A transformant obtained by introducing a DNA of (a1), (a2), or (a3) below, and (b) an alcohol dehydrogenase gene, into a bacterium of the genus Hydrogenophilus, can efficiently produce isobutanol utilizing carbon dioxide as a sole carbon source. (a1) DNA which consists of a base sequence of SEQ ID NO: 1; (a2) DNA which consists of a base sequence having 90% or more identity with SEQ ID NO: 1, the DNA encoding a polypeptide having 2-keto-acid decarboxylase activity; (a3) DNA which hybridizes with a DNA consisting of a base sequence complementary to SEQ ID NO: 1 under stringent conditions, and which encodes a polypeptide having 2-keto-acid decarboxylase activity.

Provided is a recombinant Saccharomyces cerevisiae for producing 2,3-butanediol, wherein all GPD1 and GPD2 genes involved in glycerol biosynthesis are removed and a gene encoding NADH oxidase is introduced, and wherein pyruvate decarboxylase activity is inactivated and Candida tropicalis PDC1 gene encoding Candida tropicalis pyruvate decarboxylase 1-is introduced, and wherein expression of the Candida tropicalis PDC1 gene is regulated by a GPD2 promoter.

The disclosure relates to a tyrosol-producing recombinant Escherichia coli and a construction method and application thereof and belongs to the technical field of bioengineering. The Escherichia coli undergoes heterologous expression of a codon-optimized Saccharomyces cerevisiae pyruvate decarboxylase gene ARO10*. According to the recombinant Escherichia coli, five sites of a lacI site, a trpE site, a pabB site, a pabA site and a pykF site of an Escherichia coli genome are deleted, and at the same time, the ARO10* gene is integrated at each site of the five sites to obtain a strain containing multiple copies of the ARO10* gene. On the basis of the above recombinant strain, the ARO10* gene is randomly integrated at multiple sites, and it is found that a strain with high-yield production of tyrosol can be obtained by inserting the ARO10* gene at a yccX site. Fermentation using this strain does not require inducers or antibiotics. After fermentation is carried out for 48 hours, the yield of tyrosol can reach 32.3 mM.

The present invention provides a method for producing lactic acid in a recombinant yeast cell culture using glucose as carbon source comprising a first, seed fermentation stage to produce biomass wherein the yeast is cultivated in a culture medium at a pH of 5 to 7, followed by a second, a production fermentation stage with biomass from the seed fermentation to produce lactic acid, wherein the yeast is cultivated in a culture medium at low p H using a yeast strain that is engineered to have lactate dehydrogenase (LDH) activity and optionally has decreased or knocked-out pyruvate decarboxylase (PDC) activity.

A method is useful for the biocatalytic synthesis of proteinogenic L-amino acids, such as L-alanine, L-valine, L-methionine, L-leucine, L-isoleucine or L-phenylalanine from a respective aldehyde and carbon dioxide. In particular, the method is useful for the biocatalytic synthesis of L-methionine from 3-methylthio-propanal (methional) and carbon dioxide.

The present invention provides a fungus of the genus Rhizopus having high productivity of an organic acid. The present invention also provides a mutant of the genus Rhizopus with reduced pyruvate decarboxylase activity.

Disclosed herein is a process for producing a recombinant Candida cell, which involves genetically engineering a parent Candida cell using a Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated (Cas)(CRISPR/Cas) system. A recombinant Candida cell obtained using the process and a method for producing D-lactic acid from a biomass using the recombinant Candida cell are also disclosed.

A system and method for controlling metabolic enzymes or pathways in cells to produce a chemical above the levels of a wild-type strain is disclosed. The system utilizes cells, including yeasts, bacteria, and molds, having at least two genes capable of being controlled bi-directionally with light, where one gene is turned from off to on when exposed to light and another gene is turned from on to off when exposed to light, the two genes reversing when the light is turned off. Cells may utilize any number of sequences that benefit chemical production, including sequences that: encode for constitutive transcription of light-activated transcription factor fusions; encode for a metabolic enzyme; encode for a repressor; induce expression of metabolic enzymes; and an endogenous or exogenous activator expressed by a constitutive promoter, inducible promoter, or gene circuit. These systems may be coupled to biosensors or protein cascade systems, enabling the monitoring or automation of the fermentation process to optimize production of a desired product. These systems may also allow for optimization and periodic operation of a bioreactor using light pulses.

Improved yeast strains and fermentation process for producing D-lactic acid and L-lactic acid are disclosed. The improvement lead to higher titer, higher yield, shorter time, lower pH, and higher average specific productivity.

The invention relates to engineering of acetyl-CoA metabolism in yeast and in particular to production of acetyl-CoA in a non-ethanol producing yeast lacking endogenous gene(s) encoding pyruvate decarboxylase and comprising a heterologous pathway for synthesis of cytosolic acetyl-CoA.