The present invention makes known an array of nucleotidic sequences for rapidly and simultaneously identifying the presence of certain genes that codify proteins with relevant activities in biotechnology present in a microbiological sample, and the method with which this array is used in the identification of the above mentioned genes. Specifically speaking, genes that codify for proteins relevant in the biofilm formation, in CO2 fixation, in energetic metabolism, for chemiotaxis and mobility, in iron oxidizing, in nitrogen metabolism, in sulfur assimilation, and in oxidation/reduction of sulphide compounds, are identified. This array of nucleotidic sequences is presented as a useful tool in biotechnology whenever evaluating the quality of a microbiological community is required.