In vitro and in vivo characterization and strain safety of Lactobacillus reuteri NCIMB 30253 for probiotic applications

2012 ◽  
Vol 58 (6) ◽  
pp. 776-787 ◽  
Author(s):  
Imran Sulemankhil ◽  
Mathieu Parent ◽  
Mitchell Lawrence Jones ◽  
Zhenqian Feng ◽  
Alain Labbé ◽  
...  

Lactobacillus reuteri NCIMB 30253 was shown to have potential as a probiotic by reducing the proinflammatory chemokine interleukin-8. Moreover, this strain was evaluated, by in vitro and in vivo techniques, for its safety for human consumption. The identity of the strain was investigated by metabolic profiling and 16S rRNA gene sequencing, and in vitro safety evaluations were performed by molecular and metabolic techniques. Genetic analysis was confirmed by assessing the minimum inhibitory concentration to a panel of antibiotics, showing that the strain was susceptible to 8 antibiotics tested. The ability of the strain to produce potentially harmful by-products and antimicrobial compounds was evaluated, showing that the strain does not produce biogenic amines and does not show bacteriocin activity or reuterin production. A 28-day repeated oral dose study was conducted in normal Sprague–Dawley rats to support the in vivo strain safety. Oral administration of the strain resulted in no changes in general condition and no clinically significant changes to biochemical and haematological markers of safety relative to vehicle control treated animals. This comprehensive assessment of safety of L. reuteri NCIMB 30253 supports the safety of the strain for use as a probiotic.

2018 ◽  
Vol 17 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Nadarajan Viju ◽  
Nagarajan Ezhilraj ◽  
Chellamnadar Vaikundavasagom Sunjai Shankar ◽  
Stanislaus Mary Josephine Punitha ◽  
Sathianeson Satheesh

AbstractBacteria associated with surfaces have been frequently cited as a potential source for the isolation of bioactive metabolites. In this study, bacteria associated with marine gastropod, Babylonia sp. were isolated and screened for antibacterial activity against biofilm-forming bacteria. The antibiofilm and antifouling effect of the selected surface- associated bacterial strains were examined under in vitro and in vivo conditions. Results showed that the extracellular polymeric substances (EPS) of the bacterial strain CML associated with gastropod species considerably reduced the adhesion of biofilm-forming bacteria on glass coupons. Besides, the antifouling coat prepared by incorporating of this EPS into polyurethane varnish prevented the settlement of biofoulers on test substratum submerged in marine waters. The functional groups present in the EPS were analyzed using FT-IR. The bacterium responsible for the production of the bioactive EPS was identified as Bacillus subtilis subsp. by 16S rRNA gene sequencing. More detailed characterization of the identified bioactive EPS could lead to the isolation of a novel natural antifouling product.


2019 ◽  
Vol 65 (2) ◽  
pp. 42-50 ◽  
Author(s):  
Amanul Islam ◽  
Shahinur Kabir ◽  
Abul Khair

Abstract In quest of prospective rizospheric bacteria of agricultural importance, one of the isolates from bean (Lablab niger Medikus) was identified as Bacillus siamensis based on morphological, biochemical and 16S rRNA gene sequencing data. Study was carried out to evaluate growth promotion of two tomato cultivars, in vitro and in vivo. Experiments conducted for two consecutive years, following seed treatments revealed that the bacterial isolate increased plant height by 14.66‒15.68%, shoot fresh weight by 34.5‒65.09% and root fresh weight by 75.3‒92.48% over the non-treated control. The bacterial strain showed encouraging results for plant growth promotion in pot study and hence may be useful for the growth enhancement of tomato plant.


2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Musa Saheed Ibrahim ◽  
Beckley Ikhajiagbe

Abstract Background Rice forms a significant portion of food consumed in most household worldwide. Rice production has been hampered by soil factors such as ferruginousity which has limited phosphorus availability; an important mineral component for the growth and yield of rice. The presence of phosphate-solubilizing bacteria (PSB) in soils has been reported to enhance phosphate availability. In view of this, the present study employed three bacteria species (BCAC2, EMBF2 and BCAF1) that were previously isolated and proved P solubilization capacities as inocula to investigate the growth response of rice germinants in an in vitro setup. The bacteria isolates were first identified using 16S rRNA gene sequencing and then applied as inoculum. The inolula were prepared in three concentrations (10, 7.5 and 5.0 ml) following McFarland standard. Viable rice (var. FARO 44) seeds were sown in petri dishes and then inoculated with the three inocula at the different concentrations. The setup was studied for 28 days. Results 16S rRNA gene sequencing identified the isolates as: isolate BCAC2= Bacillus cereus strain GGBSU-1, isolate BCAF1= Proteus mirabilis strain TL14-1 and isolate EMBF2= Klebsiella variicola strain AUH-KAM-9. Significant improvement in rice germination, morphology, physiology and biomass parameters in the bacteria-inoculated setups was observed compared to the control. Germination percentage after 4 days was 100 % in the inoculated rice germinants compared to 65% in the control (NiS). Similarly, inoculation with the test isolates enhanced water-use efficiency by over 40%. The rice seedlings inoculated with Bacillus cereus strain GGBSU-1 (BiS) showed no signs of chlorosis and necrosis throughout the study period as against those inoculated with Proteus mirabilis strain TL14-1 (PiS) and Klebsiella variicola strain AUH-KAM-9 (KiS). Significant increase in chlorophyll-a, chlorophyll-b and alpha amylase was observed in the rice seedlings inoculated with BiS as against the NiS. Conclusion Inoculating rice seeds with Bacillus cereus strain GGBSU-1, Proteus mirabilis strain TL14-1 and Klebsiella variicola strain AUH-KAM-9 in an in vitro media significantly improved growth parameters of the test plant. Bacillus cereus strain GGBSU-1 showed higher efficiency due to a more improved growth properties observed.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1519
Author(s):  
Meinan Chang ◽  
Fengtao Ma ◽  
Jingya Wei ◽  
Junhao Liu ◽  
Xuemei Nan ◽  
...  

Previous studies have shown that Bacillus subtilis natto affects rumen fermentation and rumen microbial community structure, which are limited to detect a few microbial abundances using traditional methods. However, the regulation of B. subtilis natto on rumen microorganisms and the mechanisms of microbiota that affect rumen fermentation is still unclear. This study explored the effects of live and autoclaved B. subtilis natto on ruminal microbial composition and diversity in vitro using 16S rRNA gene sequencing and the underlying mechanisms. Rumen fluid was collected, allocated to thirty-six bottles, and divided into three treatments: CTR, blank control group without B. subtilis natto; LBS, CTR with 109 cfu of live B. subtilis natto; and ABS, CTR with 109 cfu of autoclaved B. subtilis natto. The rumen fluid was collected after 0, 6, 12, and 24 h of fermentation, and pH, ammonia nitrogen (NH3-N), microbial protein (MCP), and volatile fatty acids (VFAs) were determined. The diversity and composition of rumen microbiota were assessed by 16S rRNA gene sequencing. The results revealed LBS affected the concentrations of NH3-N, MCP, and VFAs (p < 0.05), especially after 12 h, which might be attributed to changes in 18 genera. Whereas ABS only enhanced pH and NH3-N concentration compared with the CTR group (p < 0.05), which might be associated with changes in six genera. Supplementation with live B. subtilis natto improved ruminal NH3-N and propionate concentrations, indicating that live bacteria were better than autoclaved ones. This study advances our understanding of B. subtilis natto in promoting ruminal fermentation, providing a new perspective for the precise utilization of B. subtilis natto in dairy rations.


Author(s):  
Chen Zheng-li ◽  
Peng Yu ◽  
Wu Guo-sheng ◽  
Hong Xu-Dong ◽  
Fan Hao ◽  
...  

Abstract Burns destroy the skin barrier and alter the resident bacterial community, thereby facilitating bacterial infection. To treat a wound infection, it is necessary to understand the changes in the wound bacterial community structure. However, traditional bacterial cultures allow the identification of only readily growing or purposely cultured bacterial species and lack the capacity to detect changes in the bacterial community. In this study, 16S rRNA gene sequencing was used to detect alterations in the bacterial community structure in deep partial-thickness burn wounds on the back of Sprague-Dawley rats. These results were then compared with those obtained from the bacterial culture. Bacterial samples were collected prior to wounding and 1, 7, 14, and 21 days after wounding. The 16S rRNA gene sequence analysis showed that the number of resident bacterial species decreased after the burn. Both resident bacterial richness and diversity, which were significantly reduced after the burn, recovered following wound healing. The dominant resident strains also changed, but the inhibition of bacterial community structure was in a non-volatile equilibrium state, even in the early stage after healing. Furthermore, the correlation between wound and environmental bacteria increased with the occurrence of burns. Hence, the 16S rRNA gene sequence analysis reflected the bacterial condition of the wounds better than the bacterial culture. 16S rRNA sequencing in the Sprague-Dawley rat burn model can provide more information for the prevention and treatment of burn infections in clinical settings and promote further development in this field.


2020 ◽  
Vol 8 (4) ◽  
pp. 486
Author(s):  
Hila Korach-Rechtman ◽  
Oren Rom ◽  
Lirane Mazouz ◽  
Shay Freilich ◽  
Helana Jeries ◽  
...  

During the last few decades there has been a staggering rise in human consumption of soybean-oil (SO). The microbiome and specific taxa composing it are dramatically affected by diet; specifically, by high-fat diets. Increasing evidence indicates the association between dysbiosis and health or disease state, including cardiovascular diseases (CVD) and atherosclerosis pathogenesis in human and animal models. To investigate the effects of high SO intake, C57BL/6 mice were orally supplemented with SO-based emulsion (SOE) for one month, followed by analyses of atherosclerosis-related biomarkers and microbiota profiling by 16S rRNA gene sequencing of fecal DNA. SOE-supplementation caused compositional changes to 64 taxa, including enrichment in Bacteroidetes, Mucispirillum, Prevotella and Ruminococcus, and decreased Firmicutes. These changes were previously associated with atherosclerosis in numerous studies. Among the shifted taxa, 40 significantly correlated with at least one atherosclerosis-related biomarker (FDR < 0.05), while 13 taxa positively correlated with the average of all biomarkers. These microbial alterations also caused a microbial-derived metabolic-pathways shift, including enrichment in different amino-acid metabolic-pathways known to be implicated in CVD. In conclusion, our results demonstrate dysbiosis following SOE supplementation associated with atherosclerosis-related biomarkers. These findings point to the microbiome as a possible mediator to CVD, and it may be implemented into non-invasive diagnostic tools or as potential therapeutic strategies.


2021 ◽  
Author(s):  
Yuanyuan Wang ◽  
Hao Xu ◽  
Minghui Wei ◽  
Yuhong Wang ◽  
Wenzhe Wang ◽  
...  

Abstract BackgroundOrofacial granulomatosis (OFG) is a granulomatous inflammation (GI) disease in maxillofacial region, the underlying cause of it remains unknown. Our previous study demonstrated that tooth apical periodontitis (AP) plays a significant role in the pathogenesis of OFG, we aimed here to characterize the AP bacterial signatures of OFG patients, and identify bacteria that may be important pathogens capable of inducing OFG.ResultsThe composition of AP microbiota in OFG cases and common AP controls was compared using 16S rRNA gene sequencing, the results showed a specific AP microbiota signature in OFG patients, characterized by domination of phyla Firmicutes and Proteobacteria , notably members of Streptococcus, Lactobacillus and Neisseria. To assess the pathogenicity of the potential pathogens in OFG, we isolated and successfully in vitro cultured Streptococcus, Lactobacillus casei, Neisseria subflava, Veillonella parvula and Actinomyces from OFG patients, and injected the clinical isolates into mice respectively. Ultimately, foot pad injection with N. subflava elicited granulomatous inflammation, and the virulence of N. subflava was verified based on Koch’s postulates.ConclusionsOur findings confirmed the role of bacteria in OFG, and first suggested that the component of the host normal microbiota, N. subflava is likely a pathogen for GI.


Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 140
Author(s):  
Farideh Ghadamgahi ◽  
Saeed Tarighi ◽  
Parissa Taheri ◽  
Ganapathi Varma Saripella ◽  
Alice Anzalone ◽  
...  

P. aeruginosa strain FG106 was isolated from the rhizosphere of tomato plants and identified through morphological analysis, 16S rRNA gene sequencing, and whole-genome sequencing. In vitro and in vivo experiments demonstrated that this strain could control several pathogens on tomato, potato, taro, and strawberry. Volatile and non-volatile metabolites produced by the strain are known to adversely affect the tested pathogens. FG106 showed clear antagonism against Alternaria alternata, Botrytis cinerea, Clavibacter michiganensis subsp. michiganensis, Phytophthora colocasiae, P. infestans, Rhizoctonia solani, and Xanthomonas euvesicatoria pv. perforans. FG106 produced proteases and lipases while also inducing high phosphate solubilization, producing siderophores, ammonia, indole acetic acid (IAA), and hydrogen cyanide (HCN) and forming biofilms that promote plant growth and facilitate biocontrol. Genome mining approaches showed that this strain harbors genes related to biocontrol and growth promotion. These results suggest that this bacterial strain provides good protection against pathogens of several agriculturally important plants via direct and indirect modes of action and could thus be a valuable bio-control agent.


2021 ◽  
Author(s):  
Li Wang ◽  
Man-Yun Chen ◽  
Li Shao ◽  
Wei Zhang ◽  
Xiang-Ping Li ◽  
...  

Abstract Background: Panax notoginseng saponins (PNS) as the main effective substances from P. notoginseng with low bioavailability could be bio-converted by human gut microbiota. In our previous study, PNS metabolic variations mediated by gut microbiota have been observed between high fat, high protein (HF-HP)-diet and low fat, plant fiber-rich (LF-PF)-diet subjects. In this study, we aimed to correspondingly characterize the relationship between distinct gut microbiota profiles and PNS metabolites. Methods: Gut microbiota were collected from HF-HP and LF-PF healthy adults, respectively and profiled by 16S rRNA gene sequencing. PNS were incubated with gut microbiota in vitro. A LC-MS/MS method was developed to quantify the five main metabolites yields including ginsenoside F1 (GF1), ginsenoside Rh2 (GRh2), ginsenoside compound K (GC-K), protopanaxatriol (PPT) and protopanaxadiol (PPD). The selected microbial species, Bifidobacterium adolescentis and Lactobacillus rhamnosus, were employed to metabolize PNS for the corresponding metabolites.Results: The five main metabolites were significantly different between the two diet groups. Compared with HF-HP group, the microbial genus Blautia, Bifidobacterium, Clostridium, Corynebacterium, Dorea, Enhydrobacter, Lactobacillus, Roseburia, Ruminococcus, SMB53, Streptococcus, Treponema and Weissella were enriched in LF-PF group, while Phascolarctobacterium and Oscillospira were relatively decreased. Furthermore, Spearman’s correlative analysis revealed gut microbiota enriched in LF-PF and HF-HP groups were positively and negatively associated with PNS metabolites yields, respectively. Conclusions: Our data showed gut microbiota diversity led to the personalized bioconversion of PNS.


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