CN102268377A

CN102268377A - Method for improving lipid producing microalga biomass and lipid accumulation with two stage culture strategy of mixotrophic and nitrogen-rich-nitrogen-deficient culture

Info

Publication number: CN102268377A
Application number: CN 201110192159
Authority: CN
Inventors: 刘和; 张姗姗; 范金凤; 符波; 张丽娟
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2011-07-11
Filing date: 2011-07-11
Publication date: 2011-12-07

Abstract

Belonging to the technical field of microalga bioenergy, the invention relates to a method for improving the biomass and lipid accumulation of lipid producing microalga Scenedesmusdimorphus with a mixotrophic and nitrogen-rich-nitrogen-deficient two stage culture strategy. In the invention, organic carbon source glucose of a certain concentration is added into an autotrophic medium and is subjected to a mixotrophic culture with CO2 which serves as an autotrophic carbon source. Meanwhile, in a nitrogen-rich condition, when the microalga is cultured in high density into a stable stage, the alga solution is transferred to a nitrogen-deficient medium for culturing continuously. When the glucose concentration is 1.2-5.4g/L, the initial pH is 7, and the culture time reaches 14-16d, the microalga biomass can reach a maximum of 4.5g/L, which is 2.57 times as high as the biomass in a mixotrophic condition. In a nitrogen-deficient condition, the total lipid content of the microalga can reach a maximum of 29.62%, which is 1.6 times the total lipid content of the nitrogen-rich stage. The method of the invention, by adding an organic carbon source and providing a nitrogen-deficient condition for the two stage culture, can effectively improve the microalga biomass and promote the lipid accumulation, thus being significant for the research of large scale production of bioenergy with microalgae.

Description

Support and rich two stage of nitrogen-nitrogen stress training strategy raising produce oil micro algae biomass and grease cumulative method with holding concurrently

Technical field

Adopting holds concurrently supports and the little algae of rich two stage of nitrogen-nitrogen stress training strategy raising produce oil S.dimorphusBiomass and grease cumulative method can improve the biomass of little algae by add organic carbon source glucose in the BG11 substratum, provide the nitrogen defect condition simultaneously after little algae reaches stationary phase, can effectively improve the total lipid content of little algae.Belong to little algae bioenergy technical field.

Background technology

Little algae is a kind of of waterplant, is the energy with light mainly, is that carbon source is carried out photosynthesis and accumulated organic substance with the carbonic acid gas.The training method of present little algae is mainly photoautotrophy and cultivates, and this is determined by itself characteristic.Yet because autotrophy culturing cell density is low, the cost height of gathering has limited the raw material of little algae as biofuel.Support the hot issue that cultivation becomes the concern of domestic and international algological biology field in recent years and adopt suitable interpolation organic carbon source to hold concurrently.Holding concurrently to support to cultivate has the superiority such as output that can directly utilize existing fermentation equipment, improve biomass and active substance, helps improving active substance output in micro algae biomass and the born of the same parents.But up to now, can hold concurrently support and little algae species of heterotrophic growth limited, and restrict little algae and hold concurrently and support and the mechanism of heterotrophic growth it be unclear that.

In addition, the nutritive ingredient of nutrient solution more particularly must nutritive salt nitrogen, phosphorus, silicon etc. has considerable influence to the content and the composition of microalgae grease.Generally believe that the nitrogen defective can promote the accumulation of produce oil microalgae grease, its reason may be nitrogenous source when sufficient, and the cell growth is vigorous, and biologically active substances such as protein, lipid and nucleic acid are all normally synthetic, so the gained fatty acid content is lower.But when nitrogenous source lacked, the synthetic of nitrogenous compounds such as protein and nucleic acid was restricted, and less depot lipid and most membranous still can the continuation of nitrogenous element synthesized, and therefore the percentage composition in dry cell weight increases.

Summary of the invention

The purpose of this invention is to provide a kind of raising micro algae biomass and grease cumulative method, improve micro algae biomass and provide rich nitrogen-nitrogen stress condition to promote oil and fat accumulation by adding organic carbon source glucose, obtain a kind of two stage training strategies that promote that micro algae biomass and fat content are improved simultaneously, promote little algae to produce the industrialization of thing diesel oil.

Technical scheme of the present invention: the little algae of a kind of raising produce oil S.dimorphusBiomass and grease cumulative method, adopting holds concurrently supports and rich two stage of nitrogen-nitrogen stress training strategy, at first with little algae S.dimorphus,Algae ( Scenedesmus. dimorphus), 36(23) open in [Anhui agricultural sciences] 2008, be inoculated in the BG11 substratum that has added 1.2 ~ 5.4 g/L glucose, initial pH is 7,25 ℃ of temperature, illumination 6600lux, inorganic nitrogen-sourced NaNO ₃Concentration be 1.5g/L, aerated culture is to stationary phase, concentrates algae liquid is centrifugal then, is inoculated into NaNO ₃Concentration be in the nitrogen stress substratum of 0.3g/L, continue to be cultured to stable.Incubation time is 14 ~ 16d.Adopt the composition of BG11 substratum to be NaNO ₃: 1.5g/L, K ₂HPO ₄3H ₂O:0.04g/L, MgSO ₄7H ₂O:0.075g/L, CaCl ₂2H ₂O:0.036g/L, citric acid: 0.006g/L, ferric ammonium citrate: 0.006g/L, EDTA: 0.001g/L, Na ₂CO ₃: 0.02g/L, A ₅Solution 1mL; Trace element solution A ₅Composition be H ₃BO ₃: 2.86g/L, MnCl ₂4H ₂O:1.81g/L, ZnSO ₄7H ₂O:0.222g/L, CuSO ₄5H ₂O:0.079g/L, Co (NO ₃) ₂6H ₂O:0.0494g/L, NaMoO ₄2H ₂O:0.390g/L.

When the glucose concn that adds in the BG11 substratum was 5.4 g/L, the micro algae biomass maximum can reach 4.5g/L; Nitrogen stress stage little algae total lipid content maximum can reach 29.62%.

Beneficial effect of the present invention: the present invention adopts to hold concurrently and supports and rich two stage of nitrogen-nitrogen stress training strategy, has greatly promoted the little algae of produce oil S. dimorphusBiomass and greasy accumulation.This training strategy provides a kind of feasible approach for high-density culture and the commercial application of little algae, has great importance to utilizing micro-algae large-scale to produce the thing energy.

Description of drawings

Little algae under three kinds of culture condition of Fig. 1 S.dimorphusGrowth curve.

Little algae under three kinds of culture condition of Fig. 2 S.dimorphusIncrement.

Embodiment

Embodiment 1

Under the condition of supporting of holding concurrently, cultivate the little algae of produce oil S.dimorphus, the algae kind is from national biological experiment training center of life science institute of Zhongshan University.Experiment condition is tested with the bubbling cylindrical reactor down, and the reactor effective volume is 1.5L, gets an amount of algae kind to be inoculated in the BG11 sterilising medium that has added glucose, the initial inoculation amount is 0.05g/L, and pH is 7.0, and temperature is 25 ± 1 ℃, illumination is 6600 lux, inorganic nitrogen-sourced NaNO ₃Concentration be 1.5g/L, ventilation is that the dark period ratio of 1 L/min airlight is 14 ︰ 10, the interpolation concentration of glucose is respectively 1.2g/L, 5.4g/L.Micro algae growth concentrated algae liquid is centrifugal to the stationary phase, was inoculated into NaNO ₃Concentration be in the nitrogen stress substratum of 0.3g/L, cultivate 14 ~ 16d.When the interpolation concentration of glucose was 5.4g/L, the micro algae biomass maximum reached 4.5 g/L, and nitrogen stress stage little algae total lipid content maximum can reach 29.62%.

Little algae under three kinds of culture condition of table 1 S.dimorphusTotal lipid content

Figure 2011101921594100002DEST_PATH_IMAGE001

Little algae under three kinds of culture condition of table 2 S.dimorphusFatty acid component

Figure 2011101921594100002DEST_PATH_IMAGE002

Claims

1. one kind is improved the little algae of produce oil S.dimorphusBiomass and grease cumulative method is characterized in that adopting holding concurrently and support and rich two stage of nitrogen-nitrogen stress training strategy, at first with little algae S.dimorphusBe inoculated in the BG11 substratum that has added 1.2 ~ 5.4 g/L glucose, initial pH is 7,25 ℃ of temperature, illumination 6600lux, inorganic nitrogen-sourced NaNO ₃Concentration be 1.5g/L, aerated culture is to stationary phase, concentrates algae liquid is centrifugal then, is inoculated into NaNO ₃Concentration be in the nitrogen stress substratum of 0.3g/L, continue to be cultured to stable, incubation time is 14 ~ 16d;

The BG11 substratum is: NaNO ₃: 1.5g/L, K ₂HPO ₄3H ₂O:0.04g/L, MgSO ₄7H ₂O:0.075g/L, CaCl ₂2H ₂O:0.036g/L, citric acid: 0.006g/L, ferric ammonium citrate: 0.006g/L, EDTA: 0.001g/L, Na ₂CO ₃: 0.02g/L, A ₅Solution 1mL/L uses the deionized water constant volume; Trace element solution A wherein ₅Composition be H ₃BO ₃: 2.86g/L, MnCl ₂4H ₂O:1.81g/L, ZnSO ₄7H ₂O:0.222g/L, CuSO ₄5H ₂O:0.079g/L, Co (NO ₃) ₂6H ₂O:0.0494g/L, NaMoO ₄2H ₂O:0.390g/L;

Described nitrogen stress substratum is NaNO ₃Concentration be 0.3g/L, all the other components are with the BG11 substratum.

2. the little algae of raising produce oil according to claim 1 S.dimorphusBiomass and grease cumulative method, when it is characterized in that the glucose concn that adds in the BG11 substratum is 5.4 g/L, micro algae biomass reaches 4.5g/L.

3. the little algae of raising produce oil according to claim 1 S.dimorphusBiomass and grease cumulative method is characterized in that cultivating by rich nitrogen-nitrogen stress, make little algae total lipid content reach 29.62%.