Abstract
The present context was aimed to assess the impact of Mentha piperita L. stress at sub-inhibitory concentration on some key functional traits of coagulase-negative Staphylococcus hominis strain MANF2. Initially, the antibacterial activity of M. piperita L. leaves was determined against strain MANF2 and estimated its minimum inhibitory concentration (MIC) and sub-MIC values using standard protocols. Results showed promising antibacterial activity of M. piperita L. against strain MANF2 with MIC and sub-MIC values of 25 and 12.5%, respectively. Further, strain MANF2 growing under mild stress of M. piperita L. i.e. stressed strain (SS) was tested for its prime functional properties using standard methodologies and compared with the control strain (CS). The SS culture showed increased growth with respect to the CS culture at regular interval of time. A significant (P < 0.05) decrement in the viabilities of SS culture were estimated as compared to CS culture from pH 2.0 to 5.0. The survival potentialities of SS culture with respect to CS culture were decreased too due to the supplementation of bile salt. The SS culture showed increased hydrophobicity towards chloroform (64.3 ± 1.2%), toluene (73.3 ± 1.1%), and ethyl acetate (69.2 ± 2.2%) as compared to CS culture. Likewise, the auto-aggregation traits of SS culture (74.1 ± 1.3%) were increased with respect to CS culture (68.1 ± 1.5%). The autolysis abilities of SS culture were increased too with respect to CS culture up to 24 h. In addition, antibiotics such as penicillin G and chloramphenicol showed increased activities against SS culture, while, gentamicin showed slight reduction in its activity against SS culture. In conclusion, functional characteristics of strain MANF2 can be enhanced by supplementing mild doses of M. piperita L. without altering the antibiotic susceptible characteristics of particular strain.