Microbial Growth Detector Using Gas-Permeable Membrane

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Solution Overview

Problem

Current methods for detecting bacterial contamination in food and food processing equipment are inadequate for rapid and effective detection of multiple bacterial strains, particularly in identifying levels that could lead to food contamination.

Innovation Solution

A test device is developed that utilizes a gas-permeable membrane and a semi-permeable matrix with pH indicators to detect carbon dioxide produced during microorganism growth, allowing for rapid optical detection of bacterial growth through changes in optical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional detection methods are used for bacterial contamination, then detection can be performed, but the detection speed is slow and multiple bacterial strains cannot be effectively detected

Engineering Contradiction:
Improvedetection speedVSAvoidability to detect multiple bacterial strains
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The detection system is segmented into multiple independent detection chambers, each containing culture media selective for different bacterial strains. This allows simultaneous detection of multiple bacterial types in parallel, improving both detection speed and the ability to identify multiple strains without cross-contamination.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detection device is designed as a universal platform that can detect multiple types of bacteria using a single integrated system. By incorporating multiple culture media types and detection mechanisms in one device, it eliminates the need for separate detection procedures for different bacterial strains, thereby improving productivity while maintaining measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If rapid detection methods are implemented, then detection speed improves, but detection accuracy and reliability may be compromised

Engineering Contradiction:
Improvedetection speedVSAvoiddetection accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary culturing actions in sealed chambers before final detection, allowing bacteria to grow to detectable levels in advance. This preliminary growth phase ensures that even low-level contaminants are amplified to detectable concentrations, maintaining reliability while enabling rapid final detection through optical or other quick-read methods.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Culture media and selective agents act as intermediaries between the bacterial sample and the detection mechanism. These intermediaries enhance the detectability of bacterial presence by converting biological growth into measurable signals (such as color changes, gas production, or optical property changes), thereby maintaining high detection accuracy while enabling rapid results.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution enables rapid and effective detection of bacterial growth, improving the ability to identify contamination levels and ensuring food safety by using a simple, easy-to-use method that can be applied across various sample types.

Implementation Method 1

the gas-permeable membrane and the semi-permeable matrix are permeable to carbon dioxide, thereby permitting diffusive transport of carbon dioxide present in the growth region to the detection region

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

The indicator molecules provide rapid detection of carbon dioxide by changing optical properties in the presence of carbon dioxide that is released during bacterial growth

Methodology Applied
Scientific EffectpH indicator color change: Photochromism

Implementation Method 3

a semi-permeable matrix disposed in the detection region of the vessel, the matrix comprising a pH indicator distributed throughout the matrix

Methodology Applied
Scientific EffectSemipermeable membrane: Semipermeable Membrane

Data Source

PatentEP2566948B1Microbial growth detector
Publication Date: 2017.11.22 NEOGEN CORP
  • EP2566948B1 patent drawingFigure 1A~1E
  • EP2566948B1 patent drawingFigure 2A~2B
  • EP2566948B1 patent drawingFigure 3

AI summary

The disclosure generally relates to a test device that detects microorganism growth by detecting a gas metabolite (e.g., carbon dioxide) produced during the growth of bacteria or other microorganism in a tested sample. The test device can contain a culture growth media separated from a detection area by a gas-permeable membrane. The gas-permeable membrane permits carbon dioxide to permeate into the detection area. The detection area includes a solidified mixture of pH indicators and a gelling agent in the form of a semi-permeable matrix. The optical properties, including the absorbance of light at various wavelengths, of the detection solution change with alterations in carbon dioxide concentration. This test device can then be placed in an incubation and optical detection instrument to monitor changes in optical properties of the detection are induced during microorganism growth in the culture medium.