scholarly journals Detection of extracellular bound proteinase in EPS-producing lactic acid bacteria cultures on skim milk agar

2001 ◽  
Vol 33 (1) ◽  
pp. 45-49 ◽  
Author(s):  
T. Pailin ◽  
D.H. Kang ◽  
K. Schmidt ◽  
D.Y.C. Fung
2017 ◽  
Vol 21 (1) ◽  
pp. 9 ◽  
Author(s):  
Wendry Setiyadi Putranto ◽  
Kusmajadi Suradi ◽  
Hartati Chairunnisa ◽  
Apon Zaenal Mustopa ◽  
Puspo Edi Giriwono ◽  
...  

The Lactic Acid Bacteria with Milk Clotting Activity (MCA) were isolated from Bakasam, an Indonesian traditional fermented meat. The isolate screening was carried out using modified method of Skim Milk Agar and Milk Clotting Activity Test, and the isolate was then identified using 16S rRNA. We found 4 isolates that showed MCA of 18-20 SU/ml. Identification using 16S rRNA indicated that the isolate ALG.1.15 was 99% (FR3-F primer) and 99% (FR3-R primer) identic with Enterococcus faecium. The isolate potentially produced renin-like protease to subtitute renin from veal.  


2007 ◽  
Vol 70 (6) ◽  
pp. 1518-1522 ◽  
Author(s):  
V. B. SUÁREZ ◽  
M. L. CAPRA ◽  
M. RIVERA ◽  
J. A. REINHEIMER

The capacity of three phosphates to interrupt the lytic cycle of four specific autochthonal bacteriophages of lactic acid bacteria used as starters was assayed. The phosphates used (polyphosphates A and B and sodium tripolyphosphate–high solubility [TAS]) were selected on the basis of their capacity to sequester divalent cations, which are involved in the lytic cycle of certain bacteriophages. The assays were performed in culture media (deMan Rogosa Sharpe and Elliker broths) and reconstituted (10%, wt/vol) commercial skim milk to which phosphates had been added at concentrations of 0.1, 0.3, and 0.5% (wt/vol). Phosphate TAS was the most inhibitory one, since it was able to inhibit the lytic cycle of all bacteriophages studied, in both broths and milk. In broth, polyphosphates A and B inhibited the lytic cycle of only two bacteriophages at the maximal concentration used (0.5%), whereas in milk, they were not capable of maintaining the same inhibitory effect.


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.


2009 ◽  
Vol 57 (10) ◽  
pp. 4433-4438 ◽  
Author(s):  
Chin-Feng Liu ◽  
Chun-Ling Hu ◽  
Shen-Shih Chiang ◽  
Kuo-Chuan Tseng ◽  
Roch-Chui Yu ◽  
...  

2015 ◽  
Vol 76 ◽  
pp. 478-488 ◽  
Author(s):  
Xufeng Zheng ◽  
Nan Fu ◽  
Manlei Duan ◽  
Meng Wai Woo ◽  
Cordelia Selomulya ◽  
...  

2007 ◽  
Vol 74 (4) ◽  
pp. 387-391 ◽  
Author(s):  
Maria BT Ortolani ◽  
Gabriela N Viçosa ◽  
Vanerli Beloti ◽  
Luís A Nero

This study aimed to compare Petrifilm™ Aerobic Count (AC) plates and the conventional pour plate methodology using de Mann-Rogosa-Sharpe (MRS), Kang-Fung (KF) and Kang-Fung-Sol (KFS) culture media for screening and enumeration of lactic acid bacteria (LAB) in milk. Suspensions of 10 LAB species in reconstituted powder skim milk and 30 raw milk samples, without experimental inoculation, were tested. For selective enumeration, all samples were previously diluted in MRS, KF and KFS broths and then plated in Petrifilm™ AC and conventional pour plate methodology, using the same culture media with added agar. All plates were incubated at 37°C for 48 h in anaerobic conditions. Differences in the counts were observed only for raw milk samples using KFS in conventional methodology, when compared with the counts obtained from MRS and KF (P⩽0·05). The results showed excellent correlation indexes between both methodologies using the three culture media for LAB suspensions (r=0·97 for MRS, KF and KFS). For raw milk samples, the correlation indexes were excellent (r=0·97, for MRS) and good (r=0·84 for KF, and r=0·82 for KFS), showing some interference in Petrifilm™ AC when supplements were added, especially lactic acid. These results indicate the possibility of using Petrifilm™ AC plates for enumeration of LAB in milk, even with the use of selective supplements.


2004 ◽  
Vol 71 (1) ◽  
pp. 116-120 ◽  
Author(s):  
Ashraf N Hassan ◽  
Milena Corredig ◽  
Joseph F Frank ◽  
Morsi Elsoda

The objective of this research was to determine the effect of exopolysaccharide (EPS) production by lactic acid bacteria on the microstructure and rheology of Karish cheese, a soft acid coagulated cheese made using skim milk. An EPS-producing strain of Streptococcus thermophilus, and its EPS non-producing genetic variant were used to make comparable batches of the cheese. EPS in cheese was visualized by cryo-SEM as a large, dense, filamentous mass. Cheese made with the EPS non-producing culture was characterized by a dense protein network with smaller pores compared to that prepared with the EPS-producing culture. High elastic and viscous moduli measured by dynamic rheology were observed for EPS negative cheese and was attributed to its dense protein network. Creep test experiments demonstrated that cheese prepared with the EPS non-producing strain was more rigid and recovered its deformation, while cheese made using the EPS producing culture was more deformable. These results indicate that EPS-producing cultures can improve the physical properties of Karish cheese by reducing undesirable rigidity.


1993 ◽  
Vol 60 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Carmen Wacher-Rodarte ◽  
Marcia V. Galvan ◽  
Amelia Farres ◽  
Francisco Gallardo ◽  
Valerie M. E. Marshall ◽  
...  

SummaryUsing polymer producing (ropy) strains of lactic acid bacteria it was possible to reduce considerably the syneresis of yogurt, even with 12% total milk solids. The viscosities obtained with these strains were also similar to those obtained using normal strains and milk with 17% total solids content. The concentration of milk and the polymer produced by ropy starters had a synergic effect in increasing viscosity. Polymer production was not affected in most cases by milk concentration. One type of ropy culture (Wiesby) seemed to produce a different kind of polymer as it could not be determined by alcohol precipitation, in spite of being able to reduce syneresis and increase viscosity in yogurt. A limited number of yogurts were evaluated organoleptically, one prepared with a ropy starter strain (NCFB at 12, 14·5 and 17% total solids) and one prepared with a non-ropy strain (LL-I at 17% total solids). The results suggest that the ropy strain yogurts had different mouthfeel from the non-ropy strain yogurts; the most acceptable product overall was the ropy strain made with 12% total solids.


2021 ◽  
Vol 16 (3) ◽  
pp. 190-199
Author(s):  
Badat Muwakhid ◽  
Anik Maunatin ◽  
Anif Mukaromah Wati

The aim of this study was to evaluate the effect of the types of encapsulation materials, that is skimmed milk and Arabic gum on two probiotics Lactic Acid Bacteria (LAB), including L. plantarum DJ2 and L. plantarum DJ3. The methods of this study were separated into two stages that is probiotic resistance testing during the spray drying process and the viability of LAB after spray drying during storage of probiotic powder for one month at 4oC. Changes in the viability of LAB probiotics before and after the drying process using spray drying were determined by the total plate count. The viability of lactic acid bacteria (LAB) was observed every week for one month of storage at 4oC. The results showed that different encapsulation materials had significant different (P ≤ 0.05) on changes in resistance of probiotics powder during spray drying process. The use of Arabic gum could increase the resistance of probiotics during the spray drying process, meanwhile, the use of skimmed milk was better to be able to maintain the viability of dry probiotic powder both on L.plantarum DJ2 and L.plantarum DJ3 during storage. After four weeks of storage, there was mold and yeast in the skimmed milk and Arabic gum materials. In conclusion, both Arabic gum and skim milk could be used for encapsulation where storage of dry probiotic products is recommended during one month at 4 oC.


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