Manure Storage Tanks Research Articles

Emission Characteristics of Odorous Compounds from a Swine Farm on Jeju Island, Korea

This study investigated 26 malodorous substances emitted from a swine farm on Jeju Island, South Korea, to discern their specific emission characteristics and potential implications for workers’ health and environmental management. A detailed analysis of emissions from livestock buildings, the compost facility, and the manure storage tank was conducted. Accurate quantification involved rigorous collection methods measuring concentrations of NH3, hydrogen sulfide (H2S), trimethylamine (TMA), aldehyde compounds, volatile organic compounds (VOCs), volatile fatty acids (VFAs), p-cresol, indole, and skatole. High concentrations of NH3 and H2S, particularly in the manure storage tank, raised concerns about the health of workers. TMA levels were notably elevated in the livestock building, whereas aldehydes and VOCs remained within limits. VFAs were prevalent in the livestock building, with p-cresol, indole, and skatole in the manure storage tank. Distinct emission profiles across farm facilities highlight the need for tailored odor management strategies, ensuring worker well-being and effective environmental practices. These findings offer valuable insights for implementing targeted mitigation measures in similar agricultural settings.

Methane emission rates averaged over a year from ten farm-scale manure storage tanks

Methane (CH4) emissions from animal manure stored in outdoor tanks are difficult to predict because of several influencing factors. In this study, the tracer gas dispersion method (TDM) was used to quantify CH4 emissions from ten manure storage tanks, along with the collection of supporting information, in order to identify its emission drivers. The dataset included two tanks storing dairy cattle manure, six holding pig manure, and two with digestate from manure-based biogas plants. CH4 emissions from the tanks were measured six to 14 times over a year. Emissions varied from 0.02 to 14.30 kg h−1, or when normalised by the volume of manure stored, emission factors (EFs) varied from 0.05 to 11 g m−3 h−1. Annual average CH4 EFs varied greatly between the tanks, ranging from 0.20 to 2.75 g m−3 h−1. Normalised EFs are similar to literature values for cattle and digested manure, but at the high end of the interval for pig manure. The averaged manure temperature for all tanks varied from 10.6 to 16.4 °C, which was higher than reported in a previous Danish study. Volatile solids (VS) concentration was in average higher for cattle manure (ranging from 3.1 and 4.4 %) than pig manure (ranging from 1.0 to 3.6 %). CH4 emission rates were positively correlated with manure temperature, whereas this was not the case for VS concentration. Annual average EFs were higher for pig than for cattle manure (a factor of 2.5), which was greater than digested manure emissions (a factor of 1.2). For the pig manure storage tanks, CH4 emissions were higher for covered tanks than for uncovered tanks (by a factor of 2.3). In this study, manure storage tanks showed a large disparity in emission rates, driven not only by physical factors, but also by farm management practices.

Use of reverse osmosis concentrate for mitigating greenhouse gas emissions from pig slurry.

Due to the high global warming potential (GWP) in a short time scale (GWP100 = 28 vs. GWP20 = 86), mitigating CH4 emissions could have an early impact on reducing current global warming effects. The manure storage tank emits a significant amount of CH4, which can diminish the environmental benefit resulting from the anaerobic digestion of manure that can generate renewable energy. In the present study, we added the reverse osmosis concentrate (ROC) rich in salt to the pig slurry (PS) storage tank to reduce CH4 emissions. Simultaneously, pure NaCl was tested at the same concentration to compare and verify the performance of ROC addition. During 40 days of storage, 1.83 kg CH4/ton PS was emitted, which was reduced by 7-75% by the addition of ROC at 1-9 g Na+/L. This decrease was found to be more intensive than that found upon adding pure sodium, which was caused by the presence of sulfate rich in ROC, resulting in synergistic inhibition. The results of the microbial community and activity test showed that sodium directly inhibited methanogenic activity rather than acidogenic activity. In the subsequent biogas production from the stored PS, more CH4 was obtained by ROC addition due to the preservation of organic matter during storage. Overall, 51.2 kg CO2 eq./ton PS was emitted during the storage, while 8 kg CO2 eq./ton PS was reduced by biogas production in the case of control, resulting in a total of 43.2 kg CO2 eq./ton PS. This amount of greenhouse gas emissions was reduced by ROC addition at 5 g Na+/L by 22 and 65 kg CO2 eq./ton PS, considering GWP100 and GWP20 of CH4, respectively, where most of the reduction was achieved during the storage process. To the best of our knowledge, this was the first report using salty waste to reduce GHG emissions in a proper place, e.g., a manure storage tank.

Draft Genome Sequence of Helicobacter sp. Strain CaF467b, Isolated from a Pig Manure Storage Tank.

ABSTRACTIn this report, we present the draft genome sequence of an unclassified Helicobacter strain, CaF467b. This bacterial isolate was recovered from a pig manure storage tank. The draft genome sequence is 1,655,514 bp in length with 1,709 predicted genes and a G+C content of 34.07%.

Automatic temperature rise in the manure storage tank increases methane emissions: Worth to cool down!

A significant amount of CH4 is emitting from livestock manure (LM) storage tank, which is being counted according to the guidelines provided by the Intergovernmental Panel on Climate Change (IPCC). Among various parameters affecting CH4 conversion factor (MCF) of LM, temperature is known as the most influential factor. As a degree of temperature, atmospheric temperature (Ta), not the manure temperature (Tm), is used for determining the MCF. Currently, the closed-type tank is more common than open-type tank, which would cause the substantial difference between Ta and Tm, probably due to the automatic temperature rise (ATR). Here, we repeatedly observed the ATR by storing pig slurry (PS) in a pilot-scale tank (30 m3, surface/volume ratio of 1.9), and its consequent impact on the increased CH4 emissions by comparing with the results from a lab-scale tank (1 L, surface/volume ratio of 72.2) controlled at 30 °C. As storage began, the Tm increased gradually from 16 to 23 °C to above 30 °C even in winter (-5 °C < Ta < 15 °C). During 30 d of storage, the CH4 emissions of 1.3–2.5 kg CH4/ton PS (MCF 26–29%) was observed in the lab-scale tank, while the emissions was increased to 2.6–4.2 kg CH4/ton PS (MCF 40–50%) in the pilot-scale tank (Two-Tail test, |tt|<|tc|). For the first time, a detailed heat energy balance considering the waste heat from organic degradation, the heat requirement for warm up, and the heat loss by convection, was conducted, proving that the waste heat generated during storage was enough to reach above 30 °C. Cooling-down of LM at 20 °C was found to be effective for reducing CH4 emissions by 90%, which sufficiently offset the greenhouse gas emissions in power consumption for cooling. Our findings strongly suggest that more CH4 is emitting from LM storage tank than expected, and therefore, the IPCC needs to develop guidelines more accurately in determining MCF.

CaptureSeq: Hybridization-Based Enrichment of cpn60 Gene Fragments Reveals the Community Structures of Synthetic and Natural Microbial Ecosystems.

Background. The molecular profiling of complex microbial communities has become the basis for examining the relationship between the microbiome composition, structure and metabolic functions of those communities. Microbial community structure can be partially assessed with “universal” PCR targeting taxonomic or functional gene markers. Increasingly, shotgun metagenomic DNA sequencing is providing more quantitative insight into microbiomes. However, both amplicon-based and shotgun sequencing approaches have shortcomings that limit the ability to study microbiome dynamics. Methods. We present a novel, amplicon-free, hybridization-based method (CaptureSeq) for profiling complex microbial communities using probes based on the chaperonin-60 gene. Molecular profiles of a commercially available synthetic microbial community standard were compared using CaptureSeq, whole metagenome sequencing, and 16S universal target amplification. Profiles were also generated for natural ecosystems including antibiotic-amended soils, manure storage tanks, and an agricultural reservoir. Results. The CaptureSeq method generated a microbial profile that encompassed all of the bacteria and eukaryotes in the panel with greater reproducibility and more accurate representation of high G/C content microorganisms compared to 16S amplification. In the natural ecosystems, CaptureSeq provided a much greater depth of coverage and sensitivity of detection compared to shotgun sequencing without prior selection. The resulting community profiles provided quantitatively reliable information about all three domains of life (Bacteria, Archaea, and Eukarya) in the different ecosystems. The applications of CaptureSeq will facilitate accurate studies of host-microbiome interactions for environmental, crop, animal and human health. Conclusions: cpn60-based hybridization enriched for taxonomically informative DNA sequences from complex mixtures. In synthetic and natural microbial ecosystems, CaptureSeq provided sequences from prokaryotes and eukaryotes simultaneously, with quantitatively reliable read abundances. CaptureSeq provides an alternative to PCR amplification of taxonomic markers with deep community coverage while minimizing amplification biases.

Does overwintering change the inoculum effect on methane emissions from stored liquid manure?

Greenhouse gas (GHG) emissions, especially methane (CH4 ), from manure storage facilities can be substantial. Methane production requires adapted microbial communities ("inoculum") to be present in the manure. Complete removal of liquid dairy manure (thus removing all inoculum) from storage tanks in the spring has been shown to significantly reduce CH4 emissions over the following warm season. This study examined whether the same mitigation effect would occur after fall removal of liquid dairy manure. Emissions of CH4 , nitrous oxide (N2 O), ammonia (NH3 ), and CO2 were measured from six 11.88-m3 tanks equipped with flow-through chambers. There were three inoculated controls (20% inoculum) and three uninoculated treatments, where inoculum was completely removed in the fall/winter (0% inoculum). Direct N2 O and NH3 (indirect N2 O) were minor contributors to the total GHG budget, contributing<2% on a CO2 equivalent (CO2 e) basis. Removal of inoculum led to a 34% decrease in total emissions on a CO2 e basis and to a 29% decrease in the CH4 conversion factor compared with the inoculated control (0.37vs. 0.52; p=.01). Overall, removing inoculum in the fall reduced CH4 emissions from manure storage tanks; however, fall inoculum removal was less effective than in a previous study where inoculum was removed in the spring. The timing of inoculum removal may affect the efficiency of this CH4 mitigation strategy. However, this method may be impractical for larger manure storage tanks. Further study is required to overcome challenges of time-sensitive, complete inoculum removal from farm-scale storage tanks.

Ammonia emissions from an in-ground finisher hog manure tank

A large fraction of emitted and ultimately deposited ammonia (NH3) originates from swine waste storage. Understanding the factors that influence these emissions is important in determining how to mitigate NH3 loading of the atmosphere. Hog manure is stored in slurry pits, tanks, or lagoons. Ammonia emissions from a ground-level mid-western hog finisher manure tank collecting manure from a mean of 3508 animals was measured for 8–20 d each quarter of the year for two years. Forty of the 164 measurement days had sufficient measurements to represent entire days. These daily emissions averaged 0.44 g NH3 m−2h−1 (53.1 g d−1 AU−1, 7.2 g d−1 hd−1: AU = 500 kg animal mass, hd = 1 animal) with maximum emissions of 1.62 g NH3 m−2h−1 (194.2 g d−1 AU−1, 26.4 g d−1 hd−1). Emissions from the tank were greater on an area basis but comparable on an animal basis relative to emissions from much larger anaerobic lagoons. Emissions were correlated with air temperature and manure composition, but not wind speed or friction velocity- probably due to the turbulence created by the tank structure under all winds. Crusting of the manure surface in the tank corresponded with a non-significant 10% increase in NH3 emissions. A model of the tank emissions, based on nominal nitrogen loading rates from the literature and taking into account the configuration of the circular tank, had a mean bias error of 0.01 g NH3 m−2h−1 (0.9 g d−1 AU−1, 0.1 g d−1 hd−1) and a root mean square error of 0.26 g NH3m−2h−1 (31.6 d−1 AU−1, 4.3 g d−1 hd−1). Additional emissions measurements from such ground-level manure storage tanks with greater documentation of the manure liquid composition are needed to verify the modeling approach.

Impact of narasin on manure composition, microbial ecology, and gas emissions from finishing pigs fed either a corn-soybean meal or a corn-soybean meal-dried distillers grains with solubles diets.

An experiment was conducted to determine the effect of feeding finishing pigs a corn-soybean (CSBM) diet or a CSBM diet supplemented with 30% dried distillers grains with solubles (DDGS), in combination with or without a growth-promoting ionophore (0 or 30 mg narasin/kg of diet), has on manure composition, microbial ecology, and gas emissions. Two separate groups of 24 gilts (initial BW = 145.1 kg, SD = 7.8 kg) were allotted to individual metabolism crates that allowed for total but separate collection of feces and urine during the 48-d collection period. After each of the twice-daily feedings, feces and urine from each crate was collected and added to its assigned enclosed manure storage tank. Each tank contained an individual fan system that pulled a constant stream of air over the manure surface for 2 wk prior to air (day 52) and manure sampling (day 53). After manure sampling, the manure in the tanks was dumped and the tanks cleaned for the second group of pigs. Except for total manure Ca and P output as a percent of intake and for manure methane product rate and biochemical methane potential (P ≤ 0.08), there were no interactions between diet composition and narasin supplementation. Narasin supplementation resulted in increased manure C (P = 0.05), increased manure DM, C, S, Ca, and phosphorus as a percent of animal intake (P ≤ 0.07), and increased manure volatile solids and foaming capacity (P ≤ 0.09). No effect of narasin supplementation was noted on manure VFA concentrations or any of the gas emission parameters measured (P ≥ 0.29). In contrast, feeding finishing pigs a diet containing DDGS dramatically affected manure composition as indicated by increased concentration of DM, C, ammonia, N, and total and volatile solids (P = 0.01), increased manure DM, N, and C as a percent of animal intake (P = 0.01), increased manure total VFA and phenols (P ≤ 0.05), decreased gas emissions of ammonia and volatile sulfur compounds (VSC; P = 0.01), increased emissions of phenols and indoles (P ≤ 0.06), decreased methane production rate (P = 0.01), and slight differences in microbial ecology (R ≤ 0.47). In conclusion, feeding a diet which contains an elevated level of indigestible fiber (i.e., DDGS) resulted in more fiber in the manure which therefore dramatically affected manure composition, gas emissions, and microbial ecology, while narasin supplementation to the diet did not exhibit a significant effect on any of these parameters in the resultant swine manure.

Targeting Bacteria and Methanogens To Understand the Role of Residual Slurry as an Inoculant in Stored Liquid Dairy Manure.

Microbial communities in residual slurry left after removal of stored liquid dairy manure have been presumed to increase methane emission during new storage, but these microbes have not been studied. While actual manure storage tanks are filled gradually, pilot- and farm-scale studies on methane emissions from such systems often use a batch approach. In this study, six pilot-scale outdoor storage tanks with (10% and 20%) and without residual slurry were filled (gradually or in batch) with fresh dairy manure, and methane and methanogenic and bacterial communities were studied during 120 days of storage. Regardless of filling type, increased residual slurry levels resulted in higher abundance of methanogens and bacteria after 65 days of storage. However, stronger correlation between methanogen abundance and methane flux was observed in gradually filled tanks. Despite some variations in the diversity of methanogens or bacteria with the presence of residual slurry, core phylotypes were not impacted. In all samples, the phylum Firmicutes predominated (∼57 to 70%) bacteria: >90% were members of ClostridiaMethanocorpusculum dominated (∼57 to 88%) archaeal phylotypes, while Methanosarcina gradually increased with storage time. During peak flux of methane, Methanosarcina was the major player in methane production. The results suggest that increased levels of residual slurry have little impact on the dominant methanogenic or bacterial phylotypes, but large population sizes of these organisms may result in increased methane flux during the initial phases of storage.IMPORTANCE Methane is the major greenhouse gas emitted from stored liquid dairy manure. Residual slurry left after removal of stored manure from tanks has been implicated in increasing methane emissions in new storages, and well-adapted microbial communities in it are the drivers of the increase. Linking methane flux to the abundance, diversity, and activity of microbial communities in stored slurries with different levels of residual slurry can help to improve the mitigation strategy. Mesoscale and lab-scale studies conducted so far on methane flux from manure storage systems used batch-filled tanks, while the actual condition in many farms involves gradual filling. Hence, this study provides important information toward determining levels of residual slurry that result in significant reduction of well-adapted microbial communities prior to storage, thereby reducing methane emissions from manure storage tanks filled under farm conditions.

Changes of Microbial Diversity During Swine Manure Treatment Process.

We investigated microbial diversity in a manure storage tank (MST) storing untreated manure and an aeration tank (AT) during swine manure treatment process using the next-generation sequencing in order to find the aeration effect on microbial diversity. Proteobacteria were more abundant in the AT group than in the MST group and may include denitrifying bacteria contributing to nitrous oxide (N2O) emission or aerobic bacteria stimulated by oxygen. The opposite held true for the phyla Bacteroidetes and Firmicutes that may include anaerobic bacteria inhibited under aerobic conditions in the AT group.

Greenhouse gas and ammonia emissions from production of compost bedding on a dairy farm

Recent developments in composting technology enable dairy farms to produce their own bedding from composted manure. This management practice alters the fate of carbon and nitrogen; however, there is little data available documenting how gaseous emissions are impacted. This study measured in-situ emissions of methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O), and ammonia (NH3) from an on-farm solid-liquid separation system followed by continuously-turned plug-flow composting over three seasons. Emissions were measured separately from the continuously-turned compost phase, and the compost-storage phase prior to the compost being used for cattle bedding. Active composting had low emissions of N2O and CH4 with most carbon being emitted as CO2-C and most N emitted as NH3-N. Compost storage had higher CH4 and N2O emissions than the active phase, while NH3 was emitted at a lower rate, and CO2 was similar. Overall, combining both the active composting and storage phases, the mean total emissions were 3.9×10−2gCH4kg−1 raw manure (RM), 11.3gCO2kg−1 RM, 2.5×10−4g N2O kg−1 RM, and 0.13g NH3 kg−1 RM. Emissions with solid-separation and composting were compared to calculated emissions for a traditional (unseparated) liquid manure storage tank. The total greenhouse gas emissions (CH4+N2O) from solid separation, composting, compost storage, and separated liquid storage were reduced substantially on a CO2-equivalent basis compared to traditional liquid storage. Solid-liquid separation and well-managed composting could mitigate overall greenhouse gas emissions; however, an environmental trade off was that NH3 was emitted at higher rates from the continuously turned composter than reported values for traditional storage.

A comparative life cycle assessment highlighting the trade-offs of a liquid manure separator-composter in a Canadian dairy farm system

Greenhouse gas (GHG) emissions from enteric and manure management (MM) activities tend to dominate the carbon footprint of beef and milk production. In this study, a comparative life cycle assessment of dairy milk production (cradle-to-farm gate) was undertaken where the trade-offs of an automated composter-separator technology were contrasted to those of a conventional liquid manure storage system. A simulation of a dairy farm in Ontario, Canada was carried out using the process based manure-DeNitrification DeComposition (Manure-DNDC) model after it was calibrated to a comprehensive set of on-farm MM GHG emission measurements. Results indicated that the active composter system on this farm reduced the carbon footprint (CF) of milk production by 36% (from 1.92 to 1.23 kg CO2eq kg−1 fat-protein corrected milk). For the simulated dairy farm system with only liquid manure storage as a treatment option, the GHG emissions (mainly methane) from the manure storage tank contributed 56% of the carbon footprint, which surpassed the contribution from enteric methane emissions. On the other hand, for the dairy farm with the active composter system, GHG emissions from manure (34% of CF) and enteric emissions (31% of CF) were found to be nearly equivalent in terms of carbon footprint contribution. The composter system created other life cycle benefits (no need to import sand for bedding, increased soil carbon sequestration) and burdens (increased on-farm electricity demand for composter operation), however, the relative contributions of these additional trade-offs were small. Given these additional trade-offs were minor, the GHG mitigation potential of this manure composting technology is likely high in any region of application. In addition, the dairy system with the composter created only marginal problem shifting concerns in terms of the non-CF environmental impact categories considered. For the 146 lactating dairy cow system investigated, an estimated 1460 tCO2eq in life-cycle GHG emissions reduction can be achieved on an annual basis. The benefits of manure composter solutions should provide an impetus for jurisdictions to explore the development of climate policies that incentivize increased adoption rates of this important climate change mitigation opportunity.

Isolation and Characterization of Acinetobacter baumannii Recovered from Campylobacter Selective Medium.

Acinetobacter baumannii, a Gram-negative opportunistic pathogen, is known to cause multidrug resistant infections. This organism has primarily been isolated from clinical environments and its environmental reservoirs remain largely unknown. In the present study, we recovered seven isolates of A. baumannii growing under conditions selective for Campylobacter spp. (microaerophilic at 42°C and in the presence of antibiotics) from dairy cattle manure storage tank or surface water impacted by livestock effluents. Antibiotic susceptibility tests revealed that all of these isolates were less susceptible to at least two different clinically relevant antibiotics, compared to the type strain A. baumannii ATCC17978. Expression of resistance-nodulation-division efflux pumps, an important mechanism of intrinsic resistance in these organisms, was analyzed, and adeB was found to be overexpressed in one and adeJ was overexpressed in three isolates. Comparison of these isolates using genomic DNA Macro-Restriction Fragment Pattern Analysis (MRFPA) revealed relatively low relatedness among themselves or with some of the clinical isolates from previous studies. This study suggests that A. baumannii isolates are capable of growing under selective conditions for Campylobacter spp. and that this organism can be present in manure and water.

Ecotoxicidade da água residual de suinocultura usando minhocas Eisenia andrei como bioindicador

The waste generated by pig farmings has high toxic potential, however, its high organic load, makes them a good product for fertilization of agricultural soils. The aim of this work was to study the environmental effects arising from the use of swine wastewater using as bioindicators earthworms of the species Eisenia andrei through the parameters of lethality, avoidance and reproduction. We studied the application of biodigester wastewater and manure storage tanks wastewater in four doses (0, 100, 200 and 300 m3 ha-1) in three different soils (Oxisol, Kandiudox and Artificial Tropical Soil). The studied wastes did not cause any lethality or escape. The reproduction test showed, in most of the experiments that the plots with treated soil had an average number of hatched juveniles above those of control plots. The application of biodigester wastewater and manure storage tanks wastewater up to the dose of 300 m3 ha-1 does not negatively affect earthworm populations in the three soils analyzed.

Microbial Community and Chemical Characteristics of Swine Manure during Maturation

Swine diet formulations have the potential to lower animal emissions, including odor and ammonia (NH). The purpose of this study was to determine the impact of manure storage duration on manure chemical and microbial properties in swine feeding trials. Three groups of 12 pigs were fed a standard corn-soybean meal diet over a 13-wk period. Urine and feces were collected at each feeding and transferred to 12 manure storage tanks. Manure chemical characteristics and headspace gas concentrations were monitored for NH, hydrogen sulfide (HS), volatile fatty acids, phenols, and indoles. Microbial analysis of the stored manure included plate counts, community structure (denaturing gradient gel electrophoresis), and metabolic function (Biolog). All odorants in manure and headspace gas concentrations were significantly ( < 0.01) correlated for length of storage using quadratic equations, peaking after Week 5 for all headspace gases and most manure chemical characteristics. Microbial community structure and metabolic utilization patterns showed continued change throughout the 13-wk trial. Denaturing gradient gel electrophoresis species diversity patterns declined significantly ( < 0.01) with time as substrate utilization declined for sugars and certain amino acids, but functionality increased in the utilization of short chain fatty acids as levels of these compounds increased in manure. Studies to assess the effect of swine diet formulations on manure emissions for odor need to be conducted for a minimum of 5 wk. Efforts to determine the impact of diets on greenhouse gas emissions will require longer periods of study (>13 wk).

Effect of increasing levels of corn silage in an alfalfa-based dairy cow diet and of manure management practices on manure fugitive methane emissions

The main objective of this study was to assess the effect of dairy cow diets and manure storage management practices on manure fugitive CH4 emission in order to precisely establish the carbon footprint of Canadian milk products. The specific objectives of this study were to investigate the effect of incorporating 50 and 100% corn silage (CS) as starch sources in dairy cow diets and the effect of complete removal of residual sludge in the manure storage tank and of storage emptying frequency on manure fugitive CH4 emissions. Alfalfa silage based diets were formulated as follows: 0% corn silage (0% CS, considered as the control diet); 50% corn silage (50% CS); and 100% corn silage (100% CS). Canadian summer manure storage conditions were simulated in laboratory-scale storage structures located in a controlled-environment chamber operated at 20±1°C. The incorporation of 50 and 100% CS in dairy diets was associated with significant increases of 39 and 79%, respectively, in fugitive CH4 emissions expressed in Lday−1cow−1 from manure storage with residual sludge over a 120-day storage period. The complete removal of residual sludge in the manure storage tank resulted in fugitive methane emission reductions exceeding 97.0% irrespective of the diet composition. Emptying of the manure storage tank 2 times and 4 times over the summer period reduced fugitive CH4 emissions on average by 40 and 80%, respectively. The complete removal of the manure storage residual sludge and the increase in manure storage tank emptying frequency over the summer can be adopted as low-cost best management practices (BMPs) for substantially reducing the fugitive CH4 emissions from manure storages.

Production of wild Chlorella sp. cultivated in digested and membrane-pretreated swine manure derived from a full-scale operation plant

A wild Chlorella sp. was isolated from a manure storage tank and then cultivated under semi-continuous production conditions on four substrates, including digested swine manure (DIG) and digestate-derived liquid fractions obtained by digestate centrifugation (CLF) and ultrafiltration (ULF) in a full-scale digestate treatment plant, in order to evaluate differences in growth and depuration capacities. The microalga was capable of fast growth on some of the substrates, comparable to that obtained with 3N-BBM synthetic medium, productivities being 0.21gL−1d−1 of biomass for ULF and 3N-BBM media, 0.17gL−1d−1 biomass for CLF media and 0.10gL−1d−1 biomass for DIG media.Algal growth was affected, above all, by the chemical oxygen demand (COD) of the starting culture media which directly affected turbidity and also light availability. Nutrient contents, i.e. N and P, did not seem to affect the process. Chlorella sp. was capable of reducing about 95%–98% of N-NH4+ and 61–73% of COD, while micronutrients were almost completely removed from the cultures. However, most of the ammonia nitrogen was lost to the atmosphere due to the stripping phenomena caused by aeration and high pH during algal growth, so that only 30% of the nitrogen was successfully incorporated in the microalgal biomass.The isolated Chlorella proved to be a strong strain, capable of reducing macro- and micronutrient contents in the digested liquid streams. The full-scale digestate membrane treatment proved to be a suitable process to integrate with microalgae cultivation, improving the growth medium performance in terms of final biomass productivity.

Phylogenetic identification of methanogens assimilating acetate-derived carbon in dairy and swine manures

In order to develop approaches for reducing the carbon footprint of the swine and dairy industries, it is important first to identify the methanogenic communities that drive methane emissions from stored manure. In this study, the metabolically active methanogens in substrate-starved manure samples taken from two dairy and one swine manure storage tanks were identified using [13C]-acetate and DNA stable-isotope probing (DNA-SIP). Molecular analysis of recovered genomic [13C]-DNA revealed that two distinct clusters of unclassified methanogen populations affiliated with the Methanoculleus genus, and the populations affiliated with Methanoculleus chikugoensis assimilated acetate-derived carbon (acetate-C) in swine and dairy starved manure samples, respectively. Furthermore, carbon flow calculations indicated that these populations were the primary contributors to methane emissions during these anoxic SIP incubations. Comparative analysis of mcrA gene abundance (coding for a key enzyme of methanogenesis) for Methanoculleus spp. in fresh feces and a wider range of stored dairy or swine manure samples, by real-time quantitative PCR using newly designed specific primers, demonstrated that the abundance of this genus significantly increased during storage. The findings supported the involvement of these particular methanogen populations as methane emitters from swine and dairy manure storage tanks. The study revealed that the ability to assimilate acetate-C for growth in manure differed within the Methanoculleus genus.

Peptoniphilus stercorisuis sp. nov., isolated from a swine manure storage tank and description of Peptoniphilaceae fam. nov.

A species of a previously unknown Gram-positive-staining, anaerobic, coccus-shaped bacterium recovered from a swine manure storage tank was characterized using phenotypic, chemotaxonomic, and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies and biochemical characteristics demonstrated that this organism is genotypically and phenotypically distinct, and represents a previously unknown sub-line within the order Clostridiales, within the phylum Firmicutes. Pairwise sequence analysis demonstrated that the novel organism clustered within the genus Peptoniphilus, most closely related to Peptoniphilus methioninivorax sharing a 16S rRNA gene sequence similarity of 95.5%. The major long-chain fatty acids were found to be C14:0 (22.4%), C16:0 (15.6%), C16:1ω7c (11.3%) and C16 : 0 ALDE (10.1%) and the DNA G +C content was 31.8 mol%. Based upon the phenotypic and phylogenetic findings presented, a novel species Peptoniphilus stercorisuis sp. nov. is proposed. The type strain is SF-S1(T) ( = DSM 27563(T) = NBRC 109839(T)). In addition, it is proposed to accommodate the genera Peptoniphilus, Anaerococcus, Anaerosphaera, Finegoldia, Gallicola, Helcococcus, Murdochiella and Parvimonas in a new family of the order Clostridiales, for which the name Peptoniphilaceae fam. nov. is proposed; the type genus of the family is Peptoniphilus.