This study was done to determine the effect of pasteurization on the stability of lactic acid bacteria (LAB) and its enzyme in raw and pasteurized cow’s and goat’s milk. The total viable count for plate count of the bacterial growth concentration was higher in both pasteurized cow’s and goat’s milk at 2.48 log CFU/ml. This is followed by raw cow’s milk (1.59 log CFU/ml) and raw goat’s milk (0.65 log CFU/ml). Lactic acid bacteria (LAB) was found to be similar in both raw cow’s and goat’s milk (p>0.05), and pasteurized milk of both animals also contained the same amount of LAB (p>0.05). LAB was still detected in pasteurized milk (p
Kefir is a fermented milk obtained by fermenting milk with kefir grains. The chemical composition ofdairy and non-dairy sources may affect the growth and characterisation of lactic acid bacteria (LAB). In this study, different sources of milk (cow milk) and non-dairy milk (soymilk and coconut milk) were used as the fermentation media for kefir products. The objectives of the study were to isolate and characterise LAB from kefir drink produced from dairy and non-dairy milk. LAB was isolated using different cultural methods, such as MRS Agar, MRS with 0.8% CaCO3, and M17 Agar. The characteristics of the LAB isolates were determined using morphological, biochemical tests and the API 50 CHL kit. The physicochemical composition of the samples was determined using titratable acidity and pH level. Sensory evaluation of the kefir drink samples was also carried out. Results confirmed that the isolates were identified as Lactobacillus buchneri, Lactobacillus brevis 1, Leuconostoc mesenteroides, Lactobacillus acidophilus 3and Lactobacillus plantarum 1. The L. buchneri, L. brevis, Leu. mesenteroides and L. acidophilus are heterofermentative bacteria, whereas L. plantarum is a homofermentative bacterium. Four LAB isolates have the potential to be used as probiotic strains due to their high resistant to low pH and bile salt. The sensory scores of these products range between 5.00 and 8.00 in the 9-point hedonic scale. Most of the sensory panelists preferred cow milk kefir (p < 0.05) compared with coconut milk kefir and soy milk kefir during the sensory evaluation of all attributes. Meanwhile, the preference between coconut milk kefir and soy milk kefir was similar (p>0.05) in all attributes. Therefore, this study will be useful for probiotic manufacturers in the production of alternative probiotic drinks using dairy and non-dairy milk.
Vinegars are most widely used as preservatives in food industry. Vinegars are known for their health benefits; however, the roles of vinegar-associated microflora in locally produced vinegars are not well established. The objectives of this study are to isolate and identify the lactic acid bacteria (LAB) from black rice vinegar and coconut vinegar, measure their pH and titratable acidity, and determine their antibacterial activity. LAB was isolated using cultural method. Phenotypic characterization of LAB was carried out using Gram-staining, oxidase test, catalase test and API 50 CHL Kit. Results from API 50 CHL Kit confirmed that BRV03M strain from black rice vinegar and CV03M strain from coconut vinegar were Lactobacillus paracaseissp. paracasei. The identified bacteria in both samples were consistent as L. paracaseiusing 16S rDNAgene sequences with 93% and 99% similarity, respectively. The pH and titratable acidity percentage of both vinegars were also determined. The stability of Cell Free Supernatant-Lactic Acid Bacteria (CFS-LAB) strains within 14 days on their inhibition against selected pathogenic bacteria was determined using agar well diffusion method. The CFS-LAB strain isolated from black rice vinegar (BRV03M) was more stable within 14 days than coconut vinegar in inhibiting tested bacteria, suggesting this strain has great potential as natural antibacterial agents.
Antibiotic resistance is an ever
increasing in worldwide problem nowadays. It is happened when t he exten-
sive use of antibiotics which will creates the selective pressure resulting from mutation of normal genes and
spreading of a variety of an antimicrobial resistance. Uses of Lactobacillus as probiotics or in starter cul-
tures may serve as hosts of antibiotic resistance genes, which could be transfer or resistance to multiple an-
tibiotics. Therefore it is important to screen the susceptible or resist ance towards antibiotics which will not
tr ansferable resistance genes. In the recent study, a total of 3 7 strains of Lactobacillus species isolated from
various milk and dairy products such as goat ’s milk, cattle ’s milk , human ’s milk , homemade yogurt and
commercial yogurt were examined for the a ntibiotic p rofile using Kirby Bauer method . The results of this
study show that human’s milk has a high number of Lactobacillus isolates resistant to ampicillin (75%),
vancomycin (62.5%) and gentamycin (62.5%). Whereas Lactobacillus isolated from cattle’s milk have re-
sistant to ampicillin (42.1%), vancomycin (42.1%) and susceptible to gentamycin (0%). But however,
goat’s milk stil l has lower percentage number of resistant to ampicillin (28.0%), vancomycin (14.3%) and
are susceptible to gentamycin (0%). These results indicate that ampicillin and vancomycin resistant seems
to be very common among Lactobacillus isolates bu t g entamyci n are still susceptible used. Vancomycin
resistant are more concerned because of the emerging problem in hospital and often described as one of the
last resorts against the infection caused by multidrug resistant pathogens. Therefore, lactobacilli as probi ot-
ics would be more monitor ing when applied in food industry and clinical especially for immune
compromised patients or during anti biotherapy. Acquisition and retransfer of resistance genes should be
addressed in the new safety aspects of probiotics uses.