Imagine embarking on a mission to clean up polluted soil and groundwater. This is the essence of the MIBIREM project, which aims to identify and cultivate microorganisms capable of breaking down harmful pollutants. To achieve this, the project follows standardized procedures for collecting and treating samples, ensuring consistency and reliability across different sites.

The handbook for this project serves as a crucial guide, providing detailed instructions on how to collect, transport, treat, and store samples. It even includes a coding system to clearly identify each sample, making the process seamless and organized. The handbook is a draft handbook – a final version is foreseen to be published at the end of 2025.

When it comes to groundwater sampling, the process begins with recording on-site parameters. Picture yourself in the field, measuring the temperature, pH, dissolved oxygen, Electrical Conductivity (EC), and Oxidation-Reduction Potential (ORP) of the groundwater. You also keep an eye out for any unusual smells or colours. These samples are then analysed for various contaminants, such as petroleum hydrocarbons, PAHs, BTEXN, and more. Additional parameters like nitrate, nitrite, and dissolved metals are measured to get a comprehensive chemical profile. The collected groundwater is kept cool and filtered to capture bacteria, with DNA extracted using a special kit and stored at -20°C. For enrichment cultures, larger volumes of groundwater are collected to grow bacteria that can degrade contaminants in the presence of oxygen.

Soil sampling follows a structured approach to ensure comparability across different sites. The process is divided into three tiers. The first tier involves measuring basic parameters like pH and electrical conductivity. The second tier focuses on measuring contaminant levels, including petroleum hydrocarbons and polycyclic aromatic hydrocarbons. The third tier involves measuring extended parameters in highly contaminated samples for further analysis. It’s also important to take uncontaminated samples to understand background values.

Key contaminants in soil include petroleum hydrocarbons, PAHs, BTEXN, hexachlorocyclohexane, and cyanides. To extract DNA from soil, samples are mixed thoroughly to create a composite sample. About 50 grams of this sample is taken, kept cool, and transported to the lab. In the lab, the soil is sieved, a portion is stored at -20°C, and the sample is ground before extracting DNA using a special kit. The extracted DNA is then stored for further analysis.

For enrichment cultures, soil from the composite sample is sieved either at the site or in the lab. The samples are kept cool during transport and storage, and all steps are meticulously recorded to ensure the integrity of the samples.

Developing a standardized sampling procedure is crucial for several reasons. It ensures consistency, accuracy, and reproducibility, allowing other researchers to replicate the study and verify results. It also helps in quality control, minimizing contamination, and ensuring compliance with regulatory standards. Moreover, clear guidelines streamline the sampling process, saving time and resources.

In summary, the MIBIREM project developed and meticulously follows these procedures to ensure high-quality samples for accurate analysis and effective bioremediation efforts. For more details, refer to D1.6. Initial handbook for standardised sampling. This development was led by the project’s scientific coordinator, Thomas Reichenauer from AIT, in collaboration with all partners.