Recovery of Methanotrophic Activity Is Not Reflected in the Methane-Driven Interaction Network after Peat Mining

Aerobic methanotrophs are crucial in ombrotrophic peatlands, driving the methane and nitrogen cycles. Peat mining adversely affects methanotrophs, but activity and community composition/abundances may recover after restoration. Considering that the methanotrophic activity and growth are significantly stimulated in the presence of other microorganisms, the methane-driven interaction network, which encompasses methanotrophs and nonmethanotrophs (i.e., the methanotrophic interactome), may also be relevant in conferring community resilience. Yet, little is known of the methanotrophic interactome's response to and recovery from disturbances. Here, we determined the recovery of the methanotrophic interactome as inferred by a co-occurrence network analysis comparing pristine and restored peatlands. We coupled a DNA-based stable isotope probing (SIP) approach using [13C]CH4 to a co-occurrence network analysis derived from the 13C-enriched 16S rRNA gene sequences to relate the response in methanotrophic activity to the structuring of the interaction network. Methanotrophic activity and abundances recovered after peat restoration since 2000. “Methylomonaceae” taxa were the predominantly active methanotrophs in both peatlands, but the peatlands differed in the relative abundances of Methylacidiphilaceae and Methylocystis. However, bacterial community compositions were distinct in both peatlands. Likewise, the methanotrophic interactome was profoundly altered in the restored peatland. Structuring of the interaction network after peat mining resulted in the loss of complexity and modularity, indicating a less connected and efficient network, which may have consequences in the event of recurring/future disturbances. Therefore, determining the response of the methane-driven interaction network, in addition to relating methanotrophic activity to community composition/abundances, provided a more comprehensive understanding of the resilience of the methanotrophs

La intertextualidad como método de análisis filosófico

Ombrotrophic peatlands are a recognized global carbon reservoir. Without restoration and peat regrowth, harvested peatlands are dramatically altered, impairing its carbon sink function, with consequences for methane turnover. Previous studies determined the impact of commercial mining on the peat physico-chemical properties, and the effects on methane turnover. However, the response of the underlying microbial communities catalyzing methane production and oxidation have so far received little attention. We hypothesize that with the return of Sphagnum post-harvest, methane turnover potentials and the corresponding microbial communities will converge in a natural and restored peatland. To address our hypothesis, we determined the potential methane production and oxidation rates in a natural (as a reference), actively mined, abandoned, and restored peatland over two consecutive years. In all sites, the methanogenic and methanotrophic population size were enumerated using qPCR assays targeting the mcrA and pmoA genes, respectively. Shifts in the community composition was determined using Illumina MiSeq sequencing of the mcrA gene, and a pmoA-based t-RFLP analysis, complemented by cloning and sequence analysis of the mmoX gene. Peat mining adversely affected methane turnover potentials, but rates recovered in the restored site. The recovery in potential activity was reflected in the methanogenic and methanotrophic abundances. However, the microbial community composition was altered, more pronounced for the methanotrophs. Overall, we observed a lag between the recovery of the methanogenic/methanotrophic activity and the return of the corresponding microbial communities, suggesting a longer duration (>15 years) is needed to reverse mining-induced effects on the methane-cycling microbial communities

Antibiotics and antibiotic resistance genes in global lakes:A review and meta-analysis

Lakes are an important source of freshwater, containing nearly 90% of the liquid surface fresh water worldwide. Long retention times in lakes mean pollutants from discharges slowly circulate around the lakes and may lead to high ecological risk for ecosystem and human health. In recent decades, antibiotics and antibiotic resistance genes (ARGs) have been regarded as emerging pollutants. The occurrence and distribution of antibiotics and ARGs in global freshwater lakes are summarized to show the pollution level of antibiotics and ARGs and to identify some of the potential risks to ecosystem and human health. Fifty-seven antibiotics were reported at least once in the studied lakes. Our meta-analysis shows that sulfamethoxazole, sulfamerazine, sulfameter, tetracycline, oxytetracycline, erythromycin, and roxithromycin were found at high concentrations in both lake water and lake sediment. There is no significant difference in the concentration of sulfonamides in lake water from China and that from other countries worldwide; however, there was a significant difference in quinolones. Erythromycin had the lowest predicted hazardous concentration for 5% of the species (HC5) and the highest ecological risk in lakes. There was no significant difference in the concentration of sulfonamide resistance genes (sul1 and sul2) in lake water and river water. There is surprisingly limited research on the role of aquatic biota in propagation of ARGs in freshwater lakes. As an environment that is susceptible to cumulative build-up of pollutants, lakes provide an important environment to study the fate of antibiotics and transport of ARGs with a broad range of niches including bacterial community, aquatic plants and animals

Wplyw komponentow z osadow sciekowych na zawartosc potasu, wapnia i magnezu w wybranych roslinach uprawnych

Celem pracy było porównanie kompostów sporządzonych z osadów ściekowych z dodatkiem wapna, trocin, słomy i obornika jako źródła potasu, wapnia i magnezu dla roślin uprawnych. Sporządzone komposty wprowadzono do gleby w dawce 2% oraz 4% w stosunku do suchej masy gleby. Badane komposty przetestowano w doświadczeniu wazonowym z pszenicą, kukurydzą i rzodkiewką. Zawartość potasu w plonach roślin wzrastała wraz z dawką kompostu i jego zasobnością w ten składnik. Zwiększone dawki kompostów spowodowały wzrost zawartości wapnia w zielonce kukurydzy i korzeniach rzodkiewki natomiast w ziarnie pszenicy nastąpiło obniżenie zawartości tego pierwiastka. Nawożenie kompostami nie miało większego wpływu na zawartość magnezu w ziarnie pszenicy i w korzeniach rzodkiewki, podczas gdy w zielonce kukurydzy zanotowano wzrost zawartości tego pierwiastka.The aim of the research was to compare some composts as a potassium, calcium and magnesium source for cultivated plants. Composts were made with the addition of sewage sludge with lime, sawdust, straw and manure. The plants were fertilized with 2 and 4% compost (in relation to the dry soil in the pot). Investigated composts were tested in a pot experiment with spring wheat, maize and radish. Potassium content in crops increased according to compost doses and potassium concentration in each compost. Higher doses of compost caused increase of calcium concentration in green maize and radish roots whereas concentration of this element in wheat grain decreased. Fertilization with sewage sludge compost did not cause an increase of magnesium concentration in wheat, grain and radish roots whereas in green maize an increase of this element was observed

Dynamika zawartosci fosforu w osadach sciekowych podczas ich kompostowania z roznymi komponentami

Celem badań było określenie dynamiki zmian zawartości fosforu w osadach ściekowych podczas ich 24 tygodniowego kompostowania. Określono zawartość fosforu ogólnego i rozpuszczalnego w 0,5 mol HCl·dm⁻³. Osady ściekowe kompostowano same oraz z dodatkiem wapna, słomy, trocin i obornika. W trakcie kompostowania we wszystkich mieszaninach znacznie wzrosła zawartość fosforu ogółem oraz rozpuszczalnego w 0,5 mol·dm⁻³. Największy wzrost zawartości obu form fosforu odnotowano w kompostach, w których było najwięcej substancji organicznej. Były to komposty sporządzone z osadów ściekowych z dodatkiem trocin, słomy i obornika. W kombinacjach z samym osadem ściekowym oraz z osadem zobojętnionym wapnem odnotowano wyraźnie mniejsze zmiany zawartości fosforu ogólnego i rozpuszczalnego.The aim of the experiment was to study the fluctuation dynamics of phosphorus content in sewage sludge composted for 24 weeks. Concentrations of total and 0.5 mol·dm⁻³ soluble phosphorus were determined. Sewage sludge was composted with addition of calcium, straw, sawdust farmyard manure, and free of any additives. While being composted, all types of sewage sludge were observed to gain in the content of total phosphorus and phosphorus soluble in 0.5 mol·dm⁻³. The highest increase in both forms of phosphorus was recorded in the composts containing the highest quantities of organic matter. Those were the composts made of sewage sludge with sawdust, stra

Ocena zanieczyszczenia antropogenicznego wody rzecznej na podstwawie zróżnicowania genetycznego Aeromonas Hydrophila

Aeromonas hydrophila is a valuable indicator of the quality of water polluted by sewage and pathogens that pose a risk for humans and cold-blooded animals, including fi sh. The main aim of this research was to evaluate anthropogenic pollution of river water based on genetic diversity of 82 A. hydrophila strains by means of RAPD, semi-random AP-PCR (ISJ) and the rep-BOX conservative repeats test. Genetic diversity of A. hydrophila was HT = 0.28 (SD = 0.02) for all DNA markers (RAPD, semi random and rep-BOX). None of the analyzed electrophoretic patterns was identical, implying that there were many sources of strain transmission. The presence of genes for aerolysin (aerA), hemolysin (ahh1) and the cytotoxic enzyme complex (AHCYTOGEN) was verifi ed for all tested strains, and drug resistance patterns for tetracycline, enrofl oxacin and erythromycin were determined. The most diverse A. hydrophila strains isolated from river water were susceptible to enrofl oxacine (HS = 0.27), whereas less diverse strains were susceptible to erythromycin (HS = 0.24). The presence of the multidrug resistance marker (ISJ4-25; 1100 bp locus) in the examined strains (resistant to three analyzed drugs) indicates that intensive fi sh cultivation affects the microbiological quality of river water.Aeromonas hydrophila jest cennym wskaźnikiem jakości wody w przypadku zanieczyszczeń ściekami oraz mikroorganizmami względnie patogennymi dla człowieka i zwierząt zimnokrwistych, w tym ryb. Celem niniejszych badań była ocena zanieczyszczenia antropogenicznego na podstawie zróżnicowania genetycznego 82 szczepów A. hydrophila poprzez analizy RAPD, pół-przypadkowo amplifi kowanej klasy AP-PCR (ISJ) i konserwatywnego powtórzenia rep-BOX. Zróżnicowanie genetyczne A. hydrophila wyniosło HT = 0,28 (SD = 0,02) dla wszystkich markerów DNA (RAPD, pół-przypadkowe i rep-BOX). Wszystkie szczepy dla wszystkich markerów ujawniły indywidualny wzór elektroforetyczny, nie ujawniono jednego źródła rozprzestrzeniania się szczepów. U szczepów potwierdzono obecność genów aerolizyny (aerA), hemolizyny (ahh1) i kompleksu enzymów cytotoksycznych (AHCYTOGEN), jak również określono wzorzec oporności na tetracyklinę, enrofl oksacynę i erytromycynę. Najbardziej zróżnicowane okazały się szczepy A. hydrophila wrażliwe na enrofl oksacynę (HS = 0,27) a najmniej zróżnicowane były szczepy wrażliwe na erytromycynę (HS = 0,24). Wyselekcjonowany marker wielolekooporności (locus ISJ4-25, 1100 pz) obecny u szczepów (opornych na 3 rozpatrywane leki) świadczy o wpływie intensywnej hodowli ryb na jakość mikrobiologiczną wody rzecznej

Dynamika zawartosci wegla i azotu w osadach sciekowych podczas ich kompostowania

Celem przeprowadzonych badań było określenie zmian składu chemicznego osadów ściekowych podczas ich kompostowania z różnymi substancjami. Do badań użyto przefermentowane osady ściekowe z Miejskiej Oczyszczalni Ścieków w Olsztynie. Osady ściekowe kompostowano same bądź z dodatkiem słomy (20 i 40%), obornika (20 i 40%), trocin (20 i 40%) a także wapna. W materiałach wyjściowych i kompostowanej masie oznaczono: azot ogólny, azot amonowy, azot azotanowy i węgiel ogółem. We wszystkich badanych obiektach najintensywniejsze zmiany zawartości poszczególnych składników miały miejsce na początku kompostowania w fazie termofilnej. Doświadczenie wykazało, iż zastosowane dodatki do osadów ściekowych wpłynęły korzystnie na jakość uzyskanych kompostów. Dodatek wapna spowodował znaczne przyśpieszenie tempa przemian związków węgla i azotu a także zwiększeni zawartości przyswajalnych form azotu oraz niższy indeks C : N w gotowym produkcie. Spośród badanych dodatków organicznych najkorzystniejszy wpływ na procesy kompostowania miał obornik. Mimo, że zastosowanie wszystkich materiałów organicznych korzystnie wpłynęło na przebieg procesu kompostowania, to żaden z uzyskanych kompostów nie był w pełni ustabilizowany. Aby badane komposty mogły być uważane za pełnowartościowe to powinny one być poddane dalszemu kompostowaniu.The purpose of this study was to assess the changes in chemical composition of sewage sludge composted with different substances. Fermented sewage sludge from communal sewage treatment plant was composted alone or with the addition of straw (20 and 40%), manure (20 and 40%), sawdust (20 and 40%) and lime. Total nitrogen, ammonium nitrogen, and total carbon were determined in the components and composted matter. Additionally, pH was tested during composting. The changes in the contents of analysed components were most intensive at the beginning of composting period, during its thermophilous phase. The experiment proved that the application of sewage sludge additives improved the quality of produced composts. Lime addition accelerated the rate of carbon and nitrogen compounds conversion, increased the content of available nitrogen forms and lowered C : N ratio in the compost. Farmyard manure showed most desirable effect on composting processes. Although all the organic materials added to composts positively affected the process of composting, none of the composts obtained was completely stabilized. In order to attain the full value, the of the composts the composting process should be continued