—
Microorganisms disproportionating inorganic sulfur compounds are involved in biogeochemical cycles of elements in the modern biosphere. Sulfur-disproportionating prokaryotes are represented by 30 ...species of the
Bacteria
domain and belong to the phyla
Proteobacteria, Thermodesulfobacteria
, and
Firmicutes
. Most of the sulfur-disproportionating bacteria belong to four orders of the class
Deltaproteobacteria
. The microorganisms responsible for dismutation of sulfur compounds inhabit freshwater and shallow marine sediments, hypersaline and soda lakes, anthropogenic environments, and various natural thermal ecosystems. Most sulfur-disproportionating organisms are able to use other processes for growth, primarily dissimilatory sulfate reduction. Ability to grow autotrophically was shown for 17 sulfur-disproportionating strains from different phylogenetic groups. The biochemical mechanisms involved in disproportionation of sulfur compounds remain uncertain, which hinders the application of the current omics techniques. Comparative analysis of available complete genomes of the microorganisms capable of elemental sulfur disproportionation is provided. The presence of the complete set of the dissimilatory sulfate reduction genes was found not to be necessary for S
0
disproportionation. This process does not require dissimilatory sulfite reductase (Dsr) and adenylyl-sulfate reductase (Apr). Sulfur relay proteins and the elemental sulfur- and/or polysulfides-reducing enzymes are important in sulfur disproportionation, but different microorganisms probably employ different sulfur transferases and polysulfide reductases in these processes.
Differences in the quantitative and qualitative compositions of various physiological and biochemical groups of cultured microorganisms were revealed in biofilms formed on stony substrates in the ...littoral zone of Southern Baikal (August 2012) in the areas with different anthropogenic load. Maximal abundance of microorganisms was registered in epilithic biofilms from the area of Baikalsk Pulp and Paper Plant: organotrophs (770.2 ± 290.3 × 10
3
CFU/cm
2
); amylolytics (38.1 ± 7.7 × 10
3
CFU/cm
2
); phosphate-solubilizing microorganisms (4.8 ± 1.4 × 10
3
CFU/cm
2
); phosphate-mobilizing microorganisms (212.0 ± 27.6 × 10
3
CFU/cm
2
); phenol-oxidizing microorganisms (15.7 ± 2.4 × 10
3
CFU/cm
2
); molds (3.2 ± 0.4 × 10
3
CFU/cm
2
); and total coliform bacteria (193.3 ± 28.2 CFU/cm
2
), with the total microbial abundance (TMA at 37°C) of 24.9 ± 1.7 × 10
3
CFU/cm
2
, which indicated high degrading activity of the biofilms in response to the anthropogenic load in the area. Epilithic biofilms of the Bol’shie Koty area exhibited the lowest abundance of organotrophic and phosphate-solubilizing microorganisms, while molds were absent.
Soil microbiomes and one health Banerjee, Samiran; van der Heijden, Marcel G A
Nature reviews. Microbiology,
01/2023, Letnik:
21, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The concept of one health highlights that human health is not isolated but connected to the health of animals, plants and environments. In this Review, we demonstrate that soils are a cornerstone of ...one health and serve as a source and reservoir of pathogens, beneficial microorganisms and the overall microbial diversity in a wide range of organisms and ecosystems. We list more than 40 soil microbiome functions that either directly or indirectly contribute to soil, plant, animal and human health. We identify microorganisms that are shared between different one health compartments and show that soil, plant and human microbiomes are perhaps more interconnected than previously thought. Our Review further evaluates soil microbial contributions to one health in the light of dysbiosis and global change and demonstrates that microbial diversity is generally positively associated with one health. Finally, we present future challenges in one health research and formulate recommendations for practice and evaluation.
Over the past several decades, the use of genetically engineered microorganisms (GEMs, often referred to as Genetically Modified Microorganisms or GMMs) has become widespread in the production of ...food processing aids and other food ingredients. GEMs are advancing food production by increasing efficiency, reducing waste and resource requirements, and ultimately enabling beneficial innovations such as the cost-effective fortification of food with essential nutrients, vitamins, and amino acids, and delivery of tailored enzymes to achieve unique food processing capabilities. Regulatory agencies, including those in the European Union, United States, and Canada review the safety of GEMs when evaluating food substances produced using GEMs to ensure that both the microorganism and the resulting food substance are safe. This paper provides a summary of historical and current use of GEMs in food manufacture, an overview of frameworks that regulate their use, and a description of the safety assessment of both GEMs and food substances produced with GEMs. The paper encourages regulatory agencies around the globe to take a more aligned approach to the safety evaluation and regulatory oversight of GEM-produced food ingredients and enzymes, a category of food substances that enables more sustainable consumer food choices.
Draft Endorsed by the FEEDAP Panel
*
18 May 2017
Submitted for public consultation
15 June 2017
End of public consultation
15 September 2017
Adopted by the FEEDAP Panel
21 February 2018
...Implementation date
1 September 2018
* Sections 3.1 and 3.2 were also endorsed by the EFSA Panel on Genetically Modified Organisms (GMO), EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF) and EFSA Panel on Food Additives and Nutrient Sources Added to Food (ANS) on 18 May (GMO) and 7 June (CEF and ANS) 2017.
This guidance document is intended to assist the applicant in the preparation and the presentation of an application, as foreseen in Article 7.6 of Regulation (EC) No 1831/2003, for the authorisation of additives for use in animal nutrition. It specifically covers the characterisation of microorganisms used as feed additives or as production organisms.
This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2018.EN-1389/full
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•Thermophilic food waste digestion with varied particle size of biochar was examined.•All examined biochars (<50 μm to 3 cm) significantly improved methane production.•Bacteria ...Thermotogae and methanogens Methanothermobacter &Methanosarcina enriched.•The synergy of hydrogenotrophic and acetoclastic methanogenic pathways was achieved.•Both technical and economic feasibility of adding biochar strategy were validated.
Effectiveness of biochar addition to enhance thermophilic semi-continuous anaerobic digestion (AD) of food waste for methane production was investigated with a focus on dosage and particle size of biochar, pilot-scale application and elucidation of methanogenic pathways. Optimal dosage range of biochar was determined as 7.5 to 15 g per L working volume based on lab-scale batch AD. Effects of biochar with different particle sizes at a model dosage of 15 g/L were evaluated in a semi-continuous AD experiment, results of which showed that all the examined biochars with different particle sizes (<50 μm to 3 cm) substantially enhanced the average methane yields (0.465–0.543 L/gVS) compared to control digesters which failed due to overloading (≥3.04 gVS/L/d). No significant difference in methane yields, however, was observed among digesters with different particle sizes of biochars, except for 1–3 cm. The core reason for this phenomenon was that the biochars with different particle sizes had similar properties (e.g. density, surface area and pore size) and that the floating of large particle size (1–3 cm) of biochar with a density of 847 kg/m3 was not conducive to microbial growth. Metagenomic analysis was performed to determine the predominant microbial species and to explain the main methanogenic pathways in biochar-amended digesters using 16S rRNA sequencing. In the biochar-amended digester, bacterial phylum Thermotogae containing a major genus of Defluviitoga was selectively enriched with gradual increase of organic loadings, while simultaneously enriched methanogen genera Methanothermobacter and Methanosarcina, which showed a synergy of hydrogenotrophic and acetoclastic methanogenic pathways, jointly enhanced the methane productivity. Both technical feasibility and economic feasibility of adding biochar with simple pretreatment (e.g. smash) were validated in the pilot-scale thermophilic semi-continuous AD operations.
It has recently been shown that in anaerobic microorganisms the tricarboxylic acid (TCA) cycle, including the seemingly irreversible citrate synthase reaction, can be reversed and used for ...autotrophic fixation of carbon1,2. This reversed oxidative TCA cycle requires ferredoxin-dependent 2-oxoglutarate synthase instead ofthe NAD-dependent dehydrogenase as well as extremely high levels of citrate synthase (more than 7% of the proteins in the cell). In this pathway, citrate synthase replaces ATP-citrate lyase of the reductive TCA cycle, which leads to the spending of one ATP-equivalent less per one turn of the cycle. Here we show, using the thermophilic sulfur-reducing deltaproteobacterium Hippea maritima, that this route is driven by high partial pressures of CO2. These high partial pressures are especially important for the removal of the product acetyl coenzyme A (acetyl-CoA) through reductive carboxylation to pyruvate, which is catalysed by pyruvate synthase. The reversed oxidative TCA cycle may have been functioning in autotrophic CO2 fixation in a primordial atmosphere that is assumed to have been rich in CO2.
Purpose This retrospective study aims to compare the rate of microbial contamination in fresh, non-preserved amniotic tissue as opposed to decontaminated cryopreserved tissue, thereby being able to ...determine the efficiency of the decontamination procedures applied during amniotic tissue preparation in the Cornea Bank Essen. Methods The amniotic tissue was retrieved from donor placentas acquired through elective c-section. Tissue preparation was performed according to standard operation procedures of the Cornea Bank Essen. Briefly, the tissue is rinsed with sterile balanced salt solution (BSS) and decontaminated with BSS containing anti-infectives. Preservation included the application of a cryopreservation solution containing anti-infectives and glycerin. The tissue is stored at a temperature of -80°C. Screening for microbial contamination of amniotic tissue in its pre- and post decontamination status is part of the process. In this study, data from 107 placentas prepared in the eye bank were retrospectively evaluated for the microbiological status to determine the effectivity of the procedure. Results Out of the fresh, non-preserved amniotic tissue, 53 were tested positive for microbial contamination. The most common species identified were C.acnes and Staphylococcus spp., which jointly comprised around 80% of the detected microorganisms. Others found in the remaining placentas were of the species: Acinetobacter, Bacillus spp., Faklamia, Lactobacillus, Rothia, Micrococcus, Penicillium, Ralstonia, Streptococcus and non-specific aerobic sporulating bacteria. In contrast, 8 samples of the decontaminated cryopreserved tissue were tested positive for microorganisms with 4 placentas inhabited by C.acnes, 2 by Bacillus spp. while the remaining consisting each of the species Staphyloccocus and Ralstonia. Conclusion Overall, the decontamination measures applied during the preparation of the amniotic tissue can be regarded as effective. We found a significant reduction of the number of microorganisms detected in the amniotic tissue following antibiotic administration. However, some of the remaining species identified in the processed samples may be considered as contamination during the preparation and testing procedures. For instance, C.acnes can be considered a result of secondary contamination due to incorrect handling. Species such as Bacillus most likely managed to endure the decontamination process owing to its natural resilience against harsh circumstances.
Abstract
Phototrophic and heterotrophic microorganisms coexist in complex and dynamic structures called periphyton. These structures shape the biogeochemistry and biodiversity of aquatic ecosystems. ...In particular, microalgae–bacteria interactions are a prominent focus of study by microbial ecologists and can provide biotechnological opportunities for numerous applications (i.e. microalgal bloom control, aquaculture, biorefinery, and wastewater bioremediation). In this review, we analyze the species dynamics (i.e. periphyton formation and factors determining the prevalence of one species over another), coexisting communities, exchange of resources, and communication mechanisms of periphytic microalgae and bacteria. We extend periphyton mathematical modelling as a tool to comprehend complex interactions. This review is expected to boost the applicability of microalgae–bacteria consortia, by drawing out knowledge from natural periphyton.
This review considers the ecological diversity and functional drivers of periphyton, highlighting the role of microalgae and bacteria. It explores published concepts in greater detail, and distils knowledge draw knowledge from natural periphyton for that may be applied in biotechnology.
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