The present disclosure provides a transposon system comprising: i) a nucleotide sequence encoding polypeptides that form a CRISPR-associated transposase complex; ii) a nucleotide sequence encoding a guide RNA; and iii) a transposon, or an insertion site for a transposon, flanked by CAST complex recognition sites. The present disclosure provides a prokaryotic cell comprising a subject transposon system. The transposon system is useful for editing the genome of a target prokaryotic cell. The present disclosure provides methods for editing the genome of a target prokaryotic cell. The present disclosure further provides systems and methods for identifying, within a heterogeneous population of prokaryotic cells, prokaryotic species that are susceptible to genetic modification and gene editing.

Disclosed is an L-branched-chain amino acid-producing microorganism having enhanced activity of regulator of acetate metabolism A and a method for producing an L-branched-chain amino acids using the same.

A modified bacterium in which a function of a protein involved in binding between an outer membrane and a cell wall of cyanobacterium is suppressed or lost.

The present disclosure provides a spiramycin-producing strain, a carrimycin-producing strain, construction method therefor, use thereof and method for increasing the product yield thereof. The provided spiramycin-producing strain has an inactivated gene Lrp (Δlrp-SP); and the strain has a preservation number of CGMCC No.16056. The provided carrimycin-producing strain has an inactivated gene Lrp (Δlrp-BT); and the strain has a preservation number of CGMCC No.16055. By inactivating the gene Lrp, the yields of spiramycin and carrimycin are increased; and particularly the yield and proportion of a major component of the carrimycin, that is, 4″-O-isovalerylspiramycin III are significantly increased.

The present invention provides a culture medium for inducing an increase in a plasmid copy number and use thereof. The culture medium for inducing an increase in a plasmid copy number of the present invention has a plasmid extraction concentration increased by from 45 to 95% compared with a conventional method for inducing a plasmid copy number, and has a plasmid extraction concentration increased by from 110 to 440% compared with an induction method using a culture medium without glucose and arabinose. The culture medium plays an important role in inducing an increase in a plasmid copy number and achieving high-throughput production.

A production method for a crystal of a crystalline protein, the method including a step of inducing expression of a crystalline protein in Escherichia coli into which an expression construct of the crystalline protein has been introduced, and incubating the Escherichia coli for a predetermined time until a crystal of the crystalline protein is formed inside the Escherichia coli, and a crystal structure analysis method including a step of subjecting a crystal produced by the above-described production method to an X-ray crystal structure analysis together with the Escherichia coli, are useful as technologies for conveniently producing and analyzing a crystal of a protein.

The present disclosure provides a method for detecting L-serine based on cysteine desulfurase-containing living Escherichia coli cells, and belongs to the technical field of amino acid detection. The method includes the following steps: incubating an unknown sample with the cysteine desulfurase-containing living E. coli cells to produce a red substance, and qualitatively or semi-quantitatively detecting L-serine content in the unknown sample according to color changes of the red substance of the living E. coli cells, or quantitatively detecting L-serine content in the unknown sample by measuring absorbance of a lysate of the living E. coli cells. The detection method provided by the present disclosure is simple and convenient in process, few in reaction steps and stable in enzymatic activity of living cells.

The present disclosure provides consortia of microbes that are functionally optimized for nitrogen fixation and deliver such to plants in a targeted, efficient, and environmentally sustainable manner. The microbes within the consortium differ in nutrient utilization, temporal occupation, oxygen adaptability, and/or spatial occupation, which enables the microbes to deliver nitrogen to a cereal plant in a spatially targeted (e.g. rhizospheric) and temporally targeted (e.g. during advantageous stages of plant's life cycle) manner. The present disclosure also provides methods of creating a synthetic composition of microbes and methods of using compositions of microbes to fix atmospheric nitrogen and deliver such to a crop.

Among other things, the present disclosure provides biosynthesis polypeptides, methods, and non-naturally occurring microbial organisms for preparing various compounds such as 1,5-pentanediol, adipic acid, 1,6-hexanediol, 6-hydroxy hexanoic acid, and 2-keto carboxylic acids.

The present invention concerns a method to modulate the level of or to modify a target molecule in a subject or an environment, said method comprising: administering in said subject or providing to said environment an engineered bacterial strain comprising (i) a heterologous or engineered nucleic acid involved in the expression of a molecule of interest, wherein the expression of said molecule of interest modulates directly or indirectly the level of or modify the target molecule in said subject or environment and (ii) an autologous gene or gene set involved in the import and/or metabolism of a milk oligosaccharide; and further administering to said subject, or providing to said environment, said milk oligosaccharide; whereby the level of the target molecule in said subject or environment is modulated or the target molecule is modified in said subject or environment.