Assessing soil bacterial community and dynamics by integrated high-throughput absolute abundance quantification.

Area of Science:

• Microbial Ecology
• Environmental Microbiology
• Molecular Biology

Background:

• High-throughput sequencing (HTS) is crucial for microbial ecology, offering extensive taxonomic and relative abundance data.
• However, relative abundance alone does not accurately represent microbial community quantity or inter-sample variations.
• Existing methods lack the ability to quantify absolute microbial numbers, limiting ecological interpretations.

Purpose of the Study:

• To refine and apply an integrated high-throughput absolute abundance quantification (iHAAQ) method.
• To characterize soil quantitative bacterial communities by combining relative and absolute abundance data.
• To evaluate the iHAAQ method's efficacy in a soil phenanthrene biodegradation study.

Main Methods:

• Integrated high-throughput absolute abundance quantification (iHAAQ) method.
• Combining relative abundance data from HTS with total bacterial quantities from quantitative PCR (qPCR).
• Validation using internal reference strain EDL933 and laboratory strain WG5.

Main Results:

• The iHAAQ method was successfully validated.
• In a soil phenanthrene biodegradation study, relative and absolute abundance changes varied among bacterial taxa.
• Inhibition of microbial activity led to decreased absolute abundances but increased relative abundances for key genera like Bacillus, Flavobacterium, and Paenibacillus.

Conclusions:

• The iHAAQ method provides a more comprehensive view of soil bacterial community dynamics than HTS alone.
• Distinguishing between relative and absolute abundance is critical for accurate ecological interpretations.
• The iHAAQ method enhances the characterization of microbial communities in environmental samples.