Immobilization of Paenibacillus polymyxa with biopolymers to enhance the production of 2,3-butanediol.

Background: Paenibacillus polymyxa, is a Gram-positive, plant growth promoting bacterium, known for producing 98% optically pure 2,3-butanediol, an industrially valuable chemical for solvents, plasticizers and resins. Immobilization of Paenibacillus polymyxa has been proposed to improve the cell stability and efficiency of the fermentation process, reduce contamination and provide easy separation of butanediol in the culture broth as compared to conventional bioprocesses. This research aimed to explore the potential of Paenibacillus polymyxa with immobilization technique to produce 2,3-butanediol.

Transcriptomic analysis and cellular responses to nanoscale zero-valent iron in green microalga Raphidocelis subcapitata.

Nanoscale zero valent iron (nZVI) is used to remediate aquifers polluted by organochlorines or heavy metals and was also suggested to eliminate harmful algal blooms. nZVI can therefore affect microorganisms in the vicinity of the application area, including microalgae. However, studies on early transcriptomic effects of microalgae after exposure to nZVI are rare.

CRISPR/Cas9-Mediated Knockout of the Lycopene ε-Cyclase for Efficient Astaxanthin Production in the Green Microalga .

Carotenoids are valuable pigments naturally occurring in all photosynthetic plants and microalgae as well as in selected fungi, bacteria, and archaea. Green microalgae developed a complex carotenoid profile suitable for efficient light harvesting and light protection and harbor great capacity for carotenoid production through the substantial power of the endogenous 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. Previous works established successful genome editing and induced significant changes in the cellular carotenoid content in .

Outdoor cultivation and metabolomics exploration of Chlamydomonas engineered for bisabolene production.

Demonstrating outdoor cultivation of engineered microalgae at considerable scales is essential for their prospective large-scale deployment. Hence, this study focuses on the outdoor cultivation of an engineered Chlamydomonas reinhardtii strain, 3XAgBs-SQs, for bisabolene production under natural dynamic conditions of light and temperature. Our preliminary outdoor experiments showed improved growth, but frequent culture collapses in conventional Tris-acetate-phosphate medium.

Bicistronic expression of nuclear transgenes in Chlamydomonas reinhardtii.

In eukaryotic organisms, proteins are typically translated from monocistronic messenger RNAs containing a single coding sequence (CDS). However, recent long transcript sequencing identified 87 nuclear polycistronic mRNAs in Chlamydomonas reinhardtii natively carrying multiple co-expressed CDSs. In this study, we investigated the dynamics of 22 short intergenic sequences derived from these native polycistronic loci by their application in genetic constructs for synthetic transgene expression.

Microbial Diversity and Community Structure of Wastewater-Driven Microalgal Biofilms.

Dwindling water sources increase the need for efficient wastewater treatment. Solar-driven algal turf scrubber (ATS) system may remediate wastewater by supporting the development and growth of periphytic microbiomes that function and interact in a highly dynamic manner through symbiotic interactions. Using ITS and 16S rRNA gene amplicon sequencing, we profiled the microbial communities of four microbial biofilms from ATS systems operated with municipal wastewater (mWW), diluted cattle and pig manure (CattleM and PigM), and biogas plant effluent supernatant (BGE) in comparison to the initial inocula and the respective wastewater substrates.

Molecular design of microalgae as sustainable cell factories.

Microalgae are regarded as sustainable and potent chassis for biotechnology. Their capacity for efficient photosynthesis fuels dynamic growth independent from organic carbon sources and converts atmospheric CO directly into various valuable hydrocarbon-based metabolites. However, approaches to gene expression and metabolic regulation have been inferior to those in more established heterotrophs (e.

Farnesyl pyrophosphate compartmentalization in the green microalga Chlamydomonas reinhardtii during heterologous (E)-α-bisabolene production.

Background: Eukaryotic algae have recently emerged as hosts for metabolic engineering efforts to generate heterologous isoprenoids. Isoprenoid metabolic architectures, flux, subcellular localization, and transport dynamics have not yet been fully elucidated in algal hosts.

Results: In this study, we investigated the accessibility of different isoprenoid precursor pools for C sesquiterpenoid generation in the cytoplasm and chloroplast of Chlamydomonas reinhardtii using the Abies grandis bisabolene synthase (AgBS) as a reporter.

Advanced pathway engineering for phototrophic putrescine production.

The polyamine putrescine (1,4-diaminobutane) contributes to cellular fitness in most organisms, where it is derived from the amino acids ornithine or arginine. In the chemical industry, putrescine serves as a versatile building block for polyamide synthesis. The green microalga Chlamydomonas reinhardtii accumulates relatively high putrescine amounts, which, together with recent advances in genetic engineering, enables the generation of a powerful green cell factory to promote sustainable biotechnology for base chemical production.

Engineering a powerful green cell factory for robust photoautotrophic diterpenoid production.

Diterpenoids display a large and structurally diverse class of natural compounds mainly found as specialized plant metabolites. Due to their diverse biological functions they represent an essential source for various industrially relevant applications as biopharmaceuticals, nutraceuticals, and fragrances. However, commercial production utilizing their native hosts is inhibited by low abundances, limited cultivability, and challenging extraction, while the precise stereochemistry displays a particular challenge for chemical synthesis.

The Spermidine Synthase Gene : A Novel Auxotrophic Marker for Designed by Enhanced CRISPR/Cas9 Gene Editing.

Biotechnological application of the green microalga hinges on the availability of selectable markers for effective expression of multiple transgenes. However, biological safety concerns limit the establishment of new antibiotic resistance genes and until today, only a few auxotrophic markers exist for . The recent improvements in gene editing via CRISPR/Cas allow directed exploration of new endogenous selectable markers.

A gene regulatory network for antenna size control in carbon dioxide-deprived Chlamydomonas reinhardtii cells.

In green microalgae, prolonged exposure to inorganic carbon depletion requires long-term acclimation responses, involving modulated gene expression and the adjustment of photosynthetic activity to the prevailing supply of carbon dioxide. Here, we describe a microalgal regulatory cycle that adjusts the light-harvesting capacity at photosystem II (PSII) to the prevailing supply of carbon dioxide in Chlamydomonas (Chlamydomonas reinhardtii). It engages low carbon dioxide response factor (LCRF), a member of the squamosa promoter-binding protein (SBP) family of transcription factors, and the previously characterized cytosolic translation repressor nucleic acid-binding protein 1 (NAB1).

Rational Promoter Engineering Enables Robust Terpene Production in Microalgae.

Microalgal biotechnology promises sustainable light-driven production of valuable bioproducts and addresses urgent demands to attain a sustainable economy. However, to unfold its full potential as a platform for biotechnology, new and powerful tools for nuclear engineering need to be established. , the model for microalgal synthetic biology and genetic engineering has already been used to produce various bioproducts.

Engineering Biocatalytic Solar Fuel Production: The PHOTOFUEL Consortium.

The EU Horizon2020 consortium PHOTOFUEL joined academic and industrial partners from biology, chemistry, engineering, engine design, and lifecycle assessment, making tremendous progress towards engine-ready fuels from CO via engineered photosynthetic microbes. Technical, environmental, economic, and societal opportunities and challenges were explored to frame future technology realization at scale.

Phytoplankton consortia as a blueprint for mutually beneficial eukaryote-bacteria ecosystems based on the biocoenosis of Botryococcus consortia.

Bacteria occupy all major ecosystems and maintain an intensive relationship to the eukaryotes, developing together into complex biomes (i.e., phycosphere and rhizosphere).

High cell density cultivation enables efficient and sustainable recombinant polyamine production in the microalga Chlamydomonas reinhardtii.

Modern chemical industry calls for new resource-efficient and sustainable value chains for production of key base chemicals such as polyamines. The green microalga Chlamydomonas reinhardtii offers great potential as an innovative green-cell factory by combining fast and inexpensive, phototrophic growth with mature genetic engineering. Here, overexpression of recombinant lysine decarboxylases in C.

Introns mediate post-transcriptional enhancement of nuclear gene expression in the green microalga Chlamydomonas reinhardtii.

Efficient nuclear transgene expression in the green microalga Chlamydomonas reinhardtii is generally hindered by low transcription rates. Introns can increase transcript abundance by a process called Intron-Mediated Enhancement (IME) in this alga and has been broadly observed in other eukaryotes. However, the mechanisms of IME in microalgae are poorly understood.

Wastewater-borne microalga Chlamydomonas sp.: A robust chassis for efficient biomass and biomethane production applying low-N cultivation strategy.

Biogas/biomethane generation from microalgae biomass via anaerobic fermentation is increasingly gaining attention as CO-neutral energy source. Intensive research has shown, however, that microalgae represent a rather challenging substrate for anaerobic digestion (AD) due to their high cell wall recalcitrance and unfavourable protein content. Previously, the utilization of nitrogen-limited (low-N) microalgal biomass for continuous AD-processes was demonstrated (as proof-of-concept) with remarkable biomethane productivity.

Green algal hydrocarbon metabolism is an exceptional source of sustainable chemicals.

Microalgae are rapidly growing, low-input requiring, sun light-utilizing microorganisms capable of converting carbon dioxide into various natural products, a major portion of which are hydrocarbons. Their cellular compartmentalization and photosynthetic apparatus depend on robust turnover of two hydrocarbon classes, isoprenoids and acyl-lipids. This review summarizes the current understanding of algal hydrocarbon metabolism, including carbon partitioning capacities, the localization and size of precursor pools, environmental effects on flux distribution, and limiting factors towards efficient (heterologous) hydrocarbon production.

Ocean acidification has little effect on the biochemical composition of the coccolithophore Emiliania huxleyi.

Owing to the hierarchical organization of biology, from genomes over transcriptomes and proteomes down to metabolomes, there is continuous debate about the extent to which data and interpretations derived from one level, e.g. the transcriptome, are in agreement with other levels, e.

Growth and photosynthetic activity of Chlamydomonas reinhardtii entrapped in lens-shaped silica hydrogels.

Entrapment of microalgae in silica hydrogels enables the application as biocatalysts in continuous production of secreted products. Despite a mitigation of substrate and product diffusion limitations by lens-shaped particles, there are no reports on light supply and limitation. This study investigated the impact of hydrogel structure, particle size and biomass loading on the behaviour of the microalga Chlamydomonas reinhardtii entrapped in lens-shaped silica particles.

Extremely robust photocurrent generation of titanium dioxide photoanodes bio-sensitized with recombinant microalgal light-harvesting proteins.

Bio-dyes for light harvesting in dye-sensitized solar cells (DSSC) have the advantage of being environmentally-friendly, non-toxic alternatives, which can be produced in a sustainable fashion. Free photosynthetic pigments are unstable in the presence of light and oxygen, a situation which can hardly be avoided during the operation of DSSCs, especially in large-scale applications. We therefore investigated the recombinant light-harvesting protein LHCBM6, which naturally occurs in the photosynthetic apparatus of the green microalga Chlamydomonas reinhardtii as a bio-dye in DSSCs.

Type II flavoprotein monooxygenase PsFMO_A from the bacterium Pimelobacter sp. Bb-B catalyzes enantioselective Baeyer-Villiger oxidations with a relaxed cofactor specificity.

Microbial consortia, which degrade branched, long-chain hydrocarbons, can be regarded as a promising source of novel enzymes for the stereo- and regio-selective oxyfunctionalization of hydrocarbons. The hydrocarbon-degrading bacterium Pimelobacter sp. Bb-B was isolated from the consortium associated with the colonial hydrocarbon-excreting microalga Botryococcus braunii.

Entrapment and growth of Chlamydomonas reinhardtii in biocompatible silica hydrogels.

In this work, we aimed at improved viability and growth of the microalga Chlamydomonas reinhardtii in transparent silica hydrogels based on low-ethanol, low-sodium and low-propylamine synthesis. Investigation into replacement of conventional base KOH by buffers dipotassium phosphate and tris(hydroxymethyl)aminomethane along with increased precursor concentrations yielded an aqueous synthesis route which provided a gelation within 10 min, absorptions below 0.1 and elastic moduli of 0.