scholarly journals Flow Cytometric Assessment of Viability of Lactic Acid Bacteria

2001 ◽  
Vol 67 (5) ◽  
pp. 2326-2335 ◽  
Author(s):  
Christine J. Bunthof ◽  
Karen Bloemen ◽  
Pieter Breeuwer ◽  
Frank M. Rombouts ◽  
Tjakko Abee

ABSTRACT The viability of lactic acid bacteria is crucial for their applications as dairy starters and as probiotics. We investigated the usefulness of flow cytometry (FCM) for viability assessment of lactic acid bacteria. The esterase substrate carboxyfluorescein diacetate (cFDA) and the dye exclusion DNA binding probes propidium iodide (PI) and TOTO-1 were tested for live/dead discrimination using aLactococcus, a Streptococcus, threeLactobacillus, two Leuconostoc, anEnterococcus, and a Pediococcus species. Plate count experiments were performed to validate the results of the FCM assays. The results showed that cFDA was an accurate stain for live cells; in exponential-phase cultures almost all cells were labeled, while 70°C heat-killed cultures were left unstained. PI did not give clear live/dead discrimination for some of the species. TOTO-1, on the other hand, gave clear discrimination between live and dead cells. The combination of cFDA and TOTO-1 gave the best results. Well-separated subpopulations of live and dead cells could be detected with FCM. Cell sorting of the subpopulations and subsequent plating on agar medium provided direct evidence that cFDA labels the culturable subpopulation and that TOTO-1 labels the nonculturable subpopulation. Applied to cultures exposed to deconjugated bile salts or to acid, cFDA and TOTO-1 proved to be accurate indicators of culturability. Our experiments with lactic acid bacteria demonstrated that the combination of cFDA and TOTO-1 makes an excellent live/dead assay with versatile applications.

2010 ◽  
Vol 27 (Special Issue 2) ◽  
pp. 12-17
Author(s):  
K. Kučerová ◽  
I. Korbová ◽  
Š. Horáčková ◽  
E. Šviráková ◽  
M. Plocková

A collection of lactic acid bacteria (38 Enterococcus and 41 Lactobacillus strains) was tested for the antilisterial activity against 15 Listeria spp. strains (two L. monocytogenes, one L. ivanovii and 12 L. innocua strains) using agar spot method. Out of all 79 bacteria only six Enterococcus strains (1/3A, 3/3A, 6/4D, 6/1A, 1282 and EN3) exhibited antilisterial activity against almost all used indicator strains, when their live cells were tested. When their cell free neutralised supernatants (CFNS) were tested against four selected indicator strains (L. innocua Ln-03, Ln-06, Ln-10 and L. monocytogenes CCM5576) only two Enterococcus spp. strains were active – E. faecalis 6/1A strain from raw cow milk of minor interest due to the activity of its CFNS only against L. innocua Ln-06 and thermolability of the compound and E. mundtii 1282 strain from goat raw milk with CFNS active against 13 Listeria spp. strains including L. monocytogenes. E. mundtii 1282 strain produced probably a bacteriocin, because it completely lost the activity after treatment CFNS with proteinase K.


2014 ◽  
Vol 98 (11) ◽  
pp. 4897-4909 ◽  
Author(s):  
Gerald Bensch ◽  
Marc Rüger ◽  
Magdalena Wassermann ◽  
Susann Weinholz ◽  
Udo Reichl ◽  
...  

Author(s):  
J Aquarista Ingratubun ◽  
Frans G Ijong ◽  
Hens Onibala

Food fermentation is one of various food processing techniques that has sufficient benefits of nutrition values, and also contains lactic acid bacteria which potentially inhibit pathogenic bacteria, thus prolong shelf life of  products. Bakasang is a traditional fermented food from North Sulawesi since many years ago. Reported research of bakasang previously had described that lactic acid bacteria was the dominant isolates and therefore current research  aimed to isolate and identify the lactic acid bacteria which associated during fermentation day 1 and day 15, respectively. Raw materials used were 5 kg intestine and liver of skipjack brought from local market Bersehati Manado. The intestine and liver of skipjack were washed and smashed and mixed with 10% salt  and 5% rice  from weight of the samples and then filled into bottle to be fermented for 15 days. Every 3 days (1,3,6,9,12,15), the samples were collected and analyzed for total lactic acid bacteria by using Total Plate Count Method on de Mann Rogosa Sharpe Agar after incubation at 37°C for 24 h. The colonies  grown were transferred to Tryptic Soy Broth and followed by streaking them on Tryptic Soy Agar and the free growing colony on agar medium were isolated into slant agar which were used for biochemical test such as Gram’s staining, motility test, catalase test, oksidase test, H2S test, IMVIC test (Indole, Methyl Red, Voges Proskauer, Citrate) and carbohydrate fermentation. The results showed that Lactobacillus sp., Bacillus sp., Eubacterium sp., and Bifidobacterium sp. All these four bacteria were distributed from day 1 to day 15 of the fermentation process© Fermentasi bahan pangan merupakan salah satu dari sekian banyak teknik pengolahan makanan yang mempunyai banyak manfaat dari kualitas gizi, mengandung bakteri asam laktat sehingga menghambat bakteri patogen sehingga daya simpan lebih panjang. Bakasang merupakan makanan fermentasi tradisional masyarakat Sulawesi Utara yang sudah ada sejak lama. Penelitian yang telah dilakukan terhadap bakasang menghasilkan informasi bahwa terdapat bakteri asam laktat pada bakasang sehingga menjadi tujuan untuk mengisolasi dan identifikasi bakteri asam laktat selama proses fermentasi 1-15 hari. Bahan baku bakasang ialah jeroan (usus dan hati) ikan cakalang Katsuwonis pelamis sebanyak 5 kg yang diambil dari pasar Bersehati Manado. Sampel jeroan dibersihkan kemudian dihancurkan, ditambahkan garam 10% dan nasi 5% kemudian difermentasi selama 15 hari dengan mengambil tiap-tiap sampel setiap 1, 3, 6, 9, 12, dan 15 untuk dihitung jumlah bakteri asam laktat dengan menggunakkan metode Total Plate Count pada media de Mann Rogosa Sharpe Agar dan koloni yang tumbuh di tumbuhkan  kembali pada media Tryptic Soy Broth  dan digores kembali pada media Tryptic Soy Agar, koloni yang tumbuh digores pada media slant agar yang selanjutnya diidentifikasi bakteri asam laktat berdasarkan uji biokimia yaitu uji pewarnaan Gram, uji motility, uji katalase, uji oksidase, uji H2S dan uji IMVIC (Indole, MethylRed, Voges Proskauer, Citrate). Hasil menunjukkan bahwa selama proses fermentasi berlangsung terdapat 4 genera bakteri asam laktat sesuai yaitu Lactobacillus sp., Bacillus sp., Eubacterium sp., dan Bifidobacterium sp., ke 4 genera ini tersebar pada fermentasi hari 1 sampai hari ke 15©


1988 ◽  
Vol 51 (8) ◽  
pp. 600-606 ◽  
Author(s):  
MICHELLE M. SCHAACK ◽  
ELMER H. MARTH

The ability of Listeria monocytogenes to grow and compete with mesophilic lactic acid bacteria was examined. Autoclaved skim milk was inoculated with 103 cells of L. monocytogenes (strain V7 or Ohio)/ml, and with 5.0, 1.0, 0.5 or 0.1% of a milk culture of either Streptococcus cremoris or Streptococcus lactis. Inoculated milks were fermented for 15 h at 21 or 30°C, followed by refrigeration at 4°C. Samples were plated on McBride Listeria Agar to enumerate L. monocytogenes and on either APT Agar or plate count agar to enumerate lactic acid bacteria. L. monocytogenes survived in all fermentations, and commonly also grew to some extent. Incubation at 30°C with 5% S. lactis as inoculum appeared to be the most inhibitory combination for strain V7, causing 100% inhibition in growth based on maximum population attained. S. cremoris at the 5.0% and 0.1% inoculum levels, was slightly less inhibitory to L. monocytogenes at 37°C, but it was slightly more inhibitory to L. monocytogenes at the 1.0% inoculum level than was S. lactis. In general, S. lactis reduced the pH of fermented milks more than did S. cremoris. The population of L. monocytogenes began to decrease before 15 h in only one test combination, which was use of a 5.0% inoculum of S. cremoris and 30°C incubation. In most instances, growth of the pathogen appeared to be completely inhibited when the pH dropped below 4.75.


Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 586
Author(s):  
Heba Mostafa

To produce a new probiotic-containing food product, potato chips, as the most preferred fast food, were chosen. Preferably, it should be preserved for a long period without oxidation. The presented study aimed to compare potato chips containing two lyophilized probiotic lactic acid bacteria (Bifidobacterium longum ATCC 15708 and Lactobacillus helveticus LH-B02) in order to retard lipid oxidation. Lyophilization of probiotics was carried out into two cryoprotective media—skim milk (SM) and gelatin/glycerol (GG) as lactose-free medium. Results revealed that GG and SM media were the most suitable for lyophilization of B. longum and L. helveticus, respectively. The lyophilized live cells were incorporated in potato chips, packed and their effect on oil oxidation was assessed. Results showed that the lyophilized B. longum in SM remained alive at 6.5 log CFU/g for 4 months at 30 °C. Interestingly, potato chip bags containing B. longum lyophilized in SM medium exhibited a decrease in peroxide value (PV) and acid value (AV) of the extracted oil by 40.13% and 25%, respectively, compared to the control bags. The created probiotic potato chips containing B. longum fulfill the criteria of the probiotic product besides the prime quality and sensory attributes.


2012 ◽  
Vol 524-527 ◽  
pp. 2167-2171
Author(s):  
Ting Ting Ning ◽  
Chun Cheng Xu ◽  
Hui Li Wang ◽  
Wei Hao ◽  
Heng Lei

This experiment was conducted to determine the ensiling characteristics and microbial changes of fodder ramie silage treated without additive (Control), or with molasses (M), lactic acid bacteria (LAB), and mixtures of lactic acid bacteria and molasses (LABM). Triplicate samples were randomly opened on days 0, 3, 7, 14, 28 and 60 of ensiling for sampling and the contents were processed for quality assessment and laboratory analysis. Compared with control silage, addition of M and LABM decreased pH and butyric acid while increasing lactic acid during ensiling (P < 0.05). For the LAB treatment, the pH value declined slowly at initial days then kept relatively stable at about 5.39 and the concentration of lactic acid increased for the first 7 days then maintained stable until day 60. The control silage showed a rise in pH and a significant decline in lactic acid concentration at later stage. Microbial changes had similar trend during ensiling for all the treatments where the lactic acid bacteria increased at initial days then showed a decline at later stage. Furthermore, LAB treatment had the highest (P<0.05) lactic acid bacteria population at almost all ensiling periods. It was concluded that both M and LABM treatment can improve the fermentation quality of fodder ramie silage to some extent, but the effects of adding lactic acid bacteria still need further research.


2018 ◽  
Author(s):  
Pauline Destinugrainy Kasi ◽  
Ariandi ◽  
Heni Mutmainnah

Sago extraction processing into sago flour is generally still done in a traditional or semi-mechanical way, with less attention to aspects of hygiene, and resulted sago fermentation spontaneously. This study aimed to isolate and characterize indigenous lactic acid bacteria (LAB) from sago wastewater which obtained directly from the traditional sago processing industry in Malangke Barat, South Sulawesi. The sago wastewater was stored for 1, 3 and 7 days of fermentation. The research was conducted on the LAB isolation and purification on MRS agar medium supplemented with 0.5% CaCO3. Two purified putative LAB isolate were each obtained from 1 day fermentation and 3 days fermentation. The LAB isolate from 1 day fermentation has milky white colors and smooth-round colonies, while LAB isolates from 3 days fermentation has creamy colors and smooth-round colonies. Both of the isolate were gram positive-rods, non-motile and negative catalase reaction.


2020 ◽  
Vol 4 (4) ◽  
pp. 257
Author(s):  
Lusia Yotista Enggal Parasthi ◽  
Diana Nur Afifah ◽  
Choirun Nissa ◽  
Binar Panunggal

Background: Diarrhea disease is one of gastrointestinal disorders which is the second leading cause of death in children under five years. Food and beverage contamination is the biggest cause of diarrhea in developing countries. Nanas madu (Ananas comosus Merr.) and cinnamon (Cinnamomum burmannii) have antibacterial properties that can inhibit the growth of Escherichia coli and Salmonella typhi causing diarrhea.Objective: This study aimed to analyze the total differences of Lactic Acid Bacteria (LAB) and antibacterial activity in yoghurt with the addition of nanas madu and cinnamon extract.Methods: This was an experimental study with various treatment in adding honey cream pineapple (0%, 20%, 40%, and 60%) and cinnamon extract (4% and 6%). Total LAB was calculated using the Total Plate Count (TPC) method and antibacterial activity was tested using Kirby Bauer method.Results: There was no significant difference in yoghurt with the addition of honey cream pineapple and cinnamon extract. Yoghurt with the highest LAB was yoghurt with addition 40% of honey cream pineapple and 6% of cinnamon extract (N40M2) with total LAB 1,43 x 1019 CFU/ml. The results of the antibacterial activity showed no significant difference of inhibition zone against S. typhi¸ while there was significant difference of inhibition zone against E. coli. The highest activity against S. typhi was yoghurt with addition 60% of honey cream pineapple and 4% of cinnamon extract (N60M1) resulting 6,81 mm inhibition zone and the highest activity against E. coli was N40M1 resulting 6,77 mm of inhibition zone. Conclusion: Total LAB yoghurt with the addition of nanas madu and cinnamon extract have met FAO and SNI standards with LAB minimum 107 CFU/ml. Antibacterial activity of all yoghurt treatment categorized as medium inhibition (5-10 mm). 


2019 ◽  
Vol 7 (1) ◽  
pp. 85-92
Author(s):  
Annytha Detha

The purpose of this study was to isolate and identify the lactic acid bacteria found in Sumba mares milk. This research will be carried out from September to November 2017 at the Veterinary Laboratory of the Livestock Service Office of East Nusa Tenggara Province. The research stages are isolation of lactic acid bacteria from Sumba mares milk by growing lactic acid bacteria on MRS agar media, and identifying lactic acid bacteria with gram staining, catalase test, motility test, and total plate count testing. Based on the results of the study, the presence of lactic acid bacteria originating from Sumba mares milk was characterized by the presence of colonies of lactic acid bacteria from Sumba mares milk which grew on MRS media agar as a selective medium for lactic acid bacteria. Based on the results of testing the characteristics of lactic acid bacteria Sumba mares milk has Gram positive, the negative results in the catalase test are characterized by not forming gas bubbles when the bacteria are added with H2O2. Based on the motility test obtained negative results or bacteria are non-motile and the number of lactic acid bacteria that can be a total picture of lactic acid bacteria that exist in Sumba mares milk in milliliter of milk. The conclusion are lactic acid bacteria isolated from Sumba mares milk has characteristic as Gram positive, basil or stem shaped, negative catalase and non motile, and has a total lactic acid bacteria of 3.5 x 108 cfu/ml (est).      


Sign in / Sign up

Export Citation Format

Share Document