Effects of glucose and oxygen on arginine metabolism by coagulase-negative staphylococci.

In this study, the conversion of the amino acid arginine by two strains with arginine deiminase (ADI) activity (Staphylococcus carnosus 833 and S. pasteuri αs3-13) and a strain with nitric oxide synthase (NOS) activity (S. haemolyticus G110) was modelled as a function of glucose and oxygen availability. Both factors moderately inhibited the ADI-based conversion kinetics, never leading to full repression. However, for NOS-driven conversion of arginine by S. haemolyticus G110, oxygen was an absolute requirement. When changing from microaerobic conditions to aerobiosis, a switch from homolactic fermentation to a combined formation of lactic acid, acetic acid, and acetoin was found in all cases, after which lactic acid and acetic acid were used as substrates. The kinetic model proposed provided a suitable description of the data of glucose and arginine co-metabolism as a function of oxygen levels and may serve as a tool to further analyse the behaviour of staphylococci in different ecosystems or when applying specific food processing conditions. PMID: 28399999 [PubMed - in process]
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research