Hygromycin B is an antibiotic produced by the bacterium Streptomyces hygroscopicus. It is an aminoglycoside that kills bacteria, fungi and higher eukaryotic cells by inhibiting protein synthesis.[1]
Hygromycin B was originally developed in the 1950s for use with animals and is still added into swine and chicken feed as an anthelmintic or anti-worming agent (product name: Hygromix). Hygromycin B is produced by Streptomyces hygroscopicus, a bacterium isolated in 1953 from a soil sample. Resistance genes were discovered in the early 1980s.[2] [3]
Hygromycin B, along with aminoglycosides, inhibits protein synthesis by strengthening the interaction of tRNA binding in the ribosomal A-site. Hygromycin B also prevents mRNA and tRNA translocation by an unknown mechanism.[4]
In the laboratory it is used for the selection and maintenance of prokaryotic and eukaryotic cells that contain the hygromycin resistance gene. The resistance gene is a kinase that inactivates hygromycin B through phosphorylation.[5] Since the discovery of hygromycin-resistance genes, hygromycin B has become a standard selection antibiotic in gene transfer experiments in many prokaryotic and eukaryotic cells. Based on impurity monitor method,[6] four different kinds of impurities are discovered in commercial hygromycin B from different suppliers and toxicities of different impurities to the cell lines are described in the following external links.
Hygromycin resistance gene is frequently used as a selectable marker in research on plants. In rice Agrobacterium-mediated transformation system, hygromycin is used at about 30–75 mg L−1, with an average of 50 mg L−1. The use of hygromycin at 50 mg L−1 demonstrated highly toxic to non-transformed calli. Thus, it can be efficiently used to select transformants.[7]
Fungus Coniothyrium minitans was transformed with the hygromycin B resistance gene to improve the infection rates of Sclerotinia sclerotiorum, a fungal parasite of many crops.[8]