Metabolism of a low-solubility substrate is limited by dissolution and availability and can hardly be determined. We developed a numerical model for simultaneously calculating dissolution kinetics of such substrates and their metabolism and microbial growth (Monod kinetics with decay) and tested it with three aerobic phenanthrene (PHE) degraders: Novosphingobium pentaromativorans US6-1, Sphingomonas sp. EPA505, and Sphingobium yanoikuyae B1. PHE was present as microcrystals, providing non-limiting conditions for growth. Total PHE and protein concentration were tracked over 6-12 days. The model was fitted to the test results for the rates of dissolution, metabolism, and growth. The strains showed similar efficiency, with vmax values of 12-18 g dw g(-1) d(-1), yields of 0.21 g g(-1), maximum growth rates of 2.5-3.8 d(-1), and decay rates of 0.04-0.05 d(-1). Sensitivity analysis with the model shows that (i) retention in crystals or NAPLs or by sequestration competes with biodegradation, (ii) bacterial growth conditions (dissolution flux and resulting chemical activity of substrate) are more relevant for the final state of the system than the initial biomass, and (iii) the desorption flux regulates the turnover in the presence of solid-state, sequestered (aged), or NAPL substrate sources.
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BMC Microbiol
January 2025
The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China.
The emergence and prevalence of hypervirulent Klebsiella pneumoniae (hvKP) have proposed a great challenge to control this infection. Therefore, exploring some new drugs or strategies for treating hvKP infection is an urgent issue for scientific researchers. In the present study, the clpV gene deletion strain of hvKP (ΔclpV-hvKP) was constructed using CRISPR-Cas9 technology, and the biological characteristics of ΔclpV-hvKP were investigated to explore the new targets for controlling this pathogen.
View Article and Find Full Text PDFPlanta
January 2025
Plant-Soil Ecology Laboratory, Center for Ecology, Evolution and Environmental Changes. Faculty of Sciences, University of Lisbon, Lisbon, Portugal.
Inoculation with the PGPB Herbaspirillum seropedicae shapes both the structure and putative functions of the wheat microbiome and causes changes in the levels of various plant metabolites described to be involved in plant growth and health. Plant growth promoting bacteria (PGPB) can establish metabolic imprints in their hosts, contributing to the improvement of plant health in different ways. However, while PGPB imprints on plant metabolism have been extensively characterized, much less is known regarding those affecting plant indigenous microbiomes, and hence it remains unknown whether both processes occur simultaneously.
View Article and Find Full Text PDFNPJ Biofilms Microbiomes
January 2025
Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, Moscow, 119991, Russia.
Biofilms are critical for understanding environmental processes, developing biotechnology applications, and progressing in medical treatments of various infections. Nowadays, a key limiting factor for biofilm analysis is the difficulty in obtaining large datasets with fully annotated images. This study introduces a versatile approach for creating synthetic datasets of annotated biofilm images with employing deep generative modeling techniques, including VAEs, GANs, diffusion models, and CycleGAN.
View Article and Find Full Text PDFNat Commun
January 2025
Institute of Marine Science and Technology, Shandong University, Qingdao, China.
Lignin, as the abundant carbon polymer, is essential for carbon cycle and biorefinery. Microorganisms interact to form communities for lignin biodegradation, yet it is a challenge to understand such complex interactions. Here, we develop a coastal lignin-degrading bacterial consortium (LD), through "top-down" enrichment.
View Article and Find Full Text PDFNPJ Syst Biol Appl
January 2025
The Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA, 94608, USA.
Genome-scale metabolic models (GSMM) are commonly used to identify gene deletion sets that result in growth coupling and pairing product formation with substrate utilization and can improve strain performance beyond levels typically accessible using traditional strain engineering approaches. However, sustainable feedstocks pose a challenge due to incomplete high-resolution metabolic data for non-canonical carbon sources required to curate GSMM and identify implementable designs. Here we address a four-gene deletion design in the Pseudomonas putida KT2440 strain for the lignin-derived non-sugar carbon source, p-coumarate (p-CA), that proved challenging to implement.
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