ABSTRACT
Aims@#Bacterial lysate has been reported to possess many health-care-related benefits. This study aimed to determine the optimum conditions for producing Weissella confusa MBF8-1 lysate in two plant-based modified De Man, Rogosa, and Sharpe (MRS) media using the response surface methodology (RSM). In this study, we applied several condition factors and compared them to standard MRS media. @*Methodology and results@#Weissella confusa MBF8-1 was grown in two modified MRS media, which are MRS Vegitone and soy peptone modified-MRS. The optimized fermentation condition factors such as nitrogen sources (i.e., soy peptone, proteose peptone), dextrose concentrations, and fermentation time were measured, and the responses, such as bacteriocin-like inhibitory substance (BLIS) activity and lysate pH were observed. RSM results showed the diameter of BLIS activity-inhibition zone and pH decreases of the lysate produced in MRS Vegitone containing 1.50% dextrose, 0.75% proteose peptone for 11.75 h fermentation and in soy peptone modified-MRS containing 2.05% dextrose, 1.05% soy peptone for 7.53 h fermentation, i.e., 7.41 mm at 7.36, and 7.80 mm at 7.30, respectively. Whereas, lysate produced in standard MRS medium containing 2% dextrose, 1% peptone for 8 h fermentation showed 7.85 mm diameter of BLIS activity-inhibition zone at pH 7.26. W. confusa MBF8-1 lysate showed slightly lower pH, but higher BLIS activity when grown in standard MRS media compared to those of the two modified MRS media. @*Conclusion, significance and impact of study@#The data obtained provide the optimum condition of W. confusa MBF8-1 lysate production in plant-based media. The pH and BLIS activity possessed by W. confusa MBF8-1 lysate produced in soy peptone modified-MRS showed a more similar result as the standard one than the other modified one. Thus, the soy peptone modified-MRS is recommended as a plant-based alternative medium replacing standard MRS.
Subject(s)
WeissellaABSTRACT
OBJECTIVE@#To characterize the bacteriocin-like inhibitory-substances (BLIS) activity of Streptococcus macedonicus MBF10-2 [named BLIS(MBF10-2)], a bacteriocinogenic strain isolated from an Indonesian tofu byproduct.@*METHODS@#BLIS(MBF10-2) was obtained by culturing the bacterium, and standard deferred antagonism assays were used to demonstrate its activity. The antibacterial testing of fractions collected by filtration using 3-30 kDa cut-off membrane sizes were carried out by performing well diffusion method.@*RESULTS@#The growth of Micrococcus luteus, Streptococcus pyogenes, Lactococcus lactis, Leuconostoc mesenteroides and Weissella confusa were inhibited by BLIS(MBF10-2). Interestingly, BLIS-containing fractions obtained from sequential application on ultrafiltration membranes indicated that this bacterium Streptococcus macedonicus MBF10-2 could produces at least two antimicrobial peptides activities, one of which is likely to be a lantibiotic peptide. Potential synergistic activity against certain Gram-positive (but not Gram-negative) species when partnered with antibiotics (ampicillin, tetracycline or kanamycin) were observed.@*CONCLUSION@#Combination of some BLIS(MBF10-2) active fractions with antibiotics (ampicillin, tetracycline or kanamycin) could demonstrate synergistic activities against certain Gram-positive species.
ABSTRACT
Objective To characterize the bacteriocin-like inhibitory-substances (BLIS) activity of Streptococcus macedonicus MBF10-2 [named BLIS(MBF10-2)], a bacteriocinogenic strain isolated from an Indonesian tofu byproduct. Methods BLIS(MBF10-2) was obtained by culturing the bacterium, and standard deferred antagonism assays were used to demonstrate its activity. The antibacterial testing of fractions collected by filtration using 3–30 kDa cut-off membrane sizes were carried out by performing well diffusion method. Results The growth of Micrococcus luteus, Streptococcus pyogenes, Lactococcus lactis, Leuconostoc mesenteroides and Weissella confusa were inhibited by BLIS(MBF10-2). Interestingly, BLIS-containing fractions obtained from sequential application on ultrafiltration membranes indicated that this bacterium Streptococcus macedonicus MBF10-2 could produces at least two antimicrobial peptides activities, one of which is likely to be a lantibiotic peptide. Potential synergistic activity against certain Gram-positive (but not Gram-negative) species when partnered with antibiotics (ampicillin, tetracycline or kanamycin) were observed. Conclusion Combination of some BLIS(MBF10-2) active fractions with antibiotics (ampicillin, tetracycline or kanamycin) could demonstrate synergistic activities against certain Gram-positive species.