1.Selection of potential lactic acid bacteria from fermented Sumbawa mare’s milk as starter cultures
Ilmiyatus Safitri Devi ; Yoga Dwi Jatmiko
Malaysian Journal of Microbiology 2021;17(1):11-19
Aims:
The aim of this study was to screen lactic acid bacteria (LAB) isolates from fermented Sumbawa mare‘s milk that
meet the requirements as starter cultures, and to evaluate the effect of the selected starter culture in improving the
organoleptic quality of mare‘s milk fermentation.
Methodology and results:
The LAB isolates (13 isolates) derived from naturally fermented Sumbawa mare‘s milk were
firstly screened for acidification activity. Afterwards, the selected isolates were evaluated for the starter culture criteria
such as technological properties (proteolytic test, lipolytic test, and exopolysaccharide production), food safety test
(hemolytic test and antibiotic sensitivity test), antimicrobial activity test. The selected culture (SC) together with yogurt
starter cultures (YC) and combination between the selected isolate and a mixture of both (MC) were used to ferment
fresh mare’s milk. Six LAB isolates (DB7, BC10, DC4, BC9, DC10, and BC7) were obtained from the acidification
screening. Isolate BC10 was the most potential isolate as starter culture due to its ability in terms of acidification and
proteolytic activity, lack of lipolytic activity, no indication of pathogenic potency, as well as able to inhibit the growth of
Escherichia coli ATCC 25922. However, this isolate was resistant to antibiotics kanamycin, trimethoprim, and cinoxacin.
The isolate BC10 presented 99.99% sequence similarity with respect to Lactobacillus plantarum.
Conclusion, significance and impact of study
The selected starter culture (isolate BC10) was able to improve the
organoleptic quality of fermented mare‘s milk especially aroma compared to the other starter cultures. Therefore, L.
plantarum BC10 is a potential isolate to be used as starter culture for mare’s milk fermentation.
Lactobacillales--isolation &
;
purification
2.Probiotic potential of lactic acid bacteria isolated from Vietnamese sour-fermented fish product
Nguyen Pham Anh Thi ; Tran Huu Hau ; Nguyen Thi Nhu Huynh ; Huynh Van Liem ; Tran Kieu Dieu Thi ; Do Phuong Kieu ; Dang Huy Hoa ; Nguyen Thanh Nha ; Nguyen Pham Thien Trang ; Le Nguyen Khoi Nguyen ; Truong Thi Bich Van ; Do Tan Khang
Malaysian Journal of Microbiology 2022;18(2):222-226
Aims:
To isolate and characterize the lactic acid bacteria (LAB) strains from the “mam chua ca ro” (sour fermented fish) in the South of Vietnam and investigate their potential anti-bacterial properties.
Methodology and results:
Four LAB strains (MCR1, MCR2, MCR3 and MCR4) were isolated from the "mam chua ca ro" product and their anti-bacterial activity was determined using the spot assay and the paper disc diffusion method. The isolated LABs can inhibit Escherichia coli ATCC 25922, Staphyloccocus aureus ATCC 25923 and Vibrio parahaemolyticus BV016 and produce bacteriocin to control the growth of E. coli ATCC 25922 and S. aureus ATCC 25923, except V. parahaemolyticus. MCR2 was chosen to sequence 16S rRNA of Pediococcus acidilactic.
Conclusion, significance and impact of study
On the basis of their prominent anti-pathogenic bacteria activity, LAB strains isolated from Vietnamese sour-fermented fish products were verified as prospective probiotics.
Lactobacillales--isolation &
;
purification
;
Pediococcus acidilactici
3.A comparative profile of bactericidal action of a partially purified bacteriocin from lactic acid bacteria with antibiotics
Kojagori Laxmi Rani Bonhi ; Sabiha Imran
Malaysian Journal of Microbiology 2021;17(2):143-154
Aims:
The menace of antibiotic resistance has led to the search for alternatives, which in turn has diverted the attention
to bacteriocins, antimicrobial peptides (AMPs) produced by bacteria for their bactericidal properties. The aim of our study
was to isolate and partially purify bacteriocin from lactic acid bacteria (LAB) and comparing its antimicrobial activity with
antibiotics.
Methodology and results:
Among 38 LAB screened using agar spot assay, LAB 28D1 showed the highest
antimicrobial activity against the test bacterial strains. The proteinaceous nature of the antimicrobial compound extracted
from LAB 28D1 was confirmed by its inactivation after treatment with proteolytic enzymes. The crude bacteriocin was
found to be stable over a wide range of temperatures (60-100 °C) and pH (4-9). The bacteriocin was partially purified by
ammonium sulfate precipitation (ASP) and the activity units were 204,800 AU/mL. The total protein and the specific
activity of partially purified bacteriocin were found to be 24.585 mg and 124,954.24 AU/mg respectively. The molecular
weight of partially purified bacteriocin was determined to be 8.5 kDa approximately. The efficacy of the partially purified
bacteriocin against indicator bacterial strains was compared with antibiotics by the disc diffusion method and minimum
inhibitory concentration (MIC). According to our study, the hospital waste isolate Enterococcus spp. was found to be
multidrug-resistant (MDR) but sensitive to bacteriocin from LAB (MIC 0.06 ± 0 µg/mL).
Conclusion, significance and impact of the study
Bacteriocin from LAB has potential in combating MDR
enterococcal infections.
Bacteriocins--isolation &
;
purification
;
Lactobacillales
;
Drug Resistance, Microbial
4.Antimicrobial profile of lactic acid bacteria isolated from vegetables and indigenous fermented foods of India against clinical pathogens using microdilution method.
Ami PATEL ; Nihir SHAH ; Padma AMBALAM ; J B PRAJAPATI ; Olle HOLST ; Asa LJUNGH
Biomedical and Environmental Sciences 2013;26(9):759-764