Population Of Microorganisms Research Articles

Assessment of the Microbial Profile of Selected Commercially Prepared Food Spices in Nigeria

The microbial profiles and antibiogram patterns of some commercially prepared food spices in Nigeria were evaluated in this study. Ten selected food spices (cinnamon, coriander, black pepper, chilli pepper, suya spice, salad cream, paprika, parsley, mint and basil) were purchased from the popular Oja-Oba market in Akure, Nigeria. Standard microbiological assays were used to identify and quantify microorganisms in the spices. The antibiotic sensitivity of bacterial and fungal isolates was tested using the disk diffusion method. Twelve bacterial species (Staphylococcus aureus, Enterococcus faecalis, Lactobacillus plantarum, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Proteus mirabilis, Enterobacter aerogenes, Bacillus cereus, Clostridium perfringens, Klebsiella pneumoniae and Citrobacter freundii) were isolated from the food spices. Bacillus cereus and Enterobacter aerogenes were the most prevalent, while Proteus mirabilis, Pseudomonas aeruginosa, and Clostridium perfringens were the least frequently encountered bacterial species. Four Fungal species (Aspergillus niger, Aspergillus fumigatus, Saccharomyces cerevisiae, and Fusarium oxysporum) were also isolated from the food spices, with Aspergillus niger and Saccharomyces cerevisiae the most frequently encountered and Aspergillus fumigatus the least regularly encountered fungal species. The bacterial load of the food spices ranged from 8.0 x 103 to 9.0 x 105 CFU/ml, while the mean fungal count ranged from 2.0 x 103 to 1.2 x 105 SFU/ml. Antibiogram analysis revealed that Pefloxacin had the highest efficacy and Zinacef the least in all isolated bacterial species. At the same time, Ketoconazole exhibited the highest effectiveness in all isolated fungal species, and Nystatin showed the least effectiveness. The high population of pathogenic microorganisms coupled with the presence of Salmonella typhimurium and other enteric microorganisms in the food spices can cause severe foodborne illness to the consumers of such food spices and may lead to foodborne illness outbreaks.

Residual Dynamics of Chlorantraniliprole and Fludioxonil in Soil and Their Effects on the Microbiome.

The increased use of chlorantraniliprole and fludioxonil has sparked concerns about their residues and impact on the soil microbiome, highlighting an urgent issue requiring attention. This study investigates the residue dynamics of corn after chlorantraniliprole and fludioxonil treatments, as well as their effects on soil enzyme activity and microbial community structure. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis showed a significant decrease in chlorantraniliprole and fludioxonil residues in the soil after combined application, especially with chlorantraniliprole. This application caused a temporary reduction in urease and sucrase activities. Furthermore, high-throughput sequencing of the soil microbiome revealed a decrease in the relative abundance of Talaromyces during fludioxonil application, while Mortierela and Gibberella increased. Additionally, Vicianmibacteraceae and Vicianminbactererales saw significant increases after chlorantraniliprole application. The combined application of chlorantraniliprole and fludioxonil not only decreased the population of harmful microorganisms but also lowered residue levels in the soil when compared to individual applications. This ultimately enhanced the efficacy of control measures and promoted environmental compatibility.

Pesticides and Their Effects on Gut Microbiota: A Comprehensive Review of Environmental and Health Consequences

An increasing use of pesticides in agriculture is considered as the dangerous hazard to environment, human health, and sustainability. The effects of pesticides on organisms include decline in the amount of phytoplankton and zooplankton, development of resistance in pests and negative impacts on pollinators. These chemical residues too interfere with the biogeochemical cycles, reduce the microbial count in the soil, and are anti-neo plastic and carcinogenic in nature in different species. Concerning human health effects, the exposure to these chemicals cause cancer, deterioration of neurodevelopment, reproductive disorders as well as immune disorders. Besides, the action of pesticides is aimed at destroying both the beneficial bacteria of the gut microbiota, thus causing obesity and diabetes. The measures required for these problems include regulation and farmer awareness and schooling to stop the contamination from piling up in water bodies. Some strategies include microbial degradation, pesticide degradation and improvement of the population of microorganisms in the soil. Organic farming and sound policies are important to maintain and improve the earth’s condition, uphold the companies’ standards set by the legal frameworks, and sustain the quality of life. Therefore, the impacts of pesticides on microbiota and the interactions of hosts and microbes need to be analyzed to devise appropriate solutions. These efforts are very useful for dealing with possible health threats and ensuring environmentally friendly farming.

Assessment of the Active Sludge Microorganisms Population During Wastewater Treatment in a Micro-Pilot Plant.

Knowledge of the impact of chemicals on the environment is important for assessing the risks that chemicals can generate in ecosystems. With the help of pilot-scale micro-tests, it was possible to evaluate the biological sludge in terms of its chemical and biological composition, information that can be applied on an industrial scale in treatment plants. The important parameters analyzed in the evaluation of the biodegradability of wastewater were pH, chemical composition (NH4+, NO3-, NO2-, and PO43-), dry substance (DS), inorganic substance (IS), and organic substance (OS), and the biological oxygen demand (BOD)/chemical oxygen consumption (COD) ratio. The examination revealed the presence of free active ciliates Aspidisca polystyla, Lyndonotus setigerum, Vorticella microstoma, fixed by Zooglee, Paramecium sp., Opercularia, Colpoda colpidium, Euplotes, Didinum nasutum, Stentor, and Acineta tuberosa, metazoa Rotifers, filamentous algae, Nostoc and Anabena, and bacteria Bacillus subtilis, Nocardia, and Microccocus luteus. The novelty of this study lies in the fact that we carried out a study to evaluate the population of microorganisms starting from the premise that the probability of biodegradation of substances is directly proportional to the number of microorganisms existing in the environment and their enzymatic equipment.

The effect of Rhizobium, Azotobacter and microbial consortium (Rhizobium/Azotobacter) on some growth parameters and nodulation of chickpeas (Cicer arietinum L.)

The adoption of microbial fertilizers such as rhizobium and azotobacter can reduce the requirement for chemical fertilizers and their negative impact on the environment. Overuse of chemical fertilizers to increase productivity has been shown to increase costs, reduce the microorganism population of the soil, and cause serious human and animal health problems by accumulating in plants and entering groundwater. For this purpose, a greenhouse experiment was conducted under controlled conditions with treatments of control, nitrogenous control, rhizobium, azotobacter, and the rhizobium/azotobacter consortium. Seeds inoculated with bacteria were planted on media containing sterile sand + perlite. Plants were harvested at 50% flowering, and some yield and yield components were determined. Inoculation of chickpea seeds with rhizobium, azotobacter, and rhizobium/azotobacter combinations of bacteria had different effects, and these differences were found to be statistically significant. In the experiment, rhizobium/azotobacter treatments were effective on the wet and dry weight of plant upper parts, the number of nodules, the weight of nodules, the nitrogen content of plant upper parts, and the nitrogen content of the root of the chickpea plant. In addition, rhizobium inoculation was effective on the plant's upper part and root length, and azotobacter inoculation was effective on the wet and dry weight of chickpea roots.

Aristolochic Acids and Aristoloxazines Are Widespread in the Soil of Aristolochiaceae Herb Cultivation Fields.

The cancer risk associated with aristolochic acid (AA) exposure through the consumption of AA-containing herbal medicine has received tremendous attention in the past decades. However, environmental exposure routes from the associated medicinal herb cultivation fields have received little attention. We reveal through liquid chromatography-tandem mass spectrometry analysis of over 400 soil samples collected from three different Aristolochiaceae herb cultivation fields that AAs, which are nephrotoxic and carcinogenic, and aristoloxazines (AXs), a family of recently identified neurotoxic and genotoxic AA analogues, are widespread pollutants in these areas. In particular, aristoloxazine C was detected for the first time in the environment and was found in 318 out of 320 soil samples, at concentrations as high as 2.8 mg/kg, from an Asarum heterotropoides cultivation field. We show that in fact AXs are ecotoxic, inhibiting plant growth and significantly reducing the soil microorganism population. With the extensive cultivation of Aristolochiaceae herbs in order to meet their market demand, we believe our study points to an important environmental hazard that may place food crops and non-AA/AX-producing medicinal herbs at risk of AA/AX contamination. While previous research focused primarily on the health risks associated with exposure to AAs, this study uncovers environmental exposure as a new human exposure pathway that warrants the attention of both the general public and regulatory agencies.

Phylogenetic Analysis of Attached Microbial Communities in Aerobic and Anoxic Media for the Removal of Wastewater Nitrogen

The removal of nitrogen compounds in wastewater has been successfully developed with various activated sludge-based processes. Microorganisms immobilized in media would enhance biological efficiency by the increase in biomass concentration; however, the microbial community composition in media has not been revealed. Attached microbial communities on immobilization media were analyzed after the operation of the wastewater treatment process, comparing aerobic and anoxic reactors. A modified Ludzack–Ettinger (MLE) process was operated with immobilized media with polyvinyl alcohol and polyethylene glycol. The mixed liquor suspended solid (MLSS) concentration in an aerobic reactor was maintained at 50,000 mg/L and 40,000 mg/L in an anoxic reactor by the media. A maximum of 99% of ammonium nitrogen from the influent was calculated to be oxidized; however, the organic nitrogen produced from microbial growth reduced the overall oxidation rate. The denitrification rate increased with the addition of glucose to adjust the carbon-to-nitrogen (C/N) ratio. Based on the total nitrogen concentration, the nitrogen removal efficiency was calculated to be 48.2% following the adjustment of the C/N ratio. A phylogenetic analysis of the microbial community in immobilized media using next-generation sequencing (NGS) revealed the dominance of nitrifying and denitrifying microorganisms in the aerobic and anoxic reactors, respectively. Sequences amplified using V3–V4 region primers of the 16S rRNA gene yielded 531,188 base pairs (bp) and 396,844 bp reads from the aerobic and anoxic reactors, respectively. Operational taxonomic units (OTUs) were identified at both the phylum and genus levels, with a total of 594 from the aerobic reactor and 375 from the anoxic reactor. Proteobacteria was the dominant phylum in both the aerobic and anoxic reactors, comprising 39.7% of the aerobic reactor and 65.9% of the anoxic reactor. The dominant genera in the aerobic reactor were Nitrospira and Povalibacter. Forty-five percent of the total number of OTUs consisted of known nitrification-related genera in the aerobic reactor. In contrast, the dominant genera in the anoxic reactor were Desulfomicrobium, Desulfobulbus, and Methyloversatilis. A total of 63% of the genera associated with denitrification, including Dechloromonas and Flavobacterium, were found in the anoxic reactor. The population of microorganisms in each reactor was compared in terms of diversity by the QIIME 2 algorithm. The Chao1 index values of α-diversity were 606.05 for the aerobic reactor and 415.53 for the anoxic reactor, indicating greater population diversity in the aerobic reactor compared to the anoxic one. The widespread distribution of nitrification activities among various groups has led to diverse population characteristics in the aerobic environment, particularly within the attached community. The microbiological community present in immobilized aerobic and anoxic media will contribute to future microbial studies on wastewater treatment processes.

BURONG TILAPIA: FACTORS ON THE FERMENTATION PROCESS AND ITS MICROBIOTA

Fermented fish products hold significant prominence in the Philippines. However, its potential risks for human consumption are faced as a result of inadequate awareness of microbiological standards in its preparation. This study investigated the microbiota and fermentation process of burong tilapia, how this is influenced by fermentation factors such as salt content, temperature, and proper sanitation, and how it can impact food safety for human consumption. This study revealed that the population of aerobic microorganisms in burong tilapia was relatively high with the Aerobic Plate Count result of 2.1 x 107 CFU/g, indicating significant bacterial presence. On the other hand, a relatively low level of E. coli and Yeast and Molds count was detected having <25 CFU/g and <10 CFU/g, respectively. Moreover, it was found that low salt content, non-ideal temperature conditions and failure to strictly observe sanitation practices, all influenced the growth and proliferation of unwanted microorganisms. These results emphasize how crucial it is to optimize fermentation factors in order to guarantee both the food quality and safety of fermented fish products for human consumption. Furthermore, this case study highlights that consumer education is needed in promoting awareness and acceptance of fermented fish products in the market.

Insights into respiratory microbiome composition and systemic inflammatory biomarkers of bronchiectasis patients.

The population of microorganisms on/in the human body resides in distinct local microbiomes, including the respiratory microbiome. It remains unclear what defines a healthy and a diseased respiratory microbiome. We investigated the respiratory microbiome in chronic pulmonary infectious disease, i.e., bronchiectasis, and researched correlations between microbiome composition, systemic inflammatory biomarkers, and disease characteristics. The bronchoalveolar microbiome of 47 patients was sequenced, and their serum inflammatory mediators were quantified. The microbiomes were grouped based on their content and diversity. In addition, patients were also grouped into low- and high-response groups according to their inflammatory biomarkers' levels. Certain microbiome compositions, mainly single-species dominated, were associated with high levels of inflammatory cytokines, whereas others correlated with low inflammatory response and remained diverse. We conclude that respiratory microbiome composition is a valuable resource for the diagnostics and personalized management of bronchiectasis, which may include preserving microbiome diversity and introducing possible probiotics.

Effect of Brittleness in Rice Straw on Rumen Fermentation by In vitro Gas Production Technique

The objective of this study was to examine the impact of rice straw brittleness on its efficacy as roughage for ruminants, in comparison to a wild-type variety, utilizing an in vitro study approach. The experimental design was a complete randomized design (CRD). The experimental treatments included various breeds of rice straw (RS), such as the wild-type (WT, T1), the green brittle bred line 8 and line 13 with brittleness level-3 (GBL8-B3, T2 and GBL13-B3, T3), and the purple brittle bred line 8 with brittleness level-5 (PBL8-B5, T4). The findings revealed that the brittleness RS group had higher levels of crude protein and hemicellulose, and lower levels of cellulose compared to the wild-type group. Brittleness RS varieties showed a significantly greater gas production accumulation (p = 0.001) and IVDMD (p = 0.003) compared to the WT group. At 8 h post-incubation, the brittleness RS group showed significantly higher (p = 0.004) total of volatile fatty acids concentration compared to the WT group. After 1 h of post-incubation, GBL8-B3 exhibited the highest (p = 0.032) proportion of propionate and the lowest (0.009) C2:C3 ratio. Additionally, the brittleness RS did not have any effect on the population of ruminal microorganisms. Based on the brittleness of RS, it can be deduced that it has a greater potential as a roughage source when compared to the wild-type variety, consequently enhancing the quality of RS for roughage intake by ruminants. HIGHLIGHTS Brittleness RS exhibited elevated levels of CP, high hemicellulose content, and lower cellulose levels compared to the WT group. The brittleness RS group displayed a rapid degradation rate impacting the total VFAs concentration and C2:C3 ratio, with the GBL8-B3 group demonstrating superior utilization efficiency. The brittleness of RS is indicative of a higher potential as a roughage source when compared to the wild-type variety, thereby improving the quality of rice straw for roughage consumption by ruminants. GRAPHICAL ABSTRACT

The Emerging Role of gut Microbiota in Immunotherapy

The gastrointestinal tract contains a diverse and dynamic population of microorganisms called the gut microbiota, which is essential for immune system regulation. Recent studies have highlighted that gut microbiota has a major influence on the effectiveness of cancer immunotherapy, particularly immune checkpoint antagonists. This review explores the mechanisms of specific gut microbiota, such as Bifidobacterium and Lactobacillus, to enhance innate and adaptive immune responses, including activation of dendritic cells, polarization of macrophages, and stimulation of CD8+ T cells. In addition, this review discusses therapeutic strategies aimed at manipulating the gut microbiota to enhance the effects of immunotherapy, including fecal microbiota transplantation (FMT), probiotics, and engineered microbiota. Although these approaches have promising potential, the challenges still remain with the variability of patients and microbiota manipulation. This review emphasizes how crucial it is to combine immunotherapy and the gut microbial community to create more individualized, effective cancer treatments, which will eventually improve patient outcomes and advance the area of cancer treatment.

An experimental study of the biological impact of a superflare on the TRAPPIST-1 planets

ABSTRACT In this study, we conducted experiments to assess the biological effects of high fluences of UV radiation (UVR) on the TRAPPIST-1 planetary system (planets e, f, g within the habitable zone), unlike previous estimates made by other authors which used theoretical approaches. To this end, we first calculated the UV fluxes at the orbits of the planets of the TRAPPIST-1 system during quiescent conditions and during a superflare. We then studied the effects of UVR on microbial life by exposing UV-tolerant (Deinococcus radiodurans) and UV-susceptible bacteria (Escherichia coli) to fluences equivalent to a superflare on the unshielded surface of these planets. Based on the results of our laboratory experiments, we have found a survival fraction of $6.31\times 10^{-8}$ for D. radiodurans and a survival fraction below the limit of detection for E. coli at the surface of the planet e, which would receive the highest UVR flux. These survival fractions were higher for the planets f and g. In contrast to the results obtained by other authors which used theoretical estimates, we show that a fraction of the population of microorganisms could tolerate the high UVR fluences of a superflare on the surface of TRAPPIST-1 planets, even without any shielding such as that provided by an atmosphere or an ocean. Our study evidences the existence of methodological problems in theoretical approaches. It also emphasizes the importance of performing specifically designed biological experiments to predict microbial survival in extraterrestrial contexts.

Jivamrit as a Sustainable Approach: A Review of Natural Farming and Future Agriculture.

Green Revolution aims to boost food production and feed millions of Indians, but it also has negative effects on agriculture and society's health. Natural manures like cow dung and cow urine can counteract the adverse effects of inorganic fertilizer on soil along with improving physicochemical qualities, maintaining the soil quality, and increasing crop output. Zero Budget Natural Farming (ZBNF) formulations like Jivamrit promote soil health and microbial activities and are an excellent source of macronutrients, other micronutrients needed for plant growth, plus adds beneficial microbes, nitrogen (N2), phosphorus (P), potassium (K), and natural carbon (C). Further, conventional agricultural methods, like monocropping and heavy tillage, can damage soil bacteria which contributes to sustainable agriculture through nitrogen fixation, siderophore synthesis and nutrient absorption. A sustainable agricultural system is resource-efficient, socially and commercially competitive, ecologically sound, and supportive of society. Jivamrit, a natural organic manure, is gaining interest due to concerns about the sustainability of input-intensive agriculture systems. It promotes crop growth, quality, and yield, enhances soil pH, population, and activity of beneficial microorganisms, and helps with nitrogen fixation, phosphate solubili-zation, and easy decomposition. Long-term use of Jivamrit, may disrupt soil microbial balance, may leading to overpopulation of certain species. The current review on the Jivamrit emphasizes on the biological and chemical characterization and its significance to the agriculture.

Investigation of the Impact of Antibiotic Administration on the Preterm Infants' Gut Microbiome Using Next-Generation Sequencing-Based 16S rRNA Gene Analysis.

Background: The human gut microbiota is an extensive population of microorganisms, and it shows significant variations between periods of optimal health and periods of illness. Vancomycin-resistant Enterococcus (VRE) and carbapenem-resistant Klebsiella pneumoniae (CRKP) are both pathogenic agents (BPAs) that can colonize in the gut after dysbiosis of microbiotal composition following antibiotic treatment. Methods: This study aimed to investigate the impact of antibiotics on the microbiotal composition of the gut. For this purpose, the first pass meconiums of 20 patients and the first rectal swabs containing BPAs of the same patients after antibiotic treatment were studied using next-generation sequencing-based 16S rRNA gene analysis. The V1-V9 region of 16S rRNA was sequenced with Oxford Nanopore. Results: Twenty-five phyla were detected in the meconiums, and 12 of them were absent after antibiotic treatment. The four most prevalent phyla in meconiums were Bacillota, Pseudomonadota, Bacteroidota, and Actinomycetota. Only the relative abundance of Pseudomonadota was increased, while a significant decrease was observed in the other three phyla (p < 0.05). A significant decrease was observed in alpha-diversity in rectal swabs containing BPAs versus meconiums (p = 0.00408), whereas an increased variance was observed in beta-diversity in all samples (p < 0.05). As a result of a LEfSe analysis, Pseudomonadota was found to have a higher relative abundance in rectal swabs, and Bacillota was significantly higher in the meconiums of the twins. Conclusions: Our study strongly verified the relationship between the administration of antibiotics, dysbiosis, and colonization of BPAs in the infants' gut microbiota. Further research would be beneficial and needed, comprising the natural development process of the infants' gut microbiota.

The Gut Health Revolution: Herbs and Dietary Phytochemicals in Balancing Gut Microbiota for Optimal Human Health.

The gut microbiota is a varied population of microorganisms that live in the human gastrointestinal system. Emerging research emphasizes the importance of this microbial ecology in general health and its influence on a variety of disorders. The review explores the synergy between herbal treatment and traditional medicine, emphasizing their cultural significance and therapeutic benefits. It delves into the intricate relationship between herbal remedies, traditional healing practices, and their sustained usage over centuries. The review highlights the pivotal role of the gut microbiota in herbal medicine, elucidating how treatments influence the gastrointestinal microorganisms, impacting overall health. Dietary phytochemicals are underscored for their significance in herbal medicine and nutritional well-being, along with the interdependence of plant extracts and botanicals. The investigation explores the molecular connections between phytoconstituents and gut microbiota, aiming to deepen the understanding of herbal medicine's tailored approach to specific health challenges. The summary concludes by emphasizing herbal treatments' unique ability to regulate gut flora, contributing to overall gastrointestinal wellbeing. In closing, the review provides a concise overview, serving as a valuable resource for integrative medicine research, with recommendations for future exploration of herbal medicine's potential in healthcare.

Rhamnolipids Enhance Bioremediation of Petroleum-Contaminated Soil

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 215952, “Enhancing Bioremediation of Petroleum-Contaminated Soil Using Rhamnolipids: A Combined Laboratory and Field Study,” by Pan Ni, Lehigh University; Yonglin Ren, SPE, Stepan Oilfield Solutions; and Derick G. Brown, Lehigh University, et al. The paper has not been peer reviewed. _ Hydrocarbon spills can occur at various stages of the oil and gas exploration and production process. Treating these spills onsite to avoid more-expensive excavation and incineration processes would be beneficial. The study outlined in the complete paper aims to optimize the use of rhamnolipid biosurfactants for enhancing the bioremediation of hydrocarbon-contaminated soil. The goal of this work was to explore the effects of rhamnolipid application on hydrocarbon degradation rate under both laboratory and field conditions and to examine the effects of this treatment on the indigenous soil microorganism population. Introduction The authors write that, to the best of their knowledge, previous research studies on rhamnolipid-based soil remediation focused on either laboratory or field tests and that comparison between laboratory-scale and field-scale tests is overlooked but necessary for practical applications. Materials and Methods Materials and Chemicals. The soil used for this work (23 kg for the laboratory test, 10 metric tons for the field test) was obtained from a contaminated site in Longford Mills, Canada. The soil properties are presented in Table 1 of the complete paper. The rhamnolipid stock solution featured 9.8 wt% rhamnolipid blends in deionized water. Another commercial remediation agent (enzyme-based) was used in the field test to compare with the performance of rhamnolipid. Ammonium chloride (NH4Cl) and potassium hydrogen phosphate (K2HPO4) also were used along with sodium hydroxide (NaOH). Experimental Setup. Both laboratory and field tests were ex-situ tests using simulated soil piles. The laboratory test was conducted for 193 days. For the laboratory experiments, an aerobic/anaerobic respirometer system equipped with a low-temperature incubator was used to monitor the in-situ oxygen uptake inside eight reactors (Fig. 1). Each reactor contained 250 g of soil with rhamnolipid doses of 0, 0.1, 0.5, and 1 g/kg. The temperature was set to 25°C. Inside each reactor was placed 10 mL of 4-M NaOH in a 20-mL glass beaker to adsorb the produced CO2. A parallel set of eight reactors was prepared and operated under the same conditions. The nutrients of nitrogen and phosphorous (NH4Cl and K2HPO4) were added at specific times based on the oxygen uptake rate monitored by the respirometer. To avoid the possible inhibition of the microbes in the soil as a result of high ionic strength (greater than 160 mM) in the soil pore water, NH4Cl and K2HPO4 were added so that the molar concentration in the soil pore water did not exceed 100 mM. The field test is being conducted in Longford Mills, Ontario, Canada, and is ongoing at the time of writing. For the field test, 10 metric tons of soil were mixed to achieve homogeneity before the preparation of the soil piles. Five different treatment conditions were examined using duplicate soil piles (10 piles total), with each consisting of 1 metric ton of soil. Nutrient addition was similar to that used in the laboratory tests. Temperature and moisture were monitored every few days at five points in each soil pile, and the pH was monitored once every month at five points.

Efecto de la pendimentalina sobre el crecimiento celular de rizobacterias Promotoras de Crecimiento Vegetal (PGPR)

Pendimentalin is an herbicide used in short-cycle crops. Its indiscriminate use reduces the beneficial population of microorganisms in production systems. The objective of this work was to evaluate the effect of pendimentalin on the cell growth of rhizobacteria. The research was conducted at the Laboratory of Microbiology and Molecular Biology of the State Technical University of Quevedo, where the following experiments with pendimentalin contamination were carried out: 1) Adaptability of rhizobacteria under in vitro conditions; 2) Tolerance levels of rhizobacteria under different abiotic conditions in vitro; 3) Reduction of stress by rhizobacteria in soils. The rhizobacteria show a higher adaptability at 72 h with absorbance of 2.38 and 2.51 in the strains (CHA0, BA4-19, B03-4, PM3-14 and R4), also during this time they establish a neutral pH, despite the acidic and alkaline conditions. Strain CHA0 presented the highest number of cells under neutral pH (1.09E+09 CFU/mL). Strains BA4-19 and PM3-14 showed a slight improvement in morphological aspects. Rhizobacteria have adaptability at the in vitro level, but their use slightly reduces the toxicity of the herbicide in rice germination and growth processes.

Exploring the variations in molecular characteristics of dissolved organic matter driven by aquaculture types

In recent decades, global aquaculture has expanded rapidly, raising concerns about coastal environmental degradation due to unregulated or poorly regulated discharge of aquaculture tailwater. Despite the crucial role of dissolved organic matter (DOM) in biogeochemical processes and aquatic biodiversity, the influence of aquaculture type on the molecular characteristics of DOM remains largely unexplored. Herein, this study investigated the variations in chemical and spectroscopic properties as well as molecular characteristics and composition of DOM across different aquaculture types including crustacean, fish and shellfish. Our findings revealed notable differences in DOM quantities among different aquaculture types, with crustacean and fish aquaculture water containing higher DOM amount compared to shellfish aquaculture water. This disparity can be attributed to the more frequent formulated feeds of crustacean and fish in contrast to shellfish aquaculture. Furthermore, distinct differences were also observed in the characteristics and composition of DOM among the different aquaculture waters. Specifically, DOM in shellfish aquaculture water exhibited a higher abundance of unsaturated and reduced molecules as well as increased aromaticity compared to the other two aquaculture waters. Conversely, DOM from fish aquaculture water showed a greater contribution from terrestrial origin characterized by elevated levels of plant-based components such as lignin-like and tannin-like compounds. Interestingly, DOM from shellfish aquaculture water contained lower levels of microbial-derived components such as lipid-like and protein-like compounds, likely due to reduced microorganism populations resulting from lower nutrients availability and higher salinity. Overall, these significant variations in characteristics and composition of DOM underscore the potential impacts of aquaculture type on the DOM biogeochemical cycle and the environmental quality in aquatic ecosystems.

Numerical study of third‐grade nanofluid flow with motile microorganisms under the mixed convection regime over a stretching cylinder

AbstractThe investigation of mixed convective flow involving microorganisms in nanofluid has garnered considerable interest in recent times owing to its extensive applicability in the biomedical domain. However, there has been a lack of study investigating a comprehensive parameter analysis for the flow of a third‐grade nanofluid around a cylinder in the presence of microorganisms. This study focuses on numerically investigating the flow of nanofluid around a stretched cylinder in the presence of motile microorganisms. The study also considers convective boundary conditions. Moreover, this study explores the nanofluid qualities related to Brownian motion and thermophoresis diffusion characteristics. The variable parameters include the Prandtl number (Pr), Peclet number (Pe), buoyancy ratio parameter (Nr), mixed convection parameter (), bioconvection Lewis number (Lb), Biot number (Bi), and Marangoni number (Ma). The bvp4c issue solver tool in MATLAB is used to numerically solve the nonlinear governing differential equations. The numerical model has been validated using prior papers. Graphical representations are created to depict several important measurements, such as velocity streamlines, velocity profiles, temperature distributions, nanoparticle concentrations, densities of gyrotactic motile microorganisms, local Nusselt numbers, skin friction, and Sherwood numbers. The link between the Nusselt number and the parameters Nt and Rd suggests that as Nt falls and Rd increases, the Nusselt number increases. The skin friction value is directly proportional to the values of Nr and Nc. There is a positive correlation between the rise in the local mass transfer rate and the values of Rd and Nt. The population of mobile microorganisms grows as the values of Lb and Pe decrease.

The Relationship Between Gut Microbiome and Ophthalmologic Diseases: A Comprehensive Review.

The gut microbiome has been studied in recent years due to its association with various pathological pathways involved in different diseases, caused by its structure, function, and diversity alteration. The knowledge of this mechanism has generated interest in the investigation of its relationship with ophthalmologic diseases.Recent studies infer the existence of a gut-eye microbiota axis, influenced by the intestinal barrier, the blood-retina barrier, and the immune privilege of the eye. A common denominator among ophthalmologic diseases that have been related to this axis is inflammation, which is perpetuated by dysbiosis, causing an alteration of the intestinal barrier leading to increased permeability and, in turn, the release of components such as lipopolysaccharides (LPS), trimethylamine oxide (TMAO), and bacterial translocation. Some theories explain that depending on how the microbiome is composed, a different type of T cells will be activated, while others say that some bacteria can pre-activate T cells that mimic ocular structures and intestinal permeability that allow leakage of metabolites into the circulation. In addition, therapies such as probiotics, diet, and fecal microbiota transplantation (FMT) have been shown to favor the presence of a balanced population of microorganisms that limit inflammation and, in turn, generate a beneficial effect in these eye pathologies. This review aims to analyze how the intestinal microbiome influences various ocular pathologies based on microbial composition and pathological mechanisms, which may provide a better understanding of the diseases and their therapeutic potential.