 3, a luer valve and a quick connector are installed at one end of the feed pipe 106 and can be connected with a feed system quickly, and therefore the sterile liquid culture medium passing through the filter membrane is input into the thin film bag 3; the air outlet pipe 107 penetrates through a hole 113 arranged on the cover plate 1 and used for installing the air outlet pipe to enter the film bag 3 in a sealing way, the air outlet pipe 107 is used for discharging air introduced through the air vent pipe into the external environment from the film bag 3, and an air filter or a respirator is arranged at one end of the air outlet pipe to prevent pollutants such as bacteria and the like in the external air environment from entering the culture solution; the sampling tube 108 is sealed and passes through a hole 117 on the cover plate for installing the material taking tube into the film bag 3, and a luer valve is installed at one end of the sampling tube 108 to be isolated from the external environment.
In order to further improve the installation stability of the reactor, a support 501 for supporting the reactor is arranged at the lower end of the backing plate ring 2, the bottom of the support 501 is installed on the ground, a galvanized mesh ring 502 for supporting the film bag is arranged on the outer side of the film bag 3, the galvanized mesh ring plays an external supporting role of the film bag to prevent the film bag from expanding outwards and cracking after being connected with a liquid culture medium and algae seeds, a heat exchange jacket 503 for controlling the temperature of the film bag 3 is arranged at the bottom of the film bag 3, the heat exchange jacket 503 is connected with a constant-temperature circulating water machine, the flow and the temperature of the circulating water machine are regulated and controlled according to the culture set temperature and the actual temperature of a temperature electrode, circulating water enters from a circulating water inlet 504 of the jacket and is discharged from a circulating water outlet 505, and the discharged circulating water returns to the circulating water machine, so that the temperature of the culture solution is controlled through circulation.
In order to monitor and regulate relevant parameters in the culture process, a temperature electrode 102, a pH electrode 103 and a dissolved oxygen electrode 104 are further mounted on the cover plate, the temperature electrode 102 is of pt1000 type, the pH electrode is of Mettler InPro3030 type, the dissolved oxygen electrode is of Mettler InPro6960i/12/220 type, and circulating water temperature, flow, ventilation volume, stirring paddle rotating speed and the like are reasonably regulated according to the parameters, so that the environmental parameters meet the growth requirements of microalgae. In order to realize the sterile environment inside the film bag, the film reactor consisting of the cover plate 1, the backing plate ring 2 and the film bag 3 is firstly vacuumized to extract the air in the inner cavity, and then is sterilized by ultraviolet, radiation or electron beam sterilization technology.
The sterilized film bag system is placed on the bracket 501, so that the backing plate 2 is placed at the upper end of the bracket 501, and the bottom of the film bag 3 is placed in the stainless steel heat exchange jacket 503. At the same time, the vent tube 105 is connected to the sterile air supply system via a quick connection, the valve at the mouth of the tube is opened, and sterile air is introduced into the film bag 3, so that the compressed film bag expands. Then, the feeding pipe 106 is connected with the feeding system quickly, the sterile culture solution is fed into the film bag, and the film bag 3 expands outwards to be attached to the peripheral galvanized mesh ring 502 along with the increase of the liquid level in the film bag, so as to prevent the film bag 3 from expanding outwards continuously to cause rupture. When the liquid culture medium is filled into the thin film bag 3 with the volume of 60-80%, then the aeration and the stirring are started, the culture medium is uniformly mixed, microalgae seeds are inoculated into the sampling tube 109, and the heterotrophic or mixotrophic culture of the microalgae is started according to the set temperature and the set rotating speed of the characteristics of the microalgae seeds. When the polyculture culture is carried out, the culture device needs to be placed in a light environment or an external LED lamp 6 needs to be turned on to provide the light environment. After the microalgae culture is finished, stopping stirring and ventilating, opening the sealing hoop 4, pumping the algae liquid in the bioreactor to the outside by using a pump, then carrying out subsequent processing treatment, simultaneously cleaning the film bag 3, the stirring shaft 109, the stirring paddle 110 and the back surface of the cover plate 1, completely cleaning and drying the film bag, then reassembling the components to form a closed bioreactor film bag system, reusing the film bag system after irradiation sterilization or electron beam sterilization, and circulating the steps to form a reusable bioreactor system, thereby greatly reducing the investment, operation and maintenance cost.