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Mismanaged plastics, upon entering the environment, undergo degradation through physicochemical and/or biological processes. This process often results in the formation of microplastics (MPs), the most prevalent form of plastic debris (<1 mm). MPs pose severe threats to aquatic and terrestrial ecosystems, necessitating innovative strategies for effective remediation. Some photosynthetic microorganisms can degrade MPs but there lacks a comprehensive review. Here we examine the specific role of photoautotrophic microorganisms in water and soil environments for the biodegradation of plastics, focussing on their unique ability to grow persistently on diverse polymers under sunlight. Notably, these cells utilise light and CO2 to produce valuable compounds such as carbohydrates, lipids, and proteins, showcasing their multifaceted environmental benefits. We address key scientific questions surrounding the utilisation of photosynthetic microorganisms for MPs and nanoplastics (NPs) bioremediation, discussing potential engineering strategies for enhanced efficacy. Our review highlights the significance of alternative biomaterials and the exploration of strains expressing enzymes, such as polyethylene terephthalate (PET) hydrolases, in conjunction with microalgal and/or cyanobacterial metabolisms. Furthermore, we delve into the promising potential of photo-biocatalytic approaches, emphasising the coupling of plastic debris degradation with sunlight exposure. The integration of microalgal-bacterial consortia is explored for biotechnological applications against MPs and NPs pollution, showcasing the synergistic effects in wastewater treatment through the absorption of nitrogen, heavy metals, phosphorous, and carbon. In conclusion, this review provides a comprehensive overview of the current state of research on the use of photoautotrophic cells for plastic bioremediation. It underscores the need for continued investigation into the engineering of these microorganisms and the

Mismanaged plastics, upon entering the environment, undergo degradation through physicochemical and/or biological processes. This process often results in the formation of microplastics (MPs), the most prevalent form of plastic debris (<1 mm). MPs pose severe threats to aquatic and terrestrial ecosystems, necessitating innovative strategies for effective remediation. Some photosynthetic microorganisms can degrade MPs but there lacks a comprehensive review. Here we examine the specific role of photoautotrophic microorganisms in water and soil environments for the biodegradation of plastics, focussing on their unique ability to grow persistently on diverse polymers under sunlight. Notably, these cells utilise light and CO2 to produce valuable compounds such as carbohydrates, lipids, and proteins, showcasing their multifaceted environmental benefits. We address key scientific questions surrounding the utilisation of photosynthetic microorganisms for MPs and nanoplastics (NPs) bioremediation, discussing potential engineering strategies for enhanced efficacy. Our review highlights the significance of alternative biomaterials and the exploration of strains expressing enzymes, such as polyethylene terephthalate (PET) hydrolases, in conjunction with microalgal and/or cyanobacterial metabolisms. Furthermore, we delve into the promising potential of photo-biocatalytic approaches, emphasising the coupling of plastic debris degradation with sunlight exposure. The integration of microalgal-bacterial consortia is explored for biotechnological applications against MPs and NPs pollution, showcasing the synergistic effects in wastewater treatment through the absorption of nitrogen, heavy metals, phosphorous, and carbon. In conclusion, this review provides a comprehensive overview of the current state of research on the use of photoautotrophic cells for plastic bioremediation. It underscores the need for continued investigation into the engineering of these microorganisms and the

Mismanaged plastics, upon entering the environment, undergo degradation through physicochemical and/or biological processes. This process often results in the formation of microplastics (MPs), the most prevalent form of plastic debris (<1 mm). MPs pose severe threats to aquatic and terrestrial ecosystems, necessitating innovative strategies for effective remediation. Some photosynthetic microorganisms can degrade MPs but there lacks a comprehensive review. Here we examine the specific role of photoautotrophic microorganisms in water and soil environments for the biodegradation of plastics, focussing on their unique ability to grow persistently on diverse polymers under sunlight. Notably, these cells utilise light and CO2 to produce valuable compounds such as carbohydrates, lipids, and proteins, showcasing their multifaceted environmental benefits. We address key scientific questions surrounding the utilisation of photosynthetic microorganisms for MPs and nanoplastics (NPs) bioremediation, discussing potential engineering strategies for enhanced efficacy. Our review highlights the significance of alternative biomaterials and the exploration of strains expressing enzymes, such as polyethylene terephthalate (PET) hydrolases, in conjunction with microalgal and/or cyanobacterial metabolisms. Furthermore, we delve into the promising potential of photo-biocatalytic approaches, emphasising the coupling of plastic debris degradation with sunlight exposure. The integration of microalgal-bacterial consortia is explored for biotechnological applications against MPs and NPs pollution, showcasing the synergistic effects in wastewater treatment through the absorption of nitrogen, heavy metals, phosphorous, and carbon. In conclusion, this review provides a comprehensive overview of the current state of research on the use of photoautotrophic cells for plastic bioremediation. It underscores the need for continued investigation into the engineering of these microorga

Cyanobacteria are natural photosynthetic microbes which can be engineered for sustainable conversion of solar energy and carbon dioxide into chemical products. Attempts to improve target production often require an improved understanding of the native cyanobacterial host system. Valuable insights into cyanobacterial metabolism, biochemistry and physiology have been steadily increasing in recent years, stimulating key advancements of cyanobacteria as cell factories for biochemical, including biofuel, production. In the present review, we summarize the current progress in engineering cyanobacteria and discuss the achieved and potential utilization of these advances in cyanobacteria for the production of the bulk chemical butanol, specifically isobutanol and 1-butanol.

Cyanobacteria are natural photosynthetic microbes which can be engineered for sustainable conversion of solar energy and carbon dioxide into chemical products. Attempts to improve target production often require an improved understanding of the native cyanobacterial host system. Valuable insights into cyanobacterial metabolism, biochemistry and physiology have been steadily increasing in recent years, stimulating key advancements of cyanobacteria as cell factories for biochemical, including biofuel, production. In the present review, we summarize the current progress in engineering cyanobacteria and discuss the achieved and potential utilization of these advances in cyanobacteria for the production of the bulk chemical butanol, specifically isobutanol and 1-butanol.

Microalgae have high lipid accumulation capacity, high growth rate and high photosynthetic efficiency which are considered as one of the most promising alternative sustainable feedstocks for producing lipid-based biofuels. However, commercialization feasibility of microalgal biofuel production is still conditioned to the high production cost. Enhancement of lipid accumulation in microalgae play a significant role in boosting the economics of biofuel production based on microalgal lipid. The major challenge of enhancing microalgal lipid accumulation lies in overcoming the trade-off between microalgal cell growth and lipid accumulation. Substantial approaches including genetic modifications of microalgal strains by metabolic engineering and process regulations of microalgae cultivation by integrating multiple optimization strategies widely applied in industrial microbiology have been investigated. In the present review, we critically discuss recent trends in the application of multiple molecular strategies to construct high performance microalgal strains by metabolic engineering and synergistic strategies of process optimization and stress operation to enhance microalgal lipid accumulation for biofuel production. Additionally, this review aims to emphasize the opportunities and challenges regarding scaled application of the strategic integration and its viability to make microalgal biofuel production a commercial reality in the near future.

Microalgae have high lipid accumulation capacity, high growth rate and high photosynthetic efficiency which are considered as one of the most promising alternative sustainable feedstocks for producing lipid-based biofuels. However, commercialization feasibility of microalgal biofuel production is still conditioned to the high production cost. Enhancement of lipid accumulation in microalgae play a significant role in boosting the economics of biofuel production based on microalgal lipid. The major challenge of enhancing microalgal lipid accumulation lies in overcoming the trade-off between microalgal cell growth and lipid accumulation. Substantial approaches including genetic modifications of microalgal strains by metabolic engineering and process regulations of microalgae cultivation by integrating multiple optimization strategies widely applied in industrial microbiology have been investigated. In the present review, we critically discuss recent trends in the application of multiple molecular strategies to construct high performance microalgal strains by metabolic engineering and synergistic strategies of process optimization and stress operation to enhance microalgal lipid accumulation for biofuel production. Additionally, this review aims to emphasize the opportunities and challenges regarding scaled application of the strategic integration and its viability to make microalgal biofuel production a commercial reality in the near future.

Microalgae have high lipid accumulation capacity, high growth rate and high photosynthetic efficiency which are considered as one of the most promising alternative sustainable feedstocks for producing lipid-based biofuels. However, commercialization feasibility of microalgal biofuel production is still conditioned to the high production cost. Enhancement of lipid accumulation in microalgae play a significant role in boosting the economics of biofuel production based on microalgal lipid. The major challenge of enhancing microalgal lipid accumulation lies in overcoming the trade-off between microalgal cell growth and lipid accumulation. Substantial approaches including genetic modifications of microalgal strains by metabolic engineering and process regulations of microalgae cultivation by integrating multiple optimization strategies widely applied in industrial microbiology have been investigated. In the present review, we critically discuss recent trends in the application of multiple molecular strategies to construct high performance microalgal strains by metabolic engineering and synergistic strategies of process optimization and stress operation to enhance microalgal lipid accumulation for biofuel production. Additionally, this review aims to emphasize the opportunities and challenges regarding scaled application of the strategic integration and its viability to make microalgal biofuel production a commercial reality in the near future.

Cyanobacteria are natural photosynthetic microbes which can be engineered for sustainable conversion of solar energy and carbon dioxide into chemical products. Attempts to improve target production often require an improved understanding of the native cyanobacterial host system. Valuable insights into cyanobacterial metabolism, biochemistry and physiology have been steadily increasing in recent years, stimulating key advancements of cyanobacteria as cell factories for biochemical, including biofuel, production. In the present review, we summarize the current progress in engineering cyanobacteria and discuss the achieved and potential utilization of these advances in cyanobacteria for the production of the bulk chemical butanol, specifically isobutanol and 1-butanol.

Microalgae have high lipid accumulation capacity, high growth rate and high photosynthetic efficiency which are considered as one of the most promising alternative sustainable feedstocks for producing lipid-based biofuels. However, commercialization feasibility of microalgal biofuel production is still conditioned to the high production cost. Enhancement of lipid accumulation in microalgae play a significant role in boosting the economics of biofuel production based on microalgal lipid. The major challenge of enhancing microalgal lipid accumulation lies in overcoming the trade-off between microalgal cell growth and lipid accumulation. Substantial approaches including genetic modifications of microalgal strains by metabolic engineering and process regulations of microalgae cultivation by integrating multiple optimization strategies widely applied in industrial microbiology have been investigated. In the present review, we critically discuss recent trends in the application of multiple molecular strategies to construct high performance microalgal strains by metabolic engineering and synergistic strategies of process optimization and stress operation to enhance microalgal lipid accumulation for biofuel production. Additionally, this review aims to emphasize the opportunities and challenges regarding scaled application of the strategic integration and its viability to make microalgal biofuel production a commercial reality in the near future.

Microalgae have high lipid accumulation capacity, high growth rate and high photosynthetic efficiency which are considered as one of the most promising alternative sustainable feedstocks for producing lipid-based biofuels. However, commercialization feasibility of microalgal biofuel production is still conditioned to the high production cost. Enhancement of lipid accumulation in microalgae play a significant role in boosting the economics of biofuel production based on microalgal lipid. The major challenge of enhancing microalgal lipid accumulation lies in overcoming the trade-off between microalgal cell growth and lipid accumulation. Substantial approaches including genetic modifications of microalgal strains by metabolic engineering and process regulations of microalgae cultivation by integrating multiple optimization strategies widely applied in industrial microbiology have been investigated. In the present review, we critically discuss recent trends in the application of multiple molecular strategies to construct high performance microalgal strains by metabolic engineering and synergistic strategies of process optimization and stress operation to enhance microalgal lipid accumulation for biofuel production. Additionally, this review aims to emphasize the opportunities and challenges regarding scaled application of the strategic integration and its viability to make microalgal biofuel production a commercial reality in the near future.

Cyanobacteria are natural photosynthetic microbes which can be engineered for sustainable conversion of solar energy and carbon dioxide into chemical products. Attempts to improve target production often require an improved understanding of the native cyanobacterial host system. Valuable insights into cyanobacterial metabolism, biochemistry and physiology have been steadily increasing in recent years, stimulating key advancements of cyanobacteria as cell factories for biochemical, including biofuel, production. In the present review, we summarize the current progress in engineering cyanobacteria and discuss the achieved and potential utilization of these advances in cyanobacteria for the production of the bulk chemical butanol, specifically isobutanol and 1-butanol.

Cyanobacteria are natural photosynthetic microbes which can be engineered for sustainable conversion of solar energy and carbon dioxide into chemical products. Attempts to improve target production often require an improved understanding of the native cyanobacterial host system. Valuable insights into cyanobacterial metabolism, biochemistry and physiology have been steadily increasing in recent years, stimulating key advancements of cyanobacteria as cell factories for biochemical, including biofuel, production. In the present review, we summarize the current progress in engineering cyanobacteria and discuss the achieved and potential utilization of these advances in cyanobacteria for the production of the bulk chemical butanol, specifically isobutanol and 1-butanol.

Ethylene production in engineered cyanobacteria offers a sustainable alternative to the traditional production from fossil resources. Protein fusions and anchoring strategies are promising routes to augment the stability of recombinant proteins. Here we attempted to anchor the ethylene-forming enzyme (Efe) to several photosystemrelated proteins (including D1, PetF, and PsaE) in order to improve the ethylene producing capability in engineered cells of Synechocystis PCC 6803. Generated strains harboring fused Efe with D1 or PetF showed respectively 1.6- and 1.5-fold increase in ethylene production compared to a control strain harboring only Efe. Additionally, strains co-expressing a non-fused Efe with PsaE or PetF showed respectively 3.5- and 3.1-fold increase in ethylene production compared to the control strain. This work demonstrates the feasibility to incorporate (anchor or co-express) target enzyme(s) with specific photosystem components for facilitating highly efficient production of bulk chemicals in engineered cyanobacteria., De två första författarna delar förstaförfattarskapet

Scytonemin is a promising UV-screen and antioxidant small molecule with commercial value in cosmetics and medicine. It is solely biosynthesized in some cyanobacteria. Recently, its biosynthesis mechanism has been elucidated in the model cyanobacterium Nostoc punctiforme PCC 73102. The direct precursors for scytonemin biosynthesis are tryptophan and p-hydroxyphenylpyruvate, which are generated through the shikimate and aromatic amino acid biosynthesis pathway. More upstream substrates are the central carbon metabolism intermediates phosphoenolpyruvate and erythrose-4-phosphate. Thus, it is a long route to synthesize scytonemin from the fixed atmospheric CO2 in cyanobacteria. Metabolic engineering has risen as an important biotechnological means for achieving sustainable high-efficiency and high-yield target metabolites. In this review, we summarized the biochemical properties of this molecule, its biosynthetic gene clusters and transcriptional regulations, the associated carbon flux-driving progresses, and the host selection and biosynthetic strategies, with the aim to expand our understanding on engineering suitable cyanobacteria for cost-effective production of scytonemin in future practices.

Scytonemin is a promising UV-screen and antioxidant small molecule with commercial value in cosmetics and medicine. It is solely biosynthesized in some cyanobacteria. Recently, its biosynthesis mechanism has been elucidated in the model cyanobacterium Nostoc punctiforme PCC 73102. The direct precursors for scytonemin biosynthesis are tryptophan and p-hydroxyphenylpyruvate, which are generated through the shikimate and aromatic amino acid biosynthesis pathway. More upstream substrates are the central carbon metabolism intermediates phosphoenolpyruvate and erythrose-4-phosphate. Thus, it is a long route to synthesize scytonemin from the fixed atmospheric CO2 in cyanobacteria. Metabolic engineering has risen as an important biotechnological means for achieving sustainable high-efficiency and high-yield target metabolites. In this review, we summarized the biochemical properties of this molecule, its biosynthetic gene clusters and transcriptional regulations, the associated carbon flux-driving progresses, and the host selection and biosynthetic strategies, with the aim to expand our understanding on engineering suitable cyanobacteria for cost-effective production of scytonemin in future practices.

Cyanobacteria are photoautotrophic microorganisms that can be engineered to convert CO2 and water into fuels and chemicals via photosynthesis using solar energy in direct processes. Based on knowledge and progress in fermentative heterotrophic biobutanol production, cyanobacteria have been engineered to produce photosynthetic butanol from sunlight, water and CO2. This chapter discusses the present status of engineering cyanobacteria for photosynthetic isobutanol and 1-butanol production. Special focus is on recent advances in introducing enzymes and pathways, redirecting carbon toward the product, importance of five regions in the genetic constructs and optimization of the cultivation system. Also included are recent contributions addressing butanol tolerance, recovery of the produced photosynthetic butanol, life cycle assessment on environmental impacts, energy demand of photosynthetic butanol production and public acceptance of genetically engineered algae/cyanobacteria for biofuel production., Part of ISBN 9783110716979 9783110717044QC 20230713

Scytonemin is a promising UV-screen and antioxidant small molecule with commercial value in cosmetics and medicine. It is solely biosynthesized in some cyanobacteria. Recently, its biosynthesis mechanism has been elucidated in the model cyanobacterium Nostoc punctiforme PCC 73102. The direct precursors for scytonemin biosynthesis are tryptophan and p-hydroxyphenylpyruvate, which are generated through the shikimate and aromatic amino acid biosynthesis pathway. More upstream substrates are the central carbon metabolism intermediates phosphoenolpyruvate and erythrose-4-phosphate. Thus, it is a long route to synthesize scytonemin from the fixed atmospheric CO2 in cyanobacteria. Metabolic engineering has risen as an important biotechnological means for achieving sustainable high-efficiency and high-yield target metabolites. In this review, we summarized the biochemical properties of this molecule, its biosynthetic gene clusters and transcriptional regulations, the associated carbon flux-driving progresses, and the host selection and biosynthetic strategies, with the aim to expand our understanding on engineering suitable cyanobacteria for cost-effective production of scytonemin in future practices.

Scytonemin is a promising UV-screen and antioxidant small molecule with commercial value in cosmetics and medicine. It is solely biosynthesized in some cyanobacteria. Recently, its biosynthesis mechanism has been elucidated in the model cyanobacterium Nostoc punctiforme PCC 73102. The direct precursors for scytonemin biosynthesis are tryptophan and p-hydroxyphenylpyruvate, which are generated through the shikimate and aromatic amino acid biosynthesis pathway. More upstream substrates are the central carbon metabolism intermediates phosphoenolpyruvate and erythrose-4-phosphate. Thus, it is a long route to synthesize scytonemin from the fixed atmospheric CO2 in cyanobacteria. Metabolic engineering has risen as an important biotechnological means for achieving sustainable high-efficiency and high-yield target metabolites. In this review, we summarized the biochemical properties of this molecule, its biosynthetic gene clusters and transcriptional regulations, the associated carbon flux-driving progresses, and the host selection and biosynthetic strategies, with the aim to expand our understanding on engineering suitable cyanobacteria for cost-effective production of scytonemin in future practices.

Scytonemin is a promising UV-screen and antioxidant small molecule with commercial value in cosmetics and medicine. It is solely biosynthesized in some cyanobacteria. Recently, its biosynthesis mechanism has been elucidated in the model cyanobacterium Nostoc punctiforme PCC 73102. The direct precursors for scytonemin biosynthesis are tryptophan and p-hydroxyphenylpyruvate, which are generated through the shikimate and aromatic amino acid biosynthesis pathway. More upstream substrates are the central carbon metabolism intermediates phosphoenolpyruvate and erythrose-4-phosphate. Thus, it is a long route to synthesize scytonemin from the fixed atmospheric CO2 in cyanobacteria. Metabolic engineering has risen as an important biotechnological means for achieving sustainable high-efficiency and high-yield target metabolites. In this review, we summarized the biochemical properties of this molecule, its biosynthetic gene clusters and transcriptional regulations, the associated carbon flux-driving progresses, and the host selection and biosynthetic strategies, with the aim to expand our understanding on engineering suitable cyanobacteria for cost-effective production of scytonemin in future practices.

The production of fuels and other valuable chemicals via biological routes has gained significant attention during last decades. Cyanobacteria are prokaryotes that convert solar energy to chemical compounds in vivo in direct processes. Intensive studies have been carried out with the aim of engineering cyanobacteria as microfactories for solar fuel and chemical production. Engineered strains of photosynthetic cyanobacteria can produce different compounds on a proof-ofconcept level, but few products show titers comparable with those achieved in heterotrophic organisms. Efficient genetic engineering tools and metabolic modeling can accelerate the development of solar fuel and chemical production in cyanobacteria. This review addresses the most recent approaches to produce solar fuels and chemicals in engineered cyanobacteria with a focus on acetyl-CoA-dependent products.

The production of fuels and other valuable chemicals via biological routes has gained significant attention during last decades. Cyanobacteria are prokaryotes that convert solar energy to chemical compounds in vivo in direct processes. Intensive studies have been carried out with the aim of engineering cyanobacteria as microfactories for solar fuel and chemical production. Engineered strains of photosynthetic cyanobacteria can produce different compounds on a proof-ofconcept level, but few products show titers comparable with those achieved in heterotrophic organisms. Efficient genetic engineering tools and metabolic modeling can accelerate the development of solar fuel and chemical production in cyanobacteria. This review addresses the most recent approaches to produce solar fuels and chemicals in engineered cyanobacteria with a focus on acetyl-CoA-dependent products.

The production of fuels and other valuable chemicals via biological routes has gained significant attention during last decades. Cyanobacteria are prokaryotes that convert solar energy to chemical compounds in vivo in direct processes. Intensive studies have been carried out with the aim of engineering cyanobacteria as microfactories for solar fuel and chemical production. Engineered strains of photosynthetic cyanobacteria can produce different compounds on a proof-ofconcept level, but few products show titers comparable with those achieved in heterotrophic organisms. Efficient genetic engineering tools and metabolic modeling can accelerate the development of solar fuel and chemical production in cyanobacteria. This review addresses the most recent approaches to produce solar fuels and chemicals in engineered cyanobacteria with a focus on acetyl-CoA-dependent products.

The production of fuels and other valuable chemicals via biological routes has gained significant attention during last decades. Cyanobacteria are prokaryotes that convert solar energy to chemical compounds in vivo in direct processes. Intensive studies have been carried out with the aim of engineering cyanobacteria as microfactories for solar fuel and chemical production. Engineered strains of photosynthetic cyanobacteria can produce different compounds on a proof-ofconcept level, but few products show titers comparable with those achieved in heterotrophic organisms. Efficient genetic engineering tools and metabolic modeling can accelerate the development of solar fuel and chemical production in cyanobacteria. This review addresses the most recent approaches to produce solar fuels and chemicals in engineered cyanobacteria with a focus on acetyl-CoA-dependent products.

The production of fuels and other valuable chemicals via biological routes has gained significant attention during last decades. Cyanobacteria are prokaryotes that convert solar energy to chemical compounds in vivo in direct processes. Intensive studies have been carried out with the aim of engineering cyanobacteria as microfactories for solar fuel and chemical production. Engineered strains of photosynthetic cyanobacteria can produce different compounds on a proof-ofconcept level, but few products show titers comparable with those achieved in heterotrophic organisms. Efficient genetic engineering tools and metabolic modeling can accelerate the development of solar fuel and chemical production in cyanobacteria. This review addresses the most recent approaches to produce solar fuels and chemicals in engineered cyanobacteria with a focus on acetyl-CoA-dependent products.

The production of fuels and other valuable chemicals via biological routes has gained significant attention during last decades. Cyanobacteria are prokaryotes that convert solar energy to chemical compounds in vivo in direct processes. Intensive studies have been carried out with the aim of engineering cyanobacteria as microfactories for solar fuel and chemical production. Engineered strains of photosynthetic cyanobacteria can produce different compounds on a proof-ofconcept level, but few products show titers comparable with those achieved in heterotrophic organisms. Efficient genetic engineering tools and metabolic modeling can accelerate the development of solar fuel and chemical production in cyanobacteria. This review addresses the most recent approaches to produce solar fuels and chemicals in engineered cyanobacteria with a focus on acetyl-CoA-dependent products.

Cyanobacteria are photoautotrophic microorganisms which can be engineered to directly convert CO2 and water into biofuels and chemicals via photosynthesis using sunlight as energy. However, the product titers and rates are the main challenges that need to be overcome for industrial applications. Here we present systematic modular engineering of the cyanobacterium Synechocystis PCC 6803, enabling efficient biosynthesis of 1-butanol, an attractive commodity chemical and gasoline substitute. Through introducing and re-casting the 1-butanol biosynthetic pathway at the gene and enzyme levels, optimizing the 5 '-regions of expression units for tuning transcription and translation, rewiring the carbon flux and rewriting the photosynthetic central carbon metabolism to enhance the precursor supply, and performing process development, we were able to reach a cumulative 1-butanol titer of 4.8 g L-1 with a maximal rate of 302 mg L-1 day(-1) from the engineered Synechocystis. This represents the highest 1-butanol production from CO2 reported so far. Our multi-level modular strategy for high-level production of chemicals and advanced biofuels represents a blue-print for future systematic engineering in photosynthetic microorganisms.

Cyanobacteria are photoautotrophic microorganisms which can be engineered to directly convert CO2 and water into biofuels and chemicals via photosynthesis using sunlight as energy. However, the product titers and rates are the main challenges that need to be overcome for industrial applications. Here we present systematic modular engineering of the cyanobacterium Synechocystis PCC 6803, enabling efficient biosynthesis of 1-butanol, an attractive commodity chemical and gasoline substitute. Through introducing and re-casting the 1-butanol biosynthetic pathway at the gene and enzyme levels, optimizing the 5 '-regions of expression units for tuning transcription and translation, rewiring the carbon flux and rewriting the photosynthetic central carbon metabolism to enhance the precursor supply, and performing process development, we were able to reach a cumulative 1-butanol titer of 4.8 g L-1 with a maximal rate of 302 mg L-1 day(-1) from the engineered Synechocystis. This represents the highest 1-butanol production from CO2 reported so far. Our multi-level modular strategy for high-level production of chemicals and advanced biofuels represents a blue-print for future systematic engineering in photosynthetic microorganisms.

Cyanobacteria are photoautotrophic microorganisms which can be engineered to directly convert CO2 and water into biofuels and chemicals via photosynthesis using sunlight as energy. However, the product titers and rates are the main challenges that need to be overcome for industrial applications. Here we present systematic modular engineering of the cyanobacterium Synechocystis PCC 6803, enabling efficient biosynthesis of 1-butanol, an attractive commodity chemical and gasoline substitute. Through introducing and re-casting the 1-butanol biosynthetic pathway at the gene and enzyme levels, optimizing the 5 '-regions of expression units for tuning transcription and translation, rewiring the carbon flux and rewriting the photosynthetic central carbon metabolism to enhance the precursor supply, and performing process development, we were able to reach a cumulative 1-butanol titer of 4.8 g L-1 with a maximal rate of 302 mg L-1 day(-1) from the engineered Synechocystis. This represents the highest 1-butanol production from CO2 reported so far. Our multi-level modular strategy for high-level production of chemicals and advanced biofuels represents a blue-print for future systematic engineering in photosynthetic microorganisms.

Cyanobacteria are photoautotrophic microorganisms which can be engineered to directly convert CO2 and water into biofuels and chemicals via photosynthesis using sunlight as energy. However, the product titers and rates are the main challenges that need to be overcome for industrial applications. Here we present systematic modular engineering of the cyanobacterium Synechocystis PCC 6803, enabling efficient biosynthesis of 1-butanol, an attractive commodity chemical and gasoline substitute. Through introducing and re-casting the 1-butanol biosynthetic pathway at the gene and enzyme levels, optimizing the 5 '-regions of expression units for tuning transcription and translation, rewiring the carbon flux and rewriting the photosynthetic central carbon metabolism to enhance the precursor supply, and performing process development, we were able to reach a cumulative 1-butanol titer of 4.8 g L-1 with a maximal rate of 302 mg L-1 day(-1) from the engineered Synechocystis. This represents the highest 1-butanol production from CO2 reported so far. Our multi-level modular strategy for high-level production of chemicals and advanced biofuels represents a blue-print for future systematic engineering in photosynthetic microorganisms.

Cyanobacteria are photoautotrophic microorganisms which can be engineered to directly convert CO2 and water into biofuels and chemicals via photosynthesis using sunlight as energy. However, the product titers and rates are the main challenges that need to be overcome for industrial applications. Here we present systematic modular engineering of the cyanobacterium Synechocystis PCC 6803, enabling efficient biosynthesis of 1-butanol, an attractive commodity chemical and gasoline substitute. Through introducing and re-casting the 1-butanol biosynthetic pathway at the gene and enzyme levels, optimizing the 5 '-regions of expression units for tuning transcription and translation, rewiring the carbon flux and rewriting the photosynthetic central carbon metabolism to enhance the precursor supply, and performing process development, we were able to reach a cumulative 1-butanol titer of 4.8 g L-1 with a maximal rate of 302 mg L-1 day(-1) from the engineered Synechocystis. This represents the highest 1-butanol production from CO2 reported so far. Our multi-level modular strategy for high-level production of chemicals and advanced biofuels represents a blue-print for future systematic engineering in photosynthetic microorganisms.

Chunzi Nie,1 Zhan Wang,2 Xufeng Liu1 1Department of Military Medical Psychology, Fourth Military Medical University, Xi’an 710032, People’s Republic of China; 2Department of Orthopaedics, Gansu Provincial Hospital, Lanzhou, Gansu 730050, People’s Republic of China Background: Depressive disorder has been proven to be associated with disturbed bone metabolism. However, the effect of depression on fracture healing still lacks evidence. Materials and methods: A rat depressive model was first established by exposing the animals to chronic unpredictable stress, which was assessed using the sucrose preference test, forced swimming test, and open field test. Subsequently, the bone repairing ability was detected by micro-computed tomography and histological analysis of the femoral condyle defect rats with or without depression. To further investigate the potential mechanisms of depression on fracture healing, the osteogenic differentiation and autophagic level were compared between the bone marrow mesenchymal stem cells (BMSCs) derived from depressive and normal rats. Results: Our results showed that rats with depressive disorder significantly slowed the healing process at 4 and 8 weeks postinjury. Furthermore, the osteogenic potential and autophagy remarkably decreased in BMSCs from the depressive rats, suggesting an inherent relationship between autophagy and osteogenic differentiation. Finally, rapamycin, an autophagic agonist, significantly improved osteogenic differentiation of depressive BMSCs through autophagy activation. Conclusion: The present study indicated that depression had a negative effect on fracture healing with low osteoblast differentiation of BMSCs. Also, autophagy activation in BMSCs offers a novel therapeutic target for depressive patients with poor fracture healing. Keywords: depression, fracture healing, osteoblast differentiation, autophagy, bone marrow mesenchymal stem cells

Isobutanol is a flammable compound that can be used as a biofuel due to its high energy density and suitable physical and chemical properties. In this study, we examined the capacity of engineered strains of Synechocystis PCC 6803 containing the α-ketoisovalerate decarboxylase from Lactococcus lactis and different heterologous and endogenous alcohol dehydrogenases (ADH) for isobutanol production. A strain expressing an introduced kivdwithout any additional copy of ADH produced 3 mg L−1 OD750−1 isobutanol in 6 days. After the cultures were supplemented with external addition of isobutyraldehyde, the substrate for ADH, 60.8 mg L−1 isobutanol was produced after 24 h when OD750 was 0.8. The in vivo activities of four different ADHs, two heterologous and two putative endogenous in Synechocystis, were examined and the Synechocystis endogenous ADH encoded by slr1192 showed the highest efficiency for isobutanol production. Furthermore, the strain overexpressing the isobutanol pathway on a self-replicating vector with the strong Ptrc promoter showed significantly higher gene expression and isobutanol production compared to the corresponding strains expressing the same operon introduced on the genome. Hence, this study demonstrates that Synechocystis endogenous AHDs have a high capacity for isobutanol production, and identifies kivd encoded α-ketoisovalerate decarboxylase as one of the likely bottlenecks for further isobutanol production.

Isobutanol is a flammable compound that can be used as a biofuel due to its high energy density and suitable physical and chemical properties. In this study, we examined the capacity of engineered strains of Synechocystis PCC 6803 containing the α-ketoisovalerate decarboxylase from Lactococcus lactis and different heterologous and endogenous alcohol dehydrogenases (ADH) for isobutanol production. A strain expressing an introduced kivdwithout any additional copy of ADH produced 3 mg L−1 OD750−1 isobutanol in 6 days. After the cultures were supplemented with external addition of isobutyraldehyde, the substrate for ADH, 60.8 mg L−1 isobutanol was produced after 24 h when OD750 was 0.8. The in vivo activities of four different ADHs, two heterologous and two putative endogenous in Synechocystis, were examined and the Synechocystis endogenous ADH encoded by slr1192 showed the highest efficiency for isobutanol production. Furthermore, the strain overexpressing the isobutanol pathway on a self-replicating vector with the strong Ptrc promoter showed significantly higher gene expression and isobutanol production compared to the corresponding strains expressing the same operon introduced on the genome. Hence, this study demonstrates that Synechocystis endogenous AHDs have a high capacity for isobutanol production, and identifies kivd encoded α-ketoisovalerate decarboxylase as one of the likely bottlenecks for further isobutanol production.

Isobutanol is a flammable compound that can be used as a biofuel due to its high energy density and suitable physical and chemical properties. In this study, we examined the capacity of engineered strains of Synechocystis PCC 6803 containing the α-ketoisovalerate decarboxylase from Lactococcus lactis and different heterologous and endogenous alcohol dehydrogenases (ADH) for isobutanol production. A strain expressing an introduced kivdwithout any additional copy of ADH produced 3 mg L−1 OD750−1 isobutanol in 6 days. After the cultures were supplemented with external addition of isobutyraldehyde, the substrate for ADH, 60.8 mg L−1 isobutanol was produced after 24 h when OD750 was 0.8. The in vivo activities of four different ADHs, two heterologous and two putative endogenous in Synechocystis, were examined and the Synechocystis endogenous ADH encoded by slr1192 showed the highest efficiency for isobutanol production. Furthermore, the strain overexpressing the isobutanol pathway on a self-replicating vector with the strong Ptrc promoter showed significantly higher gene expression and isobutanol production compared to the corresponding strains expressing the same operon introduced on the genome. Hence, this study demonstrates that Synechocystis endogenous AHDs have a high capacity for isobutanol production, and identifies kivd encoded α-ketoisovalerate decarboxylase as one of the likely bottlenecks for further isobutanol production.

Two antennas, main and sub, are used for reception in Long Term Evolution (LTE) terminals nowadays. In order to have a good MIMO performance, low coupling loss and low correlation between antennas are considered. Currently, main antenna usually situates at the bottom of the phone because of Specific Absorption Rate (SAR) requirement, whereas sub antenna locates at the top of the phone providing better spatial diversity. In this paper, feasible implementations of scatterers on both non-metallic and metallic chassis phones are provided. Experimental results show that the Envelope Correlation Coefficients (ECC) can be reduced from 0.7 to 0.2 at 750 MHz after inserting scatterers. Dual-frequency operations are also possible if two scatterers are introduced on different sides of a phone chassis. © 2013 IEEE.

Although feature phones are less sophisticated than nowadays smart phones, it could be a footstone to explore the constraints and performances of various antenna types in a commercial mobile terminal. From the era of analog system to the age of digital world, a wide variety of services are embedded into a mobile terminal including text messaging, multi-media services, email, internet access, short-range wireless communications, gaming and photography. However, the handset has dramatically reduced in size and invisible antennas become a standard feature resulting in a challenging environment for antenna design. In addition, the interaction between mobile terminals and human bodies is another current issue in which mobile phone manufacturers have to account for. The antenna performance can be influenced severely when the phone is in contact with the human head and hand, whereas certain antenna designs may fail the standard of Specific Absorption Rates (SAR) though they can meet other requirements. © 2013 EurAAP.

Although feature phones are less sophisticated than nowadays smart phones, it could be a footstone to explore the constraints and performances of various antenna types in a commercial mobile terminal. From the era of analog system to the age of digital world, a wide variety of services are embedded into a mobile terminal including text messaging, multi-media services, email, internet access, short-range wireless communications, gaming and photography. However, the handset has dramatically reduced in size and invisible antennas become a standard feature resulting in a challenging environment for antenna design. In addition, the interaction between mobile terminals and human bodies is another current issue in which mobile phone manufacturers have to account for. The antenna performance can be influenced severely when the phone is in contact with the human head and hand, whereas certain antenna designs may fail the standard of Specific Absorption Rates (SAR) though they can meet other requirements. © 2013 EurAAP.

Although feature phones are less sophisticated than nowadays smart phones, it could be a footstone to explore the constraints and performances of various antenna types in a commercial mobile terminal. From the era of analog system to the age of digital world, a wide variety of services are embedded into a mobile terminal including text messaging, multi-media services, email, internet access, short-range wireless communications, gaming and photography. However, the handset has dramatically reduced in size and invisible antennas become a standard feature resulting in a challenging environment for antenna design. In addition, the interaction between mobile terminals and human bodies is another current issue in which mobile phone manufacturers have to account for. The antenna performance can be influenced severely when the phone is in contact with the human head and hand, whereas certain antenna designs may fail the standard of Specific Absorption Rates (SAR) though they can meet other requirements. © 2013 EurAAP.

Two antennas, main and sub, are used for reception in Long Term Evolution (LTE) terminals nowadays. In order to have a good MIMO performance, low coupling loss and low correlation between antennas are considered. Currently, main antenna usually situates at the bottom of the phone because of Specific Absorption Rate (SAR) requirement, whereas sub antenna locates at the top of the phone providing better spatial diversity. In this paper, feasible implementations of scatterers on both non-metallic and metallic chassis phones are provided. Experimental results show that the Envelope Correlation Coefficients (ECC) can be reduced from 0.7 to 0.2 at 750 MHz after inserting scatterers. Dual-frequency operations are also possible if two scatterers are introduced on different sides of a phone chassis. © 2013 IEEE.