Proteolytic activity of crude cell-free extract of Lactobacillus casei and Lactobacillus plantarum

Nahrung/Food ◽  
1987 ◽  
Vol 31 (3) ◽  
pp. 225-232 ◽  
Author(s):  
F. Z. Hegazi ◽  
I. G. Abo-Elnaga
1993 ◽  
Vol 2 (6) ◽  
pp. 489-496 ◽  
Author(s):  
Anne Pihlanto-Leppälä ◽  
Eero Pahkala ◽  
Veijo Antila

The aim of this study was to examine the enzymatic hydrolysis of κ-casein by isolating and identifying the released peptides. The enzymes employed in the study were chymosin, plasmin and trypsin, as well as a cell-free extract from three Lactobacillus helveticus and nine Lactobacillus casei strains. The findings showed that the bond most sensitive to the proteolytic activity of chymosin was the Phe 105-Met 106. After 24 hours of hydrolysis a few other bonds in the casein macropeptide were also cleaved. Plasmin was found to have weak proteolytic activity under the conditions of this study. When the enzyme-substrate ratio was raised from 1:200 to 1:50, a few peptides were released from the N-terminal region. Trypsin was found to hydrolyze several κ-casein bonds, and peptides were released from almost all regions of the protein. The proteases of Lactobacillus had less effect than chymosin, plasmin or trypsin. The strains could be divided into three categories. L. helveticus strains had activity on bonds in the mid-section and C-terminal region, L. casei strains EB, P3, P8 and A 1 had activity on bonds in the N- and C-terminal regions, while L. casei A5 and M9 had activity only on bonds in the C-terminal region.


1988 ◽  
Vol 51 (6) ◽  
pp. 481-484 ◽  
Author(s):  
GRACIELA M. VIGNOLO ◽  
AIDA PESCE de RUIZ HOLGADO ◽  
GUILLERMO OLIVER

The acid-producing capacity and proteolytic activity of 13 strains of Lactobacillus plantarum and 5 strains of Lactobacillus casei isolated from dry sausages was determined at different temperatures and at different NaCl concentrations. Most strains exhibited a maximum acid-producing rate at 30°C. According to the acidification rate at this temperature, strains were divided into three rate groups: fast (I), medium (II) and slow (III), with titratable acidity values above 1.7, between 0.7 and 1.4, and below 0.7, respectively. The decrease in pH ranged between 3.1 and 3.95 according to the group to which the strains belonged. The addition of 3% NaCl produced a marked decrease in the rate of acidification for strains in group II, a slight decrease for those in group I and no effect for those in group III. The proteolytic activity of the strains under study reached a maximum at 40°C, with values between 5.2 and 10 mg% tyrosine released. At 30°C, and in the presence of 3% NaCl, the greatest activity (5.4 mg% tyrosine) was observed in L. plantarum GV 417 and the lowest (3.4 mg% tyrosine) in L. plantarum GV 420. A decrease of approximately 80% in proteolytic activity for all strains was observed in the presence of 5% NaCl.


2018 ◽  
Vol 3 (3) ◽  
pp. 85
Author(s):  
Novi Permata Sari ◽  
Rafika Sari ◽  
Eka Kartika Untari

Bacteriocin is a secondary metabolite product of lactic acid bacteria (LAB) which have an antimicrobial and potentially as a natural preservative. LAB isolates used in this study were Lactobacillus brevis, Lactobacillus casei and Lactobacillus plantarum. This study aimed to determine the antibacterial activity of bacteriocin produced by each isolate of LAB including the influence of pH and heating variation against Bacillus cereus, Bacillus subtilis and Staphylococcus epidermidis. Antibacterial activity test was done by using disc diffusion method. method. Confirmation test using proteolytic enzyme aimed to analyse that the inhibition zone produced from the activity of bacteriocin. The inhibition zone produced from L. brevis, L. casei and L. plantarum against B. cereus were 15.70, 16.43 and 14.50 mm, against B. subtilis were 13.37, 14.10 and 12.53 mm and against S. epidermidis were 11.37, 14.50 and 12.45 mm. The activity of each bacteriocin decreased with the addition of trypsin and catalase, bacteriocin was active in the pH range of 2-10 and heating temperature of 40-121oC. Statistical test showed that the addition of trypsin, catalase and the variation of pH also heating had significant differences (p<0.05) to antibacterial activity produced by bacteriocin from L. brevis, L. casei and L. plantarum. 


2003 ◽  
Vol 13 (2-3) ◽  
pp. 145-157 ◽  
Author(s):  
Raffaella Di Cagno ◽  
Maria De Angelis ◽  
Vivek K. Upadhyay ◽  
Paul L.H. McSweeney ◽  
Fabio Minervini ◽  
...  

1977 ◽  
Vol 40 (9) ◽  
pp. 600-602 ◽  
Author(s):  
JASJIT SINGH ◽  
B. RANGANATHAN

Biochemical changes in selected gamma-irradiation induced mutants of Lactobacillus bulgaricus and Lactobacillus casei were examined. Cultures were tested after 24 h of incubation at 37 C for titratable and volatile acidities and proteolytic activity. The gamma-irradiation induced mutants exhibited 50–95% greater proteolytic activity than the unirradiated parent culutres. Some of the mutants produced greater titratable and volatile acidities in milk as compared to parent cultures. Two mutant cultures, Lb/G-1 from L. bulgaricus 59 and Lc/G-1 from L. casei RTS released significantly greater amounts of soluble nitrogen and amino nitrogen in whole casein and selected fractions than did parent cultures. Combining the mutant cultures with Streptococcus lactis C10 or Streptococcus cremoris C1 resulted in greater acid producing ability than that of the parent cultures mixed with the streptococci.


Sign in / Sign up

Export Citation Format

Share Document