Provided are amino acid sequences of ketoreductase polypeptides that are useful for asymmetrically synthesizing chiral alcohol compounds, its preparation process as well as reaction process under industrial-relevant conditions. Also provided are polynucleotide sequences encoding engineered ketoreductase polypeptides, engineered host cells capable of expressing engineered ketoreductase polypeptides, and methods of producing chiral alcohol compounds using engineered ketoreductase polypeptides. Compared to other enzymes, the engineered ketoreductase polypeptides provided by the invention have better catalytic activity and thermal stability, allowing purification of the enzyme solution by heat treatment, which is advantageous for the production of enzymes and the industrial application of enzymatic reactions. The use of the engineered polypeptides of the present invention greatly simplifies the production process of chiral alcohol compounds, reduces the cost of production and the impact on the environment, and has good industrial application prospects.

Cells are grown in 3D culture and topological features obtained by photomicrography are correlated to cell viability and cell cell interactions.

Cells are grown in 3D culture and topological features obtained by photomicrography are correlated to cell viability and cell cell interactions.

The invention provides a mutant hydrolase protein with enhanced kinetics and functional expression, as well as polynucleotides encoding the mutant proteins and methods of using the polynucleotides and mutant proteins.

The invention provides a mutant hydrolase protein with enhanced kinetics and functional expression, as well as polynucleotides encoding the mutant proteins and methods of using the polynucleotides and mutant proteins.

Cells are grown in 3D culture and topological features obtained by photomicrography are correlated to cell viability and cell interactions.

Cells are grown in 3D culture and topological features obtained by photomicrography are correlated to cell viability and cell interactions.

The present invention provides a sewage treatment biological agent and a preparation method and application thereof. The sewage treatment biological agent according to an embodiment of the present invention includes an induced nucleus. The induced nucleus has good bioaffinity. A microbial flora can be attached to the induced nucleus to achieve rapid growth. As the microbial flora gathers and grows on the induced nucleus, the granulation is gradually achieved by the sewage treatment biological agent to facilitate the sewage treatment. The microbial flora grows on the induced nucleus, and the growth process of microbial flora is a covering growth process which starts from the induced nucleus and gradually expands outward and centers on the induced nucleus. During the growth of microbial flora, extracellular polymers are secreted, which can further promote the granulation process by the sewage treatment biological agent.

The present invention provides a sewage treatment biological agent and a preparation method and application thereof. The sewage treatment biological agent according to an embodiment of the present invention includes an induced nucleus. The induced nucleus has good bioaffinity. A microbial flora can be attached to the induced nucleus to achieve rapid growth. As the microbial flora gathers and grows on the induced nucleus, the granulation is gradually achieved by the sewage treatment biological agent to facilitate the sewage treatment. The microbial flora grows on the induced nucleus, and the growth process of microbial flora is a covering growth process which starts from the induced nucleus and gradually expands outward and centers on the induced nucleus. During the growth of microbial flora, extracellular polymers are secreted, which can further promote the granulation process by the sewage treatment biological agent.

Provided are a Bacillus subtilis genetically engineered bacterium for producing tagatose and a method for preparing tagatose. The genetically engineered bacterium comprises constructing thermostable ?-glucan phosphorylases, thermostable glucose phosphomutases, thermostable glucose phosphate isomerases, thermostable 6-tagatose phosphate epimerases, and thermostable 6-tagatose phosphate phosphatases which are independently expressed or co-expressed. The usage of the genetically engineered bacterium can effectively convert starch into tagatose. Compared with existing methods for producing tagatose, the method has advantages such as suitability for whole-cell recycling, high safety, high yield, simple production process, low cost, and easiness in large-scale preparation.