JPH11211714A - Method for testing effect of alga-preventing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and positively judge the effect of a depressant against breeding alga. SOLUTION: A depressant against breeding alga with a specific concentration is accommodated in a test tube 20 that is a culture container as a sample along with a culture liquid containing an alga cell, thus cultivating the alga cell of the sample in the test tube in a culture room. Then, the absorbance of the sample in the test tube during the cultivation is calculated based on a measurement result by a transmission-type chlorophyll measuring device 10, the change in the cell density of the alga cell of the sample with time is obtained based on the absorbance, and the effect of the depressant against breeding alga is judged based on the change in the cell density of the alga cell being obtained with time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for testing the efficacy of an anti-algal agent for preventing algae from adhering to and propagating on buildings and the like.

[0002]

2. Description of the Related Art Anti-algal agents have been developed to prevent algae from adhering to and propagating on buildings and the like. Such an anti-algal agent is mixed in a paint or the like and applied to a portion of the outer wall or the like where alga proliferates, so as to prevent the algae from proliferating in that portion.

[0003] However, it is not easy to determine how effective such an anti-algal agent is actually. As a test method to determine the efficacy of the alga-proofing agent, a test piece coated with a paint or the like mixed with an alga-proofing agent is exposed outdoors, and the efficacy of the alga-proofing agent is determined based on the algal propagation state on the test piece. Outdoor exposure methods are known. In such an outdoor exposure method, it is necessary to expose the test piece outdoors for a long time, so that there is a problem that it takes a long time to determine the efficacy of the anti-algal agent. In addition, depending on the environmental conditions in an outdoor place to which the test piece is exposed, the breeding state of the algae may be different, so that it may not be possible to accurately determine the efficacy of the antialgal agent.

[0004] As a test method for judging the effectiveness of an alga repellent in a room against such an outdoor exposure method, a tropical cabinet method indicated in the UK Building Material Evaluation Standard (MOAT) is known. In this tropical cabinet method, first, a cement slurry is applied to a sterilized test tube, and a paint mixed with an anti-algal agent is applied thereto. When the paint cures, five types of algae (Nostoc muscorum, Os
spray with cillatoria tenuis). Thereafter, the test tube is placed in a tropical cabinet (fluorescent heating device), and is heated by fluorescence for 42 days, and the occurrence of algae in the test tube is visually determined. Thereby, the efficacy of the anti-algal agent is determined.

[0005]

In such a tropical cabinet method, the occurrence of algae in a test tube is visually determined. Therefore, as in the case of the outdoor exposure method, the determination is made by an individual. There is a difference, and it may not be possible to accurately determine the efficacy of the anti-algal agent. In addition, there is a problem that a special device called a tropical cabinet is required, and it cannot be easily implemented.

The present invention has been made to solve such a problem, and an object of the present invention is to easily carry out the method and to quantitatively determine the basic efficacy of the alga-controlling agent. An object of the present invention is to provide a method for testing the efficacy of an algal agent.

[0007]

According to the method for testing the efficacy of an anti-algal agent of the present invention, a predetermined concentration of an anti-algal agent is contained in a culture container together with a culture solution containing algal cells as a sample. The method is characterized in that algal cells in a culture vessel are cultured indoors, and the efficacy of the antialgal agent is determined based on a change in the cell density of the algal cells in the culture vessel during the culture.

[0008] The cell density of the algal cells in the culture vessel is determined based on the absorbance of the sample in the culture vessel.

[0009] The absorbance is calculated based on the result of measurement by a transmission chlorophyll measuring device.

[0010]

Embodiments of the present invention will be described below.

In the method for testing the efficacy of an alga-controlling agent of the present invention, first, an alga-controlling agent to be evaluated for efficacy is selected, and after dissolving the alga-controlling agent, the diluted alga-cide is diluted with a culture solution to 1000 to 0.1 mg / ml. Make a dilution of the alga repellent at a given concentration in the l range. And
A culture solution (control) containing no antialgal agent is added to the obtained diluted solution of the algal agent to prepare a sample.

After a predetermined amount of algal cells are added to the sample thus obtained, the sample is put into a test tube, which is a culture vessel, and stirred. Thereafter, the test tube is placed in a culture room at a constant temperature and humidity, and algal cells are cultured in the culture room. In the culture room, the irradiation of the fluorescent lamp and the stop of the irradiation are alternately repeated every several hours so that the environmental conditions are the same as the outdoor environment.

[0013] The change over time in the cell density of the algal cells in a test tube placed in the culture chamber is measured. The change in the cell density of the algal cells in the test tube is calculated based on, for example, the absorbance of the sample in the test tube measured by the transmission-type chlorophyll measurement device.

FIG. 1 is a schematic diagram showing an example of a transmission-type chlorophyll measuring apparatus for measuring the absorbance of a sample for calculating the cell density of algal cells cultured in a test tube.
The transmission-type chlorophyll measurement device 10 has a light-shielding box 11 in which light is prevented from entering, and a test tube 20 containing a sample is vertically supported in the light-shielding box 11. A support 12 is provided. Light from a light source 13 disposed outside the light-shielding box 11 is applied to the inside of the light-shielding box 11.
The light applied to the inside 1 is condensed by the condenser lens 14. The light condensed by the condenser lens 14 becomes horizontal parallel light, and is
The light is irradiated toward the test tube 20 supported above.

The parallel light leveled by the condenser lens 14 is transmitted by the interference filter 15 disposed in front of the condenser lens 14 so that only light having a center wavelength of 660 nm is transmitted.
The test tube 20 is passed through a throttle 16 disposed between the test tube 20 supported by the support table 12 and the interference filter 15.
The sample inside has been irradiated. Test tube 2 through aperture 16
The light applied to the sample in the tube 0 passes through the sample in the test tube 20 and is applied to the photovoltaic cell 17 that is vertically arranged to face the test tube 20. The photovoltaic cell 17 outputs a voltage proportional to the intensity of irradiated light, and the output voltage is measured by a voltmeter 18 disposed outside the light-shielding box 11.

In the transmission type chlorophyll measuring device 10 having such a configuration, the intensity of light transmitted through the sample in the test tube 20 supported on the support base 12 is measured based on the voltage output from the photocell 17. You. Then, the absorbance of the sample in the test tube 20 is determined based on the measured light intensity. Absorbance A of sample in test tube 20
Is the intensity I of light transmitted through the sample in a test tube (blank test tube) containing a sample containing no algal cells.
Based on o and the intensity I of light transmitted through the sample in the test tube (sample test tube) containing the sample containing the algal cells, it is calculated by the following equation (1).

A = -log (I / Io) (1) The voltage measured by the voltmeter 18 when the light transmitted through the sample in the sample test tube is irradiated on the photovoltaic cell 17 is V,
The voltage measured by the voltmeter 18 when the light transmitted through the sample in the blank test tube is irradiated on the photovoltaic cell 17 is Vo
Then, the intensities I and Io of the light transmitted through the sample in each test tube are expressed by the following equations (2) and (3), respectively.

I = kV (2) Io = kVo (3) Accordingly, the absorbance A of the sample in the sample test tube represented by the formula (1) is represented by the following formula (4).

A = −log (I / Io) = − log (kV / kVo) = log (Vo / V) (4) When the absorbance of the sample in the sample test tube is calculated by the equation (4), The cell density of the algal cells corresponding to the absorbance of the sample is determined based on a previously prepared calibration curve indicating the relationship between the cell density of the algal cells and the absorbance. A calibration curve showing the relationship between the cell density of the algal cells and the absorbance is created by measuring the absorbance of the undiluted solution of the cell solution of the algal cells of which the cell density is known and the dilution thereof using a toma hemocytometer or the like. You.

When the cell density of the algal cells in the sample in the sample test tube is determined in this way, the alga-proofing effect of the alga-proofing agent contained in the sample is evaluated based on the change over time in the cell density. That is, it is determined that the lower the cell density of the algal cells in the sample in the sample test tube placed in the culture chamber, the higher the algal protection effect of the antialgal agent.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Five kinds of anti-algal agents of different systems, namely, organic nitrogen-based (symbol ON), pyridine-based (symbol PY), triazine-based (symbol TR), thiazole-based (symbol TH), and imidazole-based (symbol IM) )), Each algicidal agent is dissolved in ethanol, and then diluted with a culture solution to obtain a diluent having five concentrations of 100, 30, 10, 2, and 0.5 mg / l. Were prepared respectively. In addition, a culture solution (control) containing no antialgal agent was also prepared.

9.5 mg of each dilution in each anti-algal agent
/ L was added to each test tube together with 0.5 mg / l of the cell solution of algal cells, and the mixture was stirred. As the cell solution of algal cells, algae actually generated in a building were collected, separated and cultured, and used. This cell fluid contains algae,
It contained only Protococcus virdis.

After measuring the absorbance of the sample in each test tube with the transmission type chlorophyll measuring device 10, each test tube was allowed to stand in the culture room. The culture room is controlled at a temperature of 26 ± 3 ° C. and a humidity of 60 ± 10% RH, and is irradiated with a 3000 lx fluorescent lamp for 14 hours.
The irradiation stop for 0 hours is alternately repeated.

After leaving each test tube in the culture room, 7 days
The absorbance of the sample in each test tube was measured every 14 days, 21 days, and 28 days using the transmission-type chlorophyll measurement device 10, and the cell density of algal cells in each sample was determined based on each absorbance.

FIG. 2 is a graph showing a change in cell density at each concentration of the organic nitrogen-based algicide (ON). At a concentration of 10 mg / l or less, the cell density of the algal cells in the sample containing the organic nitrogen-based algagic agent (ON) gradually increased, and the alga cell did not exhibit the efficacy as an algagic agent. , 30mg / l
At the above concentrations, the cell density of the algal cells decreased with time, and the algal cells were completely killed after 21 days.

At the time when the cultivation period had passed 14 days, a remarkable difference based on the concentration was observed in the efficacy of each algicidal agent as an algicidal agent.

FIG. 3 is a graph showing the relationship between the concentration of all antialgal agents after 28 days and the cell density of algal cells. In the samples containing the pyridine-based antialgal agent (PY) and the thiazole-based (TH), the algal cells were completely killed at a concentration of 10 mg / l or more, respectively. Further, in the samples containing each of the organic nitrogen-based (ON) and triazine-based (TR) anti-algal agents, the algal cells were completely killed at a concentration of 30 mg / l or more. On the other hand, in the sample containing the imidazole-based (IM) anti-algal agent, the concentration was 10 mg /
At l, the growth of algal cells was suppressed, and the degree of growth could be halved compared to the control. However, even at a concentration of 100 mg / l, algal cells could not be completely killed. Therefore, the imidazole-based (IM) algicidal agent was not found to be sufficiently effective as an antialgal agent.

[0028]

As described above, the method for testing the efficacy of an alga-controlling agent according to the present invention is based on the fact that algae are actually cultured in a culture solution containing the alga-controlling agent and the cell density of algal cells is changed during the culture. Based on the, to determine the efficacy of the anti-algal agent,
The efficacy of the anti-algal agent can be accurately and reliably determined.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a transmission-type chlorophyll measurement device used for measuring the absorbance of a sample in the method for testing the efficacy of an alga-controlling agent of the present invention.

FIG. 2 is a graph showing a change in cell density at each concentration of an organic nitrogen-based alga protection agent in Examples.

FIG. 3 is a graph showing the relationship between each concentration and cell density of all five kinds of algicides after 28 days in Examples.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 transmission chlorophyll measuring device 11 light-shielding box 12 support base 13 light source 14 condenser lens 15 interference lens 16 aperture 17 photocell 18 voltmeter 20 test tube

Claims (3)

[Claims] Claims: 1. An alga protection agent having a predetermined concentration is accommodated in a culture vessel as a sample together with a culture solution containing algal cells, and the algal cells in the culture vessel are cultured in a culture chamber. A method for testing the efficacy of an algicidal agent, comprising determining the efficacy of an algatic agent based on a change in the cell density of algal cells in a culture vessel during a period of time. 2. The cell density of algal cells in the culture vessel,
The method for testing the efficacy of an antialgal agent according to claim 1, which is obtained based on the absorbance of a sample in a culture vessel. 3. The method of claim 2, wherein the absorbance is calculated based on a measurement result obtained by a transmission-type chlorophyll measuring device.