BackgroundColon cancer (CRC) is one of the most significant health problems worldwide. Using Exopolysaccharides (EPSs)-produced probiotics as alternative colon cancer therapies depends on an anti-tumor effect and influences the immune system. This study isolated different probiotic EPS lactic acid bacteria (LAB) strain producers from traditional Egyptian fermented dairy products to evaluate their antiproliferative and anti-tumor effects on the HCT-116 colon cancer cell line.ResultsEPS LAB were studied for their probiotic and antioxidant activity. The cytotoxicity effects on HCT-116 cells were analyzed. Two isolates Limosilactobacillus fermentum RE 245 (Accession No. PQ215810), and Limosilactobacillus fermentum RE 280 (Accession No. PQ215848) showed resistance against gastrointestinal conditions: low pH (> 40%), bile salt-resistant (57.36% and 76.21%, respectively), more than 90% when exposed to simulated gastric juice conditions. Isolates RE245 and RE 280 had the strongest inhibitory effect on HCT-116 cells reaching 86% and 70%, respectively, with an increase in the ratio of apoptosis induction. The induction of apoptosis was achieved via the up-regulation of IL-2 and the downregulation of BCL-2, PARK, TARC, LIF, IL-4, IL-6, CD1A, and CD1B genes in HCT-116 cells.ConclusionFrom the EPS LAB isolates’ results, they might be an excellent candidate for functional food production and as a potential alternative treatment to treat colon cancer.

PurposeThe soil-borne diseases have limited the development of agricultural production in Guizhou Province of southwest China which was caused by long-term continuous cropping of crops. To reduce the limit factors of continuous cropping of corps has become an urgent problem.MethodsReductive soil disinfestation (RSD) is an environmentally friendly soil amendment technology. In this study, high-throughput sequencing was used to investigate the mechanisms of RSD technology to improve long-term continuous cropping soil health. The examination focused on discerning how RSD influences the composition and structure of the rhizosphere microbial community.ResultThe results demonstrated that: (1) RSD treatment increased the content of soil organic matter (SOM), alkaline hydrolyzed nitrogen (AN), available phosphorus (AP), available potassium (AK) and pH; (2) RSD changed the fungal and bacterial community structure and the relative abundance of pathogenic microorganisms (e.g., Fusarium) was reduced, while the beneficial microorganisms (e.g., Trichoderma and Penicillium) was increased. (3) AN and pH had a greater impact on the bacterial community in the rhizosphere soil than on the fungal community. (4) RSD treatment improved the agronomic traits of tobacco and reduced the disease incidence of root rot disease.ConclusionOur results revealed that RSD treatment improved the physicochemical properties of continuous cropping tobacco soil and maintain the soil nutrient balance, resulting in the effective alleviation of continuous cropping barriers.

Abstract Background Plant growth-promoting rhizobacteria (PGPR) are beneficial microorganisms that inhabit the rhizosphere. PGPR play a role in stimulating plant growth and development and enhancing plant resistance and tolerance to biotic and abiotic stresses. To effectively fulfil their roles, PGPR engage in intricate interactions with one another, a phenomenon that occurs within the rhizosphere. Mainbody. This collaborative synergy among PGPR species within the rhizosphere is essential for them to perform their functions optimally. Nonetheless, the precise mechanisms and dynamics of PGPR-PGPR interactions, particularly at the transcriptomic level, remain the subject of ongoing research. Scientists are actively exploring and studying how these microorganisms interact and coordinate their activities within the rhizosphere, shedding light on the molecular processes underpinning their cooperative efforts. In this review, we undertake a thorough examination centred on the communication systems that regulate interactions among PGPR in the rhizosphere. Our examination delves into the mechanisms by which this communication triggers alterations at both the transcriptomic and metabolomic levels. Additionally, we assess the cutting-edge omics technologies currently available to study these intricate processes. Conclusion Understanding the modes of communication and molecular mechanisms underlying these interactions is crucial for harnessing their full potential, particularly in sustainable agriculture. By exploring transcriptomic and metabolomic alterations driven by these interactions, as well as the integration of advanced omics technologies, researchers can uncover new insights into decoding these complex processes, paving the way for innovative strategies to enhance sustainable agriculture.

BackgroundDue to inadequacies in the current management practices of navel orange orchards in southern Jiangxi, there is a deficiency in phosphorus content and a decline in overall soil quality. Therefore, developing microbial formulations that increase soil fertility while meeting green ecological standards is highly important. Rhizobacteria promote plant growth through various mechanisms, and given the critical role of phosphorus in plant growth and development, the development and application of such microbial agents offer an effective approach to address the aforementioned issues.ResultsThis study screened two strains of bacteria with high phosphate solubilization capabilities from the roots of navel oranges in southern Jiangxi. These strains were inoculated into potted plants to investigate their potential to promote plant growth. A comparison of the growth indicators of the experimental and control groups, as well as the enzyme activity indicators of navel orange leaves, revealed that both strains exhibited good growth-promoting effects. Furthermore, whole-genome sequencing of the two strains was conducted, and by comparing data from 31 housekeeping genes, strain X42 was preliminarily identified as Bacillus bombysepticus, and strain G62 was identified as Bacillus velezensis. The comparison also revealed the presence of phosphate solubilization-encoding genes in both strains, with strain G62 lacking the genes for phytate mineralization and inorganic phosphorus dissolution, which may prevent it from utilizing additional organic phosphorus sources.ConclusionThis study not only confirms the positive impact of two highly efficient phosphate-solubilizing Bacillus strains on the growth of navel oranges in southern Jiangxi but also deepens the understanding of the genetic basis of phosphate-solubilizing traits through whole-genome analysis. These findings are highly important for the development of biofertilizers and their application in sustainable agriculture, especially in terms of improving soil quality and increasing crop yields.

BackgroundHeyndrickxia coagulans, recognized for its probiotic attributes and resilience as an endospore-forming bacterium, is increasingly studied for health supplement applications. This study aimed to evaluate the probiotic potential and safety of novel H. coagulans isolated from stingless bee honey, a new source for this bacterium, and to characterize their multifunctional probiotic properties.ResultsWe isolated two novel H. coagulans, TBRC-18260 and TBRC-18261, and conducted comprehensive in vitro analyses to assess their probiotic traits such as acid and bile salt tolerance, self-aggregation, and pathogen inhibition. Both isolates were also evaluated for safety through antibiotic susceptibility testing and hemolytic activity. Functional properties, including GABA production, antioxidant activity, were examined to establish their potential as probiotics. TBRC-18260 and TBRC-18261 exhibited core probiotic characteristics and showed excellent survivability under acidic conditions and in the presence of bile salts. They displayed strong antimicrobial activity against various pathogens and demonstrated significant GABA production and antioxidant capabilities. The safety assessments confirmed their non-hemolytic nature and susceptibility to a wide range of antibiotics.ConclusionThe novel H. coagulans isolates, TBRC-18260 and TBRC-18261, with their robust probiotic properties, antioxidant activities, and safety profiles, emerged as promising candidates for the development of functional foods and dietary supplements. This study enhances the biodiversity of available probiotics and supports the continuous search for novel strains with unique health-promoting characteristics.

BackgroundOral diseases with high prevalence worldwide are recognized as severe health problems. Probiotics are used to prevent oral diseases, including dental caries, oral malodor, periodontitis, and subgingival plaque. In this study, we aimed to confirm the antibacterial effect of probiotics on oral pathogens and to assess their characterization and safety as probiotics.MethodsThe antibacterial effects of Lacticaseibacillus rhamnosus MG4706, Lacticaseibacillus paracasei MG4715, and Limosilactobacillus reuteri MG4722 on the growth biofilm formation of Streptococcus mutans, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis were evaluated. We also investigated the production of antibacterial substances (H2O2 and reuterin) by these strains and their ability to adhere to oral epithelial cells. The safety of L. reuteri MG4722 was verified through whole-genome sequencing analysis and antibiotic susceptibility, lactate dehydrogenase activity, hemolytic activity, and bile acid hydrolase activity. The reuterin biosynthesis genes of L. reuteri MG4722 were identified using genomic analysis.ResultsL. reuteri MG4722 significantly inhibited the growth of S. mutans, A. actinomycetemcomitans, and P. gingivalis and suppressed the biofilm formation by A. actinomycetemcomitans. In addition, it showed considerable adhesion ability to oral epithelial cells. L. reuteri MG4722 produced H2O2 and reuterin as antibacterial substances, as confirmed by the presence of genes encoding the antibacterial compounds reuterin, reuteran, and reutericyclin. L. reuteri MG4722 showed no hemolysis, bile salt hydrolase activity, antibiotic resistance or toxicity to HT-29 cells, and no antibiotic-resistance genes were identified.ConclusionL. reuteri MG4722 demonstrated antibacterial effects on oral pathogens by producing antibacterial substances and adhering to oral epithelial cells. These results suggest that L. reuteri MG4722 could be an effective probiotic for oral health.

BackgroundThe ubiquity of ammonical nitrogen (NH3-N) in aquatic habitats is a contradictory phenomenon since it serves a crucial function in maintaining these ecosystems, yet when levels are too high, they can have adverse effects on ecological balance and human welfare. An extensive set of batch tests were used in this study to see how well the bacterial species Klebsiella sp. broke down ammonical nitrogen (NH3-N).ResultsThe research results established that Klebsiella sp. has a remarkable capacity to adapt to ammonical nitrogen concentrations of up to 125 mg/l over a long period of time. The adaptation process depends on several factors such as biomass abundance, ammonical nitrogen concentration, pH, and temperature. This study identified the optimal method for the absorption of ammonical nitrogen (NH3-N) from a solution at a concentration of 100 parts per million (ppm), achieving an efficiency of 89 ± 1.5% mg/g under specified conditions. At a pH of 6.5, the adsorbent dosage was 0.3 g in 50 milliliters of NH3-N at a temperature of 26 degrees C. We used an extensive range of analytical techniques, such as Scanning Electron Microscopy, Xray diffraction, Brunauer-Emmett-Teller analysis, Transmission Electron Microscopy, and Fourier-Transform Infrared Spectroscopy, to confirm the accuracy of our results. The study also showed that the biosorption process closely followed pseudo-second-order kinetics and the Langmuir model, which propose that both physical and chemical processes were involved. The thermodynamic studies also showed that this process can happen on its own and can be used in industry.ConclusionThis study emphasizes the great ability of Klebsiella sp. to reduce NH3-N, providing important knowledge for water quality management and aquatic ecosystem preservation.Graphical

IntroductionRice root gall is a severe infection caused by the rice root-knot nematode Meloidogyne graminicola. Overuse of chemical nematicides intensifies the need for a suitable biocontrol agent. Nematode infestation in plants alters the associated microbiome; however, their correlations need to be better understood. Hence, this work aimed to unravel the changes in indigenous endophytic bacterial community composition of rice root because of infection caused by M. graminicola and also to identify dominant bacteria strains as a potential biological control agent.Material & MethodsThe endophytic bacterial community of non-infected rice root and gall was analysed using a 16 S rRNA gene-based metagenomics approach. The dominant endophytic bacterial community was further isolated and screened for its PGP and nematicidal activity using bacterial cell suspension and culture filtrate to identify a potential biocontrol agent.Result and DiscussionOur results show that nematode infection has altered the bacterial community composition, and a distinct community existed between gall and non-infected roots. This shift in the microbial community is associated with reduced species richness due to infection. We also observed that a few endophytic genera like Chryseobacterium, Rhizobium, Gemmata, and Pseudomonas that were unique to gall are reported to have been associated either with nematode or may have been recruited by plants as a growth promoter to combat nematode infection. Other bacterial endophytes that are specific to the non-infected root microbiome, like Delftia, Bacillus, Pantoea, Acidovorax, and Azorhizobium, are hypothesised to remain associated with rice seeds, and they possess biological control/plant growth promotion abilities. Further, after screening all isolates, Enterobacter sp. strain SSNI 8 isolated from a non-infected root was evaluated for its efficiency in acting as a nematicidal agent against M. graminicola, and we found that the strain showed 90% nematode mortality with its culture filtrate which may possess some secondary metabolites antagonistic to the nematode.ConclusionOverall, this study provided a comprehensive view of endophytes associated with gall in non-infected roots and identified a potential biocontrol agent.

Abstract Purpose Brown fermented milk has become more popular with consumers due to its high nutritional value, creamy texture, delicious caramel flavor, and brownish color. Brown yoghurt (BY), made from buffalo milk fortified with probiotic bacteria was evaluated as an innovative functional dairy product. Methods Standardized buffalo milk with a 1:1 protein/fat ratio was homogenized and browned at 97 ± 1 °C for 4 h. At 42 °C, it was inoculated with a 2.0% mixed starter culture and then divided into 4 portions. Bifidobacterium bifidum NRRL B-41410 and Lacticaseibacillus rhamnosus NRRL B-442, as probiotic bacteria, were added individually or in combination at a rate of 1.0% to create three treatments. The last portion without probiotics was served as a control BY. Results B. bifidum showed the highest viable counts when added alone or in combination with L. rhamnosus, particularly on days 7 and 15. However, the addition of B. bifidum did not improve the physical and sensory properties of the BY, which were similar to those of the control. Adding L. rhamnosus, either alone (T3) or in combination with B. bifidum (T4), greatly improved the viscosity, hardness, flavor compounds, and sensory scores of the BY. The antioxidant activity against DPPH and ABTS radicals was also significantly enhanced. T3 and T4 also had a thicker body, a smoother and creamier texture, and a light caramel taste combined with a pleasant sour taste. Hydroxymethylfurfural (HMF) concentration in BY was affected slightly by bacteria strains and storage time. Conclusions Standardized buffalo milk fortified with L. rhamnosus alone or in combination with B. bifidum can produce a higher-quality BY that is more acceptable as an innovative functional dairy product.

BackgroundPseudomonas spp. are well-studied plant growth promoters, particularly in the context of root colonization. However, the specific genetic factors that determine its fitness in the rhizosphere remain largely unexplored. This study breaks new ground by employing transposon insertion sequencing (Tn-Seq) to identify the genetic factors in Pseudomonas asiatica JR11 that are crucial for colonizing corn roots.ResultsWe created a transposon mutant library of P. asiatica JR11 with 91,884 insertion sites and subjected it to three consecutive enrichment cycles within the corn root system. A total of 79 genes were identified as essential for root colonization (negatively-selected), while 22 genes were found to counteract root colonization efficiency (positively-selected), with both sets being commonly present across all three cycles. These genes involve amino acid metabolism, cell wall biosynthesis, and protein functions. Additionally, we found four negatively-selected and four positively-selected hypothetical proteins that consistently influenced root colonization fitness.ConclusionsThe identification of these molecular determinants opens up exciting possibilities for further research. Understanding these pathways could lead to the development of novel strategies for enhancing the fitness of P. asiatica JR11 during corn root colonization, with potential implications for plant growth promotion and agricultural practices.