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Endophytic fungi are recognized as promising source of diverse bioactive compounds. In particular, mangrove-derived fungal endophytes are known to provide distinct microbial diversity capable of producing various pharmacologically active compounds, due to their exposure to various environmental stresses. This study investigated the antibacterial activity and toxicity of extracts of endophytic fungi isolated from mangrove Lumnitzera racemosa, collected in Bali, Indonesia. Following fungal isolation procedure, three endophytic fungal isolates, namely ER1, ER2 and ER3 were isolated from healthy tissue of stem and fruit of L. racemosa. Each isolated fungus was cultivated on rice media for 4 weeks, followed by extraction using ethyl acetate and solvent removal by vacuum rotary evaporator, yielding three extracts. Each ethyl acetate extract was partitioned between aquaeous methanol and n-hexane. All of the resulting methanol extracts were subjected to phytochemical analysis and tested for their antibacterial and toxicity. Antibacterial assay was performed with microdilution technique, whereas the toxicity was screened through brine shrimp lethality test (BSLT). Phytochemical analysis indicated the presence of alkaloids, terpenoids, triterpenoids, and polyphenols in each extract. When tested for their antibacterial activity against Staphylococcus aureus ATCC 25923, all of the tested extracts were found to be inactive up to the tested concentration of 1000 µg/mL. Albeit no activity was found in antibacterial assay, all of the tested extracts displayed toxic effect against brine shrimp with LC50 values ranging from 324.94 to 406.68 µg/mL. Many toxicity studies on natural products employing BSLT revealed positive correlations with their cytotoxicity against various solid tumor cell lines. Thus, result of this study implied all of the tested extracts merit further investigation of their cytotoxic activity towards cancer cell lines. [ABSTRACT FROM AUTHOR]

Fermentation is a method used to prolong the shelf-life and taste of fruit. Tempoyak is a fermented food made from durian pulps. Accumulating works were conducted to isolate and characterize the microbial communities using culture-dependent methods, with little effort in identifying the diversity using culture-independent approaches like next-generation sequencing (NGS) in tempoyak. The culture-dependent method showed several limitations such as tedious technique in plating, biasness in morphological identification and incompatibility of media selection for microbial growth. To date, the NGS allowed identification of the unculturable microbes up to species level. The purpose of this study is to screen the microbial communities in tempoyak using amplicon sequencing by targeting 16S rRNA and ITS2 for determining the diversity of bacterial and fungal communities respectively. On the other hand, this study also compared the complex microbial structure from the first day, T0 to day 14, T14 of the fermentation process. Here, we observed that sample T14 showed more diverse in both bacterial and fungal populations as compared to sample T0. Overall, genus Lactobacillus are the most abundant microbes representing the bacterial community. This study highlighted the importance of the NGS in characterizing the complex microbial communities in fermented food, for which could be useful to screen for potential unculturable microbial communities hindered by the limitation of culture-dependent approach. [ABSTRACT FROM AUTHOR]

Microbial communities contribute to most organisms in our environment and have greater capacity to transform the world around. However, a large number of them remain uncultivable. Identification and functional validation of the uncultured microbial communities in environmental samples remains a challenging task. Metagenomics has become one of the indispensable tools for studying the diversity and function of these uncultured microbes. Our sample has been collected from a public toilet of an undeveloped area in North Coimbatore District, Tamil Nadu, INDIA. Waste effluents from this public toilet were used to generate electricity for the area using Microbial Fuel Cell (MFC) which involves bio-film formation which helps in electron transfer. Our study aims in identification of the diverse microbial community present in urine sample and to functionally annotate the gene responsible for biofilm formation aiding in electron transfer process. As metagenomic studies are becoming widespread, a large number of computational tools and a wide range of bioinformatics pipelines have been developed for metagenomic assembly, taxonomic and functional annotation. Choosing an appropriate tool is crucial and requires validation. In this present study, a range of bioinformatics tools were used quantify the sequence reads, taxonomic classification of the microbial population in the urine sample, assembly of the mixed sequence reads of multiple species and to attain functional annotation of the hypothetical protein. [ABSTRACT FROM AUTHOR]

The ecological crisis in the coastal zone of Lake Baikal, which began in 2010-2011, caused changes in the taxonomic composition of microbial communities in the water and sponges. To identify these changes and their possible cause, we analyzed and compared the composition and diversity of microbial communities in the Baikal bacterioplankton and endemic sponges, Lubomirskia baikalensis, using high−throughput 16S rRNA sequencing. The microbial diversity in the Baikal bacterioplankton was higher than in the microbiome of the sponge body L. baikalensis. By 2015, the microbial community in sponges consisted of abundant Cyanobacteria, Bacteroidetes, Proteobacteria, and Actinobacteria and became more similar to the biofouling community. Bacteria associated with human activity were often found in the water and sponge communities. During this period, the amplicon sequences of some opportunistic human pathogens were detected in the coastal water and sponges. The obtained results dramatically demonstrate the anthropogenic impact on the ecosystem of the coastal zone of Lake Baikal. [ABSTRACT FROM AUTHOR]

The status, abundance and diversity of soil microbial communities are one of the main basic indicators for the assessment and monitoring of forest ecosystems. In the context of the important role that microorganisms play in forest ecosystems, it is crucial to study and monitor their abundance in soil habitats. In order to supplement the knowledge about the soil microbial communities in the different soil horizons, we studied 16 soil profiles from the territory of Vitosha Nature Park. The soils from tested areas 1-8 are determined as Dystric Cambisols and the soils form tested areas 9-16 as Umbrisols. The main soil characteristics: pH, total nitrogen content, humus and organic carbon content have been studied using standard laboratory analyses. The total microbial number of the individual soil horizons have been established respectively for the Dystric Cambisols A and B horizons, for the Umbrisols A1 and A horizons. The Koch method was used. The percentage distribution of the main microbial groups: spore-forming and non-sporeforming microorganisms, actinomycetes and micromycetes have been determined. For all studied soils, a decrease in the total microflora with an increase in the depth of the soil profile was found. In Umbrisols this decrease is less compared to Dystric Cambisols. In both soil types, the results show a significant reduction in the group of micromycetes in the underlying soil horizon, regardless of soil type. In soils with higher acidity, a higher percentage of the micromycetes is observed, regardless of soil type and soil horizon. Higher values of the correlation coefficient were found when comparing the microbial abundance in the lower soil horizons with the humus content, compared to the upper soil horizons. [ABSTRACT FROM AUTHOR]

Potentially toxic elements such as arsenic and antimony represent dangerous contaminants for the ground and surface water around abandoned Sb deposits in Slovakia. Therefore, we are working on a complex study on the material from tailings, including mineralogy, water quality and microbial inhabitants of the contaminated waters. The aim of the work presented here, was to observe the chemical composition of iron ochres and the role of the microbial diversity in the mobilization or immobilization of As and Sb from a contaminated landfill. In 2018, arsenic rich (up to 28.3 wt%) and Sb rich (up to 2.7 wt%) samples of HFO were collected at four localities in Slovakia. All samples were analyzed, after appropriate dilution, for As and Sb. An Illumina MiSeq sequencing platform was applied to detect microbial species composition of the ochre samples. For all four sites (Pezinok, Medzibrod, Dúbrava and Čučma), we report a chemical composition and a detailed description of the species composition. The most common species of all sites were Rhodoferax spp. (dissimilatory iron reducing bacteria) and Methylobacter spp. (facultative methylotroph). The highest difference in frequency of the bacterial species composition were observed at the site Čučma, where one species (Methylobacter spp.) formed the majority of the sample. The abundance and high diversity of bacterial community have proven to be highly important in the process of mobilization or immobilization of the potentially toxic elements. [ABSTRACT FROM AUTHOR]

The amplification of environmental DNA is one of the main steps in microbial diversity profiling of environmental samples. To represent the microbial community in the soil, DNA extraction is initially needed. The major inhibitor in the soil is a humic acid which greatly inhibits the ability of enzymes to amplify DNA. The protocol provided with the commercial kit was not able to resolve the problem. We, therefore, introduced a modification for soil sample treatment with AICI3 as a flocculating agent that is capable of removing the humic substance contained in peat soil. This technique was superior to the original instruction for extracting DNA with the FastDNA® Spin Kit for Soil (MP Bio, USA). [ABSTRACT FROM AUTHOR]

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The Algerian Sahara is characterized by a heterogeneity of edaphic conditions and climatic dissimilarities; however, information on biological indicators of arid soils is weakly documented in this area. The researchers who have studied the biological activities of the soils of the arid regions have underlined their low organic matter content, particularly their very low rates of organic nitrogen; a low humification because seriously inhibited by a significant mineralization. The objective of the current work is to study the microbial biomass densities and organic matter fractions for different types of soil, under two arid soil in Algerian Sahara. The experiment was conducted in an alluvial soil in traditional palm grove of Guerrara, and in a saline soil in experimental field of university of Ouargla. Composite soil samples (10 subsamples each) were collected aseptically at 0-20 cm depth on two diagonal transects drawn over an area of 12 ha. The following germs densities were determined: Bacteria, Fungi and Actinomycetes. The soil organic matter fractions, the textural fractions, chemical attributes (organic C, total N, total limestone and gypsum) were also determined. The microbial groups count on both soils reveals that the bacterianmicroflora present a numerical superiority followed by the actinomycetes and finally fungi. The micro-organisms densities except fungal density, showed a prevalence of the bacterianmicroflora, and actinomycetes in alluvial soil compared to saline soil. Fractionation of soil organic matter show that all fractions are better represented in alluvial soil except non-extractable organic carbon (NEOC) which are better represented in saline soil. This confirms that alluvial soil has a relatively large biological activity than saline soil and that humification process is relatively pronounced by comparing it with the saline soil, which tends to contain little polycondenseshumic compounds. [ABSTRACT FROM AUTHOR]

Oil palms ((Elaeis guineensis Jacq.), have been widely cultivated in Sumatera for over two planting generations and occupied lands with various soil characteristics. In order to investigate microbial diversity in various soil characteristics of oil palm plantation, a molecular analysis called Terminal Restriction Length Polymorphism (T-RFLP) was adopted. The aim of this research was to analyze the bacterial diversity within several oil palm plantations in Sumatera. DNA extraction was performed using soil DNA extraction kit and analysis was performed using fragment analysis following T-RFLP techniques. Data analysis was performed using MICA III public database. The result showed that soil samples were grouped into two clusters based on their chemical properties. Both HhaI and HinfI digestions affected the number of culturable bacteria dominancy. HhaI was more suitable for revealing a possible culturable genera and species abundance. Dominant genera were detected in each cluster. Cluster-2, which consisted of peat soils, was dominated by Clostridium, Burkholderia, Catenibacterium and Pasteuria. As the diversity of microbes reveals soil fertility, the result showed that metagenomic approach could be used to predict soil fertility indicator, in order to improve agricultural practices for oil palm cultivation. [ABSTRACT FROM AUTHOR]

Anaerobic digestion process is a microbial decomposition of organic matter into methane and carbon dioxide in the absence of oxygen. Lately, current trends in the development of methods for monitoring, modelling and control of microbial growth that characterizes the process of anaerobic digestion and biogas production, are of particular interest. In the same time with experimental research, substantial efforts have been put into the mathematical modelling of anaerobic digestion process used for biogas production. This paper presents a literature review regarding the mathematical models used in anaerobic digestion process optimization for biogas production. [ABSTRACT FROM AUTHOR]

Microbial diversity is an important component of all ecosystems. In humans, disruption of the microbial ecosystem of the gut can lead to serious health consequences. We have designed a CURE that investigates the effects of environmental disruption on the microbial diversity of a laboratory "pond" ecosystem. This CURE is an update of a "Pond in a Jar" project that has been a part of the introductory biology lab course at ULM for over 15 years. In the updated CURE, students utilize microbiological techniques to quantitatively and qualitatively assess microbial diversity following chemical disruption of the ecosystem. We intend for this CURE to address the following STEM skills: 1) Ability to apply the process of science; 2) Scientific communication; and 3) Data analysis. Experience from the initial implementation of the CURE led to revisions to better guide students in quantitative analysis and interpretation of results. The current version also incorporates identification of bacteria by 16S rDNA sequencing. We will present the results of this ongoing effort. [ABSTRACT FROM AUTHOR]

Ants are social insects that live in symbiosis with their environment. Dense ant colonies means higher risk of infection; therefore, ants have adapted a defense system against parasites and pathogens through the production of antimicrobial secretions from their metapleural gland. This study aims to evaluate the microbial diversity of worker ants in the built environment of Campbell University. Solenopsis invictica ants were collected from Campbell University and bacteria were isolated using culture-based methods, identified using 16S rRNA sequencing, and assessed for antibiotic production. Approximately 1.2 x 103 CFU/ant were cultured from ants collected on campus using Luria Bertani Agar incubated at 25°C. Based on colony morphology, 32 bacteria were isolated to be identified. Of these isolates, 17 were sent for sequencing after successful 16S rRNA amplification by PCR. DNA sequencing identified 9 isolates at the genus/species level and 8 at the genus level. Antimicrobial assays of some isolates demonstrated activity against Staphylococcus epidermidis and Escherichia coli. Most of the isolated bacteria exhibited antimicrobial properties. A comparative study to outside environments will determine if the bacteria isolated from Campbell ants are carrying are unique to ants in other environments. [ABSTRACT FROM AUTHOR]

This study is focused on the microbial diversity of anthropogenic sediments in the area Zemianske Kostoľany. The studied substrates represent heterogeneous soil-ash mixture with a significant content of arsenic-rich fly ash and contain increased concentrations of several other potentially toxic elements (Hg, Zn, Cu). Total arsenic contents in soils collected from sampling sites ranged from 93 to 634 ppm. Identified species of microscopic fungi were: Alternaria sp., Aspergillus niger, Cladosporium sp., Mucor sp., Mycocladus sp., Paecilomyces sp., Penicillium sp., Rhizopus stolonifer var. stolonifer and several species of the genus Trichoderma. The next step was evaluation of selected species Aspergillus niger in ability for the removal of arsenic from contaminated substrates by bioleaching, biovolatilization and bioaccumulation. It was released approximately 17.04 % of total arsenic by bioleaching and 13.72 % of total arsenic was accumulated in mycelium. Almost 49 % of total arsenic was volatilized. Little more than 20 % of total arsenic stayed in the solid substrates. Obtained results show important role of microscopic filamentous fungi in polluted environment and possibility their use in bioremediation of contaminated substrates (soils and sediments) in model locality [ABSTRACT FROM AUTHOR]

The diversity and abundance of soil microorganisms are affected by land use and fertilizer application, and these microbial community attributes can provide an insight into soil health. Two methods, microbial plate culture and PCR-DGGE, were employed to study the dynamic changes of the microbial communities in a typical black soil in a long-term land use and fertilization field experiment in Northeast China. Three land use ecosystems were studied, grass land ecosystem (GE), bare land ecosystem (BE), and crop land ecosystem (CE). Fertilization treatments were applied only in cropped land ecosystem and consisted of no fertilizer (CK), chemical fertilizer (NP), and chemical fertilizer combined with manure (NPM). The results indicated that human activities in CE have altered both the diversity and abundance of soil microorganisms. Fertilizer increased the diversity and abundance of the microbial community indicating enhanced soil fertility. Fertilizer together with composted manure enhanced both abundance and diversity of the microbial community compared to synthetic fertilizers alone. The diversity of the microbial community was highest in GE, followed by CE, and was lowest in BE. [ABSTRACT FROM PUBLISHER]