Protein-based biorefining driven by nitrogen-responsive transcriptional machinery.

Biotechnol Biofuels

1Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, 5 South Zhongguancun Street, Haidian District, Beijing, 100081 People's Republic of China.

Published: February 2020

Background: Protein-based bioconversion has been demonstrated as a sustainable approach to produce higher alcohols and ammonia fertilizers. However, owing to the switchover from transcription mediated by the bacterial RNA polymerase σ to that mediated by alternative σ factors, the biofuel production driven by σ-dependent promoters declines rapidly once cells enter the stationary phase or encounter stresses. To enhance biofuel production, in this study the growth phase-independent and nitrogen-responsive transcriptional machinery mediated by the σ is exploited to drive robust protein-to-fuel conversion.

Results: We demonstrated that disrupting the ammonia assimilation pathways driven by glutamate dehydrogenase and glutamine synthetase could sustain the activity of σ-mediated transcription under ammonia-accumulating conditions. In addition, two σ-dependent promoters, and , were identified as suitable candidates for driving pathway expression. Using these promoters, biofuel production from proteins was shown to persist to the stationary phase, with the net production in the stationary phase being 1.7-fold higher than that derived from the optimal reported σ-dependent promoter lacO. Biofuel production reaching levels 1.3- to 3.4-fold higher than those of the σ-dependent promoters was also achieved by and under stressed conditions. Moreover, the σ-dependent promoters realized more rapid and stable production than that of σ-dependent promoters during fed-batch fermentation, producing up to 4.78 g L  of total biofuels.

Conclusions: These results suggested that the nitrogen-responsive transcriptional machinery offers the potential to decouple production from growth, highlighting this system as a novel candidate to realize growth phase-independent and stress-resistant biofuel production.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7045595PMC
http://dx.doi.org/10.1186/s13068-020-1667-5DOI Listing

Publication Analysis

Top Keywords

biofuel production
20
σ-dependent promoters
20
nitrogen-responsive transcriptional
12
transcriptional machinery
12
stationary phase
12
production
8
growth phase-independent
8
σ-dependent
6
promoters
6
biofuel
5

Similar Publications

Food waste offers a potential source for bioethanol production, but productivity depends on the chemical composition of the raw materials and the processes involved. However, assessment of the environmental sustainability of these processes is often absent and can be carried out using the Life Cycle Assessment (LCA) methodology. This study aimed to perform an LCA on bioethanol production from mixtures of different wastes, including tubers, fruits, and processed foods, focusing on the gate-to-gate phase.

View Article and Find Full Text PDF

Background: Aspergillus niger is an important lignocellulose-degrading enzyme-producing strain. Multiple regulatory factors regulate the synthesis of lignocellulose-degrading enzymes in A. niger.

View Article and Find Full Text PDF

Prenol production in a microbial host via the "Repass" Pathways.

Metab Eng

January 2025

Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, USA. Electronic address:

Prenol and isoprenol are promising advanced biofuels and serve as biosynthetic precursors for pharmaceuticals, fragrances, and other industrially relevant compounds. Despite engineering improvements that circumvent intermediate cytotoxicity and lower energy barriers, achieving high titer 'mevalonate (MVA)-derived' prenol has remained elusive. Difficulty in selective prenol production stems from the necessary isomerization of isopentenyl diphosphate (IPP) to dimethylallyl diphosphate (DMAPP) as well as the intrinsic toxicity of these diphosphate precursors.

View Article and Find Full Text PDF

A Fast-Pass, Desorption Electrospray Ionization Mass Spectrometry Strategy for Untargeted Metabolic Phenotyping.

J Am Soc Mass Spectrom

January 2025

Department of Chemistry, Center for Innovative Technology, Vanderbilt University, Nashville, Tennessee 37235, United States.

Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) provides direct analytical readouts of small molecules that can be used to characterize the metabolic phenotypes of genetically engineered bacteria. In an effort to accelerate the time frame associated with the screening of mutant libraries, we have developed a high-throughput DESI-MSI analytical workflow implementing a single raster line-scan strategy that facilitates the collection of location-resolved molecular information from engineered strains on a subminute time scale. Evaluation of this "Fast-Pass" DESI-MSI phenotyping workflow on analytical standards demonstrated the capability of acquiring full metabolic profiling information with a throughput of ∼40 s per sample.

View Article and Find Full Text PDF

The Jerusalem artichoke (JA), a plantrelated to sunflowers and native to North America, has long been valued for its versatility, especially during periods of food scarcity. This resilient crop serves multiple purposes, functioning as a vegetable, medicinal herb, grazing crop, and even a biofuel source. In recent years, interest in JA has grown, largely due to its high nutritional profile and associated health benefits.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!