Guangzhou Institute of Geochemistry proposes a new technology to study unculturable functional microorganisms at the single-cell level

The traditional DNA-stable isotope probe (DNA-SIP) technology can identify functional microorganisms that play a role in degradation in the real environment, but only partial DNA information of functional microorganisms can be obtained.
The isolation of functional microorganisms cannot study functional genes and metabolic pathways, which limits the application of these microorganisms with degradation functions in environmental pollution control
.

In this context, anchoring and accurately sorting functional microbial cells, obtaining genomic information, and then revealing their metabolic characteristics and tapping their in situ repair potential have become a hot and difficult point in environmental microbial research
.

Recently, associate researcher Li Jibing and researcher Luo Chunling of Guangzhou Institute of Geochemistry, Chinese Academy of Sciences combined magnetic nanoparticle-mediated separation technology (MMI), DNA-SIP and single-cell Raman sorting (RACS) technology to develop MMI- SIP-RACS technology
.

In the study, researchers took phenanthrene in oil-contaminated water as the research object, used MMI technology to enrich and degrade microbial cells, and used SIP and RACS technology to lock and isolate target microbial cells, and then explore the genetics of these cells at the single-cell level.
characteristics and degradation mechanisms
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The study showed that MMI-SIP-RACS significantly enriched phenanthrene-degrading bacteria and achieved effective isolation of representative functional microbial single cells
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The results of SIP amplicon sequencing, single-cell 13C translocation in Raman spectroscopy, and single-cell genome sequencing comprehensively confirmed that Novosphingobium sp.
is a functional microorganism involved in the in situ degradation of phenanthrene in sewage
.

The study also reconstructed the phenanthrene metabolic pathway of Novosphingobium microbial cells, and analyzed several novel PAHs degradation genes such as phenanthrene dioxygenase (Phn) and naphthalene dioxygenase (Nah) genes
.

　　The new MMI-SIP-RACS method proposed in this study realizes the in situ enrichment, identification and isolation of PAHs-degrading microorganisms at the single-cell level, and can directly link the function of specific microbial cells with genotype, which is an effective method for separation of microorganisms.
A new tool for the degradation of microbial cells by organic pollutants in the environment
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　　The related results were published in Environmental Science & Technology
.

The research was funded by the National Natural Science Foundation of China, the Key Field R&D Program of Guangdong Province, and the "Tu Guangchi Outstanding Young Scholar" of the Guangzhou Institute of Geochemistry
.

Link to a new paper on the study of functional non-culturable microorganisms at the single-cell level: https://pubs.
acs.
org/doi/10.
1021/acs.
est.
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