Provided herein are compositions and methods for modulating induction of quorum sensing in bacterial cells. For example, provided herein is a method of inducing method of inducing quorum sensing, where the method includes: culturing a bacterial strain, wherein the bacterial strain comprises a first nucleic acid sequence encoding a first activator polypeptide, wherein expression of the first activator polypeptide produces a quorum sensing molecule precursor; a second nucleic acid sequence encoding a second activator polypeptide, wherein expression of the second activator polypeptide produces a quorum sensing; a third nucleic acid sequence encoding a third activator polypeptide that is capable of activating the quorum sensing system; a fourth nucleic acid sequence encoding a gene of interest, and contacting the bacterial strain with an inducer molecule; and converting the inducer molecule into a quorum sensing molecule, thereby allowing induction of quorum sensing.

Disclosed is an auto-induction regulatory system based on quorum sensing, comprising luxI, luxR and egfp, wherein, the promoter for controlling the expression of luxI and luxR is selected from P.sub.luxI, P.sub.BB or P.sub.J23100; the promoter for controlling the expression of egfp is selected from P.sub.luxI, P.sub.luxI(T-38C) or P.sub.luxI(C-77T). Also disclosed are an application of the auto-induction regulatory system based on quorum sensing in the automatic regulation of expression of a target gene of engineered Escherichia coli, as well as an application thereof in the preparation of alginate lyase and esterase. Further disclosed are a recombinant expression vector and a recombinant engineered bacterium comprising the auto-induction regulatory system based on quorum sensing.

Disclosed herein are programmable bacteria for tumor-targeted immunotherapeutic delivery. In certain embodiments, the programmable bacteria comprise at least one synchronized lysis circuit contained in a single operon which are capable of being further engineered to cyclically produce anti-cancer therapeutic agents including but not limited to nanobodies against immune checkpoint inhibitors and over-expressed markers in cancers, toxins, tumor antigens, cytokines, and chemokines. In some embodiments, the programmable bacteria comprise at least one synchronized lysis circuit contained in a single operon and at least one plasmid producing a therapeutic agent, i.e., at least one plasmid comprising a nucleic acid sequence which encodes a therapeutic agent. The disclosure also provides methods of curing and treating cancer using the programmable bacteria.

Biofilms are provided which are capable of regulating their own thickness, reducing contamination and preventing biofouling. Constructs are introduced into bacteria that comprise nucleic acid molecules encoding an autoinducer synthase polypeptide, a transcriptional regulator and a biofilm dispersal protein. Nucleic acid molecules may also be introduced which encode a nitric oxide synthase, an epoxide hydrolase, or both. Biofilms of the bacteria may be used to reduce biofouling and contamination of a surface.

Biofilms are provided which are capable of regulating their own thickness, reducing contamination and preventing biofouling. Constructs are introduced into bacteria that comprise nucleic acid molecules encoding an autoinducer synthase polypeptide, a transcriptional regulator and a biofilm dispersal protein. Nucleic acid molecules may also be introduced which encode a nitric oxide synthase, an epoxide hydrolase, or both. Biofilms of the bacteria may be used to reduce biofouling and contamination of a surface.

Biofilms are provided which are capable of regulating their own thickness, reducing contamination and preventing biofouling. Constructs are introduced into bacteria that comprise nucleic acid molecules encoding an autoinducer synthase polypeptide, a transcriptional regulator and a biofilm dispersal protein. Nucleic acid molecules may also be introduced which encode a nitric oxide synthase, an epoxide hydrolase, or both. Biofilms of the bacteria may be used to reduce biofouling and contamination of a surface.

Disclosed herein are programmable bacteria for tumor-targeted immunotherapeutic delivery. In certain embodiments, the programmable bacteria comprise at least one synchronized lysis circuit contained in a single operon which are capable of being further engineered to cyclically produce anti-cancer therapeutic agents including but not limited to nanobodies against immune checkpoint inhibitors and over-expressed markers in cancers, toxins, tumor antigens, cytokines, and chemokines. In some embodiments, the programmable bacteria comprise at least one synchronized lysis circuit contained in a single operon and at least one plasmid producing a therapeutic agent, i.e., at least one plasmid comprising a nucleic acid sequence which encodes a therapeutic agent. The disclosure also provides methods of curing and treating cancer using the programmable bacteria.

The present invention generally relates to the biotechnology engineering, and specifically to genetically modified methylotrophic bacteria which produce lactate. More specifically, the present invention provides a methylotrophic bacterium modified to have an increased expression of a polypeptide having lactate dehydrogenase activity. The present invention further provides a method for producing lactate using a genetically modified bacterium of the present invention.

The present invention generally relates to the biotechnology engineering, and specifically to genetically modified bacteria of the genus Methylobacillus which have improved properties making them particularly useful in large scale methanol fermentations. More specifically, the present invention provides a bacterium of the genus Methylobacillus which has been modified to have a decreased production of exopolysaccharides (EPS) compared to an otherwise identical bacterium that does not carry said modification. The present invention further provides a method for producing a biochemical compound using a genetically modified bacterium of the present invention.

Provided herein are compositions and methods for modulating induction of quorum sensing in bacterial cells. For example, provided herein is a method of inducing method of inducing quorum sensing, where the method includes: culturing a bacterial strain, wherein the bacterial strain comprises a first nucleic acid sequence encoding a first activator polypeptide, wherein expression of the first activator polypeptide produces a quorum sensing molecule precursor; a second nucleic acid sequence encoding a second activator polypeptide, wherein expression of the second activator polypeptide produces a quorum sensing; a third nucleic acid sequence encoding a third activator polypeptide that is capable of activating the quorum sensing system; a fourth nucleic acid sequence encoding a gene of interest, and contacting the bacterial strain with an inducer molecule; and converting the inducer molecule into a quorum sensing molecule, thereby allowing induction of quorum sensing.