Impact of Dietary Patterns on H. pylori Infection and the Modulation of Microbiota to Counteract Its Effect. A Narrative Review

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the stomach and can induce gastric disease and intra-gastric lesions, including chronic gastritis, peptic ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. This bacterium is responsible for long-term complications of gastric disease. The conjunction of host genetics, immune response, bacterial virulence expression, diet, micronutrient availability, and microbiome structure influence the disease outcomes related to chronic H. pylori infection. In this regard, the consumption of unhealthy and unbalanced diets can induce microbial dysbiosis, which infection with H. pylori may contribute to. However, to date, clinical trials have reported controversial results and current knowledge in this field is inconclusive. Here, we review preclinical studies concerning the changes produced in the microbiota that may be related to H. pylori infection, as well as the involvement of diet. We summarize and discuss the last approaches based on the modulation of the microbiota to improve the negative impact of H. pylori infection and their potential translation from bench to bedside.

Iron-dependent mutualism between Chlorella sorokiniana and Ralstonia pickettii forms the basis for a sustainable bioremediation system

Mutualism between microalgae and bacteria is ubiquitous, but remains underexplored as a basis for biodegradation of anthropogenic pollutants. In industrial systems, poor iron uptake by microalgae limits growth, bioprocessing efficacy, and bioremediation potential. Iron supplementation is costly and ineffective because iron remains insoluble in aqueous medium and biologically unavailable. In aquatic environments, microalgae develop an association with bacteria that solubilize iron by production of siderophore, which increases the bioavailability of iron as a public good. Algae, in exchange, provides dissolved organic matter to bacteria to sustain such interkingdom associations. Therefore, using a case study of azo dye degradation, we combine environmental isolations and synthetic ecology as a workflow, establishing a microbial community to degrade industrially relevant Acid Black 1 dye. We create a mutualism between previously non-associated chlorophyte alga Chlorella sorokiniana and siderophore-producing bacterium Ralstonia pickettii, based on the eco-evolutionary principle of exchange of iron and carbon. This siderophore-mediated increased iron bioavailability increases reductive iron uptake, growth rate, and azoreductase-mediated dye degradation of microalga. In exchange, C. sorokiniana produces galactose, glucose, and mannose as major extracellular monosaccharides, supporting bacterial growth. We propose a mechanism whereby extracellular ferrireductase is crucial for azoreductase-mediated dye degradation in microalgae. Our work demonstrates that bioavailability of iron, which is often overlooked in industrial bio-designs, governs microalgal growth and enzymatic processes. Our results suggest that algal-bacterial consortia based on the active association are a self-sustainable mechanism to overcome existing challenges of micronutrient availability in bioremediation systems and their industrial translation.

Effect of tillage and weed management practices on micronutrient availability in post-harvest soil under maize-wheat cropping system

Tillage practices play a major role in nutrient dynamics under different cropping systems. The objective of this study was to examine the influence of different tillage practices and weed management on micronutrient availability in soil. The treatments included three tillage in main plot and four weed management practices in sub plot were arranged in a spilt plot design with three replications.Measurements made at the end of 4 years, showed that in the 0-15 cm soil depth, effect of different tillage and weed management practices on soil properties was significant. The values of soil pH and EC declined under ZT. The mean value of SOC (8.9 g kg-1) was reported higher under ZT. Higher value of Zn and Fe was reported under ZT (3.63 mg kg-1, 15.49 mg kg-1) followed by CT (2.87 mg kg-1, 13.65 mg kg-1) and FIRBS (2.47 mg kg-1,13.47 mg kg-1) respectively. In case of Cu, the higher value (1.32 mg kg-1) was reported under ZT followed by FIRBS (1.30 mg kg-1) and CT (1.22 mg kg-1). Trend was reverse in case of Mn and content was significantly higher (9.4 mg kg-1) under CT followed by ZT (9.02 mg kg-1) and FIRBS (8.70 mg kg-1). The results suggested that ZT can play a vital role in sustaining micronutrient availability due to decreased soil pH and the greater amount of organic matter compared to other tillage methods.

Growth and production of conilon coffee under fertilization of nitrogen and molybdenum (Mo)

Nitrogen is the most applied nutrient in Coffea canephora crops, due to the high requirement of the crop and low availability in most soils. The efficiency of nitrogen fertilization can be maximized by applying molybdenum, due to the role of molybdenum in the nitrate’s metabolism. This study was conducted during two coffee production cycles under field conditions. It aimed to evaluate the effects of applying molybdenum on the growth and production of conilon coffee, subjected to different amounts of nitrogen. The experiment was conducted from June 2018 to May 2020. The experimental design used was in randomized blocks, in a 2 x 5 factorial scheme, the first factor being the absence and presence of molybdenum fertilization (4 kg ha-1 year-1) and the second factor, nitrogen doses (300, 500, 700, 900 and 1,100 kg ha-1 year-1) applied in five plots, during fruit development. We evaluated the conilon growth variables in each agricultural year, in addition to the yield of processed coffee and grain yield. The length of plagiotropic branches, number of nodes per side branch, number of rosettes and fruits per productive branch were closely related to the coffee yield and were influenced by the nitrogen fertilization. Increasing doses of nitrogen promoted quadratic increases in coffee yield, with addition of 35.3% and 88.9% for the 2019 and 2020 harvests, respectively, indicating that maximum coffee productivity is genetically defined and affected by environment conditions and management. For the harvest 2020, the application of molybdenum resulted in an increase in the length of the orthotropic stem and plagiotropic branches, in addition to providing increase of 3.7% in the yield of C. canephora. This suggested that there was a reduction in micronutrient availability in the soil, throughout the experimental period, limiting the growth and production of coffee in the second year

Effect of Different Levels of Fertilizers on Productivity and Nutrient Dynamics of Browntop Millet

A field experiment was conducted at Agricultural Research Station, Baljigapade, Chikkaballapur taluk and district, which comes under the Eastern Dry Zone of Karnataka during Kharif season 2018. The experimental plot in the field was laid out following a randomized complete block design (RCBD) with fourteen treatments and three replications. The treatments included two levels of N and P2O5 (20 and 30 kg ha-1) and three levels of K2O (10,20 and 30 kg ha-1). Farmyard manure was applied at the rate of 6.25 t ha-1 to all the treatments except absolute control. Results indicated that application of 30 kg N+30 kg P2O5+30 kg K2O ha-1 with Farm Yard Manure (FYM) increased the micronutrient availability in soil N (150.29 kg ha-1), P2O5 (17.60 kg ha-1), K2O (160.84 kg ha-1). Application of FYM @ 6.25 t ha-1+30 kg N+20 kg P2O5 +20 kg K2O ha-1 significantly increased growth, yield, macronutrient content and uptake by brown top millet grain and straw against absolute control. The grain yield of browntop millet was increased by 61.46 percent in T10 and 59.07 percent in T9 as compared to the absolute control.