Described herein are cyanobacteria encapsulated in hydrogels. Also described herein are consortia that include encapsulated cyanobacteria and heterotrophic microbes. The encapsulated cyanobacteria can be autotrophic and can provide nutrients to the heterotrophic microbes, which can utilize the nutrients to grow and produce useful products.

The present disclosure describes methods for generating microbial strains expressing a heterologous bacterial glucose permease gene that produce biomolecules of interest. In aspects, the disclosure provides novel bacterial strains, which express a heterologous bacterial glucose permease gene whose expression is controlled by a native Corynebacterium glutamicum promoter or a mutant promoter derived therefrom. Also provided herein are methods for producing a library of bacterial glucose permease genes using a promoter ladder comprising a plurality of promoters derived from Corynebacterium glutamicum.

The present invention provides a genetically modified lactic acid bacterium capable of producing diacetyl under aerobic conditions. Additionally the invention provides a method for producing diacetyl using the genetically modified lactic acid bacterium under aerobic conditions in the presence of a source of iron-containing porphyrin and a metal ion selected from Fe.sup.3+, Fe.sup.2+ and Cu.sup.2+. The lactic acid bacterium is genetically modified by deletion of those genes in its genome that encode polypeptides having lactate dehydrogenase (E.C 1.1.1.27/E.C.1.1.1.28); -acetolactate decarboxylase (E.C 4.1.1.5); water-forming NADH oxidase (E.C. 1.6.3.4); phosphotransacetylase (E.C.2.3.1.8) activity; and optionally devoid of or deleted for genes encoding polypeptides having diacetyl reductase ((R)-acetoin forming; EC:1.1.1.303); D-acetoin reductase; butanediol dehydrogenase ((R,R)-butane-2,3-diol forming; E.C. 1.1.1.4/1.1.1.-) and alcohol dehydrogenase (E.C. 1.2.1.10) activity. The invention provides for use of the genetically modified lactic acid bacterium for the production of diacetyl and a food product.

The present disclosure describes methods for generating microbial strains expressing a heterologous bacterial glucose permease gene that produce biomolecules of interest. In aspects, the disclosure provides novel bacterial strains, which express a heterologous bacterial glucose permease gene whose expression is controlled by a native Corynebacterium glutamicum promoter or a mutant promoter derived therefrom. Also provided herein are methods for producing a library of bacterial glucose permease genes using a promoter ladder comprising a plurality of promoters derived from Corynebacterium glutamicum.

Described herein are cyanobacteria encapsulated in hydrogels. Also described herein are consortia that include encapsulated cyanobacteria and heterotrophic microbes. The encapsulated cyanobacteria can be autotrophic and can provide nutrients to the heterotrophic microbes, which can utilize the nutrients to grow and produce useful products.

The present disclosure describes methods for generating microbial strains expressing a heterologous bacterial glucose permease gene that produce biomolecules of interest. In aspects, the disclosure provides novel bacterial strains, which express a heterologous bacterial glucose permease gene whose expression is controlled by a native Corynebacterium glutamicum promoter or a mutant promoter derived therefrom. Also provided herein are methods for producing a library of bacterial glucose permease genes using a promoter ladder comprising a plurality of promoters derived from Corynebacterium glutamicum.

The invention relates to a method for homo-ethanol production from lactose using a genetically modified lactic acid bacterium of the invention, where the cells are provided with a substrate comprising dairy waste supplemented with an amino nitrogen source (such as acid hydrolysed corn steep liquor). The invention further relates to genetically modified lactic acid bacterium and its use for homo-ethanol production from lactose in dairy waste. The lactic acid bacterium comprises both genes (lacABCD, LacEF, lacG) encoding enzymes catalysing the lactose catabolism pathway; and transgenes (pdc and adhB) encoding enzymes catalysing the conversion of pyruvate to ethanol. Additionally a number of genes (ldh, pta and adhE) are deleted in order to maximise homo-ethanol production as compared to production of lactate, acetoin and acetate production.

The present invention provides a genetically modified lactic acid bacterium capable of producing diacetyl under aerobic conditions. Additionally the invention provides a method for producing diacetyl using the genetically modified lactic acid bacterium under aerobic conditions in the presence of a source of iron-containing porphyrin and a metal ion selected from Fe.sup.3+, Fe.sup.2+ and Cu2+. The lactic acid bacterium is genetically modified by deletion of those genes in its genome that encode polypeptides having lactate dehydrogenase (E.C 1.1.1.27/E.C.1.1.1.28); -acetolactate decarboxylase (E.C 4.1.1.5); water-forming NADH oxidase (E.C. 1.6.3.4); phosphotransacetylase (E.C.2.3.1.8) activity; and optionally devoid of or deleted for genes encoding polypeptides having diacetyl reductase ((R)-acetoin forming; EC: 1.1.1.303); D-acetoin reductase; butanediol dehydrogenase ((R,R)-butane-2,3-diol forming; E.C. 1.1.1.4/1.1.1.-) and alcohol dehydrogenase (E.C. 1.2.1.10) activity. The invention provides for use of the genetically modified lactic acid bacterium for the production of diacetyl and a food product.

A target substance can be efficiently produced by culturing, in a medium, a coryneform bacterium in which the activity of a PTS protein relating to fructose uptake is reduced or lost as compared with a parent strain and the bacterium can produce the target substance, allowing the target substance to form and accumulate in a culture; and collecting the target substance from the culture.