JP2005287337A - Method for counting number of mold cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for counting the number of mold cells in a specimen by the culture for a short time and capable of accurately counting the cell number. <P>SOLUTION: The extended multiple mycelia of a mold 13 cultured by a liquid culture or a mold 13 cultured on a microporous membrane 1 of a microporous membrane supporting material 4 are photographed 5 and the shape, area and luminous intensity are recognized and analyzed by an image analytic means 10. The number of the mold 13 can be counted by the culture for a short time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention collects the cultured filamentous fungi with a microporous membrane, optically images the collected filamentous fungi, and measures the filamentous fungi by causing the image analysis means to recognize the characteristic shape of the filamentous fungus. Method and collection of filamentous fungi with a microporous membrane, and after culturing the filamentous fungi on the microporous membrane for a short time, the fungi are optically imaged and the characteristic shape of the filamentous fungus is recognized and analyzed by image analysis means It is related with the method of measuring filamentous fungi by making it.

  The conventional method for testing filamentous fungi is the same as the method for testing microorganisms. To measure the number of bacteria in a test material, for example, when the test material is liquid, it is smeared directly on the agar plate medium. If there is no microorganism, the microorganism is cultured on the agar plate medium by coating the liquid from which the microorganisms are washed out on the agar plate medium to form a single colony. An agar plate method is used in which the number of microorganisms in a test material is measured while observing the developed colonies with the naked eye.

In addition, as a method for measuring microorganisms using a membrane filter, there is a method as described in (for example, see Patent Document 1 and Patent Document 2), which includes adenosine triphosphate (hereinafter referred to as ATP) degrading enzyme. After the solution is applied to the membrane filter, the microorganisms in the test material are collected by filtration on the dried membrane filter, and if necessary, cultured for the required time, and then with a liquid extraction reagent and a luminescent reagent for extracting ATP. When a certain luciferin luciferase is sprayed in the form of a mist, luciferin and luciferase react with ATP, and one photon is emitted by oxidation of one molecule of luciferin. doing.
JP 11-137293 A JP-A-6-237793

  In such a conventional method for testing filamentous fungi, a sample is smeared or mixed on an agar plate medium in the same manner as a general microorganism testing method, so the amount of test material to be tested is limited to about 1 ml. It is impossible to inspect test materials that require a small amount of filtration, and it takes 5 to 10 days to incubate until the test results are obtained. It takes a long time, which is a major disadvantage in terms of time and economy. In some cases, there is a problem that the product must be shipped before the test results are known, and the time required to measure the number of filamentous fungi in the test material It is required to shorten the time.

  Moreover, the conventional filamentous fungus resistance test is based on JISZ2911, the GK method, etc. which are official methods, and uses an agar plate medium. As a result, even if the bacterial test is completed in 18 to 72 hours, the test period of the filamentous fungus is 5 to 10 days, which causes the product inventory period to be prolonged, and shortening the test time of the filamentous fungus is required. In addition, the evaluation of antibacterial agents is based on the presence or absence of inhibition circle growth, and volatile antibacterial agents have a problem that it is difficult to accurately grasp the antibacterial performance. It is required to weigh.

  In addition, the method of measuring filamentous fungi with or without culturing using a membrane filter, when culturing, placing the membrane filter that collected the filamentous fungus on a plate agar medium, If the membrane filter and the medium are not completely in contact, such as when air enters between the membrane filter and the plate agar medium, the nutrients in the medium will not reach the filamentous fungus collected on the membrane filter, and the filamentous fungus collected on the membrane filter. However, even if the same sample is cultured, there is a problem that the growth of the filamentous fungus is not constant for each membrane filter, and the size of the colony varies. Has been.

  In addition, in the case of no culture, in the examination of the test material in which the test material contains a fluorescent foreign substance that emits light in the same manner as the filamentous fungus, the fluorescence foreign substance that emits light in the same manner as the filamentous fungus and the fluorescence of the microorganism. There is a problem that a clear difference cannot be obtained, and an accurate measurement of the number of filamentous fungi is impossible, and there is a demand for accurate measurement of the number of filamentous fungi.

The present invention solves such a conventional problem, and can measure the number of filamentous fungi in the test material in a shorter time than the conventional method for measuring the number of filamentous fungi in the test material. Filamentous fungi are cultured in a liquid medium and then filtered into a microporous membrane to suppress variation in growth, allowing accurate measurement of the fungi, and optical imaging of the filamentous fungi cultured for the required time. An object of the present invention is to provide a filamentous fungus measurement method capable of measuring the number of filamentous fungi existing in an original sample by recognizing and analyzing the characteristic shape of the fungus by an image analysis means.
Another object of the present invention is to provide a filamentous fungus measurement method capable of measuring the performance of only an antibacterial agent.

  In order to achieve the above object, the method for measuring filamentous fungi of the present invention comprises an image analysis means for recognizing and analyzing the shape, area, and emission luminance after imaging mycelia extending to a plurality of cultured filamentous fungi. is there.

  As a result, a method for measuring the number of filamentous fungi capable of recognizing the shape or area of the filamentous fungus and the emission luminance is obtained.

  In the present invention, filamentous fungi are cultured in a liquid medium and then filtered through a microporous membrane.

  As a result, a method for measuring the filamentous fungus capable of stably culturing the filamentous fungus without unevenness is obtained.

  Further, the present invention is one in which filtration is performed with a microporous membrane and culture is performed on the microporous membrane for a required time.

  Thereby, it is possible to measure the number of filamentous fungi present in the test material on the microporous membrane, and it is possible to obtain a filamentous fungus measurement method capable of mass-filtering the specimen.

  In addition, the present invention uses a pore-sized microporous membrane through which bacteria and contaminants pass, but filamentous fungi do not pass.

  Thereby, bacteria other than filamentous fungi or contaminants can be separated, and a filamentous fungus measurement method capable of mass-filtering a specimen is obtained.

  In the present invention, a microporous membrane having a pore size of 10 to 30 μm is used.

  As a result, it is possible to filter and separate minute bacteria or impurities of 10 μm or less and efficiently collect only filamentous fungi. In addition, since the pore size is as large as 10 to 30 μm, the filterability is improved and a large amount of specimen can be filtered, so that a method for measuring filamentous fungi capable of measuring a small amount of filamentous fungi is obtained.

  Moreover, this invention uses the liquid culture medium or solid culture medium which selectively cultures only a filamentous fungus.

  As a result, a method for measuring filamentous fungi is obtained in which the cultivation of other bacteria is suppressed and only the filamentous fungi are cultured specifically.

  Moreover, this invention sets the culture | cultivation temperature of filamentous fungi to 20-25 degreeC.

  Thereby, filamentous fungi can be selectively cultured, and further a filamentous fungus measurement method capable of suppressing bacteria other than filamentous fungi is obtained.

  In addition, the present invention uses a solvent, a powder having a background quenching effect, or a substance corresponding thereto.

  As a result, a method for measuring the fungus capable of distinguishing the light emission of the target fungus from the light emission of the background is obtained.

  In addition, the present invention uses ink that has a background quenching effect.

  As a result, a method for measuring the fungus capable of distinguishing the light emission of the target fungus from the light emission of the background is obtained.

  In the present invention, filamentous fungi are imaged once after culturing for a predetermined time, and an antibacterial agent is added to the filamentous fungus and cultured again to confirm the growth of the mycelium.

  As a result, a filamentous fungus measurement method capable of evaluating the antibacterial action is obtained.

  According to the present invention, it is possible to provide a method for measuring filamentous fungi that is effective in rapidly measuring filamentous fungi in a short culture time. In addition, a method for measuring filamentous fungi capable of evaluating the antibacterial action of the antibacterial agent against the filamentous fungus can be provided.

  According to the first aspect of the present invention, after imaging mycelia extending to a plurality of cultured filamentous fungi, the shape, area, and emission luminance are recognized and analyzed by image processing. It has the effect that it can be measured in the culture. In addition, the agar culture method that is currently the mainstream requires 5 to 10 days for the inspection time of filamentous fungi, and currently, the colony formed by the agar culture method of filamentous fungi is visually confirmed. In the present invention, since the image analysis means recognizes the state in which the mycelium of the filamentous fungus has grown in a short period of culture, the inspection time can be shortened, and the product is stored in stock during the filamentous fungus inspection period. In addition, the inspection cost can be reduced financially.

  The invention according to claim 2 of the present invention is such that the filamentous fungus is cultured in a liquid medium for a required time and then filtered to the microporous membrane of the microporous membrane support to optically image the microorganism. Has the effect of growing to a predetermined size.

  The invention according to claim 3 of the present invention is such that the filamentous fungus is filtered on the microporous membrane of the microporous membrane support and cultured on the microporous membrane for a predetermined time. It is possible to measure the number of filamentous fungi present in the sample, and to perform mass filtration of the specimen.

  The invention according to claim 4 of the present invention is such that after culturing a filamentous fungus in a liquid medium, it is filtered through a pore-sized microporous membrane through which bacteria and impurities do not pass and the filamentous fungus does not pass. It is possible to isolate the bacteria or contaminants of the sample and to filter the sample in a large amount.

  In the invention according to claim 5 of the present invention, a microporous membrane having a pore size of 10 to 30 μm is used after culturing filamentous fungi in a liquid medium. Bacteria rarely clump and grow to 10 μm or more, and by setting the pore size of the microporous membrane to 10-30, filtration of bacteria or contaminants is possible. In the case of filamentous fungi, Since the mycelium of the filamentous fungus is elongated, the filamentous fungus becomes larger than 10 to 30 μm when cultured for a predetermined time, and has an action that can be collected by the microporous membrane. Further, since the pore size is as large as 10 to 30 μm, it has an effect of efficiently filtering a large amount of specimen.

  The invention according to claim 6 of the present invention uses a solid medium or a liquid medium for selectively cultivating only filamentous fungi. By using an SCD medium, a GP medium or the like, other bacteria can be used. It has the effect of suppressing culture and specifically culturing only filamentous fungi.

  Further, the invention according to claim 7 of the present invention is to culture at 20 to 25 ° C. as a temperature for selectively culturing the filamentous fungus, and has an effect that the filamentous fungus can be separated and cultured. Moreover, since there is a difference in the growth temperature between bacteria and filamentous fungi, it has the effect of efficiently separating the bacteria and filamentous fungi.

  The invention according to claim 8 of the present invention is to use a solvent, a powder having a background quenching effect, or a substance corresponding thereto, and distinguish between the emission of the target filamentous fungus and the emission of the background. Has the effect of being able to

  Further, the invention according to claim 9 of the present invention is to use a black ink having a background quenching effect, and has an effect that the light emission of the target filamentous fungus and the light emission of the background can be distinguished.

  Further, the invention according to claim 10 of the present invention is to take an image of a filamentous fungus once after culturing for a predetermined time, add an antibacterial agent to the filamentous fungus, and then re-cultivate to confirm the growth of the mycelium. It has the effect of antibacterial evaluation of antibacterial agents against bacteria.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
After culturing the test material filamentous fungus selectively in culture, preferably in PDA medium, GP medium or SCD medium for 6 to 72 hours at a temperature suitable for filamentous fungus growth, preferably at 20 to 25 ° C. As shown in FIG. 1, a culture solution obtained by cultivating a test material for a required time on a microporous membrane support 4 (a filter chip manufactured by Matsushita Ecosystems) comprising a microporous membrane 1, a pressing ring 2 and a base 3 is filtered to obtain a filamentous fungus. Filtration of viable and dead cells or a compound that develops viable cells on the side where the light is collected is performed, and filamentous fungi are imaged with a microorganism measuring device (not shown) having a color light-receiving lens. In addition, the microorganism measurement has a light source that irradiates excitation light by filtering live and dead cells or a compound that fluoresces living cells on the side where the filamentous fungus is collected, and a fluorescence light-receiving lens that receives the light that is fluorescent by the excitation light. The filamentous fungus is imaged with an apparatus (not shown).

  Then, as shown in FIG. 2, the luminance of the light emitting point is measured by the luminance measurement 6 and the binarization 7 is performed with the reference luminance value as a boundary, and the light emitting point having a luminance value equal to or higher than the reference value is obtained. The area of the shape and the branch point peculiar to the filamentous fungus recognized in the shape determination 8 are recognized to determine whether the luminescence is a filamentous fungus, and the bright spot determined to be the filamentous fungus is measured. To do. Thus, the image analysis means 10 is used to recognize and analyze the division of the mycelium, which is a characteristic shape of the filamentous fungus, so as not to erroneously measure microorganisms other than the filamentous fungus or the contaminants in the test material 9. Thus, the filamentous fungi collected in the microporous membrane 1 can be accurately measured 9.

  In the above configuration, it is possible to provide a method for measuring the number of filamentous fungi that performs negative positive discrimination of filamentous fungi in the test material.

  In addition, by using the microporous membrane 1 having a pore size of preferably 10 to 30 μm in which the bacteria or contaminants pass through the pore size of the microporous membrane 1 and the cultured filamentous fungus does not pass, Microorganisms 11 other than the filamentous fungi as shown in FIG. 3 or contaminants 12 in the test material pass through the microporous membrane 1, and the cultured filamentous fungus 13 is collected on the microporous membrane, and the filamentous fungi are collected. It is possible to accurately measure the filamentous fungus 13 without being affected by the contaminants 12 in the test material, and to increase the pore size of the microporous membrane 1 to increase the contaminants in the test material. The filterability of the test material, which was difficult to filter due to the influence of 12, becomes easy and can be filtered in large quantities.

(Embodiment 2)
The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The test material is filtered on a microporous membrane support 4 comprising a microporous membrane 1, a holding ring 2 and a base 3 as shown in FIG. 1, and filamentous fungi 13 are collected as shown in FIG. On the opposite side, a medium 14 for selectively enriching and culturing the filamentous fungus 13 is attached, preferably a PDA medium, a GP medium or an SCD medium, and preferably at a temperature suitable for the growth of the filamentous fungus for 6 to 72 hours. After culturing at 25 ° C., the medium 14 is removed to filter the viable and dead cells or the compound that develops or fluoresces the live cells, and the filamentous fungus 13 is imaged 5 with a microorganism measuring device (not shown). The medium 14 to be used contains a thickener in order to prevent the medium 14 from leaking to the side of the microporous membrane 1 where the filamentous fungus 13 is collected during the cultivation so that the medium 14 has a viscosity. By using the liquid medium, the medium components are uniformly adhered to the microporous membrane 1, and the culture medium 14 is prevented from leaking to the surface of the microporous membrane 1 where the filamentous fungus 13 is collected, thereby enhancing the culture effect. be able to. Further, when the microporous membrane 1 having a thickness of 10 to 30 μm is irradiated with excitation light, the background microporous membrane 1 reflects more than the light emission of the filamentous fungus 13, making it impossible to distinguish the filamentous fungus 13 from the background. Therefore, it is possible to suppress reflection by filtering the ink having a background quenching effect into the microporous film 1.

  Then, as shown in FIG. 3, the image captured 5 is analyzed by the image analysis means 10, and the microbial colonies other than the filamentous fungus 13 are recognized by recognizing and analyzing the mycelial division that is a characteristic shape of the filamentous fungus 13. Alternatively, the impurities 12 in the test material are not measured 9 by mistake, and the filamentous fungus 13 collected in the microporous membrane 1 can be accurately measured 9.

  In the above configuration, it is possible to provide a filamentous fungus measurement method capable of measuring 9 the original number of filamentous fungi 13 present in the test material.

  Filtration of the cultured test material into a microporous membrane, or whether the test material was filtered after culturing the microporous membrane and then cultivating the test material, or the number of filamentous fungi present in the test material Can be weighed in a shorter time than before, and can be applied in the shipment inspection of filamentous fungi in the food, pharmaceutical and chemical products fields.

Whole sectional view showing a microporous membrane support according to Embodiments 1 and 2 of the present invention The flowchart which shows the image analysis means of Embodiment 1 of this invention Schematic image obtained by imaging on the microporous membrane of Embodiments 1 and 2 of the present invention Whole sectional view showing a microporous membrane support according to Embodiment 2 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microporous membrane 2 Pressing ring 3 Base 4 Microporous membrane support body 5 Imaging 6 Luminance measurement 7 Binarization 8 Shape judgment 9 Measurement 10 Image analysis means 11 Microorganisms other than filamentous fungi 12 Contaminants 13 Filamentous fungi 14 Medium

Claims (10)

A method for measuring filamentous fungi, comprising image analysis means for recognizing and analyzing the shape, area, and luminance of emitted light after irradiating an image by irradiating excitation light to a plurality of filamentous fungi that have been cultured. The method of measuring a filamentous fungus according to claim 1, wherein the filamentous fungus is cultured in a liquid medium for a required time and then filtered to the microporous membrane of the microporous membrane support. 2. The method for measuring filamentous fungi according to claim 1, wherein the filamentous fungus is filtered on the microporous membrane of the microporous membrane support and cultured on the microporous membrane for a required time. 3. The method of measuring a filamentous fungus according to claim 2, wherein the filamentous fungus is cultured in a liquid medium, and then filtered through a pore-sized microporous membrane through which bacteria and contaminants do not pass and filamentous fungi do not pass. 5. The method of measuring a filamentous fungus according to claim 4, wherein a microporous membrane having a pore size of 10 to 30 [mu] m is used after culturing the filamentous fungus in a liquid medium. 6. The method for measuring a filamentous fungus according to claim 1, wherein a solid medium or a liquid medium for selectively culturing only the filamentous fungus is used. The method for measuring a filamentous fungus according to claim 1, wherein the filamentous fungus is cultured at a temperature of 20 to 25 ° C. for selectively culturing the filamentous fungus. The method for measuring filamentous fungi according to any one of claims 1 to 7, wherein a solvent having a background quenching effect, powder, or a substance corresponding thereto is used. 9. The method for measuring filamentous fungi according to claim 8, wherein ink with a background quenching effect is used. 10. Measurement of filamentous fungi according to claims 1 to 9, wherein the fungus is imaged once after culturing for a predetermined time, the antibacterial activity is evaluated by adding the antibacterial agent to the filamentous fungus, culturing again, and confirming the growth of the mycelium Method.

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