Population Of Microorganisms Research Articles

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.

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.

Emisi Metana (CH4) pada Beberapa Metode Pengelolaan Limbah Sawah di Kecamatan Anjir Pasar Kabupaten Barito Kuala

Paddy fields for all of Indonesia are 8.1 million ha, about 43% are in Java and about 57% are outside Java. Paddy fields are part of the wetlands. Paddy fields control the global climate through the gases they produce and have a greenhouse effect. One of the greenhouse gases is methane, therefore the purpose of this study was to determine the effect of rice field waste management on methane emissions and the population of methanogenic microorganisms. The research method used is one-factor Completely Randomized Design (RAL). The factor tested was the method of managing rice waste before planting rice with five treatments namely: A = Rice field waste was slashed and then lifted into the mound after a few days of being returned to the field; B = Rice field waste is carried out management slashed, rolled up, reversed, and stretched; C = Rice field waste is slashed, planted with traces and then slashed again after the trace is transferred to land outside the research plot; D = Rice field waste sprayed with herbicide 2 times; E = Ricefield waste sprayed with herbicide 1 time and then soil in the tractor. Each treatment was repeated four times so 20 units of the experimental. CH4 gas retrieval used the hood method while the microorganism population used the MPN (most probable Number) method. The results showed that the rice field waste management method had an effect on methane emissions and populations of methanogen microorganisms in the planting and vegetative phases, while the generative phase had no effect.

A coupled metabolic flux/compartmental hydrodynamic model for large-scale aerated bioreactors

Spatial variation of microorganism populations in stirred-tank bioreactors, caused by the interactions of complex multiphase flows and microorganism metabolism, results in undesirable performance characteristics and significant challenges in scale-up activities. In this work, a novel modelling approach is developed to investigate these coupled processes in bioreactors, which involves the integration of a computational fluid dynamics-informed compartmental hydrodynamic and a dynamic flux balance (DFB) model. This coupling poses significant computational challenges especially when dealing with transient scenarios. To tackle these challenges we developed a fast point-location algorithm to solve the DFB model at different bioreactor locations. To validate the presented modelling approach, a binary search tree-based metabolic model for E. coli was developed and integrated with a flow-informed compartmental model of a large-scale four-impeller aerated bioreactor in fed-batch operation. The model results exhibit favorable agreement with the concentration profiles reported in literature for both lab-scale and industrial scale bioreactors. Furthermore, the ability of the approach to deal with transient scenarios permitted to study the effect of oxygen closed loop control responses and the occurrence of oscillatory behaviour which were crucial to explain part of the data.

Soil Microbial Community Structure and Carbon Stocks Following Fertilization with Organic Fertilizers and Biological Inputs.

The application of organic fertilizers and biological inputs to soil inevitably affects its quality, agrochemical indicators, and microbiota. Sustainable agriculture is based on continuously learning about how to properly manage available soil, water, and biological resources. The aim of the study was to determine changes in microorganism communities and carbon stocks in infertile soils for fertilization using different organic fertilizers and their combinations with bio-inputs. Genetic analysis of microorganism populations was performed using the NGS approach. Our study showed that the application of organic fertilizers affects the soil microbiota and the taxonomic structure of its communities. Specific groups of bacteria, such as Bacillota, were promoted by organic fertilization, meanwhile the abundance of Pseudomonadota and Ascomycota decreased in most treatments after the application of poultry manure. Metagenomic analysis confirmed that the use of bio-inputs increased the relative abundance of Trichoderma spp. fungi; meanwhile, a significant change was not found in the representatives of Azotobacter compared to the treatments where the bio-inputs were not used. The positive influence of fertilization appeared on all the studied agrochemical indicators. Higher concentrations of Corg and Nmin accumulated in the soil when we used granulated poultry manure, and pHKCl when we used cattle manure.

Diversified Cover Crops and No-Till Enhanced Soil Total Nitrogen and Arbuscular Mycorrhizal Fungi Diversity: A Case Study from the Karst Area of Southwest China

The deteriorating soil health under continuous monoculture is commonly found across various cropping systems. This study evaluated the effects of different tillage practices (conventional tillage and no till) and species mixtures (legumes and grasses) on arbuscular mycorrhizal fungi (AMF) community properties, soil nutrients, and enzyme activity in a 3-year experiment. Compared with traditional tillage, the number of AMF species under no-till conditions was increased, with the Glomus group being dominant. Under different tillage conditions, TN (total N) and AN (available N) contents under no till were significantly higher than those under conventional tillage, while no significant differences among other nutrients were found. The activities of soil acid phosphatase (S-ACP), soil dehydrogenase (S-DHA), and soil sucrose (S-SC) under conventional tillage were significantly higher than those under no till, and the cover crop mixtures also had an exclusive advantage in yield. Soil organic matter (SOM) indicated a significant negative correlation with glomalin-related soil protein (GRSP). The increase in diversity associated with the AMF species community was strongly correlated with the increase in three enzyme activities, and AN was negatively correlated with all species. Tillage did not significantly change soil chemistry, except for AN, and the high concentration of AN led to a decrease in AMF species. The results of this study showed that no till was an effective measure for enriching soil micro-organism population. Additionally, soil AMF diversity was improved by cover crop mixtures, and microbial diversity was higher than that under monoculture cover crops. Different AMF groups responded differently to tillage and cover crop mixtures. Across all mixtures, the combination of hairy vetch (Vicia villosa R.) and ryegrass (Lolium perenne L.) performed the best.

Prebiotic and probiotic potential of fermented milk with cashew (Anacardium occidentale) by-products evaluated in microbiome model

This study aimed to assess the functional attributes of the cashew by-product (CB) in fermented milk with the probiotic strain Lacticaseibacillus paracasei subsp. paracasei F19® (F19®) and the starter Streptococcus thermophilus ST-M6® (ST-M6®) using the Simulator of Human Intestinal Microbial Ecosystem (SHIME®). Two formulations of the fermented milk were assayed, in duplicates: Treatment 1 (T1, without CB) and Treatment 2 (T2, with CB). The strains behavior in the formulations and other bacterial groups of interest were assessed in SHIME®. The populations of the microbiota microorganisms and of the starter and probiotic strains were determined by PMA-qPCR. Metabolites produced in SHIME® reactors fermentation associated with nitrogen balance, antioxidant and phenolic compounds, and short-chain fatty acids (SCFA) were also measured. In SHIME®, both formulations had positive effects on the microbiota (an increase in Bifidobacterium spp. and Lactobacillus spp. and a decrease in Clostridium and Gamma Proteobacteria phyla). Considering these findings, probiotic fermented milk with F19®and ST-M6®, with or without cashew by-product, appears promising for a novel food product with enhanced nutrition, potentially classified as a synergistic synbiotic or at least a probiotic product.

Genome assembly and variant analysis of two Saccharomyces cerevisiae strains isolated from stingless bee pollen

Products from stingless bees are rich reservoirs of microbial diversity, including yeasts with fermentative potential. Previously, two Saccharomyces cerevisiae strains, JP14 and IP9, were isolated from Jataí (Tetragonisca angustula) and Iraí (Nannotrigona testaceicornis) bees, respectively, aiming at mead production. Both strains presented great osmotic and sulfite tolerance, and ethanol production, although they have a high free amino nitrogen demand. Herein, their genomes were sequenced, assembled, and annotated, and the variants were compared to the S. cerevisiae S288c reference strain. The final assembly of IP9 and JP14 presented high N50 and BUSCO scores, and more than 6430 protein-coding genes. Additionally, nQuire predicted the ploidy of IP9 as diploid, but the results were not enough to determine the ploidy of JP14. The mitochondrial genomes of IP9 and JP14 presented the same gene content as S288c but the genes were rearranged and fragmented in different patterns. Meanwhile, the genes with mutations of high impact (e.g., indels, gain of stop codon) for both yeasts were enriched for transmembrane transport, electron transfer, oxidoreductase, heme binding, fructose, mannose, and glucose transport, activities related to the respiratory chain and sugar metabolism. The IP9 strain presented copy number gains in genes related to sugar transport and cell morphogenesis; in JP14, genes were enriched for disaccharide metabolism and transport, response to reactive oxygen species, and polyamine transport. On the other hand, IP9 presented copy number losses related to disaccharide, thiamine, and aldehyde metabolism, while JP14 presented depletions related to disaccharide, oligosaccharide, asparagine, and aspartate metabolism. Notably, both strains presented a killer toxin gene, annotated from the assembling of unmapped reads, representing a potential mechanism for the control of other microorganisms population in the environment. Therefore, the annotated genomes of JP14 and IP9 presented a high selective pressure for sugar and nitrogen metabolism and stress response, consistent with their isolation source and fermentative properties.

The Hidden Powers of Glomalin: Insights into Soil Health and Functionality

Agricultural practices such as the application of inorganic fertilizers and pesticides have profound effects on soil, altering its physical and chemical properties and consequently impacting soil biota composition and diversity. Since plant health is intricately linked to soil health, managing soil in a manner that conserves and enhances soil biota can significantly improve crop yield and quality. The rhizosphere, the zone directly influenced by plant roots, harbours high populations of active microorganisms and plays a vital role in plant-microbe interactions. One of the most crucial symbiotic relationships in the rhizosphere is between plants and arbuscular mycorrhizal fungi (AMF). AMF form mutualistic associations with the roots of various plant species, including major crops and contribute to defence against soil-borne pathogens, nutrient cycling and soil aggregation. Glomalin, a glycoprotein secreted by AMF, plays a crucial role in soil aggregation, stability and carbon sequestration. It enhances soil structure, binds with soil particles, stabilizes aggregates and promotes water infiltration and retention. It also plays a role in sequestering toxic metals, reducing their availability to plants and mitigating their harmful effects on soil biota. Managing glomalin in soil involves practices such as minimizing tillage to preserve the hyphal network, maintaining living roots through cover crops to sustain fungal colonization and optimizing nutrient inputs to support fungal activity without overloading the soil. AMF and glomalin play pivotal roles in agricultural sustainability and soil ecosystem functioning, highlighting the importance of conserving and enhancing these beneficial microbial associations for improved soil health and crop productivity.

Biofilm Formation by Quorum Sensing and Manners to Deal It

Background: Quorum sensing (QS) is one of the main regulatory systems which have various effects on populations of microorganisms. This process has been found in a diverse array of microorganisms (various bacterial taxa, microalgae and fungi). QS is required for different activities of microorganisms such as, virulence factor secretion, motility, competence, biofilm and sporulation. There are different molecules as signals in disparate microorganisms. Biofilm formation is one of the significant functions of QS. Biofilms are groups of microorganisms that are tied to a surface (biotic or abiotic). One of the remarkable effects of biofilm formation seems to be the persistence against hostile environmental condistions. Biofilm formation have been widely reported as a pathogenesis strategy in microorganisms. Here we describe QS and biofilm formation in some important microorganisms and describe some of the suggested strategies for eradication of microbial biofilms. Conclusion: Inhibition of biofilms formation can have detectable effects on the treatment of infectous diseases. In this line, multiple approaches have been suggested to inhibit the biofilm formation by microorganisms.

Enhancement of microbial community dynamics and metabolism in compost through ammonifying cultures inoculation

The efficient use of livestock and poultry manure waste has become a global challenge, with microorganisms playing an important role. To investigate the impact of novel ammonifying microorganism cultures (NAMC) on microbial community dynamics and carbon and nitrogen metabolism, five treatments [5% (v/w) sterilized distilled water, Amm-1, Amm-2, Amm-3, and Amm-4] were applied to cow manure compost. Inoculation with NAMC improved the structure of bacterial and fungal communities, enriched the populations of the functional microorganisms, enhanced the role of specific microorganisms, and promoted the formation of tight modularity within the microbial network. Further functional predictions indicated a significant increase in both carbon metabolism (CMB) and nitrogen metabolism (NMB). During the thermophilic phase, inoculated NAMC treatments boosted carbon metabolism annotation by 10.55%–33.87% and nitrogen metabolism annotation by 26.69%–63.11. Structural equation modeling supported the NAMC-mediated enhancement of NMB and CMB. In conclusion, NAMC inoculation, particularly with Amm-4, enhanced the synergistic interaction between bacteria and fungi. This collaboration promoted enzymatic catabolic and synthetic processes, resultng in positive feedback loops with the endogenous microbial community. Understanding these mechanisms not only unravels how ammonifying microorganisms influence microbial communities but also paves the way for the development of the composting industry and global waste management practices.

An Evaluation of Long-Term Contaminated Soil from a Manufactured Gas Plant for in Situ Biodegradation Potential and as a Source of Ferrocyanide-Degrading Bacteria

Despite the high abundance and potential toxicity of ferrocyanide in the environment, data on the bioremediation of these complexes in contaminated soils are missing. In this study we isolated forty bacterial species presented in soil highly contaminated with ferrocyanide complexes, originating from a Manufactured Gas Plant (MGP). All bacterial strains were resistant to ferrocyanide (500 mg L−1). Six isolates showed better growth in the presence of ferrocyanide and were able to use it as a sole nitrogen source. One of them was able to assimilate ferrocyanide‐derived nitrogen and carbon. The strains varied in their tolerance to the ferrocyanide. The Minimum Inhibitory Concentration (MIC) values determined in the rich medium ranged from 1400 mg L−1 to 2000 mg L−1 and in all cases were greater than those set on the minimal medium. Molecular analysis revealed that the investigated isolates had the highest similarity to the Bacillus and Rummeliibacillus lineages. Rummeliibacillus was recognized for the first time for its ferrocyanide-degrading potential. Soil samples collected from MGP sites indicated that the overall indigenous population of microorganisms was low. Total cyanide content ranged from 220 mg kg−1 to 346 mg kg−1. Additionally, elevated Pb concentrations and an imbalanced C:N:P ratio were observed. Our study provides new information about the presence of a well-acclimated bacterial community associated with long-term ferrocyanide-contaminated soil. This bacterial community could play an important role in MGP site bioremediation processes and has the potential for application for other bioremediation purposes; however, it is likely limited due to unfavorable environmental conditions.

Evaluation of strategies to improve the quality of Tanzania grass (Megathyrsus maximum) silage with increasing levels of mata-pasto hay (Senna obtusifolia)

Context Seasonal variations between the rain and dry seasons are the main obstacle to agricultural productivity in tropical regions, making it essential to conserve surplus for periods of scarcity. One of the limiting factors in ensiling grasses is moisture, requiring the use of additives or withering. Using a mixture of grasses and legumes can be an alternative to balance the advantages and disadvantages of both in the ensiling process, and mata-pasto hay (MPH) can be an option. Aims This study evaluated different forms of Tanzania grass (Megathyrsus maximum) and MPH silages, as well as silages with increasing levels of MPH. Methods Silages of Tanzania grass and MPH in their natural form, as well as silages with increasing doses of MPH, were evaluated for nutritional value, degradability in situ. The microbiology was also evaluated. Key results Among the types of silages, natural MPH and wilted MPH were superior to natural Tanzania grass silage. The use of MPH in Tanzania grass silages improves fermentation processes, the population of beneficial microorganisms, resulting in better nutritional value of these silages. Conclusions Natural and wilted MPH hay silages are qualitatively better compared to natural Tanzania grass silage. Increasing doses of MPH improve the quality of the silage. A recommended dose is 30% of MPH hay. Implications Adding MPH to silages is a way to reduce the negative impacts of this weed on pastures. However, further studies with the use of complementary additives are needed.