Lactic Acid Bacteria
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2021 ◽  
Vol 11 (21) ◽  
pp. 9867
Author(s):  
Mihaela Dumitru ◽  
Dan Cristian Vodnar ◽  
Simon Elemer ◽  
Georgeta Ciurescu ◽  
Mihaela Habeanu ◽  
...  

A total of 15 strains of lactic acid bacteria (LAB) were isolated from the broiler chicken’s gastrointestinal tract. All isolates were phenotypical and genetically identified. Among these isolates, only six were biochemical (API 50 CHL and ABIS soft) and genetically (16S rRNA sequencing) confirmed as Lactobacillus acidophilus, Limosilactobacillus fermentum, Levilactobacillus brevis, and Ligilactobacillus salivarius. Probiotic properties, including tolerance to pH (pH 2.0 and 3.0), bile salts (0.3% oxgall), hemolysis activity, and antibiotic susceptibility, were evaluated. Three isolates of the latter isolates showed high resistance at low pH values (73.74% to 98.20%) and bile salt concentrations (77.89% to 99.49%). The antibiotic test presented 100% resistance of LAB to gentamicin, lincomycin, enrofloxacin, and streptomycin lower than the 0.5 mm inhibition zone diameter. Selected strains (L. acidophilus IBNA 64, L. salivarius IBNA 33, and L. salivarius IBNA 41) were exposed to the spray-drying process based on observable probiotic potential. A maltodextrin-glucose solution was used as a thermoprotectant. After spray drying, a reduction in strain viability was noted (108 to 104 CFU/g). In conclusion, only L. salivarius (IBNA 33 and IBNA 41) could be used as a possible probiotic, and further studies are needed to ensure their safe application in the animal nutrition field with beneficial effects for improving performance and pathogen microorganism control from intestines equilibrating the microbiota composition.


Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 238
Author(s):  
Sung-Joon Mo ◽  
Bora Nam ◽  
Chu-Hyun Bae ◽  
Soo-Dong Park ◽  
Jae-Jung Shim ◽  
...  

Red ginseng has powerful potential for use as a prebiotic, but its use is limited due to its antibacterial activity. The aim of this study is to present panax ginseng’s endophytic lactic acid bacteria capable to overcome the antibacterial activity of red ginseng and improve their characteristic. Lactobacillus paracasei HY7017 (HY7017) was cultured in a medium supplemented with red ginseng. The probiotic properties and immune-enhancing effects of HY7017 were investigated in vitro and in vivo. HY7017 was proliferated strongly in RGE and had significantly improved properties compared with an L. paracasei type strain ATCC25302. HY7017 cultured in RGE-supplemented medium increased the production of nitric oxide, TNF-α, and IL-6 in macrophages, and increased IL-12 and IFN-γ secretion in splenocytes. Furthermore, HY7017 restored WBC counts, increased the amount of IL-2 and IFN-γ released, and enhanced the cytotoxicity of natural killer cells when orally administered to immunosuppressed mice. Moreover, HY7017 has properties that make it suitable as a probiotic, such as stability in the gastrointestinal tract and adhesion to Caco-2 cells. This study showed that HY7017 cultured with RGE may contribute to the development of probiotics to enhance immunity.


2021 ◽  
Vol 8 ◽  
Author(s):  
Aprajita Singh ◽  
Sajjad Karimi ◽  
Aleksandar Vidakovic ◽  
Johan Dicksved ◽  
Markus Langeland ◽  
...  

Changes in gut microbial composition over time in rainbow trout fed differentially processed diets supplemented with the filamentous fungi Neurospora intermedia were investigated in a 30-day feeding trial. Fish were fed a reference diet, non-preconditioned diet (NPD), or preconditioned (heat-treated) diet (PD), with the same inclusion level of N. intermedia in diets NPD and PD. Gut microbiota were analyzed on day 0, 10, 20, and 30. Gut microbial composition was similar for all diets on day 0, but was significantly different at day 10 and day 20. On day 30, the gut again contained similar communities irrespective of diet. The overall gut microbiota for each diet changed over time. Abundance of Peptostreptococcus and Streptococcus was higher in the initial days of feeding in fish fed on commercial diet, while a significant increase in lactic acid bacteria (Lactococcus lactis) was observed on day 30. Feed processing (preconditioning) did not contribute largely in shaping the gut microbiome. These results indicate that dietary manipulation and duration of feeding should be considered when evaluating gut microbial composition in cultured fish. A minimum 30-day feeding trial is suggested for gut microbiome, host and diet interaction studies.


Author(s):  
José R. Linares-Morales ◽  
Iván Salmerón-Ochoa ◽  
Blanca E. Rivera-Chavira ◽  
Néstor Gutiérrez-Méndez ◽  
Samuel B. Pérez-Vega ◽  
...  

Author(s):  
Azita Faraki ◽  
Fatemeh Rahmani

Probiotics and Lactic Acid Bacteria play important roles such as the production of antimicrobial compounds and other metabolites. So they have positive effects on human health. When reactive oxygen species generated in excess or cellular defenses are deficient, biomolecules can be damaged by the oxidative stress process. Various studies have shown that the best way to protect the human body from the effects of oxidation reactions is to avoid them, which can be accomplished by using antioxidants. Due to the damages of synthetic antioxidants, their usage has been discussed. Nowadays natural antioxidants derived from bio-resources have recently gained a lot of attention as a potential replacement for synthetic antioxidants. Probiotic bacteria are thought to defend against oxidative stress by restoring the gut microbiota, according to hypothesis of some scientists. This type of microorganisms indicated their antioxidant activity by producing and increasing antioxidant enzymes, production of secondary metabolites, small hydrolyzed peptides in food, resistance to the presence of hydrogen peroxide, and production of intracellular and extracellular compounds such as Exopolysaccharides. Also, they have shown their positive effect on in vivo models. In conclusion, according to the results of studies, lactic acid bacteria and probiotics are significant sources of natural antioxidants. Therefore, they have important research value and market development potential. Also, it should be noted that the mechanism of antioxidant activity of this group of microorganisms has not been fully investigated, this requires further research.


Author(s):  
Iraj Hasani ◽  
Abbas Akhavan Sepahi ◽  
Shahram Shoeibi ◽  
Gholamhassan Asadi Aghdash

Different strains of lactic acid bacteria are the most common micro-organisms known as probiotics. Two major kinds of probiotic bacteria are members of the genera Lactobacillus and Bifidobacterium, that are generally associated with the genus Lactobacillus which play a vital role in the body health, as well as the ability to produce antimicrobials and vitamins in the gastrointestinal tract. The purpose of the study was the isolation of probiotics in traditional cheeses that are produced from the natural flora of the newborn mammalian digestive tract. Bacteria from lamb and kid abomasum are added to milk. The curd is slaughtered from the abomasum of a lamb or kid that is suckling and has now no longer began out to devour forage, after which its belly is dried, that is referred to as curd. In this study, sixteen samples of cheeses local to Markazi province of Iran have been prepared. The isolated bacteria have been examined for morphological, biochemical, probiotic properties, and molecular identity. Out of sixteen traditional cheese samples, five kinds of Lactobacillus have been diagnosed through PCR. L. casei strain J026 strain was identified in the traditional cheese samples as the most genera. Using probiotic starters from local sources is a beneficial strategy for producing traditional cheese, which the native strains are more compatible with the humans’ intestinal flora and therefore may also higher play their probiotic’s characteristic.


2021 ◽  
Author(s):  
Lucas von Gastrow ◽  
Remy Amelot ◽  
Diego Segond ◽  
Stephane Guezennec ◽  
Florence Valence ◽  
...  

Understanding how microbes disperse in ecosystems is critical to understand the dynamics and evolution of microbial communities. However, microbial dispersal is difficult to study because of uncertainty about the vectors that may contribute to their migration. This applies to both microbial communities in natural and human-associated environments. Here, we studied microbial dispersal among French sourdoughs and flours used to make bread. Sourdough is a naturally fermented mixture of flour and water. It hosts a community of bacteria and yeasts whose origins are only partially known. We analyzed whether flour is a carrier of sourdough yeast and bacteria and studied whether microbial migration occurs between sourdoughs. The microbial community of a collection of 46 sourdough samples, as well as that of the flour from which each was made, was studied by 16S rDNA and ITS1 metabarcoding. No sourdough yeast species were detected in the flours. Sourdough lactic acid bacteria (LAB) were found in only five flour samples, and they did not have the same amplicon sequence variant (ASV) as found in the corresponding sourdough. The species shared between the sourdough and flour samples are commonly found on plants and are not known to be alive in sourdough. Thus, the flour microorganisms did not appear to grow in the sourdough microbial community. Dispersal between sourdoughs was also studied. Sourdoughs shared no yeast ASV, except in few cases where groups of three to five bakers shared some. These results suggest that there is little migration between sourdoughs, except in a few situations where bakers may exchange sourdough or be vectors of yeast dispersal themselves.


Author(s):  
Pranotee Gawade

Abstract: Biopreservation is the method of employing natural microflora and their antimicrobial compounds to extend the storage life and improve the safety of foods. Streptococcus lactis was the first pure strain of lactic acid bacteria which was isolated from milk by Liszt. He named it bacterium lactis. Lactic acid bacteria are gram-positive, acid-tolerant, have low Guanine-Cytosine content and are generally non-sporulating, non-respiring, either spherical cocci or rod-shaped bacilli bacteria that share most of them their metabolic and physiological characteristics. These bacteria are mostly present in decomposing plants and milk products. They have an increased tolerance to acidity. Most species are incapable of respiration and therefore media used for lactic acid bacteria include a carbohydrate source. At the end of carbohydrate fermentation, these bacteria give out lactic acid as a major end product. The review focuses on the process of lactic acid production by lactic acid bacteria and its expanding importance in a variety of disciplines. Keywords: Lactic acid bacteria, bio preservative, food, microflora


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