The invention relates to a method for preparing a yeast which is capable of simultaneously fermenting a pentose and a hexose sugar, the method comprising providing a yeast which comprises: one or more heterologous genes encoding an enzyme of a pentose metabolic pathway, a disruption of a gene encoding a ribulose-phosphate 3-epimerase and a disruption of a gene encoding a glucose-6-phosphate isomerase, and one or more overexpressed endogenous genes encoding an enzyme of the pentose phosphate pathway; and subjecting the yeast to evolutionary engineering on a medium comprising a hexose sugar and at least one pentose sugar, selecting for a yeast with improved growth rate when grown on a media comprising a hexose and at least one pentose sugar, so as to obtain an evolved yeast.

The invention relates to an enzyme composition, a process for the preparation thereof and the use of the enzyme composition in enzymatic hydrolysis.

The invention relates to an enzyme composition, a process for the preparation thereof and the use of the enzyme composition in enzymatic hydrolysis.

The present invention relates to a microorganism variant having the ability to extracellularly produce heme, and more particularly to a metabolically engineered microorganism variant having the ability to extracellularly produce heme and a method of producing heme using the same. According to the present invention, heme, an organometallic compound which is increasingly used as a health food or food supplement for the treatment of porphyria, can be extracellularly secreted and produced in high yield using the microorganism variant, but not conventional chemical synthesis or enzymatic synthesis.

Disclosed are compositions, methods, and systems for propagating microorganisms for fermentation.

Disclosed are compositions, methods, and systems for propagating microorganisms for fermentation.

Disclosed is oleaginous yeast and its application, belonging to the technical field of microorganisms. The oleaginous yeast provided by the disclosure has been deposited in China Center for Type Culture Collection on May 21, 2020, with an accession number of CCTCC NO: M 2020139. The oleaginous yeast provided by the disclosure can use a hydrolysate of cheap lignocellulose biomass as the substrate. Xylose and glucose in the hydrolysate are simultaneously utilized to produce oil, so the sugar utilization efficiency and production intensity are enhanced. After 8 days of fed-batch fermentation, the oil yield can reach 31.33 g/L, and the oil content can reach 60.83%. The waste resources can be reutilized, and the production cost is reduced, so the oleaginous yeast has wide application prospects.

Disclosed is oleaginous yeast and its application, belonging to the technical field of microorganisms. The oleaginous yeast provided by the disclosure has been deposited in China Center for Type Culture Collection on May 21, 2020, with an accession number of CCTCC NO: M 2020139. The oleaginous yeast provided by the disclosure can use a hydrolysate of cheap lignocellulose biomass as the substrate. Xylose and glucose in the hydrolysate are simultaneously utilized to produce oil, so the sugar utilization efficiency and production intensity are enhanced. After 8 days of fed-batch fermentation, the oil yield can reach 31.33 g/L, and the oil content can reach 60.83%. The waste resources can be reutilized, and the production cost is reduced, so the oleaginous yeast has wide application prospects.

Acetate is a potent microbial inhibitor which can affect the performance of yeast in ethanolic fermentation. The present disclosure provides a recombinant microbial host cell having (i) a first genetic modification for increasing the activity of one or more proteins that function in a first metabolic pathway to convert acetate into an alcohol in the microbial host cell; (ii) a second genetic modification for increasing the activity of one or more proteins that function in a second metabolic pathway to import glycerol in the recombinant microbial host cell (iii) a third genetic modification for increasing the activity of one or more proteins that function in a third metabolic pathway to convert a C5 carbohydrate into ethanol in the microbial host cell. The recombinant microbial host cell comprises and natively expresses native proteins that function in a fourth native metabolic pathway to produce glycerol in the microbial host cell.

The invention provides an assay for identifying a bacterium capable of binding elemental heavy metal, comprising the following steps: cultivating a test bacterium in a suitable first culture medium; immersing at least a surface portion of a test tool into the first culture medium for a second predetermined period of time, said surface portion being coated by elemental heavy metal, respectively; removing said test tool from said first culture medium and optionally rinsing the test tool; contacting a second culture medium with the surface portion coated by elemental heavy metal of said test tool removed in the previous step; and identifying the test bacterium as being capable of binding elemental heavy metal from growth of the test bacterium in said second culture medium.