Degeneration of solventogenic Clostridium strains is one of the major barriers in bio-butanol production. A degenerated Clostridium beijerinckii NCIMB 8052 strain (DG-8052) was obtained without any genetic manipulation. Supplementation of CaCO3 to fermentation medium could partially recover metabolism of DG-8052 by more than 50 % increase of cell growth and solvent production. This study investigated the protein expression profile of DG-8052 and its response to CaCO3 treatment. Compared with WT-8052, the lower expressed proteins were responsible for disruption of RNA secondary structures and DNA repair, sporulation, signal transduction, transcription regulation, and membrane transport in DG-8052. Interestingly, accompanied with the decreased glucose utilization and lower solvent production, there was a decreased level of sigma-54 modulation protein which may indicate that the level of sigma-54 activity may be associated with the observed strain degeneration. For the addition of CaCO3, proteomic and biochemical study results revealed that besides buffer capacity, Ca(2+) could stabilize heat shock proteins, increase DNA synthesis and replication, and enhance expression of solventogenic enzymes in DG-8052, which has a similar contribution in WT-8052.
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http://dx.doi.org/10.1007/s10295-016-1754-6 | DOI Listing |
Sci Rep
January 2025
Department of Animal Science, University of Tennessee, 2506 River Drive, Knoxville, TN, 37996, USA.
Feedlot cattle may be subjected to digestive disorders, including ruminal acidosis, due to high concentration of grain in their diet. Therefore, novel feeding strategies are required to maximize animal performance and mitigate economic losses in the operation. This study employed a two-period crossover design to assess the effect of direct ruminal administration of native rumen microorganisms (NRM) inoculation on cattle that underwent a high-grain challenge.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Laboratory for Protein Crystallography, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
[FeFe]-hydrogenases catalyze the reversible two-electron reduction of two protons to molecular hydrogen. Although these enzymes are among the most efficient H-converting biocatalysts in nature, their catalytic cofactor (termed H-cluster) is irreversibly destroyed upon contact with dioxygen. The [FeFe]-hydrogenase CbA5H from has a unique mechanism to protect the H-cluster from oxygen-induced degradation.
View Article and Find Full Text PDFBioresour Technol
January 2025
College of Bioscience and Bioengineering, Institute of Applied Microbiology, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China. Electronic address:
J Dairy Sci
December 2024
Department of Dairy and Food Sciences, South Dakota State University, Brookings, South Dakota 57007; School of Animal Sciences, Virginia Tech, Blacksburg, VA. Electronic address:
The objective of this study was to evaluate the effects of a rumen-derived direct-fed microbial (DFM) product on performance, blood biomarkers, ruminal fermentation, and bacterial abundance in dairy cows during the transition period until 100 DIM. Fifty-six Holstein cows were enrolled in a randomized complete block design from -21 to 100 DIM. Cows were blocked based on expected calving date, parity, and previous lactation milk yield for multiparous or genetic merit for primiparous cows.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Leiden Institute of Chemistry, Leiden University, PO box 9502, 2300 RA Leiden, The Netherlands.
A relatively unexplored energy source in synthetic cells is transmembrane electron transport, which like proton and ion transport can be light driven. Here, synthetic cells, called nanoreactors, are engineered for compartmentalized, semiartificial photosynthetic H production by a [FeFe]-hydrogenase (Hase). Transmembrane electron transfer into the nanoreactor was enabled by MtrCAB, a multiheme transmembrane protein from MR-1.
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