AUTHOR=Tong Yaobin , Li Yiyi , Qin Wenpan , Wu Shengchun , Xu Weiping , Jin Peng , Zheng Zhanwang 

TITLE=New insight into the metabolic mechanism of a novel lipid-utilizing and denitrifying bacterium capable of simultaneous removal of nitrogen and grease through transcriptome analysis

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1258003

DOI=10.3389/fmicb.2023.1258003

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>Issues related to fat, oil, and grease from kitchen waste (KFOG) in lipid-containing wastewater are intensifying globally. We reported a novel denitrifying bacterium <italic>Pseudomonas</italic> CYCN-C with lipid-utilizing activity and high nitrogen-removal efficiency. The aim of the present study was aim to explore the metabolic mechanism of the simultaneous lipid-utilizing and denitrifying bacterium CYCN-C at transcriptome level.</p></sec><sec><title>Methods</title><p>We comparatively investigated the cell-growth and nitrogen-removal performances of newly reported <italic>Pseudomonas glycinae</italic> CYCN-C under defined cultivation conditions. Transcriptome analysis was further used to investigate all pathway genes involved in nitrogen metabolism, lipid degradation and utilization, and cell growth at mRNA levels.</p></sec><sec><title>Results</title><p>CYCN-C could directly use fat, oil, and grease from kitchen waste (KFOG) as carbon source with TN removal efficiency of 73.5%, significantly higher than that (60.9%) with sodium acetate. The change levels of genes under defined KFOG and sodium acetate were analyzed by transcriptome sequencing. Results showed that genes <italic>cyo</italic>, <italic>CsrA</italic>, <italic>PHAs</italic>, and <italic>FumC</italic> involved in carbon metabolism under KFOG were significantly upregulated by 6.9, 0.7, 26.0, and 19.0-folds, respectively. The genes <italic>lipA</italic>, <italic>lipB</italic>, <italic>glpD</italic>, and <italic>glpK</italic> of lipid metabolic pathway were upregulated by 0.6, 0.4, 21.5, and 1.3-folds, respectively. KFOG also improved the denitrification efficiency by inducing the expression of the genes <italic>nar</italic>, <italic>nirB</italic>, <italic>nirD</italic>, and <italic>norR</italic> of denitrification pathways.</p></sec><sec><title>Conclusion</title><p>In summary, this work firstly provides valuable insights into the genes expression of lipid-utilizing and denitrifying bacterium, and provides a new approach for sewage treatment with reuse of KFOG wastes.</p></sec>