Bisphenol A (BPA), as both an endocrine disrupting compound and an important industrial material, is broadly distributed in coastal regions and may cause adverse effects on mangrove ecosystems. Although many BPA degraders have been isolated from various environments, the in-situ active BPA-degrading microorganisms in mangrove ecosystem are still unknown. In this study, DNA-based stable isotope probing in combination with high-throughput sequencing was adopted to pinpoint the microbes actually involved in BPA metabolism in mangrove sediments. Five bacterial genera were speculated to be associated with BPA degradation based on linear discriminant analysis (LDA) effect size (LEfSe) analysis, including Truepera, Methylobacterium, Novosphingobium, Rhodococcus and Rhodobacter. The in-situ BPA degraders were different between mudflat and forest sediments. The Shannon index of microbes in heavy fractions was significantly lower than that in light fractions. Besides, phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) demonstrated that the functional genes relevant to cytochrome P450, benzoate degradation, bisphenol degradation and citrate cycle were up-regulated significantly in in-situ BPA-degrading microbes. These findings greatly expanded the knowledge of indigenous BPA metabolic microorganisms in mangrove ecosystems.

Abstract This study aimed to evaluate the air and water contamination level and to identify the microbes isolated from a rodent facility located at the Federal University of Uberlândia, Minas Gerais, Brazil. Colony forming units (CFU) per milliliter was used for monitoring water quantitatively; CFU per cubic meter was used for air monitoring. The isolated colonies were identified for qualitative monitoring. Due to absence of specific parameters for these facilities, the results were analyzed according to Brazilian and international standards, depending on which best suited each sample. The mean total number of microorganisms in water ranged from 0.015 ± 0.02 to 0.999 ± 0.91 CFU/mL. The number of microorganisms in air ranged from 9.1 ± 4.6 to 351.56 ± 158.2 CFU/m³. Forty-one microorganisms identified in the samples obtained from the rodent facility were potentially pathogenic or opportunistic for animals and humans (e.g., Corynebacterium spp.). We concluded that the water and air samples were contaminated with potentially pathogenic or opportunistic microorganisms that can harm rodents and humans. On the basis of our observations, specific sanitary standards suitable for these facilities should be developed for controlling microbial contamination, which will prevent zoonosis and ensure the reliability of scientific results obtained from animal experiments.

Bacterial cellulose (BC) produced by the Komagateibacter sucrofermentas VKPM B-11267 bacteria was used as a carrier for immobilization of acetic acid bacteria Gluconobacter oxydans in amperometric biosensors. The bioreceptor was formed on the surface of a screen-printed graphite electrode modified with thermally expanded graphite (TEG) or on the surface of a porous three-dimensional material, nickel foam (NF). Structural features of these materials contributed to the creation of a firm contact between the electrode material and the surface of the BC on which the bacterial cells were immobilized. Scanning electron microscopy showed that bacteria not only sorb on the surface of BC but are also able to penetrate the inner volume of the film. Conductivity of both types of biosensors was studied using impedance spectroscopy and the resistance of the graphite electrode was shown to decrease by three orders of magnitude after its surface is modified with TEG. Bioelectrodes containing BC were used in the construction of an amperometric biosensor for glucose determination. The sensitivity of the biosensor was 3 μA/mM × cm². Thus, BC in combination with TEG and NF can be used to create three-dimensional electrodes of bioelectrocatalytical devices.

Microorganisms are stupendous source of secondary metabolites, having significant pharmaceutical and industrial importance. Genome mining has led to the detection of several cryptic metabolic pathways in the natural producer of secondary metabolites (SMs) such as actinobacteria and fungi. Production of these bioactive compounds in considerable amount is, however, somewhat challenging. This led to the search of using epigenetics as a key mechanism to alter the expression of genes that encode the SMs toward higher production in microorganisms. Epigenetics is defined as any heritable change without involving the changes in the underlying DNA sequences. Epigenetic modifications include chromatin remodeling by histone posttranslational modifications, DNA methylation, and RNA interference. Biosynthetic gene cluster for SMs remains in heterochromatin state in which the transcription of constitutive gene is regulated by epigenetic modification. Therefore, small-molecule epigenetic modifiers, which promote changes in the structure of chromatin, could control the expression of silent genes and may be rationally employed for discovery of novel bioactive compounds. This review article focuses on the types of epigenetic modifications and their impact on gene expression for enhancement of SM production in microorganisms.

Several nematode species can be found in different densities in almost any soil ecosystem, and their diversity in those ecosystems depends on numerous reasons, such as climatic conditions and host presence. Cereals are one of the main hosts of plant-parasitic nematodes (PPN), chiefly root-lesion nematodes (RLN, Pratylenchus spp.) and cereal cyst nematodes (CCN, Heterodera spp.). These nematodes are known as major parasites of the cereal crops; however, agricultural areas accommodate various nematodes showing biological variation. The diversity of parasitic nematodes on cereals in the Sakarya provinces of Türkiye, where cereals are intensively grown and located in the middle of two climatic zones, has not been well studied. Therefore, in this study, we aimed to determine the diversity, identification, and molecular phylogeny of PPNs in wheat-growing ecosystems in the Hendek, Pamukova, Geyve, Akyazı, and Central districts of Sakarya. The diversity of PPNs was calculated using the Shannon diversity index. Thirteen PPN genera were detected in 92% of soil samples. Heterodera filipjevi was identified in 24% of the soil samples using morphological, morphometrical, and molecular tools. In the morphological and molecular analyses, intraspecific polymorphism was observed in H. filipjevi populations. The result indicated that the high infestation rate of H. filipjevi was recorded from Geyve and Pamukova, followed by Hendek and Akyazı; however, a low infestation rate was detected in the Central district. The moderate value of the Shannon index of migratory nematode species was obtained in wheat fields as 2.31, whereas the value of evenness was 0.93, implying moderate diversity and high evenness of nematodes. This study is the first comprehensive report on H. filipjevi from wheat cropping areas in the Sakarya province. Intensified cereal cropping systems with/without non-cereal rotations increased the risk of plant-parasitic nematodes, especially RLNs and H. filipjevi infection of wheat production areas in the province.

Livestock grazing, the main type of management activity in grasslands drives the structure and function of these ecosystems. However, the responses of soil microbial biomass and community composition to grazing remain poorly understood, compared with plants, nutrients and soil properties. We conducted a meta-analysis of independent grazing intensity (low grazing intensity, intermediate grazing intensity and high grazing intensity) experiments, including 69 studies with 934 paired observations, in steppe ecosystems of China and evaluated their effects on soil microbial biomass and community composition. Our results revealed that high grazing intensity consistently reduces total microbial biomass, the biomass of bacteria, fungi, actinomycetes, gram-positive bacteria and gram-negative bacteria by 33%, 31%, 53%, 14%, 19% and 36%, respectively, whereas low grazing intensity has limited effect on these microbial variables. High grazing intensity strongly reduced the numbers of bacteria, fungi and actinomycetes by 92%, 65%, 30%, respectively, but low grazing intensity had limited effects on them. The responses of fungal numbers to grazing intensity were positively correlated with those of plant aboveground biomass. Meanwhile, the response of bacterial numbers was positively correlated to that of soil bulk density. Our findings indicate that aboveground plant biomass and soil bulk density might be the underlying drivers that change the numbers of fungi and bacteria to grazing intensities in China. Our findings highlight the negative effect of high grazing intensity on soil microbial biomass and numbers in natural grasslands.

Currently, there are substantial knowledge gaps on the impacts of cover crops on soil resources in tree cropping systems, wherein they are typically planted in interrow alleys and maintained for multiple years. While cover crops uptake soil nutrients and water, they can also prevent soil water evaporative losses and return nutrients to soils via decomposition of plant residues and stimulation of microbial nutrient cycling. This field sampling study examined variances in soil conditions across 5- and 7-year-old, cover cropped pecan orchards. We collected soil beneath cover crops and beneath adjacent trees, where soil was kept bare, to evaluate impacts of cover on the soil biota, nutrients, carbon, and their dynamics across a production season. We employed routine soil chemical analyses, phospholipid fatty acid (PLFA) analysis, and high throughput sequencing of 16 S rRNA genes and ITS regions for soils collected at four time points. We revealed that the cover cropped alley soils contained higher relative abundances of microbes that use labile soil substrates in resource rich conditions than did the tree row soils. Soil chemical analyses provided additional evidence that the cover crops did not deplete soil nutrients and reduce soil moisture, but rather, enhanced soil nutrient and moisture contents during many of the sampling time points. Notably, cover crop plant species correlated with soil nutrients and plant beneficial microbes, which may warrant consideration when selecting cover crop species. The tree row and cover cropped alley soils had different proportions of plant-beneficial mycorrhizal fungi. The tree rows supported higher numbers of ectomycorrhizal (ECM) fungi and alleys had higher relative abundances of arbuscular mycorrhizal (AM) fungi, suggesting potential benefits for tree species like pecan, which support dual colonization by AM and ECM Fungi. Altogether, the cover crops enhanced soil carbon, nutrients, and microbial populations in a pecan orchard and these impacts were frequently larger in a 7-year-old versus 5-year-old orchard.

Concern about increasing incidents of petroleum hydrocarbon spills and spillage into different marine environments is rising day by day due to enhanced human activities in marine water. The toxic compounds of spilled petroleum hydrocarbon in marine water lead to the immediate death of numerous marine organisms as well as initiate various vicious biogeochemical cycles in the marine environment resulting in prolonged toxic impacts on the marine environment. Recently, many sophisticated techniques, including physical methods, chemical methods, and biological methods, have been developed and adopted for the treatment of marine environments polluted with petroleum compounds. However, biological treatment is one of the most promising methods in this field by which microorganisms such as bacteria, fungi, and algae are used for biodegradation of pollutants such as the spilled petroleum hydrocarbon into neutralized or eco-friendly compounds. This review has been focused on different aspects of the pollution of the marine ecosystem by oil, mainly Petroleum hydrocarbons, the fate of spilled oil in marine environments and the role of microbial communities in it, as well as various techniques, especially the bioremediation and biodegradation of spilled oil including the factors affecting the capacity of techniques. Moreover, some future aspects of research in the field of biodegradation and bioremediation of spilled oil have been proposed.