Description:FIELD OF THE INVENTION
[0001] The present invention relates to the field of analytical instrumentation and microbiological diagnosis, and more particularly, the present invention relates to the dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis.
BACKGROUND FOR THE INVENTION:
[0002] The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was published, known, or part of the common general knowledge in any jurisdiction as of the priority date of the application. The details provided herein the background if belongs to any publication is taken only as a reference for describing the problems, in general terminologies or principles or both of science and technology in the associated prior art.
[0003] Microorganisms, such as fungi and bacteria, constantly release volatile organic compounds (VOCs), which are small gas molecules carrying vital information regarding their identity, biochemical roles, and the environmental conditions to which they respond. Microbial VOCs hold vast potential in scientific and practical applications, providing information for disease diagnosis, monitoring food quality, detecting environmental pollutants, and optimizing industrial fermentations. It is challenging to obtain VOCs from the microbial cultures in containers such as Petri dishes. Previously, it has been risky for researchers to open up the dish to get headspace gases. This subjects the sterile interior to the surrounding air, which may taint the sample or dilute VOC concentrations, ultimately impairing both the reliability and stability of the analyzed microbial ecosystem.
[0004] Microbial activity must be regulated in various scientific and industrial procedures, including fermentation, soil microbiology, water treatment, and medical diagnosis. Analysis of microbial activity by the quantification of volatile organic compounds (VOCs) and gases evolved during microbial growth and metabolism is an extremely useful method. The gases, such as ethanol, methane, carbon dioxide, hydrogen sulfide, and ammonia, are indicative microbial metabolic signature molecules and can provide useful information on microbial identity, health, metabolic status, and environmental associations.
[0005] However, existing methods for microbial gas sampling are constrained by several severe limitations:
- 1. Contamination Risk: Nearly all standard methods of gas sampling involve opening culture containers or puncturing through non-resealing ports, which involves a high risk of contaminating the culture with outside air, microorganisms, or particulate material, especially with sterile or anaerobic systems.
- 2. Disturbing Microbial Habitats: Hand sampling has been discovered to cause pressure change, air exchange, or sample loss, and it can break down delicate microbial communities, distort results, or prevent microbial growth. This is particularly critical in anaerobic cultures, where exposure to oxygen is lethal to the target microbes.
- 3. Degradation or loss of VOCs: VOCs are active chemically, small in size, and volatile to the point where they evaporate or degrade upon opening containers since the present sampling systems do not maintain native gas composition, and therefore analytical information could be incomplete or inaccurate.
- 4. No Real-Time Integration: The majority of designs incorporate manual sampling at a fixed interval, which is inaccurate, time-consuming, and will not react to rapid microbial activity changes since current methods are not adapted to undertake continuous or automatic real-time monitoring of microbial gases.
- 5. Incompatibility with Small or Disposable Systems: Sophisticated analytical systems are typically too large or invasive to use within small systems like Petri dishes, disposable fermenters, or field microcosms. As a result, researchers have fewer constraints on where and how they can monitor gas-phase microbial dynamics.
[0006] In light of the foregoing, there is a need for the Dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis that overcomes problems prevalent in the prior art.
[0007] The solution provided by the Invention is the Auto-Sealing Smart Microbial Sampling Valve, which directly confronts these challenges by delivering a small, automatic, and contamination-free sample interface. It allows for the sampling of gases or the addition of real-time gas monitoring instruments without opening the culture system, in a non-destructive manner, without compromising sterility, internal pressure, or analyte integrity. Its self-sealing diaphragm prevents air intrusion after sampling, and a check-valve gas port permits safe diversion of VOCs to remote analyzers. Its onboard VOC-optimized microchamber improves detection sensitivity, and other sensors provide real-time, wireless monitoring of primary gases and environmental parameters. With safer, more accurate, and fully compatible gas-phase sampling, the invention opens new promise in microbiology research, environmental analysis, and industrial bioprocess control.
OBJECTS OF THE INVENTION:
[0008] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
[0009] The principal object of the present invention is to overcome the disadvantages of the prior art by providing the Dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis.
[0010] Another object of the present invention is to provide the Dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis that is the Auto-Sealing Smart Microbial Sampling Valve, which directly confronts these challenges by delivering a small, automatic, and contamination-free sample interface.
[0011] Another object of the present invention is to provide the Dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis that allows for the sampling of gases or the addition of real-time gas monitoring instruments without opening the culture system, in a non-destructive manner, without compromising sterility, internal pressure, or analyte integrity.
[0012] Another object of the present invention is to provide the Dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis that is self-sealing diaphragm prevents air intrusion after sampling, and a check-valve gas port permits safe diversion of VOCs to remote analyzers.
[0013] Another object of the present invention is to provide the Dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis that improves detection sensitivity, and other sensors provide real-time, wireless monitoring of primary gases and environmental parameters.
[0014] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY OF THE INVENTION:
[0015] The present invention provides a dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis.
[0016] The system overcomes these challenges by utilizing a sterile, non-penetrating, and tightly controlled process for VOC trapping, eliminating the need to vent the culture vessel. The technology operates in two harmonized stages. In the initial stage, the gas collection valve, situated directly on top of the Petri dish, is opened to allow VOCs to migrate into a special chamber or tube. Throughout the operation, the delivery valve closest to the gas chromatograph is shut firmly, closing trapped gases and preventing contamination. In the second step, the collection valve is closed and the delivery valve is opened in order to achieve a regulated release of VOCs into the analysis instrument aided with mild pressure, e.g., syringe push. This serial process maintains the integrity of the gas sample and microbial culture, along with internal conditions, and prevents environmental contamination. The result is a stable sampling procedure that is sterile, minimizes the likelihood of contamination, and allows VOCs to be transferred with absolute precision. Its modularity and low profile enable it to be easily incorporated in any laboratory configuration and automated for high-throughput operation. The simplicity of its construction, designed for standard labware, makes it easy to implement in clinical microbiology labs, food safety testing labs, environmental field study sites, and bioprocessing facilities, which is especially useful in applications where accuracy, cleanliness, and reproducibility are crucial. This invention might be seen as a bright, smell-perceptive straw—sipping microbial that gingerly and consistently spews gases for the sake of scientific investigation. It transforms microbial VOC sampling from a cumbersome process into an efficient, scalable, and scientifically refined process. It not only reduces sampling to a streamlined process but also transforms the way scientists, clinicians, and technicians handle microbial systems, making them accessible for additional research without interruption and establishing new horizons in microbiological diagnostics and analytical science.
[0017] The main feature of the present innovation is its two-stage, two-valve gas sampling device, which enables scientists to collect and analyze the gases released from microbes without opening the vessel or disturbing the sample. Such gases could be harvested, of course, but any such measures would involve opening the Petri dish or employing complicated, costly equipment that contaminates or leads to gas loss. What is fresh and new about it is,
- 1. Two Independent Values for Two Independent Steps. Most designs feature a single route for gas transfer and collection. The current invention features two valves—one located near the Petri dish and the other near the gas analysis device (e.g., a gas chromatograph, or GC). It is a two-valve system which enables:
 Collecting gas only when required.
 Safe storage of the gas until analyzed.
 Greater control and specificity regarding when each step is performed.
- 2. No Opening the Petri Dish No opening of the lid or penetration into the sample is required, something that would contaminate or ruin the sensitive conditions within. The technology does not open the Petri dish, maintaining the natural conditions the microbes require and the integrity of the test.
- 3. Small, Simple, and Affordable. The majority of VOC sampling devices are bulk or use costly pumps or vacuum systems. The equipment used in this study is small, transportable, and easy to use, even in less-equipped laboratories or in the field. It utilizes manual or low-pressure push mechanisms (e.g., a plunger for a syringe) rather than complex equipment, making it inexpensive and straightforward to use.
- 4. Improved Sample Integrity and Accuracy. Since the gas is isolated between the two valves and discharged only when in use, it is unlikely to be lost, diluted, or contaminated which translates to more precise test results.
[0018] The present invention provides a simple yet significant improvement in gas sampling, as it utilizes two synchronized valves to capture and release microbial gases safely, eliminating the need to open the culture dish or use clunky, high-tech equipment. It transforms a hazardous, messy procedure into a clean, controlled, and speedy one—particularly for actual laboratories that must produce dependable results with minimal effort.
BRIEF DESCRIPTION OF DRAWINGS:
[0019] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
[0020] FIGURE 1. Schematic illustration of the Dual-Valve Microbial Gas Sampling and Delivery System developed for sterile, noninvasive sampling and transfer of volatile organic compounds (VOCs) from enclosed microbial culture environments.
[0021] FIGURE 2. Representation of the sampling syringe piercing a self-sealing silicon septum layer located at the first junction of the first valve (V1).
[0022] FIGURE 3. Description of the functioning of the first valve (V1) that is intended for manual opening and closing.
[0023] FIGURE 4. Illustration of VOC sample collection by syringe upward plunger movement, with the first valve (V1) open and the second valve (V2) [8] closed.
[0024] FIGURE 5. Representation of the VOC sample injection process into the analysis instrument (e.g., gas chromatography system) through downward plunger motion of the syringe.
DETAILED DESCRIPTION OF DRAWINGS:
[0025] While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and the detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claim.
[0026] As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein are solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers, or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles, and the like are included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.
[0027] In this disclosure, whenever a composition or an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same composition, element, or group of elements with transitional phrases “consisting of”, “consisting”, “selected from the group of consisting of, “including”, or “is” preceding the recitation of the composition, element or group of elements and vice versa.
[0028] The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, several materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.
[0029] The present invention provides Dual-valve microbial gas sampling system for non-invasive volatile organic compound analysis.
[0030] The Dual-Valve Microbial Gas Sampling System for Noninvasive VOC Analysis is a new system designed to overcome the limitations of conventional microbial gas sampling procedures. The system provides safe, sterile, and non-perturbing VOC sampling of the volatiles emitted from microbial cultures grown in half-closed or closed vessels, such as Petri plates, flasks, or culture bottles. VOCs are volatile and generally odorless molecules, as well as microbial metabolic chemical traces. Reagents are informative in that they are used in species identification, metabolic fingerprinting, spoilage detection, disease diagnosis, and environmental monitoring. Traditional techniques of microbial VOC analysis of culture require breaking the seal on the culture vessel, which can lead to contamination interference, sample integrity breakdown, and disturbance in the internal environment. Such interferences can modulate microbial metabolism, redistribute VOC concentrations, and induce false or misleading analytical measurement. In addition, most of the latest VOC sampling systems are impractical and faulty or dependent on costly, large, energy-demanding instrumentation. They are not suitable for field applications outside specialized laboratories, particularly in remote locations or low-resource settings.
[0031] This invention avoids these issues with a low-cost, portable, and inexpensive dual-valve system. The first valve, located on one side of the culture vessel, allows for the removal of gas without opening the vessel. The second valve, located near the analytical apparatus (e.g., a gas chromatograph), controls the timed release of the captured sample. It delivers a two-step process that ensures the VOC sample is transported and sampled in a clean, contaminant-free, controlled environment with an inner microbial culture, ensuring sample integrity and platform independence for both automated and manual equipment. Its ease of use, mobility, and versatility make it a significant revolution in microbial VOC analysis, enabling its application in a variety of scientific and industrial settings. The Dual-Valve Microbial Gas Sampling System for Noninvasive Volatile Organic Compound (VOC) Analysis is among the company's newer offerings, which synergize to overcome the long-standing problems of gas entrapment and microbial culture analysis. Fungi, bacteria, and other microorganisms emit VOCs—small, commonly aromatic molecules—during metabolism. These molecules serve as biochemical markers and are valuable in identifying microbial species, studying growth patterns, detecting food system spoilage, diagnosing infections in clinical microbiology, and researching microbial activity in environmental and industrial settings. It is susceptible to sampling of these VOCs. Conventional methods typically involve opening the culture vessel, e.g., Petri dish or flask, to gain access to the entrapped gas in the headspace above the developing microbes. This can compromise the culture, with possibilities of contamination and introduction of inert air that will interfere with gaseous equilibrium. Intrusions of small magnitude will primarily contaminate the sample quality by loss or dilution of VOCs and measurement error. Besides this, most existing gas sampling equipment is large in size, power-consuming, and costly, and therefore is stored by only affluent laboratories.
[0032] The two-valve system, as described here, is a way to avoid such limitation by stepwise, non-penetrating gas build-up. The system utilizes two best-fitted valved positions: one close to the culture vessel for controlled headspace gas draw-off without opening the vessel, and the second close to the gas analysis unit (e.g., gas chromatograph) for proper sample release during analysis. The method maintains microbial cultures closed and in a sterile state, with the gas sample being kept in an unbroken state throughout. Light, portable, and low-cost, the apparatus is convenient both for laboratory and field use as well as an ideal instrument for the maintenance of microbial research, diagnostics, and environmental surveillance in high-resource and low-resource environments. The Dual-Valve Microbial Gas Sampling System for Noninvasive Volatile Organic Compound (VOC) Analysis is a new tool that will be useful for microbial VOC sampling and analysis in the vicinity of, or inside, near-closed or closed culture vessels, such as Petri dishes. VOCs are odor-causing, volatile organic compounds (VOCs) released by microorganisms as metabolic byproducts. These molecules are of primary importance in the identification of microbes, monitoring physiological function, detecting contamination or spoilage, and diagnosing infections in medical or environmental samples. Currently, sampling protocols often involve breaking the headspace connectivity of the gas in the vessel that holds the culture to ensure connectivity across the microbes. Outside contaminants gain access to the sample, disrupt key internal conditions, and contaminate or dilute the VOC print, yielding incorrect or unreliable readings. Moreover, most VOC sampling instruments on the market are technology-dependent, bulky, or extremely costly, e.g., those that are barely ready for use on a large scale, especially in low-resource environments or in the field.
[0033] This invention eliminates such restrictions in a double-valve sterile, controlled, and non-contaminating VOC sampling system. The upper valve allows for siphoning off the headspace gases without allowing air to enter the interior. The lower valve, positioned as close as possible to the analytical instrument (i.e., a gas chromatograph), enables the controlled venting of the trapped sample. This two-stage design maintains sterile processes, preserves environmental conditions, and enables high-integrity sampling. This economically and low-complexity mini system is highly versatile for application in laboratory, clinical, and in-situ environmental samples, representing a technological innovation in the analysis of microbial VOC. This invention fills a significant gap in microbial volatile organic compound (VOC) sampling technologies, offering a portable, effective, and noninvasive format with a two-stage, dual-valve design. Some of the more conventional techniques used for VOC collection from microbial cultures most often require opening the culture vessel, such as a Petri dish, with resulting drawbacks. They can involve possible contamination of samples, disruption of microbial microenvironment, and dilution or loss of VOC due to interaction with ambient air as these limitations compromise the accuracy, reliability, and reproducibility of downstream analysis results, particularly in applications where accuracy is crucial, such as clinical diagnostics, food safety analysis, environmental analysis, and microbial ecology studies.
[0034] The two-valve system of the invention provides integrity for both the gas sample and the microbial culture. Valve 1 is located very close to the vessel of the microbial culture and serves as a point of controlled access to headspace gases, while Valve 1 serves to provide the selective release of VOCs without physically opening the container, to maintain sterility and internal gaseous equilibrium, further valve 1 is also equipped with a microbial-grade filter to prevent cross-contamination and is constructed from chemically inert and sterilizable materials, including polytetrafluoroethylene (PTFE), borosilicate glass, and stainless steel. Chosen materials are compatible with a very broad range of microbial cultures and VOCs, including acidic, alkaline, and reactive chemicals, thereby increasing their usage. Valve 2 is placed at the proximal end inlet of the GC or other analytical system. It is a control gate employed to regulate the flow between the stored sample and the time of injection. It is operated manually or electronically and designed in such a manner that any leakage in forward direction or contamination with ambient air is avoided. During the analysis step, once the user has powered on the GC syringe or pump system, Valve 2 is activated, allowing the VOC sample that was pre-pulled from the headspace through Valve 1 to be routed directly into the instrument without handling or exposure. The stepwise process—venting the gas initially by opening Valve 1, then closing Valve 1 and opening Valve 2 to press the sample—demonstrates the system as an undisturbed, unidirectional, sterile channel from culture environment to analytical phase. The two-stage, two-valve method enhances VOC sample reproducibility by minimizing disturbance to the microbial culture and preserving the native chemical content of the effused gases. In addition, its compact and modular design facilitates easy integration into most experimental equipment, ranging from disposable cell cultures to long-term incubations and field diagnostic portability. It also enables simplicity of use in settings with limited resources, such as rural clinics, mobile labs, or field research stations where full laboratory facilities are not available. Overall, this invention is superior to non-invasive microbial VOC sampling in that it offers a scalable, precise, and easy-to-use solution compared to traditional techniques.
[0035] The system works in two alternate steps. First, Valve 1 is opened but Valve 2 is closed. Such an arrangement enables the employment of a vacuum system, mini syringe, or gas-tight pump to siphon VOCs from the headspace of the microbial culture into an intermediate collection channel or storage chamber located between the two valves. This allows for the potential of gas collection without the need to open the Petri dish, thereby preserving the sterility and environmental conditions of the microbial culture. Following a successful gas pulling and trapping within the intermediate tubing or chamber, Valve 1 is closed to seal the microbial atmosphere once more. Valve 2 is opened for step 2, and the trapped VOC sample can be manually forced out with a syringe plunger or automatically pumped into the gas chromatography instrument for analysis. Valve 1 is maintained closed during this step to prevent backflow or contamination of the microbial culture vessel. This two-step, two-valve process is the hallmark innovation of the invention. It provides unprecedented control of gas sampling of microbial headspaces. Unlike current systems that conduct simultaneous delivery and sampling, which can double contamination or cause sample damage, this system is compartmentalized into two independent, distinct steps: collection and delivery. A double-valve setup maintains the Petri dish sealed and intact from microcontamination throughout the process, thereby preserving the original microbial environment and sample integrity. The setup is also provided for temporarily holding the gas sample between valves in case immediate analysis is not possible, making it easy to operate for delayed analysis or batch sampling operations.
[0036] The low profile of the invention makes it suitable for mass application in a broad range of applications. From use in high-resource laboratories to point-of-care and focused field operations in low-resource settings, the invention is compact, modular, and constructed from inexpensive materials, including PTFE tubing, sterilizable plastic parts, and miniaturized valves. Its most basic manual operation, the system employs not a single watt of electricity, but syringe motion under manual power for draw and delivery of gases. More expensive implementations will typically include micro-pumps, servo or solenoid-controlled computer-regulated automatic valves, and electronic interfacing to gas chromatographs or other VOC sensor platforms. The system also accommodates a large volume of other types of microbial culture vessels aside from Petri dishes. It is found to be very handy for use in flasks, culture bottles, vials, and in-line bioreactor systems, providing maximum flexibility for industrial process monitoring of fermentation processes, environmental monitoring, and laboratory work. The system can also provide compatibility with pre-concentration devices, such as sorbent traps or cold traps, to facilitate the sampling of very low-concentration VOCs from large headspaces. It can also be equipped with accurate real-time sensors, such as CO₂, temperature, or humidity sensors, to record environmental data associated with each gas sample, providing more context for the microbial response, further the double-valve design minimizes dead space between valves, as a critical consideration for preserving the VOC concentration gradient, which leads to more accurate analysis, particularly in cases where unstable, reactive, or adsorbable compounds are present on the tubing walls.
[0037] The system is also employed in clinical diagnosis, where VOCs are used to identify fungal or bacterial infections caused by specific fungal or bacterial pathogens. Some Mycobacterium tuberculosis complex bacteria, for instance, release certain VOCs that can be detected by such a system as noninvasive markers for diagnosis. Microbial spoilage, which affects food quality control, generates certain VOCs that the system can measure without compromising the food sample. Meanwhile, in environmental microbiology, the volatilization of VOCs from soil or water can be influenced by microbial processes, nutrient cycling, or contamination. In biotechnological fermentation, the system can continuously or batch-wise track headspace gases during fermentation, which has the potential to aid in process optimization, contamination detection, and monitoring of shifts in microbial metabolism. The system can be scaled up and produced too. The whole system element can be produced by using low-cost production methods like injection molding, CNC milling, or 3D printing. The valves can be bought commercially or ordered directly as designed-to-order microfluidic valve designs. Modular construction makes the device easy to assemble and repair with minimal instruction. It may be shipped as a standalone instrument, as an accessory to refurbished gas chromatographs, or even as a component of an integrated diagnostic or monitor system. The invention is also sterilizable by autoclave or ethylene oxide and can be used in sterile and clinical settings.
[0038] Innovatively put, the current invention is unique compared to other VOC sampling systems in that it is easy, efficient, and sterile. It does not require a Petri dish with complex sampling ports or built-in detection sensors, thereby being compatible with regular laboratory materials after the fact. The two-valve system enables direct and effective phase differentiation between analysis and sampling, resulting in greater flexibility, improved sample gas protection, and enhanced results. This one-step technology—with but one additional valve and staged treatment of gas—is a titanic leap forward in laboratory-style microbial VOC sampling technology. Essentially, this invention provides researchers, clinicians, and field scientists with an efficient yet expensive tool. It enables clean, noninvasive, and accurate microbial gas sampling, and it promises to unlock the door to more universal use of VOC-based microbial analysis in diverse habitats. Wherever applied -- a field lab in a distant soil-quality monitor, a hospital in diagnosing infection, or a brewery in monitoring yeast fermentation -- the Dual-Valve Microbial Gas Sampling System is to make microbial VOC sampling economical, precise, and reproducible. That it's economical makes it scalable, that it is compact makes it transportable, and that it is sterilized makes it sound scientific and diagnostic. Having solved a long-standing issue with an inspirational and practical design, the invention is a valuable addition to the practice of environmental monitoring and microbial analysis.
[0039] It should be appreciated that, while an explanatory discussion of the novel feature of the Auto-Sealing Smart Microbial Sampling Valve has been given concerning its application in Petri dish-based sampling environments, as depicted by the accompanying figures and description, the basic principles, elements, and operations of the device are, per se more or less flexible and scalable. An experienced practitioner will immediately recognize that the same valve system, with minimal or no adaptation, can be utilized across a broad range of microbial populations and sampling situations. For instance, the Auto-Sealing Smart Microbial Sampling Valve demonstrates unprecedented flexibility in a wide range of uses beyond typical Petri dish arrangements. Its sanitary, noninvasive sampling design makes it in very high demand in medicinally related usage, e.g., blood culture tubes to detect disease-promoting pathogens or specialty wound monitoring chambers to analyze volatile organic compounds (VOCs) that are precursors to infection. In environmental science, the valve may be incorporated into soil sampling pods to monitor in situ microbial emissions, water pollution chambers to assess the health of aquatic ecosystems, or in composting systems to track the progression of decomposition through microbial gas signatures. Its use is also observed in industrial settings, such as being used with fermentation vessels for brew brewery quality control, food spoilage pouches to alert against microbial spoilage, and bioreactor sampling ports that maintain sterility while performing emissions monitoring. In hostile or remote environments, the valve's small size provides a place for closed-system bio capsules in spacecraft or deep-sea chambers to study unusual microbial life. These figures highlight the modularity, precision, and adaptability of the valve, adding testament to its role as a pathbreaking tool in microbial VOCs analysis in the scientific, medical, and industrial arenas.
[0040] FIGURE 1. Schematic illustration of the Dual-Valve Microbial Gas Sampling and Delivery System developed for sterile, noninvasive sampling and transfer of volatile organic compounds (VOCs) from enclosed microbial culture environments. This two-step, compact system permits high-fidelity sampling of gaseous metabolic products released by microorganisms grown in routine Petri dishes with no disruption to sterility or internal environmental conditions. The system combines two important elements: an initial sampling valve [6] and a final delivery valve (V2) [8], situated at key points along the gas transfer line. The initial valve (V1) [5] is inserted into the side or middle of the top lid [2] of a typical Petri dish and leads directly to a sterile, gas-tight syringe [1]. This permits accurate withdrawal of headspace gas from over the microbial culture, which occupies the lower dish compartment [3]. The process of sampling is started by opening V1 and keeping V2 closed to allow VOCs to be sucked into the syringe without causing back-contamination or exposure to the environment. After the sample of gas is taken, V1 is shut down, and the second valve V2, located close to the inlet port of the analyzer instrument, usually a gas chromatograph (GC) [10], is opened. Through the sampling line [7] and injection line [9], V2 regulates the controlled release of the headspace sample to be injected into the GC or equivalent analytical platform. This stepwise operation of valves—such that at any moment, one valve only is open—maintains sterile separation between stages. It avoids environmental contamination, retains microbial headspace conditions, and retains sample integrity. This modular, aseptic strategy enables precise real-time metabolic profiling of cultured microbes via VOC analysis, promoting applications in microbial diagnostics, ecological monitoring, and bioprocess optimization.
[0041] FIGURE 2. Representation of the sampling syringe piercing a self-sealing silicon septum layer [11] located at the first junction [4] of the first valve (V1) [5]. The septum facilitates sterile puncture without venting to ambient air, preserving the aseptic condition of the culture vessel. Another second intersection [6] of the same silicon sealing layer [11] is also illustrated, showing its suitability for either gas removal or interface with a second transfer line. The septum provides a physical and microbial barrier to carry out gas sampling operations.
[0042] FIGURE 3. Description of the functioning of the first valve (V1) [5] that is intended for manual opening and closing. The valve mechanism provides the user with selective access to the Petri dish headspace gas without compromising sterility. In the open position, VOCs can be drawn out; in the closed position, the system is sealed off from the outside, preventing ambient contamination and maintaining internal culture conditions.
[0043] FIGURE 4. Illustration of VOC sample collection by syringe upward plunger movement [1], with the first valve (V1) [5] open and the second valve (V2) [8] closed. This arrangement allows for VOCs within the microbial headspace within the Petri dish [2] to be sucked into the syringe without releasing any portion of the sample into the external atmosphere or the analytical system.
[0044] FIGURE 5. Representation of the VOC sample injection process into the analysis instrument (e.g., gas chromatography system) through downward plunger motion of the syringe [1]. During this step, the first valve (V1) [5] is closed to seal the culture chamber, and the second valve (V2) [8] is opened to facilitate the directed transfer of samples. This arrangement maintains the microbial environment undisturbed while delivering the trapped VOC sample for analysis accurately.
[0045] The disclosure has been described with reference to the accompanying embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein.
[0046] The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein. , Claims:We Claim:
1) A dual-valve microbial gas sampling system for non-invasive volatile organic compound (VOC) analysis, the system comprising:
- a sterile gas-tight sampling syringe (1);
- a first valve (V1) (5) mounted on the lid (2) of a microbial culture vessel, said first valve (5) being configured for manual operation and provided with a self-sealing septum (11) at a first junction (4) to permit sterile puncture;
- a second valve (V2) (8) positioned at the proximal end of an analytical device (10);
- a sampling line (7) connecting said first valve (5) and said second valve (8); and
- an injection line (9) connected to said second valve (8) for transfer of the VOCs to the analytical device (10);
- wherein the system allows VOC sampling from a microbial headspace and controlled delivery to the analytical device without opening the culture vessel or compromising sterility.
2) The system as claimed in claim 1, wherein said first valve (5) is operable to permit entry of the syringe (1) plunger in an upward motion for gas withdrawal while keeping said second valve (8) closed, thereby enabling non-invasive sample collection.
3) The system as claimed in claim 1, wherein said second valve (8) is configured to be opened after closure of said first valve (5), to permit VOC injection through downward plunger motion into the analytical device (10), thus maintaining a sealed microbial environment.
4) The system as claimed in claim 1, wherein said self-sealing septum (11) is constructed of silicon and provides a microbial barrier to prevent ambient contamination during insertion or removal of the syringe needle.
5) The system as claimed in claim 1, wherein said valves (5, 8), said sampling line (7), and said injection line (9) are constructed from chemically inert and sterilizable materials selected from polytetrafluoroethylene (PTFE), borosilicate glass, or stainless steel.
6) The system as claimed in claim 1, wherein said first valve (5) comprises a microbial-grade filter to prevent inward or outward transfer of microbial contaminants during sampling.
7) The system as claimed in claim 1, wherein said dual-valve configuration allows temporary storage of VOCs within the sampling line (7) or syringe (1) for delayed or batch-wise analysis.
8) The system as claimed in claim 1, wherein the sampling system is adapted for compatibility with microbial culture vessels selected from Petri dishes, flasks, vials, culture bottles, or bioreactors.
9) The system as claimed in claim 1, wherein the analytical device (10) is selected from gas chromatography (GC), gas sensors, or mass spectrometry systems, and the valves (5, 8) are operable manually or electronically to regulate VOC flow and prevent cross-contamination or sample degradation.