Biology subjects

Pierrelee, M.

Publications and source records attributed to Pierrelee, M..

2 recordsLinked to original sources

bioRxiv2025

An integrated meta-omics approach for identifying candidate organic micropollutant degraders in complex microbial communities

Biotransformation is a significant determinant of the fate of organic micropollutants (OMPs) in natural and engineered environments; yet identifying OMP-transforming microorganisms remains challenging. Integrating metagenomics and metatranscriptomics, we searched for correlations between the biotransformation of ammonia and atenolol and the transcriptional activity of metagenome-assembled genomes (MAGs) across five nitrifier-rich cultures in batch experiments. The biotransformation of ammonia correlated with the activity of ammonia-oxidizing bacterium Nitrosomonas europaea but not with the activity of other bacteria, including several ammonia oxidizers. Additionally, the biotransformation of ammonia correlated with the transcript abundance of the ammonia monooxygenase (AMO) expressed by N. europaea but not with the transcript abundance of AMO at the community level. Atenolol biotransformation correlated with the activity of four MAGs representing three heterotrophic genera: Terrimonas, Flavobacterium, and Zeimonas. It did not correlate with the total transcript abundance of any member of a comprehensive set of amidohydrolases, which are predicted to transform this drug. By contrast, it correlated with the expression of the amidohydrolase asparagine synthase (AsnB) identified in the Terrimonas and Flavobacterium MAGs. In summary, we present a novel association-based method for elucidating biotransformation processes robust to variability in enzyme reaction kinetics with implications for OMP control. SynopsisThe fate of organic micropollutants in natural and engineered systems depends greatly on biotransformation by microbes. This study proposes an approach for identifying these microbes with implications for the study and control of organic micropollutant removal. ABSTRACT GRAPHICS O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/639455v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@17c7f1org.highwire.dtl.DTLVardef@147b9eforg.highwire.dtl.DTLVardef@1fffc9eorg.highwire.dtl.DTLVardef@121fd96_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2019

Transcriptome responses associated with carbon and energy flows under high salinity stress suggest the overflow of acetyl-CoA from glycolysis and NADPH co-factor induces high lipid accumulation and halotolerance in Chlorella sp. HS2

Previously, we isolated Chlorella sp. HS2 (referred hereupon HS2) from a local tidal rock pool and demonstrated its halotolerance and relatively high biomass productivity under different salinity conditions. To further understand acclimation responses of this alga against high salinity stress, we performed transcriptome analysis of triplicated culture samples grown in freshwater and marine conditions at both exponential and stationary growth phases. De novo assembly followed by differential expression analysis identified 5907 and 6783 differentially expressed genes (DEGs) respectively at exponential and stationary phases from a total of 52770 transcripts, and the functional enrichment of DEGs with KEGG database resulted in 1445 KEGG Orthology (KO) groups with a defined differential expression. Specifically, the transcripts involved in photosynthesis, TCA and Calvin cycles were downregulated, whereas the upregulation of DNA repair mechanisms and an ABCB subfamily of eukaryotic type ABC transporter was observed at high salinity condition. In addition, while key enzymes associated with glycolysis pathway and triacylglycerol (TAG) synthesis were determined to be upregulated from early growth phase, salinity stress seemed to reduce the carbohydrate content of harvested biomass from 45.6 dw% to 14.7 dw% and nearly triple the total lipid content from 26.0 dw% to 62.0 dw%. These results suggest that the reallocation of storage carbon toward lipids played a significant role in conferring the viability of this alga under high salinity stress, most notably by remediating high level of cellular stress partially caused by ROS generated in oxygen-evolving thylakoids.\n\nSummary StatementRedirection of storage carbon towards the synthesis of lipids played a critical role in conferring the halotolerance of a Chlorella isolate by remediating excess oxidative stress experienced in photosystems.

microbiology↗