CN118256550A

CN118256550A - Application of cytoplasmic enzyme fructose-1, 6-bisphosphatase gene and method for promoting growth of nannochloropsis

Info

Publication number: CN118256550A
Application number: CN202410571363.4A
Authority: CN
Inventors: 周涵韬; 张正盈; 李妍妍; 朱红梅
Original assignee: Xiamen University
Current assignee: Xiamen University
Priority date: 2024-05-09
Filing date: 2024-05-09
Publication date: 2024-06-28

Abstract

The invention discloses application of a cytoplasmic enzyme fructose-1, 6-bisphosphatase gene and a method for promoting growth of nannochloropsis. Wherein the cytoplasmic enzyme fructose-1, 6-bisphosphatase has the purpose of promoting photosynthesis of the nannochloropsis and/or improving photosynthetic yield of the nannochloropsis. Has practical significance in the photosynthetic autotrophic growth of the nannochloropsis.

Description

Application of cytoplasmic enzyme fructose-1, 6-bisphosphatase gene and method for promoting growth of nannochloropsis

Technical Field

The invention relates to the field of genetic engineering, in particular to application of a cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) gene and a method for promoting growth of nannochloropsis.

Background

Microalgae are fast-growing photoautotrophic organisms that can use the energy of sunlight to fix carbon dioxide in the atmosphere into organic biomass by cultivation. Microalgae biomass is a sustainable and renewable feedstock that can be used to produce value-added products such as animal feeds and foods, health products, pharmaceuticals, personal care products, biofuels, and chemical feedstocks.

The nannochloropsis has long production and application history, is one of important microalgae sources for producing the EPA and the bait for aquaculture, has high commercial value and has important position in microalgae production. A significant problem in industrial applications is the low yield of microalgae biomass, and the plant type of nannochloropsis plays an important role in microalgae biomass yield, photosynthesis efficiency and yield.

The calvin-benson cycle is the main pathway for photosynthesis of higher plants to fix carbon and is also the most important carbon dioxide fixation mechanism in modern biospheres. The synthesized carbohydrate can be retained as starch in chloroplasts, or exported to the cytoplasm for sucrose biosynthesis. Sucrose is a major export and storage form of higher plant soluble carbohydrates which is imported into sink tissues and then used to maintain cell metabolism, cell wall biosynthesis and respiration, or converted to starch for storage. Fructose-1, 6-bisphosphatase (FBPase 1; EC 3.1.3.11) is a rate-limiting enzyme in the Calvin cycle and is the main regulatory step in sucrose biosynthesis. Fructose-1, 6-bisphosphatase (FBPase) catalyzes the breakdown of fructose-1, 6-bisphosphate into fructose-6-phosphate (F6P) and Pi. There are two types of fbpases in microalgae: cytoplasmic enzyme (cyFBPase) and chloroplast isoenzyme (cpFBPase). Overexpression of fructose-1, 6-bisphosphatase (cy-FBPase) can improve growth and biomass accumulation in higher plants.

In the prior art, the biomass yield of the common cultivation of the nannochloropsis is limited by the limited growth efficiency, so that the photoautotrophic cultivation effect of the nannochloropsis is poor. Because the photosynthesis efficiency of the transgenic strain is improved by modifying the nannochloropsis through the genetic engineering technology at present, the nannochloropsis has more growth advantages, and is particularly important.

The prior art discloses that decreasing expression of the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) in plants such as Arabidopsis thaliana can result in decreased synthesis of sucrose, accumulation of phosphorylated intermediates, and increased starch synthesis. CN103305488B discloses that the sucrose content of transgenic plants is significantly improved by over-expressing cy-FBPase and that drought tolerance of transgenic plants is significantly improved.

The genome size of the nannochloropsis is about 30Mb, six species are in the genus, wherein a plurality of species complete whole genome sequencing, but at present, part of unknown functional genes exist in the genome, and the genome has larger difference similarity with plant genes which are photosynthetic and have lower similarity in terms of gene similarity and gene function, so that the target genes or methods for improving plant photosynthesis are difficult to be directly applied to the nannochloropsis.

Disclosure of Invention

In order to achieve the above object, the present invention provides an application of a cytoplasmic enzyme fructose-1, 6-bisphosphatase to promote photosynthesis of nannochloropsis and/or increase photosynthetic yield of nannochloropsis, so as to solve the problems of the prior art.

The invention also provides a recombinant nannochloropsis which overexpresses the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase), which has the purpose of promoting the photosynthesis of the nannochloropsis and/or improving the photosynthetic yield of the nannochloropsis.

Further, the algal cells of the recombinant nannochloropsis are transferred into a nucleic acid sequence of a gene of a cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase).

Further, a recombinant vector containing a sequence for encoding the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) is prepared, and then the recombinant vector is transformed and introduced into the nannochloropsis to obtain the recombinant nannochloropsis.

Further, the recombinant nannochloropsis is obtained by introducing a recombinant vector containing a (cyFBPase) gene sequence into a nannochloropsis N.gaditana CCMP 526.

The invention provides a method for promoting growth of nannochloropsis, which is characterized in that the gene of the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) of the recombinant nannochloropsis is overexpressed, and the nannochloropsis is cultivated normally.

The invention provides a method for improving photosynthetic yield of nannochloropsis, which is characterized in that the gene of a cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) of the recombinant nannochloropsis is overexpressed, and the nannochloropsis is cultivated normally.

The inventor researches and discovers that (cyFBPase) genes can influence the cell growth of the nannochloropsis, and the nannochloropsis strong light synthetic growth material can be obtained by constructing (cyFBPase) a nannochloropsis transgenic strain with over-expressed genes. The overexpression (cyFBPase) of the gene in the nannochloropsis can promote the photosynthesis of the nannochloropsis, thereby promoting the growth of cells and obviously improving the photosynthetic yield. Has practical significance in the photosynthetic autotrophic growth of the nannochloropsis.

Drawings

FIG. 1 is a diagram showing the result of electrophoresis of the PCR amplification test (cyFBPase) sequence in example 1.

FIG. 2 is a graph showing the detection results of qRT-PCR in example 2.

FIG. 3 is a graph showing the cell count and biomass results of the recombinant nannochloropsis strain of example 2.

FIG. 4 is a graph showing the results of maximum photosynthetic efficiency (Fv/Fm) and luminous energy utilization efficiency of the recombinant nannochloropsis strain of example 2.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention. The specific techniques or conditions are not identified in the examples and are performed according to techniques or conditions described in the literature in this field or according to the product specifications. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The nannochloropsis in the following experiments were derived from N.gaditana CCMP 526.

The following example of the culture medium:

f/2 artificial seawater culture Medium (ASW) (in the case of an amount of 800ml configuration): 24g of sea salt (purchased from FAUNA MARIN in Germany) is dissolved in 800mL of pure water, 8mL of Tris-HCL (purchased from Solarbio) is added, and after uniform mixing, high-temperature sterilization is carried out under the conditions of 121 ℃ and 20 min; a further 16mL of f/2 stock solution (50X) (purchased from Sigma-Aldrich) was added at the time of use.

F/2 solid culture plates (in the case of an amount of 800ml configuration): 24g of sea salt (purchased from FAUNA MARIN in Germany) was dissolved in 800mL of pure water, 8mL of Tris-HCl (purchased from Solarbio) and 1.5% agar (purchased from Solarbio) were added, and after mixing, high-temperature sterilization was performed at 121℃for 20 min; 16mL of f/2 stock solution (50X) (purchased from Sigma-Aldrich) was added at the time of use.

Example 1: cloning of the Nannochloropsis-Nannochloris cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) Gene

Extraction and reverse transcription of nannochloropsis RNA

1. The total RNA of the microalgae cells is extracted by adopting a polysaccharide polyphenol plant total RNA extraction kit (Genebetter, item no: R38-50), and the steps comprise:

(1) And (3) pre-cooling the grinding module in liquid nitrogen until no bubbles emerge, wherein the pre-cooling is finished. 4 steel balls with the diameter of 3mm are added into a 2mL liquid nitrogen grinding tube, a sample with the diameter of about 50mg is put into the liquid nitrogen grinding tube, and the mixture is put into liquid nitrogen for precooling. All pre-cooled centrifuge tubes are inserted into a grinding module, put into a grinding instrument, set to be 55 in frequency and vibrate for 30s.

(2) Immediately after milling, 550uL of lysate was added and vortexed for 20s (or blown evenly with a pipette). The lysate was centrifuged at 13000rpm for 5-10min and uncleaved chips were precipitated.

(3) The supernatant (typically 480uL, taking care not to aspirate the interface precipitants) was carefully aspirated into a gDNA filter, which was placed in a collection tube and centrifuged at 13000rpm for 1min, leaving the filtrate. Adding 0.5 times of absolute ethyl alcohol into the filtrate, and blowing and mixing uniformly by a liquid-transferring gun.

(4) Each transfer less than 750uL of the supernatant mixture to a gDNA filter, centrifuge at 13000rpm for 2min, and discard the filtrate. At this point, most of the gDNA was removed and RNA and a small amount of gDNA remained adsorbed on the membrane.

(5) The gDNA filter was removed and placed in an RNA adsorption column, centrifuged at 13000rpm for 30sec, and the filtrate was discarded.

(6) 500UL of rinse RW was added and centrifuged at 13000rpm for 30sec, and the filtrate was discarded. Repeating once.

(7) The RNA adsorption column was put back into the empty collection tube, centrifuged at 13000rpm for 2min, and the ethanol remaining on the membrane was removed.

(8) Taking out the RNA adsorption column, placing in an RNase-free 1.5mL centrifuge, suspending and dripping 30-50uL of RNase-free H ₂ O into the center of the RNA adsorption membrane, standing at room temperature for 1min, and centrifuging at 13000rpm for 1min. And centrifuging to obtain the total RNA solution.

2. Reverse transcription to obtain cDNA

The experiments used Evo M-MLVRT Mix Kit (+ GDNA CLEAN) reverse transcription kit and specific components from Ai Kerui Biotech Co.Ltd were as shown in tables 1-3:

(1) Genomic DNA removal

The following mixtures were prepared in RNase-free centrifuge tubes:

TABLE 1 reaction System Table

Component (A)	Volume of
		5×gDNAcleanbuffer	2μl
TotalRNA	100ng～1μg
		gDNAcleanReagent	1μl
RNase-freeddH2O	to10μL

Gently beating and mixing by a pipette. 42 ℃ for 2min.

(2) Preparing first strand cDNA synthesis reaction liquid

The following mixtures were prepared in RNase-free centrifuge tubes:

TABLE 2 reaction System Table

Gently beating and mixing by a pipette.

(3) The first strand cDNA synthesis reaction was performed under the following conditions

TABLE 3 reaction System Table

Temperature (temperature)	Reaction time
		37℃	15min
85℃	5sec

The product can be used for PCR reaction immediately or stored at-20deg.C and used within half a year; in order to avoid repeated freezing and thawing of cDNA, the cDNA should be stored at-80℃after being split.

Second, obtaining the full-length cDNA sequence

PCR amplification was performed on the gene of the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) using Phusion DNA polymerase from Siemens technology (China), the primer sequences were as follows:

P-NgFBP-F：cacactctaaaccccaataaaATGGCGACTAAAGACATCG。SEQ ID NO:1。

P-NgFBP-R：gtcgtcatccttgtaatccgccaaggccaactctttc。SEQ ID NO:2。

The reaction system and the steps are as follows:

(1) The reaction solutions shown in table 4 were prepared on ice:

TABLE 4 reaction System Table

Component (A)	Volume of
		10×HFreactionbuffer	10μl
dNTP(10mMapiece)	1μl
		Nannochloropsis cDNA	1μl
Phusion enzyme (10U/. Mu.L)	0.5μl
		P-NgFBP-F(10μM)	2μl
P-NgFBP-R(10μM)	2μl
		ddH₂O	33.5μl

(2) The PCR reaction conditions were: pre-denaturation at 98 ℃ for 30s; denaturation at 98℃for 10s; annealing at 60 ℃ for 30s;

(3) Extending at 72 ℃ for 3min; carrying out denaturation, annealing and extension for 40 cycles in total; finally, final extension is carried out for 5min at 72 ℃;

(4) The 1% agarose gel was used for gel electrophoresis detection of PCR results, and the electrophoresis results are shown in FIG. 1, so that a 1068bp cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) sequence was obtained.

(5) And (3) recovering agarose gel electrophoresis products, wherein an OMEGA agarose gel DNA recovery kit is adopted to recover the agarose gel electrophoresis products, and the operation steps are carried out according to instructions to obtain the gene (the sequence is shown as SEQ ID NO: 3) of the nannochloropsis cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase).

ATGGCGACTAAAGACATCGACAATGTGGGTGGCGATACAGACACCAAGACACTCCAGCGCTTCATTATCTCCGCCACCA

AGGACATTCAATTGACCTTGCTGATGACTTCGATCCAGATGGGCTGCAAGTCCATCGCCCGGGCTGTCCGCAAGGCCGG

CATCGCGGGCCTCTACGGCTTGCACGGGTCGGAGAACGTGTCCGGGGACCAGGTCAAGAAACTGGACGTGCTCTCGGAC

GAGATATTCGTCAACTGCCTCAAGGAGTCACACTGCTGCGCGGTGCTTGTGTCTGAGGAACGGGACGATCCCATCATTG

TAGAAGCTGCGAAAGCAGGAAAATACTGTGTGGCATTCGATCCCTTGGACGGATCCTCCAATATCGACTGCAACGTCTC

CACAGGGACCATCTTCGCCATCTACGAGCGGATTTCCGCCTCCGACCAGTCACCAAGCGTAACGGACATTCTCCGGGCA

GGCACGGCCATCGTCGCGGCGGGATACTGCATGTACGGCTCGGCCACAGACCTGGTGCTGACCTTCGGCCATGGGGTGC

ACCGTTTCACGCTAGACCCGACATTGGGCGAGTTCATTCACACTCAGGGGCCTGTAAAGCTGCCTGCTAAGCCGAAGCA

TATCTACTCCTGTAACGAGGGAAATTATTCCTTGTGGGATGATGCCATGCGTGCCGCAGTCGACGCTTTTAAGCACCAG

GACCCGCCTTACGCGGCGCGTTACGTCGGGTCCATGGTGTCGGATGTGCACCGTACCTTGCTCTACGGGGGCATCTTTC

TTTACCCTGCGGACCGCAAGAGCAAGATTGGAAAGTTGCGCGTCCTTTACGAGGGTTTTCCCATGGCCAAAATAGTGGA

AGATGCAGGCGGTATCGCCACCACGGGTCTGTTTCAGGGCAAGATACAGCGCGTGCTGGACCTGCACCCTTCCAACGTG

CATGACCGCTGCCCGATCATCCTCGGGACCCCCTCGGACGTGCAGAGGGTGCTCGACGTCTACGCCCAGGTCATCTCTAAAGCCGCCACTGACCCCAAGCCGAAAGAGTTGGCCTTGGCGTGA.SEQ ID NO:3.

Example 2: overexpression of the Nannochloropsis glomerata cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) gene

Construction of a vector for overexpressing the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase)

To investigate the function of the gene for the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase), a 1068bp fragment containing the coding region of the gene for the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) was inserted correctly into the HSP-TUB-Zeocin vector (see Fengjuan Li,et el.High-efficiency nuclear transformation of the oleaginous marine Nannochloropsis species using PCR product.Bioscience,Biotechnology,and Biochemistry,Volume 78,Issue 5,4May 2014,P812–817,https://doi.org/10.1080/09168451.2014.905184). Gibson one-step cloning kit (the gel recovery product was ligated with the expression vector at 50℃for 60min, ligation reaction was shown in Table 5. 2. Mu.L of the reaction solution was transformed into E.coli. Colony PCR was performed under conditions of 98℃pre-denaturation for 30s, 98℃denaturation for 10s, 60℃annealing for 30s, 72℃extension for 1min, denaturation, annealing for 35 cycles, 72℃final extension for 5min, sequencing by Beijing, biological sciences Co., ltd. Sequencing the correctly positive monoclonal amplified culture was performed to extract the plasmid, namely the expression vector of HSP-cyFBP.

TABLE 5 reaction System Table

Component (A)	Volume of
		CyFBPase Gene	1μg
HSP-TUB-Zeocin vector backbone	1μl
		10*buffer	5μl

Sequencing results show that the open reading frame of cyFBPase gene has 1068bp (shown as SEQ ID NO: 4) and codes 356 amino acids.

MATKDIDNVGGDTDTKTLQRFIISATKDIQLTLLMTSIQMGCKSIARAVRKAGIAGLYGLHGSENVSGDQVKKLDVLSDEIFVNCLKESHCCAVLVSEERDDPIIVEAAKAGKYCVAFDPLDGSSNIDCNVSTGTIFAIYERISASDQSPSVTDILRAGTAIVAAGYCMYGSATDLVLTFGHGVHRFTLDPTLGEFIHTQGPVKLPAKPKHIYSCNEGNYSLWDDAMRAAVDAFKHQDPPYAARYVGSMVSDVHRTLLYGGIFLYPADRKSKIGKLRVLYEGFPMAKIVEDAGGIATTGLFQGKIQRVLDLHPSNVHDRCPIILGTPSDVQRVLDVYAQVISKAATDPKPKELALA.

SEQ ID NO:4。

The P-HSP-cyFBP expression vector is amplified, cultured and extracted to obtain plasmid, and stored at-20 deg.C for use.

Construction of transgenic algae strain

(1) Culturing and collecting the nannochloropsis cells:

the nannochloropsis is cultivated for about 6 days to logarithmic phase (1-5 x 10 ⁷ cells/ml), 30-50ml of algae liquid is taken according to each reaction, 4000g is taken, 10min is taken, and algae cells are collected by centrifugation at 4 ℃.

(2) Algae cell treatment

The centrifugally collected algal cells were transferred to a 1.5ml centrifuge tube, washed 3 times with 375mM sterile sorbitol pre-cooled on ice, and desalted (4000 g,10min,4 ℃). 100. Mu.l 375Mm sorbitol was added to each reaction and resuspended, 3-5. Mu.g linearized P-HSP-cyFBPase expression vector plasmid and 30-50. Mu.g salmon sperm DNA (H1060, soy baby) were added, gently flicked, mixed, placed on ice for 30min and transferred to a 2Mm electric shock cup.

(3) Parameters of electric shock

The shock parameters were 2200v,50 μf,600Ohm,

After the shock is completed, the actual voltage is shown to be typically less than 2200V for a duration of 15-20ms.

(4) Recovery

Immediately after the electric shock, the cells were transferred to a 15ml centrifuge tube containing 10ml f/2 artificial seawater medium and incubated at 22℃for 24-48h with low light (50. Mu. Mol). After the completion of the culture, the concentrated algae solution was centrifuged (4000 g,10min,4 ℃) and spread evenly on resistant plates of f/2+zeocin (2. Mu.g/ml), 3-5 plates were spread per reaction.

(5) Negative control

Sorbitol treated algal cells were not added with DNA, shocked, recovered in the same way as the other reactions, and finally plated on zeocin resistant plates and non-resistant f/2 solid culture plates, respectively.

(6) Screening of resistant algal strains

Typically, 3-4 weeks later, resistant clones were visualized on plates, and after 4-5 weeks, resistant clones were picked and cultured in liquid f/2 artificial seawater medium.

(7) Screening of overexpressed algal strains

The amount of LHC expressed in the over-expressed strain was measured by qRT-PCR in comparison with the wild type (i.e., nannochloropsis), and the reaction system (20. Mu.L) was as shown in Table 6, with reference to SYBR Green Pro Taq HS pre-mixed qPCR kit (containing Rox) instructions. The reaction procedure was as follows: 30sec at 95 ℃; denaturation at 95℃for 5s, annealing/extension at 60℃for 30s;40 cycles; dissolution profile: denaturation at 95℃for 15s; annealing at 60 ℃ for 60s; stop at 95℃for 15s. The primer sequences were as follows: cyFBPase forward primer: 5'-GCGGTGCTTGTGTCTGAGGAA-3' (SEQ ID NO: 5); reverse primer: 5'-GCTCGTAGATGGCGAAGATGGT-3' (SEQ ID NO: 6), reference gene β -actin forward primer: 5'-AGCTGCCGGATGGTAACGTG-3' (SEQ ID NO: 7), reverse primer: 5'-GCTCGCCTCCTTGCCGATAA-3' (SEQ ID NO: 8). The qRT-PCR detection results are shown in FIG. 2. Wherein WT is wild type, ngFBP is a positive clone selected, i.e., recombinant nannochloropsis strain. As can be seen from fig. 2, ngFBP has significantly higher RNA expression levels than the wild type.

TABLE 6 reaction System Table

Third, growth analysis of overexpressed algae strain

(1) Microalgae cultivation: sterile pure culture of nannochloropsis and recombinant nannochloropsis strain NgFBP were cultured to log phase with 100mL cell culture flasks in 20mL f/2 Artificial Seawater (ASW) medium under sterile conditions. The culture environment conditions are as follows: the light incubator is set with the light intensity of 50 mu mol m ^–2s^–1, the light and dark cycle is carried out for 12h to 12h, and the temperature is 22 ℃.

(2) Algae cell count: the samples were quantified for cell concentration in nannochloropsis (N.gaditana CCMP 526) by flow cytometry (Backman Coulter, cytoFlex S) using a fluorescent channel with excitation light at 488nm and emission light at 685 nm.

(3) Detecting the fluorescence intensity of microalgae chlorophyll: the above parameters were determined using a multi-excitation wavelength modulated chlorophyll fluorescence meter (multi-color PAM, walz) and a software program PAM Win 3: taking samples of algae liquid in an experimental group and a control group in the middle section of the photoperiod of the 3 rd day, and measuring fluorescent parameters of a light system II (PS II) in dark adaptation for 20min at a culture temperature (22 ℃) comprises: maximum photosynthetic efficiency (Fv/Fm), actual photosynthetic efficiency (Y (II)); and calculates the light energy utilization efficiency by using the formula.

As shown in the results of FIGS. 3 and 4, the cell number and the light energy utilization efficiency in the experimental group alga strain (recombinant nannochloropsis strain NgFBP) are obviously higher than those of the control group WT, which indicates that the gene of the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) plays a role in regulating and controlling the growth of nannochloropsis cells.

In conclusion, the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) gene is separated from the nannochloropsis, and the transgenic function verification analysis of the nannochloropsis shows that the cytoplasmic enzyme fructose-1, 6-bisphosphatase (cyFBPase) gene has remarkable effect in promoting the growth and photosynthesis of the nannochloropsis cells, improves the limitation of photoautotrophic to the growth of the nannochloropsis, and has important significance for the photoautotrophic growth of the nannochloropsis.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives, and variations may be made in the above embodiments by those skilled in the art without departing from the spirit and principles of the invention.

Claims

1. The cytoplasmic enzyme fructose-1, 6-bisphosphatase has the purpose of promoting photosynthesis of the nannochloropsis and/or improving photosynthetic yield of the nannochloropsis.

2. A recombinant nannochloropsis which overexpresses the cytoplasmic enzyme fructose-1, 6-bisphosphatase, which has the purpose of promoting the photosynthesis of nannochloropsis and/or improving the photosynthetic yield of nannochloropsis.

3. The recombinant nannochloropsis of claim 2, wherein the algal cells of the recombinant nannochloropsis are transformed with a nucleic acid sequence of a gene of a cytoplasmic enzyme fructose-1, 6-bisphosphatase.

4. The recombinant nannochloropsis of claim 3, wherein the recombinant vector comprising the sequence encoding the cytoplasmic enzyme fructose-1, 6-bisphosphatase is prepared and then transformed into nannochloropsis to obtain the recombinant nannochloropsis.

5. The recombinant nannochloropsis of claim 3, wherein said recombinant nannochloropsis is obtained by introducing a recombinant vector comprising a gene sequence of the cytoplasmic enzyme fructose-1, 6-bisphosphatase into nannochloropsis N.gaditana CCMP 526.

6. A method for promoting growth of nannochloropsis, which is characterized in that the recombinant nannochloropsis' cytoplasmic enzyme fructose-1, 6-bisphosphatase gene of claim 2 is over-expressed, and the nannochloropsis is cultivated normally.

7. A method for improving photosynthetic yield of nannochloropsis, which is characterized in that the recombinant nannochloropsis' cytoplasmic enzyme fructose-1, 6-bisphosphatase gene in claim 2 is over-expressed, and then the nannochloropsis is cultivated normally.