A method of making silk articles including preparing a silk fibroin solution including silk fibroin and microalgae, and introducing the silk fibroin solution into a solvent bath including a crosslinking agent. The method can incorporate 3D printing techniques to allow for easy fabrication of the articles into various forms. The silk articles can provide a cell-friendly matrix that allows 3D encapsulation of microalgae while maintaining normal cell proliferation and functions for an extended period of time.

A method of making silk articles including preparing a silk fibroin solution including silk fibroin and microalgae, and introducing the silk fibroin solution into a solvent bath including a crosslinking agent. The method can incorporate 3D printing techniques to allow for easy fabrication of the articles into various forms. The silk articles can provide a cell-friendly matrix that allows 3D encapsulation of microalgae while maintaining normal cell proliferation and functions for an extended period of time.

Presented herein are Synechococcus strains engineered to express the bacterial ethylene-forming enzyme (EFE) that exhibit unstable ethylene production due to toxicity and genomic instability induced by accumulation of the EFE-byproduct guanidine. Co-expression of EFE and Sll1077 significantly enhanced genomic stability and enabled the resulting Synechococcus strain GD-EFE7942 to achieve sustained high-level ethylene production. The engineered strains and methods disclosed herein are useful for guanidine degradation pathways and for ethylene bioproduction in cyanobacteria.

Provided herein, in some embodiments, are engineered cells and use of the same for increased hydrogen production. In particular, provided herein are genetically engineered cells comprising a polynucleotide encoding a fusion protein comprising a photosystem I (PSI) protein and an algal hydrogenase, as well as methods for producing such genetically engineered cells. Also provided herein are methods for increasing hydrogen (H.sub.2) production in cells.

Provided herein, in some embodiments, are engineered cells and use of the same for increased hydrogen production. In particular, provided herein are genetically engineered cells comprising a polynucleotide encoding a fusion protein comprising a photosystem I (PSI) protein and an algal hydrogenase, as well as methods for producing such genetically engineered cells. Also provided herein are methods for increasing hydrogen (H.sub.2) production in cells.

The invention provides non-naturally occurring microbial organisms containing butadiene or 2,4-pentadienoate pathways comprising at least one exogenous nucleic acid encoding a butadiene or 2,4-pentadienoate pathway enzyme expressed in a sufficient amount to produce butadiene or 2,4-pentadienoate. The organism can further contain a hydrogen synthesis pathway. The invention additionally provides methods of using such microbial organisms to produce butadiene or 2,4-pentadienoate by culturing a non-naturally occurring microbial organism containing butadiene or 2,4-pentadienoate pathways as described herein under conditions and for a sufficient period of time to produce butadiene or 2,4-pentadienoate. Hydrogen can be produced together with the production of butadiene or 2,4-pentadienoate.

The invention provides non-naturally occurring microbial organisms containing butadiene or 2,4-pentadienoate pathways comprising at least one exogenous nucleic acid encoding a butadiene or 2,4-pentadienoate pathway enzyme expressed in a sufficient amount to produce butadiene or 2,4-pentadienoate. The organism can further contain a hydrogen synthesis pathway. The invention additionally provides methods of using such microbial organisms to produce butadiene or 2,4-pentadienoate by culturing a non-naturally occurring microbial organism containing butadiene or 2,4-pentadienoate pathways as described herein under conditions and for a sufficient period of time to produce butadiene or 2,4-pentadienoate. Hydrogen can be produced together with the production of butadiene or 2,4-pentadienoate.

A method of generating electricity in a body of water includes providing a colony of sulfur-reducing bacteria, a colony of sulfur-oxidizing bacteria, and a colony of denitrifying bacteria submerged in the body of water. The colony of sulfur-reducing bacteria can be used to convert at least a portion of sulfates present in the body of water to hydrogen sulfide. The colony of sulfur-oxidizing bacteria can be used to convert the hydrogen sulfide to sulfuric acid, which can react with manganese to produce hydrogen gas. The colony of denitrifying bacteria can be used to convert at least a portion of nitrogen oxides in the body of water to nitrogen gas, which can be bubbled through a portion of water from the body of water to remove dissolved oxygen gas. The hydrogen gas and oxygen gas can be combined in a fuel cell generator to generate electricity.

Disclosed are an apparatus and a method for recovering effective resources including nitrogen and phosphorus. According to one aspect of the present embodiment, provided are an apparatus and a method for recovering effective resources, which efficiently recover resources such as methane, nitrogen, and phosphorus while minimizing the use of chemicals.

A bacterially induced crystal particle is formed by a composite shell that encloses a hollow space. The composite shell layer includes a biomaterial and a metallic material. The biomaterial includes cell wall or cell membrane of a bacterium. The metallic material includes oxides, sulfides, selenides, acid salt compounds of a transition metal, or any combination thereof. When the bacterially induced crystal particle is spheric, the composite shell is formed by two dome-shaped portions, and a thickness of each of the dome-shaped portions is not less than 1/73 of a diameter of the bacterially induced crystal particle. Alternatively, when the bacterially induced crystal particle is rod-shaped, the thickness of the dome-shaped portions is not less than 1/73 of a width of the bacterially induced crystal particle, and a thickness of the cylindrical portion is not less than 1/37 of the width of the bacterially induced crystal particle.