According to the present disclosure, a method for producing stem cells is provided, comprising applying tetrakis-pivaloyloxymethyl 2-(thiazol-2-ylamino) ethylidene-1, 1-bisphosphonate (PTA) to blood cells or immune cells, and inducing stem cells from said blood cells or immune cells.

Ergothioneine-producing engineered bacteria and a construction method and use thereof are provided. The construction method includes: integrating a constitutive promoter PrrnD and an ergothioneine-synthesizing gene cluster egtABCDE derived from Mycolicibacterium neoaurum into a genome of Escherichia coli as a starting strain; and further mutating glutamate at a position 271 in an ATP phosphoribosyltransferase (HisG) gene of a strain produced above into lysine to produce the ergothioneine-producing engineered bacteria. With glucose as a main raw material, a fermentation culture can be conducted with the engineered bacteria to produce ergothioneine. The fermentation with the engineered bacteria to synthesize ergothioneine has advantages such as simple process and high production efficiency, can avoid the use of organic solvents and antibiotics in large quantities, and is suitable for industrial production.

The disclosure provides methods for improving sperm function and fertilizing ability for assisted reproduction techniques. The methods provided by the disclosure, in some embodiments entail sequential changes of temperature, bicarbonate concentration, albumin concentration and calcium ionophore.

Improved production of recombinant proteins in E. coli, reliant on tightly controlled autoinduction, triggered by phosphate depletion in stationary phase. The process also provides an optimized autoinduction media, enabling routine batch production at various culture volumes where cells densities routinely reach 5-7 g cell dry weight per liter and offer protein titers above 2 g/L. The methodology has been validated with a set of diverse heterologous proteins and is of general use for the facile optimization of routine protein expression from high throughput screens to fed-batch fermentation.

The present invention generally relates to a medium composition and method for culturing mesenchymal stem cells (MSCs), in which the medium comprises an epithelial cell adhesion molecule (EpCAM) peptide, particularly a truncated EpCAM polypeptide containing the extracellular domain (EpEX). It significantly enhances cell proliferation and multipotency of the MSCs.