1. Bacteriocin-like inhibitory substance (BLIS) activity of Streptococcus macedonicus MBF10-2 and its synergistic action in combination with antibiotics
Sharon Edith GRAZIA ; Sumayyah SUMAYYAH ; Fakhri Subhana HAITI ; Amarila MALIK ; Muhamad SAHLAN ; Muhamad SAHLAN ; Nicholas C.K. HENG
Asian Pacific Journal of Tropical Medicine 2017;10(12):1140-1145
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.
2.Optimization of the production of Weissella confusa MBF8-1 lysate in plant-based media by using response surface methodology
Revi Pribadi ; Sheila Odilia ; Wibowo Mangunwardoyo ; Muhamad Sahlan ; Amarila Malik
Malaysian Journal of Microbiology 2020;16(5):364-374
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.
Weissella