Molecular Biology Analyses

When stimulating natural self-purification processes during in-situ remediation of volatile organic compound (VOC) contamination, failure to observe important boundary conditions can lead to the accumulation of metabolites (such as c-DCE and VC).

Studies show a direct correlation between the complete dechlorination of LCKW and the presence of certain enzymes found exclusively in bacteria of the species Dehalococcoides mccartyii.

The following analyses are offered under the product name CENSUS® to determine the natural degradation potential at solvent-contaminated sites:

• Quantification of Dehalococcoidesgene copies.
• Quantification of methanotrophic microorganisms capable of very effectively utilizing chlorinated hydrocarbons, such as TCE, through cometabolism under aerobic conditions.
• Quantification of ethenotrophic microorganisms capable of utilizing vinyl chloride as a substrate under aerobic conditions.

The QuantArrayChlor® method enables a comprehensive assessment of the biodegradation potential of chlorinated contaminants. It can be used under both aerobic and anaerobic conditions. It can be used to determine whether microorganisms capable of degrading LCKWs are present at the site. Furthermore, their abundance can be quantified. In addition, the method helps to more precisely determine the underlying degradation mechanisms.

The following analyses are offered under the product name QuantArrayChlor® to assess the biodegradation potential of the full spectrum of common chlorinated pollutants:

• Quantification of key halorespiring bacteria (Dehalococcoides, Dehalobacter, Dehalogenimonas, Desulfitobacterium, etc.) to assess their potential for the reductive dechlorination of chloroethene, chloroethane, chlorobenzene, chlorophenol, and chloroform
• Quantification of Bacteria Capable of Co-Oxidizing TCE, DCE, and Vinyl Chloride
• Quantification of functional genes involved in aerobic (co)metabolic pathways or competing biological processes.

QuantArray BGC® is a molecular biology-based analytical method for the simultaneous quantification of numerous microorganisms and genes involved in key biogeochemical processes in the subsurface. These include, among others, sulfate and iron reduction, sulfur and metal oxidation, nitrification, denitrification, fermentation, acetogenesis, and methanogenesis.

This method makes it possible to create a comprehensive biogeochemical profile (BGC profile) of a site. This allows for an assessment of the key microbial material transformation processes at the site and an evaluation of the potential for biological degradation processes.

QuantArray NSZD® is a molecular biology-based analytical method for assessing natural degradation processes (Natural Source Zone Depletion, NSZD). In a single analysis, it quantifies a broad spectrum of functional genes from the microorganisms involved in the dissolution, volatilization, and biodegradation of contaminant phases in the subsurface.

Methanogenesis plays a central role in this process, supplemented by other microbial communities such as methanotrophs, sulfate reducers, iron reducers, denitrifiers, fermenters, acetogens, as well as biosurfactants and mucus-forming organisms. By quantifying these genes in parallel, QuantArray NSZD® enables a comprehensive assessment of microbial processes and, consequently, of the biological degradation potential in the LNAPL source zone.

QuantArrayPetro® is a molecular biological analytical method that, in a single test, detects both specific microorganisms and functional genes involved in the aerobic, cometabolic, and anaerobic degradation of petroleum-derived hydrocarbons. These include, among others, BTEX, MTBE, toluene, ethylbenzene, benzene, xylene, and naphthalene.

Since petroleum hydrocarbons are complex mixtures of hundreds of aliphatic, aromatic, cyclic, and heterocyclic compounds and can be degraded via many different biological pathways, QuantArrayPetro® enables a comprehensive assessment of microbial degradation potential by simultaneously quantifying numerous degradation genes. The analysis includes, among others, genes for:

• aerobic (e.g., dioxygenases, monooxygenases) and anaerobic BTEX degradation (e.g., BSS, ABC),
• MTBE and TBA degradation,
• aerobic (NAH, NAG, PHN) and anaerobic naphthalene degradation (NMS, ANC), as well as
• aerobic and anaerobic degradation of alkanes (e.g., alkB, assA).

QuantArrayPetro® demonstrates how effectively various petroleum hydrocarbons can be degraded naturally. It provides a detailed analysis of numerous aerobic and anaerobic degradation pathways and quantifies their potential at the site.

Next-Generation Sequencing ( NGS) refers to a molecular biology method in which the DNA molecules contained in the sample material are sequenced comprehensively and accurately.

It is possible to detect the taxonomic characteristics of microorganisms, determine their relative abundances, and even identify individual species. This allows for the description of entire microbial communities and the characterization of predominant biogeochemical processes.

This makes it possible to track how microbial communities change —whether due to pollutants, over time, or in response to process flows and remediation measures that have been implemented.

Using the NGS data obtained, suitable CENSUS qPCR targets can be selected for subsequent molecular biological monitoring.