Progresses and challenges of engineering thermophilic acetogenic cell factories.

Thermophilic acetogens are gaining recognition as potent microbial cell factories, leveraging their unique metabolic capabilities to drive the development of sustainable biotechnological processes. These microorganisms, thriving at elevated temperatures, exhibit robust carbon fixation abilities via the linear Wood-Ljungdahl pathway to efficiently convert C substrates, including syngas (CO, CO and H) from industrial waste gasses, into acetate and biomass via the central metabolite acetyl-CoA. This review summarizes recent advancements in metabolic engineering and synthetic biology efforts that have expanded the range of products derived from thermophilic acetogens after briefly discussing their autotrophic metabolic diversity.

Arabinose as an overlooked sugar for microbial bioproduction of chemical building blocks.

The circular economy is anticipated to bring a disruptive transformation in manufacturing technologies. Robust and industrial scalable microbial strains that can simultaneously assimilate and valorize multiple carbon substrates are highly desirable, as waste bioresources contain substantial amounts of renewable and fermentable carbon, which is diverse. Lignocellulosic biomass (LCB) is identified as an inexhaustible and alternative resource to reduce global dependence on oil.

Design, Analysis, and Implementation of a Novel Biochemical Pathway for Ethylene Glycol Production in .

The platform chemical ethylene glycol (EG) is used to manufacture various commodity chemicals of industrial importance, but largely remains synthesized from fossil fuels. Although several novel metabolic pathways have been reported for its bioproduction in model organisms, none has been reported for gas-fermenting, non-model acetogenic chassis organisms. Here, we describe a novel, synthetic biochemical pathway to convert acetate into EG in the industrially important gas-fermenting acetogen,.

Prospecting Biochemical Pathways to Implement Microbe-Based Production of the New-to-Nature Platform Chemical Levulinic Acid.

Levulinic acid is a versatile platform molecule with potential to be used as an intermediate in the synthesis of many value-added products used across different industries, from cosmetics to fuels. Thus far, microbial biosynthetic pathways having levulinic acid as a product or an intermediate are not known, which restrains the development and optimization of a microbe-based process envisaging the sustainable bioproduction of this chemical. One of the doors opened by synthetic biology in the design of microbial systems is the implementation of new-to-nature pathways, that is, the assembly of combinations of enzymes not observed , where the enzymes can use not only their native substrates but also non-native ones, creating synthetic steps that enable the production of novel compounds.

Genetic and metabolic engineering challenges of C1-gas fermenting acetogenic chassis organisms.

Unabated mining and utilisation of petroleum and petroleum resources and their conversion to essential fuels and chemicals have drastic environmental consequences, contributing to global warming and climate change. In addition, fossil fuels are finite resources, with a fast-approaching shortage. Accordingly, research efforts are increasingly focusing on developing sustainable alternatives for chemicals and fuels production.

Synergistic substrate cofeeding stimulates reductive metabolism.

Advanced bioproduct synthesis via reductive metabolism requires coordinating carbons, ATP and reducing agents, which are generated with varying efficiencies depending on metabolic pathways. Substrate mixtures with direct access to multiple pathways may optimally satisfy these biosynthetic requirements. However, native regulation favouring preferential use precludes cells from co-metabolizing multiple substrates.

Filling the human resource gap through public-private partnership: Can private, community-based skilled birth attendants improve maternal health service utilization and health outcomes in a remote region of Bangladesh?

Background: In Sunamganj there are fewer than four skilled providers per 10,000 population and just 27% of births are assisted by a skilled attendant. We evaluate a private community skilled birth attendant (P-CSBA) model, developed through the GSK-CARE Frontline Health Worker Programme, designed to address this gap and report on changes in service utilization and health outcomes from baseline to three years post-baseline.

Methods: This analysis presents the results of a pre-post cross sectional design.

Sustained Dechlorination of Vinyl Chloride to Ethene in -Enriched Cultures Grown without Addition of Exogenous Vitamins and at Low pH.

Trichloroethene (TCE) bioremediation has been demonstrated at field sites using microbial cultures harboring TCE-respiring whose growth is cobalamin (vitamin B)-dependent. Bioaugmentation cultures grown ex situ with ample exogenous vitamins and at neutral pH may become vitamin-limited or inhibited by acidic pH once injected into field sites, resulting in incomplete TCE dechlorination and accumulation of vinyl chloride (VC). Here, we report growth of the -containing bioaugmentation culture KB-1 in a TCE-amended mineral medium devoid of vitamins and in a VC-amended mineral medium at low pH (6.

Synthetic biology strategies for improving microbial synthesis of "green" biopolymers.

Polysaccharide-based biopolymers have many material properties relevant to industrial and medical uses, including as drug delivery agents, wound-healing adhesives, and food additives and stabilizers. Traditionally, polysaccharides are obtained from natural sources. Microbial synthesis offers an attractive alternative for sustainable production of tailored biopolymers.

Exploring biochemical pathways for mono-ethylene glycol (MEG) synthesis from synthesis gas.

Mono-ethylene glycol (MEG) is an important petrochemical with widespread use in numerous consumer products. The current industrial MEG-production process relies on non-renewable fossil fuel-based feedstocks, such as petroleum, natural gas, and naphtha; hence, it is useful to explore alternative routes of MEG-synthesis from gases as they might provide a greener and more sustainable alternative to the current production methods. Technologies of synthetic biology and metabolic engineering of microorganisms can be deployed for the expression of new biochemical pathways for MEG-synthesis from gases, provided that such promising alternative routes are first identified.

Experimental validation of in silico model-predicted isocitrate dehydrogenase and phosphomannose isomerase from Dehalococcoides mccartyi.

Gene sequences annotated as proteins of unknown or non-specific function and hypothetical proteins account for a large fraction of most genomes. In the strictly anaerobic and organohalide respiring Dehalococcoides mccartyi, this lack of annotation plagues almost half the genome. Using a combination of bioinformatics analyses and genome-wide metabolic modelling, new or more specific annotations were proposed for about 80 of these poorly annotated genes in previous investigations of D.

Investigating Moorella thermoacetica metabolism with a genome-scale constraint-based metabolic model.

Moorella thermoacetica is a strictly anaerobic, endospore-forming, and metabolically versatile acetogenic bacterium capable of conserving energy by both autotrophic (acetogenesis) and heterotrophic (homoacetogenesis) modes of metabolism. Its metabolic diversity and the ability to efficiently convert a wide range of compounds, including syngas (CO + H2) into acetyl-CoA have made this thermophilic bacterium a promising host for industrial biotechnology applications. However, lack of detailed information on M.

New insights into Dehalococcoides mccartyi metabolism from a reconstructed metabolic network-based systems-level analysis of D. mccartyi transcriptomes.

Organohalide respiration, mediated by Dehalococcoides mccartyi, is a useful bioremediation process that transforms ground water pollutants and known human carcinogens such as trichloroethene and vinyl chloride into benign ethenes. Successful application of this process depends on the fundamental understanding of the respiration and metabolism of D. mccartyi.

Characterizing the metabolism of Dehalococcoides with a constraint-based model.

Dehalococcoides strains respire a wide variety of chloro-organic compounds and are important for the bioremediation of toxic, persistent, carcinogenic, and ubiquitous ground water pollutants. In order to better understand metabolism and optimize their application, we have developed a pan-genome-scale metabolic network and constraint-based metabolic model of Dehalococcoides. The pan-genome was constructed from publicly available complete genome sequences of Dehalococcoides sp.