System for detecting the presence of microorganisms present in a sample, characterized in that it comprises: - an enclosure comprising a closed internal space bounded by a receptacle and a lid that is intended to be affixed to the receptacle to close the enclosure hermetically, - an electronic unit for acquiring pH-measurement data, which is integrated into said enclosure, - two second electrical contacts (241, 251) that are connected to the electronic acquiring unit and arranged inside the enclosure, - a heating unit integrated into the enclosure with a view to heating the internal space of the enclosure, - a unit for measuring and managing temperature, comprising a temperature-measuring probe placed inside the enclosure, - an electrical power source for powering the electronic acquiring unit and the heating unit, - a processing unit connected to said electronic acquiring unit and configured to process the measurement data and comprising a module for detecting the presence of microorganisms via analysis of the variation in the pH measured in the liquid sample, - an instrumented container housed in the internal space of the receptacle and intended to receive said sample, said container comprising: - walls comprising a first surface, called the internal surface, which makes contact with the internal volume thereof intended to receive said sample, and a surface, called the external surface, opposite said internal surface, - a reference electrode and a pH-measuring electrode that are integrated into at least a first wall of said walls of the container and that each comprise at least two conductive portions that are connected together, a first portion arranged on the internal surface and intended to make contact with the liquid sample placed inside the container, and a second portion arranged on the external surface and comprising two separate first electrical contacts (141, 151) that are accessible from outside the container, its first electrical contacts (141, 151) each bearing against a separate second electrical contact (241, 251) of said enclosure. - an enclosure comprising a closed internal space bounded by a receptacle and a lid that is intended to be affixed to the receptacle to close the enclosure hermetically, - an electronic unit for acquiring pH-measurement data, which is integrated into said enclosure, - two second electrical contacts (241, 251) that are connected to the electronic acquiring unit and arranged inside the enclosure, - a heating unit integrated into the enclosure with a view to heating the internal space of the enclosure, - a unit for measuring and managing temperature, comprising a temperature-measuring probe placed inside the enclosure, - an electrical power source for powering the electronic acquiring unit and the heating unit, - a processing unit connected to said electronic acquiring unit and configured to process the measurement data and comprising a module for detecting the presence of microorganisms via analysis of the variation in the pH measured in the liquid sample, - an instrumented container housed in the internal space of the receptacle and intended to receive said sample, said container comprising: - walls comprising a first surface, called the internal surface, which makes contact with the internal volume thereof intended to receive said sample, and a surface, called the external surface, opposite said internal surface, - a reference electrode and a pH-measuring electrode that are integrated into at least a first wall of said walls of the container and that each comprise at least two conductive portions that are connected together, a first portion arranged on the internal surface and intended to make contact with the liquid sample placed inside the container, and a second portion arranged on the external surface and comprising two separate first electrical contacts (141, 151) that are accessible from outside the container, its first electrical contacts (141, 151) each bearing against a separate second electrical contact (241, 251) of said enclosure. - walls comprising a first surface, called the internal surface, which makes contact with the internal volume thereof intended to receive said sample, and a surface, called the external surface, opposite said internal surface, - a reference electrode and a pH-measuring electrode that are integrated into at least a first wall of said walls of the container and that each comprise at least two conductive portions that are connected together, a first portion arranged on the internal surface and intended to make contact with the liquid sample placed inside the container, and a second portion arranged on the external surface and comprising two separate first electrical contacts (141, 151) that are accessible from outside the container, its first electrical contacts (141, 151) each bearing against a separate second electrical contact (241, 251) of said enclosure.