Production of Volatile Compounds by Lactococcus lactis sp. Strain at Different Growth Phases

Aims: The present study aimed at identifying secondary metabolites produced during the growth of Lactococcus lactis sp. strain

Study Design: The bacteria strain was grown at different time intervals.

Place and Duration of Study: The work was done at the Microbiology and Fermentation Technology Department, Central Food Technological Research Institute (CFTRI), India, between May 2014 and May 2015.

Methodology: The strain was grown in M17 broth for 56 h to determine the growth curve. Produced volatile compounds were studied by Gas Chromatography and Mass Spectrophotometer (GC-MS) at different phases of culture growth.

Results: Results showed that lag phase was extended for about six h. Exponential phase (log phase) lasted for the next 6 to 18 h, stationary phase 18 to 40 h, and decline phase started after 40 to 48 h. GC-MS analysis of the volatile compounds resulted in the identification of 18, 20, 18, and 17 compounds respectively during the lag phase, the logarithmic phase, the stationary phase and the decline phase. Out of the total of 50 volatiles compounds identified, 4 compounds viz., Benzyl alcohol; Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methyl propyl)-; 5-Isopropylidene-3,3-dimethyl-dihydrofuran-2-one, and Cyclohexane, 1,3,5-trimethyl-2-octadecyl- were present at different peaks area in all growth phases of the cultured strain. Numerous of these volatile compounds produced revealed to possess biological activities.

Conclusion: The incubation period affected the production of volatile compounds. L. lactis was observed to produce wide-ranging bioactive compounds for human therapeutic applications as well as various industrial applications. Also, many secondary metabolites were produced by the strain at the logarithmic phase.