The ability of <I>Bacillus mojavensis</I> PS17 to grow and synthesize exogenous enzymes at low temperatures

Abstract

Relevance. Microorganisms growing at low temperatures play a key role in the biochemical cycles in cold ecosystems. These microorganisms secrete enzymes with a wide range of activity at low temperature, which can be used in various fields of the biotechnology industry.Methods. To study the psychrotolerant ability of Bacillus mojavensis PS17 bacteria, a bacterial suspension prepared from a nocturnal culture was used. The ability of Bacillus mojavensis PS17 to grow at low temperatures was studied by kinetic measurement of optical density (OD) at a wavelength (l) of 595 nm. For this purpose, bacterial suspension of Bacillus mojavensis PS17 was inoculated into a basal medium and incubated at various low temperatures (5, 8, and 12 ± 1 °C) for 12 hours. The growth curve was measured every hour using a spectrophotometer. The activity of exogenous enzymes was determined by inoculation and incubation at a temperature of 4 ± 1 °C a Bacillus mojavensis PS17 bacterial suspension on a basal medium amended with 1% of different substrates such as milk powder, Tween-80 and sodium carboxymethylcellulose.Results. The results showed that Bacillus mojavensis PS17 can grow at low temperatures. Evaluation of the activity of exogenous enzymes showed that the isolated enzymes of the studied strain do not lose their properties in conditions of low temperatures. The studied psychrotolerant properties of Bacillus mojavensis PS17 bacteria can be used in various manufacturing biotechnology such as food, textile and pharmaceutical.