CN109321429B

CN109321429B - Automatic bacterium picking instrument and microorganism screening method

Info

Publication number: CN109321429B
Application number: CN201811140500.XA
Authority: CN
Inventors: 承磊; 王权; 周正; 蔡颖鹏; 曾碗秋; 王琼; 张雪
Original assignee: Foshan Desong Scientific Instrument Co ltd; Biogas Institute of Ministry of Agriculture
Current assignee: Biogas Institute of Ministry of Agriculture
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-09-08
Anticipated expiration: 2038-09-28
Also published as: CN109321429A

Abstract

The invention discloses an automatic bacteria selecting instrument and a microorganism screening method. Compared with the prior art that the liquid transfer workstation is combined with the microplate reader, the liquid transfer workstation is combined with the turbidimeter, the influence of the measuring environment on the growth of the microorganisms is lower, and the growth condition of the microorganisms can be rapidly and accurately measured and determined under the conditions of anaerobic environment and other conditions that the exposure time is reduced as much as possible; in addition, the turbidimeter can directly read the turbidity in the hole and then generate a picking sequence file of the liquid transfer workstation for the liquid transfer workstation to pick microorganisms. The invention is based on the screening method for obtaining the single bacterial strain provided by the automatic bacteria selecting instrument, and the single bacterial strain is separated from the complex sample by using the automatic bacteria selecting instrument for screening, so that the single bacterial strain with obvious growth is obtained.

Description

Automatic bacterium picking instrument and microorganism screening method

Technical Field

The invention relates to an automatic bacteria selecting instrument and a microorganism screening method thereof, in particular to a bacteria selecting instrument for high-throughput culture and screening of microorganisms and a method for screening microorganisms by using the bacteria selecting instrument.

Background

The liquid transfer workstation is an instrument capable of automatically transferring and diluting high-flux liquid reagents. The automatic hole site plate transfer and distribution device can automatically complete the work of transfer, dilution, distribution and the like according to the type of the micro-porous plate and the setting of a meaningful hole site. The equipment has important value in the high-throughput culture and screening work of microorganisms, the value of each hole site of the microporous plate is read by instruments such as a microplate reader, the growth condition of the microorganisms is determined according to the read result and a threshold value, and the hole sites needing to be extracted and transferred are manually set, so that the working time is greatly prolonged. When the culture must be kept in an anaerobic environment or otherwise in a condition that minimizes exposure time, the process of reading by the microplate reader and then transferring may result in destruction of the culture.

This drawback is overcome by turbidimeters, which are devices for measuring the turbidity of a liquid, and include the scattered light type, the transmitted scattered light type, and the like, and are collectively called optical turbidimeters. The principle is that when light irradiates the liquid level, a certain correlation exists between the ratio of incident light intensity, transmitted light intensity and scattered light intensity and the turbidity of the water sample, and the turbidity of the water sample is measured by measuring the ratio of the transmitted light intensity, the scattered light intensity and the incident light intensity or the ratio of the transmitted light intensity and the scattered light intensity. Optical turbidimeters are used in laboratories and also in automated continuous measurements on site.

The microplate readers or turbidimeters on the market at present are large in size, and read data cannot be directly used by a pipetting workstation. Based on this, need design an automatic fungus appearance of choosing, combine move liquid workstation and turbidimeter, realize efficient separation work, the while is anaerobic environment or other to try hard to reduce exposure time also can screen the microorganism fast accurately high-efficiently.

Disclosure of Invention

In order to solve the problems, the invention aims to provide an automatic bacteria selecting instrument and a microorganism high-throughput screening method thereof, and the equipment can be used for quickly and efficiently culturing and screening microorganisms and is convenient for researchers to use.

In order to achieve the above object, the present invention provides an automatic bacteria selecting instrument, comprising:

move liquid work station, move liquid work station including liquid suction module and Y axle tray, liquid suction module installs in moving liquid work station's upper casing, and liquid suction module drives by X axle driver and realizes the X axle and remove, Y axle tray is installed on moving liquid work station's the year thing board of bottom, and Y axle tray drives by Y axle driver and realizes the Y axle and remove, be equipped with a plurality of board position districts on the Y axle tray, the board position district that is located the lower left corner is hollow structure. The liquid suction module of the liquid transfer workstation can suck liquid, and the liquid is transferred and diluted by moving on the X axis.

The turbidimeter, the turbidimeter is installed in the board position district outside in the lower left corner, the turbidimeter includes the U type arm that realizes the Y axle removal by step motor drives, and the Y axle tray is located between the upper and lower wall pole of U type arm, be equipped with the transmitter on the upper and lower wall pole of U type arm respectively and with transmitter complex receiver. During operation, the micropore board has been placed to the board position district in the lower left corner, and the micropore board is transparent structure, and U type arm removes at X axle direction, and when whenever reaching a hole of micropore board, the light that the transmitter sent is received by the receiver after the downthehole liquid of micropore board, and according to the signal that the receiver received, control system calculates the turbidity of downthehole liquid, and then learns the downthehole microorganism growth condition of micropore board.

The control system comprises a controller, the controller is in signal connection with the liquid transfer workstation and the turbidimeter, the controller is a conventional single chip microcomputer, and an implantation program controls the operation of the liquid transfer workstation and the turbidimeter; specifically, for the liquid transfer workstation, the liquid suction of the liquid suction module is controlled, the X-axis driver is controlled to drive the liquid suction module to move in the X-axis direction, and the Y-axis driver is controlled to drive the Y-axis tray to move in the Y-axis direction; and for the turbidity meter, controlling the emitter to emit light, calculating the turbidity of the liquid in the micropores according to the received information of the receiver, and controlling the stepping motor to drive the U-shaped arm to move in the Y-axis direction to read the information of the liquid in the micropores.

Further, the turbidimeter is still including left side board, right side board, bottom plate, preceding connecting plate and the back connecting plate that constitutes the turbidimeter skeleton, step motor and U type arm are located the skeleton, the skeleton upside is equipped with the lens hood, handles the part shading in the skeleton, makes the signal that the transmitter sent can be received smoothly to the receiver, prevents that external light from disturbing the light that influences the receiver and receive the transmitter and send, and then the judgement of influence liquid turbidity in to the micropore.

Further, a screw rod and a limiting rod are arranged between the left side plate and the right side plate, the stepping motor is connected with the screw rod through a transmission gear, the screw rod penetrates through a threaded hole in the lower side of the U-shaped arm to be in threaded connection with the U-shaped arm, and the limiting rod penetrates through a through hole in the lower side of the U-shaped arm. The rotary motion is converted into linear motion through the screw, the motion accuracy is high, the speed reduction ratio is high, the structure is simple, the manufacture is convenient, the work is stable, no noise is generated, and large axial force can be transmitted; the limiting rod enables the U-shaped arm to move only along the length direction of the screw rod, the U-shaped arm is prevented from rotating along with the screw rod, and the U-shaped arm can accurately scan the microporous plate between the U-shaped arms; the transmission gear is a reduction gear combination, so that the high-speed rotation of the stepping motor is converted into the low-speed rotation of the screw rod through the transmission gear.

Furthermore, an initial position sensor is arranged on the rear connecting plate close to the left side plate, a control circuit board is arranged on the bottom plate, and a USB interface connected with the control circuit board is arranged on the right side plate. When the micro-porous plate is not read, the U-shaped arm is initialized to return to the initial position sensor, the receiver receives signals of the transmitter under the conditions of no illumination and no illumination of the micro-porous plate, and the signals are converted by the control system to position the zero point and the full point of the transmittance for later calculation of the transmittance of illumination; the control circuit board is provided with a control circuit of the turbidimeter, the control circuit controls the operation of the receiver, the emitter and the stepping motor, optical signals collected by the receiver are converted into turbidity of liquid through processing, the control circuit is in signal connection with the control system and is controlled by the control system, and the control system can automatically produce and pick files according to returned liquid turbidity information; the USB interface is used for connecting and communicating the turbidimeter with external equipment.

Further, the emitter adopts a 600- & 605nm LED and a lens group to collimate emitted light or a 650nm semiconductor laser with a collimating lens, which is selected by using OD600 and OD660 according to the classical microorganism concentration detection; the receiver adopts the CdS photosensitive resistor, because the turbidimeter integrated on the liquid-moving workstation is in more environment stray light, and the photoelectric cell is adopted as the receiver and is easily saturated by the environment light, the CdS photosensitive resistor is adopted, and the CdS photosensitive resistor has better concentration signal linear characteristic.

Further, the liquid suction module comprises a plurality of liquid transferring heads, and the liquid transferring heads are driven by the suction rod to realize the suction of the liquid. The principle of the liquid suction module is similar to that of a needle cylinder for suction, the liquid on the liquid transfer head suction tray is moved up and down by the suction rod, the liquid transfer head can also move in the vertical direction, the liquid is sucked by the liquid transfer head and is controlled by the control system, and the liquid transfer work station can transfer and dilute liquid reagents, so that the high-throughput screening of microorganisms is facilitated.

Furthermore, a waste material groove is arranged on the object carrying plate, the waste material groove is of an inclined structure, and liquid after being discarded is directly poured into the waste material groove and is discharged from the waste material groove.

The invention provides a microorganism screening method of an automatic bacteria selecting instrument, which is used for obtaining a single bacterial strain and comprises the following steps:

and step S1, preparing an original sample, diluting the original sample by using a liquid transfer workstation of the automatic bacteria picking instrument, adding the diluted original sample into a culture medium to obtain a culture medium sample, and subpackaging the culture medium sample into micropores of a microplate by using the liquid transfer workstation of the automatic bacteria picking instrument. The original sample is a complex sample, the original sample comprises a plurality of strains, and the method aims to obtain a target single strain in the complex sample.

And step S2, culturing the culture medium sample in the micropore plate at constant temperature at the growth temperature of the target bacterial strain until the target bacterial strain grows. The target strain refers to a single strain to be obtained, and grows after being cultured for a period of time at a temperature suitable for the growth of the strain; the appropriate growth temperature and the number of days of culture of the target strain are determined by inquiring the conventional growth environment of the strain after the name of the strain is known to those skilled in the art.

And step S3, reading the turbidity value of the culture medium in each micropore on the micropore plate by using a turbidity meter on the automatic bacteria selecting instrument for the culture medium sample after the culture is finished, and generating a selecting file.

And step S4, setting a minimum OD value for selecting bacteria by the automatic bacteria selecting instrument according to the detection result of the turbidimeter in the selecting file, and selecting the culture medium in the micropores with the OD value larger than the minimum OD value by the liquid transferring workstation, namely selecting the culture medium in the micropores in which the microorganisms have grown to obtain a single strain.

Further, in step S3 of the method for screening microorganisms according to the present invention, the reading of the turbidity value of the medium in each well of the microplate by the turbidimeter comprises the steps of:

step S31, placing the microplate at the lower left corner of the Y-axis tray, initializing the U-shaped arm of the turbidimeter to return to the initial position sensor, reading signals of no illumination and no plate illumination, and determining the zero point and the full point of the transmittance as the zero point and the full point of the transmittance for calculating the transmittance;

step S32, the Y-axis tray moves towards the turbidimeter, when the tray moves to the first row of holes of the micro-porous plate and is positioned right above the light source at the lower part of the U-shaped arm, the tray stops moving, then the U-shaped arm moves gradually from the initial position to the far end according to the set program, and the controller reads the transmissivity of the hole after the tray reaches the lower part of one hole and converts the transmissivity into the optical density value;

and step S33, repeating the steps S31-S32 to finish reading the whole micro-porous plate, and generating a picking file by a controller, wherein the controller is a single chip microcomputer.

The invention has the beneficial effects that:

compared with the prior art that the liquid transfer workstation is combined with the microplate reader, the liquid transfer workstation is combined with the turbidimeter, the influence of the measuring environment on the growth of the microorganisms is lower, and the growth condition of the microorganisms can be rapidly and accurately measured and determined under the conditions of anaerobic environment and other conditions that the exposure time is reduced as much as possible; in addition, the turbidimeter can directly read the turbidity in the hole and then generate a picking sequence file of the liquid transfer workstation for the liquid transfer workstation to pick microorganisms;

the liquid transfer workstation provided by the invention can transfer and dilute a liquid reagent, the liquid suction module sucks liquid, the X-axis driver drives the liquid suction module to move in the X-axis direction, the Y-axis driver drives the Y-axis tray to move in the Y-axis direction, and the liquid transfer head of the liquid suction module can also move in the vertical direction, so that three-axis linkage is realized, a microporous plate placed on the Y-axis tray is transferred and diluted with liquid, and the culture and screening of microorganisms are facilitated;

the turbidimeter provided by the invention is arranged outside a plate position area at the lower left corner of a pipetting workstation, a Y-axis tray is positioned between an upper wall rod and a lower wall rod of a U-shaped arm of the turbidimeter, a microporous plate is placed on the Y-axis tray, a receiver and a transmitter above and below the U-shaped arm read information through the movement of the U-shaped arm, and the turbidity of liquid in each micropore of the microporous plate is calculated, so that the growth condition of microorganisms in each pore of the microporous plate is known, the information of the microorganisms in the micropore is simply and conveniently known, and the screening of researchers is facilitated;

the invention is based on the screening method for obtaining the single bacterial strain provided by the automatic bacteria selecting instrument, and the single bacterial strain is separated from the complex sample by using the automatic bacteria selecting instrument for screening, so that the single bacterial strain with obvious growth is obtained, and a researcher can conveniently research the single bacterial strain.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the present invention with the front safety shield of the upper housing removed;

FIG. 3 is a schematic illustration of a turbidimeter of the present invention;

FIG. 4 is a schematic view of a turbidimeter of the present invention with the light shield removed;

FIG. 5 is a top view of the turbidimeter of the present invention with the light shield removed.

In the figure: 1. a pipetting workstation; 11. a liquid pumping module; 111. a pipetting head; 112. a suction rod; 12. a Y-axis tray; 13. an upper housing; 14. an X-axis driver; 15. a loading plate; 16. a Y-axis driver; 17. a board area; 18. a waste chute; 2. a turbidimeter; 201. a stepping motor; 202. a U-shaped arm; 203. a transmitter; 204. a receiver; 205. a left side plate; 206. a right side plate; 207. a base plate; 208. a front connecting plate; 209. a rear connecting plate; 210. a light shield; 211. a screw; 212. a limiting rod; 213. a transmission gear; 214. an initial position sensor; 215. a control circuit board; 216. and a USB interface.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described with reference to the accompanying drawings. In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. In addition, the X-axis direction of the present invention indicates the longitudinal direction of the carrier plate, the Y-axis direction indicates the width direction of the carrier plate, and the Z-axis direction indicates the direction perpendicular to the carrier plate, i.e., the vertical direction.

Example 1

An automatic bacteria selecting instrument, comprising:

pipetting workstation 1, as shown in fig. 1-2, pipetting workstation 1 includes liquid suction module 11 and Y axle tray 12, liquid suction module 11 is installed in pipetting workstation 1's last casing 13, liquid suction module 11 is driven by X axle driver 14 and is realized the X axle and remove, Y axle tray 12 is installed on the year thing board 15 of pipetting workstation 1 bottom, Y axle tray 12 is driven by Y axle driver 16 and is realized the Y axle and remove, be equipped with 9 board position districts 17 on the Y axle tray 12, the board position district 17 that is located the lower left corner is hollow structure, install the micropore board in the board position district 17 of lower left corner, 384 micropores on the micropore board of this embodiment. The liquid suction module 11 comprises a plurality of liquid transferring heads 111, and the liquid transferring heads 111 are driven by a suction rod 112 to realize the suction of liquid; a waste material groove 18 is arranged on the carrying plate 15.

A turbidimeter 2, as shown in fig. 1, 3, 4 and 5, wherein the turbidimeter 2 is installed outside the plate position area 17 at the lower left corner, the turbidimeter 2 comprises a U-shaped arm 202 driven by a stepping motor 201 to realize Y-axis movement, a Y-axis tray 12 is positioned between upper and lower wall rods of the U-shaped arm 202, and the upper and lower wall rods of the U-shaped arm 202 are respectively provided with a transmitter 203 and a receiver 204 matched with the transmitter 203; the emitter 203 uses a 650nm semiconductor laser with a collimating lens and the receiver 204 uses a CdS photo resistor.

The turbidimeter 2 further comprises a left side plate 205, a right side plate 206, a bottom plate 207, a front connecting plate 208 and a rear connecting plate 209 which form a turbidimeter framework, the stepping motor 201 and the U-shaped arm 202 are located in the framework, and a light shield 210 is arranged on the upper side of the framework. A screw 211 and a limiting rod 212 are arranged between the left side plate 205 and the right side plate 206, the stepping motor 201 is connected with the screw 211 through a transmission gear 213, the screw 211 penetrates through a threaded hole in the lower side of the U-shaped arm 202 to be in threaded connection with the U-shaped arm 202, and the limiting rod 212 penetrates through a through hole in the lower side of the U-shaped arm 202. An initial position sensor 214 is arranged on the rear connecting plate 209 close to the left side plate 205, a control circuit board 215 is arranged on the bottom plate 207, and a USB interface 216 connected with the control circuit board 215 is arranged on the right side plate 206.

The control system comprises a controller, the controller is in signal connection with the pipetting workstation and the turbidity meter, the controller is a conventional single chip microcomputer, the implantation program controls the operation of the pipetting workstation and the turbidity meter, and the control system adopts an AtmelATmega328p type single chip microcomputer. Specifically, for the liquid transfer workstation 1, the single chip microcomputer controls the liquid suction of the liquid suction module 11, the single chip microcomputer controls the X-axis driver 14 to drive the liquid suction module 11 to move in the X-axis direction, and the single chip microcomputer controls the Y-axis tray 12 to move in the Y-axis direction; for the turbidimeter 2, the single chip microcomputer controls the emitter 203 to emit light, calculates the turbidity of the liquid in the micropores according to the received information of the receiver 204, and controls the stepping motor 201 to drive the U-shaped arm 202 to move in the Y-axis direction to read the information of the liquid in the micropores.

Example 2

This example provides a screening method for screening a single strain based on the automatic bacteria selector in example 1 based on example 1, where the original sample in this example is a complex sample containing anaerobic bacteria in intestinal tract, and the purpose of this example is to obtain a single strain with significant growth in the original sample, and the method in this example includes the following steps:

step S1, preparing an original sample, diluting the original sample by using a liquid transfer workstation of the automatic bacteria picking instrument, adding the diluted original sample into a YCFA culture medium to obtain a culture medium sample, and subpackaging the culture medium sample into micropores of a 384 micro-pore plate by using the liquid transfer workstation of the automatic bacteria picking instrument;

step S2, culturing the culture medium sample in the microporous plate in a constant temperature incubator outside an automatic bacteria selecting instrument for 5 days, and then, growing the target strain, wherein the culture temperature in the constant temperature incubator is 37 ℃;

step S3, reading the turbidity value of the culture medium in each micropore on the micropore plate by using a turbidity meter on an automatic bacteria picking instrument for the culture medium sample after the culture is finished, and generating a picking file;

and step S4, setting a minimum OD value for selecting bacteria by the automatic bacteria selecting instrument according to the detection result of the turbidimeter in the selecting file, and selecting the culture medium in the micropores with the minimum OD value by the liquid transferring workstation to obtain a single strain.

The conditions of the screening and the results after the screening are shown in table 1:

TABLE 1 selection of anaerobic enterobacteria strains

By screening the microorganisms by using a bacteria selecting instrument, the separation flux of the microorganism strains can reach 100-.

In the above steps S1 and S4, the automatic bacteria picking apparatus is used to dilute and pick the liquid in the wells of the plate 1 by using the pipetting head 111 of the liquid pumping module 11, the pipetting head 111 is provided with a plurality of wells, the wells are placed on the Y-axis tray 12, the wells are uniformly provided with a plurality of wells, the Y-axis driver 16 drives the wells on the Y-axis tray to move in the Y-axis direction, the X-axis driver 14 drives the pipetting head 111 of the liquid pumping module 11 to move in the X-axis direction, the Z-axis driver drives the pipetting head 111 to move in the vertical direction, and the pipetting head 111 dilutes and picks the liquid in the wells of the wells by three-axis linkage.

In the step S3, the reading of the turbidity value of the medium in each well of the microplate by the turbidimeter comprises the following steps:

step S31, placing the microplate in the lower left corner position of the Y-axis tray 12, initializing the U-shaped arm 202 of the turbidimeter 2 to return to the initial position sensor 214, wherein the microplate is not between the transmitter and the receiver, the transmitter 203 does not work, reading the signal of the receiver 204 and transmitting the signal to the control system, and the control system positions the zero point of the transmission degree of the signal; then the emitter 203 works, the receiver 204 receives the signal and transmits the signal to the control system, and the signal at the moment positions the full point of the transmittance; the full and zero points of transmission are used to calculate the liquid transmission.

Step S32, the microplate on the Y-axis tray 12 is driven by the Y-axis driver 16 to move toward the turbidimeter 2, and when the first row of wells of the microplate is located right above the emitter 203 on the lower portion of the U-shaped arm 202, the microplate stops moving, and then the U-shaped arm 202 is driven by the stepping motor 201 to move gradually from the initial position to the far end according to the set program, i.e., to move toward the X-axis direction, and when the U-shaped arm 202 reaches below one well, the light signal sent by the emitter 203 and received by the receiver 204 is transmitted to the controller, and the controller compares the signal with the zero point and the full point to calculate the transmittance of the well, and then converts the transmittance into the optical density.

And step S31, repeating the steps S31-S32, completing the reading of the whole microplate, and generating a picking file by the controller.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides an automatic choose fungus appearance which characterized in that includes:

the liquid transfer workstation (1) comprises a liquid suction module (11) and a Y-axis tray (12), the liquid suction module (11) is installed in an upper shell (13) of the liquid transfer workstation (1), the liquid suction module (11) is driven by an X-axis driver (14), the Y-axis tray (12) is installed on a carrying plate (15) at the bottom end of the liquid transfer workstation (1), the Y-axis tray (12) is driven by a Y-axis driver (16), a plurality of plate position areas (17) are arranged on the Y-axis tray (12), and the plate position area (17) at the lower left corner is of a hollow structure;

the turbidimeter (2) is installed on the outer side of a plate position area (17) at the lower left corner, the turbidimeter (2) comprises a U-shaped arm (202) driven by a stepping motor (201), a Y-axis tray (12) is located between an upper wall rod and a lower wall rod of the U-shaped arm (202), and the upper wall rod and the lower wall rod of the U-shaped arm (202) are respectively provided with a transmitter (203) and a receiver (204) matched with the transmitter (203);

a control system comprising a controller in signal connection with the pipetting station (1) and the turbidimeter (2);

the turbidimeter (2) further comprises a left side plate (205), a right side plate (206), a bottom plate (207), a front connecting plate (208) and a rear connecting plate (209) which form a turbidimeter framework, the stepping motor (201) and the U-shaped arm (202) are located in the framework, and a light shield (210) is arranged on the upper side of the framework;

a screw rod (211) and a limiting rod (212) are arranged between the left side plate (205) and the right side plate (206), the stepping motor (201) is connected with the screw rod (211) through a transmission gear (213), the screw rod (211) penetrates through a threaded hole in the lower side of the U-shaped arm (202) to be in threaded connection with the U-shaped arm (202), and the limiting rod (212) penetrates through a through hole in the lower side of the U-shaped arm (202);

an initial position sensor (214) is arranged at the end, close to the left side plate (205), of the rear connecting plate (209), a control circuit board (215) is arranged on the bottom plate (207), and a USB interface (216) connected with the control circuit board (215) is arranged on the right side plate (206).

2. The automatic bacteria selecting instrument as claimed in claim 1, wherein the emitter (203) adopts 600 and 605nm LED and lens set for emitting light collimation or 650nm semiconductor laser with collimating lens, and the receiver (204) adopts CdS photoresistor.

3. The automatic bacteria picking instrument according to claim 1, wherein the liquid suction module (11) comprises a plurality of liquid transferring heads (111), and the liquid transferring heads (111) are driven by a suction rod (112) to realize liquid suction.

4. The automatic bacteria picking instrument according to claim 1, wherein a waste trough (18) is arranged on the carrying plate (15).

5. A microorganism screening method using the automatic bacteria screening apparatus according to claim 1, which is used for obtaining individual strains, comprising the steps of:

step S1, preparing an original sample, diluting the original sample by using a liquid transfer workstation of the automatic bacteria picking instrument, adding the diluted original sample into a culture medium to obtain a culture medium sample, and subpackaging the culture medium sample into micropores of a microplate by using the liquid transfer workstation of the automatic bacteria picking instrument;

step S2, culturing the culture medium sample in the micropore plate in the step S1 at constant temperature at the growth temperature of the target strain until the target strain grows;

step S3, reading the turbidity value of the culture medium in each micropore on the microplate of the culture medium sample cultured in the step S2 by using a turbidity meter on an automatic bacteria picking instrument, and generating a picking file;

6. The microorganism screening method of an automatic bacteria screening apparatus in accordance with claim 5, wherein the step of S3, wherein the reading of the turbidity value of the medium in each well of the microplate by the turbidity meter comprises the steps of:

step S31, placing the microplate in the lower left corner position of the Y-axis tray (12), initializing the U-shaped arm (202) of the turbidimeter to return to the initial position sensor (214), reading the signals of no illumination and no plate illumination, and determining the zero point and the full point of the transmittance for calculating the transmittance;

step S32, the Y-axis tray (12) moves towards the turbidimeter, when the first row of holes of the microplate is positioned right above the light source at the lower part of the U-shaped arm (202), the movement is stopped, then the U-shaped arm (202) moves gradually from the initial position to the far end according to the set program, and the controller reads the transmissivity of the hole after each hole reaches the lower part of the hole and converts the transmissivity into the optical density value;

and step S33, repeating the steps S31-S32, completing the reading of the whole micro-pore plate by the turbidimeter, and generating a picking file by the controller.