Proteolytic activity of three probiotic strains in semi-hard cheese as single and mixed cultures: Lactobacillus acidophilus, Lactobacillus paracasei and Bifidobacterium lactis

2009 ◽  
Vol 19 (8) ◽  
pp. 467-475 ◽  
Author(s):  
C.V. Bergamini ◽  
E.R. Hynes ◽  
S.B. Palma ◽  
N.G. Sabbag ◽  
C.A. Zalazar
Author(s):  
Shahin Zomorodi

The present study was investigated the survival of probiotic strains, namely Lactobacillus acidophilus (LAFTI-L10) and Bifidobacterium lactis (LAFTI-B94), in both microencapsulated and free forms in Doogh as a yogurt drink. The effects of probiotic strains on physicochemical and sensory properties, stability, and microstructures of Doogh were evaluated during storage for 45 days in a cold room at a temperature of 5±1 °C. The statistical analysis of the results showed that the number of L. acidophilus and B. lactis in free forms decreased about 1.1 and 2.2 log cycles, respectively. However, the number of the microencapsulated forms were remained relatively constant during the storage period. Both free and microencapsulated forms were successful in keeping the counts of L. acidophilus and B. lactis in Doogh high enough for the therapeutic minimum (106-107 cfug-1) after 45 days. Nonetheless, the number of microencapsulated probiotics was higher than that of the free cells. The acidity, pH, and stability were significantly different between the samples. The microstructure of the samples was affected by the microencapsulation of bacteria because the sample distribution of the clusters and particles was more regular in the samples containing microencapsulated probiotics than in those containing free forms. According to the results of sensory evaluations, probiotics not only exerted no adverse effects on the physicochemical and sensory properties of Doogh but also improved the stability, microstructure, and flavor of this drink. Therefore, Doogh can be considered an effective food carrier for the delivery of probiotic organisms.


2021 ◽  
pp. 136-143
Author(s):  
Yu. O. Shulpekova ◽  
V. Yu. Rusyaev

This article reviewed the mechanisms of action of probiotics and the possible effects of individual strains on the general wellbeing if they are taken daily.The content and activity of bacteria in food products should be regulated by special guidelines. The balanced nutrition allows us to get healthy strains in a natural way. Daily consumption of certain strains as part of functional food products is promising for the prevention of obesity, type 2 diabetes mellitus, non-alcoholic fatty liver disease, functional intestinal disorders, colon cancer, cardiovascular diseases and depression. The issues of safety of novel probiotic strains newly introduced in clinical practice require careful consideration. Synbiotics can comprise probiotic strains of bacteria (Lactobacillus acidophilus La-14, Lactobacillus rhamnosus Lr-32, Bifidobacterium lactis Bl-04) with tolerance to acid, pepsin and bile salts, as well as the prebiotic inulin and vitamins B1, B2, B6 and B12 contributing to survival of beneficial bacteria. L. acidophilus is a common probiotic that occurs in the natural environment and food products, no cases of antibiotic resistance of this species have been established. Strains Lactobacillus acidophilus La-14, Lactobacillus rhamnosus Lr-32, Bifidobacterium lactis Bl-04 have a high adhesion capacity, strong inhibitory effects on intestinal pathogens, including fungi, anti-inflammatory effects, help to eliminate oxalates. As can be seen from the above, the use of probiotics and synbiotics is one of the most promising preventive fields of medicine.


2005 ◽  
Vol 71 (10) ◽  
pp. 5794-5804 ◽  
Author(s):  
M. Andrea Azcarate-Peril ◽  
Olivia McAuliffe ◽  
Eric Altermann ◽  
Sonja Lick ◽  
W. Michael Russell ◽  
...  

ABSTRACT Two-component regulatory systems are one primary mechanism for environmental sensing and signal transduction. Annotation of the complete genome sequence of the probiotic bacterium Lactobacillus acidophilus NCFM revealed nine two-component regulatory systems. In this study, the histidine protein kinase of a two-component regulatory system (LBA1524HPK-LBA1525RR), similar to the acid-related system lisRK from Listeria monocytogenes (P. D. Cotter et al., J. Bacteriol. 181:6840-6843, 1999), was insertionally inactivated. A whole-genome microarray containing 97.4% of the annotated genes of L. acidophilus was used to compare genome-wide patterns of transcription at various pHs between the control and the histidine protein kinase mutant. The expression pattern of approximately 80 genes was affected by the LBA1524HPK mutation. Putative LBA1525RR target loci included two oligopeptide-transport systems present in the L. acidophilus genome, other components of the proteolytic system, and a LuxS homolog, suspected of participating in synthesis of the AI-2 signaling compound. The mutant exhibited lower tolerance to acid and ethanol in logarithmic-phase cells and poor acidification rates in milk. Supplementation of milk with Casamino Acids essentially restored the acid-producing ability of the mutant, providing additional evidence for a role of this two component system in regulating proteolytic activity in L. acidophilus.


2019 ◽  
Vol 16 (1) ◽  
pp. 0010
Author(s):  
Raheem Et al.

This study focuses on the biodegradation of oxymatrine insecticide by some soil fungi isolated from four agriculture stations. The results showed that the highest degradation rate 94.66% was recorded by Ulocladium sp. at 10 days and A. niger recorded the lowest degradation rate 45.86%, while at 20 days Ulocladium sp. also showed the highest degradation rate 94.98% and the lowest degradation rate reached to 82.49% with A.niger. The mix (Exerohilum sp.+Ulocladium sp.) recorded the highest degradation rate of oxymatrine insecticide 90.22%, 88.51%, 85.34%  at 4, 8 and 12 ppm.The use of mixed isolates enhanced the biodegradation process. There is no study of oxymatrine biodegradation so this study is the first of its kind in the region which can be used as a baseline study for incoming studies


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