Beneficial Lactic Acid Bacteria
K. Balamurugan, U. Prithika in Pocket Guide to Bacterial Infections, 2019
Agriculture, medicine, and food industry are not the only application fields for LAB and their products. Many cosmetic ingredients have been developed using LAB and bifidobacteria. Supernatants of these bacteria contain lactate and amino acids, which contribute to the hydration of the skin. Studies revealed that skim milk fermented by Streptococcus thermophilus had skin hydrating, antioxidative, cytoprotective, and pH control effects. Aloe vera fermented by Lactobacillus plantarum possessed four times higher skin moistening effect than nonfermented A. vera juice. Soybean milk fermented by Bifidobacterium breve demonstrated the potential to enhance hyaluronic acid production in human cell culture. Streptococcus thermophilus YIT 2084 proved capable to produce hyaluronic acid used as conventional cosmetic ingredient (Izawa and Sone 2014). Lactic acid itself is primarily used as moisturizer and pH regulator, additionally possessing multiple other properties such as antimicrobial activity, skin lightening, and hydration (Vijayakumar et al. 2008).
What Milk and Dairy Products Can Do for the Human Body
Mehwish Iqbal in Complementary and Alternative Medicinal Approaches for Enhancing Immunity, 2023
Yoghurt has religious importance as a holy food product and is utilised in many spiritual festivals and ceremonies among Buddhists and Hindus. Traditional yoghurt is manufactured by cooling buffalo or cow milk to room temperature, subsequently adding artisanal cultures (acquired by the black slopping method) which are permitted to develop and multiply overnight or within two to four days gradually, depending on the season, till the adjusted product is established. Commercially, yoghurt is synthesised by fermentation of boiled or pasteurised cow or buffalo milk, utilising both moderate temperature (mesophilic) and heat-loving (thermophilic) determined starters in different blends. The frequently established LAB cultures in preparation of yoghurt are strains of Lactococcus lactis ssp. cremoris, Streptococcus thermophilus, Lactobacillus acidophilus, Lactococcus lactis ssp. lactis, Lactobacillus helveticus, Lactococcus lactis ssp. lactis biovar diacetylactis and Lactobacillus delbrueckii ssp. bulgaricus (Mallappa et al., 2021). Moreover, many authors have investigated the microbial variation of yoghurt utilising culture-reliant methods (Koirala et al., 2014; Soomro & Masud, 2007) (Table 23.1).
Non-VLPs
Paul Pumpens in Single-Stranded RNA Phages, 2020
Concerning the immune activity of the CRISPR system against RNA phages, a breakthrough investigation was performed by Virginijus Šikšnys’ excellent team (Tamulaitis et al. 2014). By their investigation of nucleic acid specificity and mechanism of CRISPR interference for the Streptococcus thermophilus complex, the authors found that the type III-A StCsm complex targeted RNA and not DNA. When expressed in E. coli, the StCsm complex restricted the phage MS2 in a Csm3 nuclease-dependent manner. It was stressed by the authors that the phage MS2 is a preferable model to investigate RNA targeting by the CRISPR-Cas system in vivo because no DNA intermediate is formed during the life cycle of this phage. The pCRISPR_MS2 plasmid carried the synthetic CRISPR array of five repeats interspaced by four 36-nucleotide spacers targeting correspondingly the maturation, lysis, coat, and replicase sequences of MS2 RNA. The data demonstrated clearly that the StCsm complex conveyed in vivo resistance to the RNA phage MS2 in the heterologous E. coli host (Tamulaitis et al. 2014).
High intake of dietary fructose in overweight/obese teenagers associated with depletion of Eubacterium and Streptococcus in gut microbiome
Published in Gut Microbes, 2019
Roshonda B Jones, Tanya L Alderete, Jeniffer S Kim, Joshua Millstein, Frank D Gilliland, Michael I Goran
The aim of this study was to identify associations between individual dietary macronutrients and components of the gut microbiome of adolescents. Results suggest that dietary fructose intake is negatively associated with the abundance of the bacterial species Eubacterium eligens. It is known that E. eligens, along with other members of the phylum Firmicutes, have fewer polysaccharide-degrading enzymes than those members of the phylum Bacteroidetes.27 One study showed that the related species Eubacterium rectale, which is involved in butyrate production, is decreased in mice that were fed a high sugar diet.27 Results shown here also suggest that dietary fructose consumption is negatively associated with microbes belonging to the genus Streptococcus, including the species Streptococcus thermophilus. Streptococcus thermophilus has been shown to ferment lactose and sucrose and can also metabolize the monosaccharide fructose.28 However, the link between fructose and the overall genus of Streptococcus is still largely unexplored. Remarkably, while the specific species Streptococcus thermophilus is known to be non-pathogenic, the microbes belonging to the genus Streptococcus was associated with the development of multiple metabolic disorders.29 Results from the current study suggest that high levels of fructose could also be related to low abundances of the beneficial bacteria Streptococcus thermophilus.
Lactic acid bacteria and bifidobacteria deliberately introduced into the agro-food chain do not significantly increase the antimicrobial resistance gene pool
Published in Gut Microbes, 2022
Vita Rozman, Petra Mohar Lorbeg, Primož Treven, Tomaž Accetto, Majda Golob, Irena Zdovc, Bojana Bogovič Matijašić
The distribution of MICs is shown in Supplementary Figure S1. In bifidobacteria, a bimodal distribution, indicative of acquired resistance,13 was observed for tetracycline, erythromycin, and clindamycin, whereas in lactococci it was also observed for aminoglycosides (gentamicin, kanamycin, streptomycin, neomycin). Leuconostoc isolates exhibited susceptibility to five groups of antimicrobials but showed presumed acquired resistance to kanamycin, neomycin, and clindamycin (Supplementary Table S1). On the other hand, a large proportion of pediococci displayed resistance to several antimicrobials with a unimodal distribution of MICs. Consistent with considerable evidence of acquired resistance in enterococci,10 bimodal or multimodal distributions of MICs were noted for each antimicrobial tested, with the exception of vancomycin. Surprisingly, resistance in Streptococcus thermophilus and Staphylococcus sp. was detected at a very low frequency (Supplementary Table S1).
The effect of leech extracts on endothelial cell coagulation-related factors and endothelial dysfuction-related molecules
Published in Clinical and Experimental Hypertension, 2019
Lixu Xu, Xue Li, E Zhang, Hao Liang, Weiting Li, Shangyi Wang, Shuliang Song, Aiguo Ji
Lactobacillus was obtained by multiple screening in yogurt containing only Lactobacillus and Streptococcus thermophilus. The yoghurt samples were streaked into MRS solid medium (containing 10 g/L peptone, 10 g/L beef extract, 5 g/L yeast extract, 2 g/L K2HPO4, 0.58 g/L MgSO4·7 H2O, 0.25 g/L MnSO4·H2O, 2 g/L diammonium citrate, 20 g/L glucose, 5 g/L sodium acetate, 8 mL/L twain80, 1.5% - 2% agar) and incubated at 37°C for 2–3 d. Single colonies were picked and crossed again to purify the Lactobacillus strain three times. The purified Lactobacillus strains were sent to Sangon Biotech (Shanghai) Co., Ltd. for 16sRNA gene sequencing and confirmation analysis.
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