Cow Dung Research Articles

Antibiotic Resistance Profiles of Escherichia coli and Salmonella spp. Isolated From Dairy Farms and Surroundings in a Rural Area of Western Anatolia, Turkey.

Background Antibiotic resistance is a significant public health issue worldwide. Antibiotic-resistant zoonotic bacteria such as Escherichia coli (E. coli), Campylobacter, Salmonella, Listeria, Coxiella, and Mycobacterium can be particularly isolated from biofertilizers. Epidemiological studies have shown that cases of foodborne infections and intoxications are significantly related to animal-derived foods. The presence of these species in aquatic environments indicates areas or organisms contaminated with animal or human feces. Especially, the presence of E. coli in aquatic environments has become a serious problem worldwide. Pathogenic strains of E. coli cause waterborne and foodborne diseases. Materials and methods This study included a total of 290 samples collected from five different dairy farms between April and September 2023 which comprised 20 samples of cow manure, 20 samples of milk, three samples of dairy workers' hand washing water, five samples ofsoil, five samples of water, and five samples of vegetables. The samples taken from the farms were homogenized with 0.1% peptone water at a ratio of 1/10. They were then cultured on xylose lysine deoxycholate (XLD), eosin methylene blue agar (EMB), and blood agar media, and gram-negative colonies were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the VITEK2 automated system (BioMerieux Inc., Durham, NC). Amplification of the isolated DNA extracts was performed with A.B.T.™ 2X HS-PCR MasterMix (A.B.T Laboratory Industry, Arnavutköy, Turkey) in the SimpliAmp™ thermal cycler (Thermo Fischer Scientific Inc., Waltham, MA) and visualized by agarose gel electrophoresis. Results Among the 52E. coli strains isolated in our study, the highest antibiotic sensitivity rate was observed in meropenem, while the lowest sensitivity rates were determined in cefazolin and cefuroxime. While two of the Salmonella spp. (n = 2) isolates were found to be resistant to tetracycline, and one was found to be resistant to penicillin and ampicillin. No resistance to trimethoprim/sulfamethoxazole was detected in either isolate. Extended-spectrum beta-lactamases (ESBLs) were detected in only four (7.7%) E. coli strains. While tetA, tetB, and TEM genes were seen in almost all E. coli strains, they were not found in Salmonella spp. Conclusion In conclusion, our study revealed the presence of antimicrobial resistance genes in E. coli and Salmonella spp. isolates collected from various farms and environmental samples, which render the antimicrobials used for disease treatment ineffective. Consequently, research should be undertaken to prevent the development of new resistance genes in our country, as creating new medications and treatment strategies for these diseases is costly and time-intensive.

Relevance of Natural Farming in Present Scenario of Bihar, India: A Review

Agriculture is holistic approach of science. It is convergence of field crops, horticultural crops, forestry, animal science, poultry, microbiology, soil science etc. If we pick one subject it will be injustice to the science of cultivation. The Father of modern-day natural farming is Masanobu Fukuoka. This is also known as Fukuoka Method. Do-nothing farming or Natural way of farming is an ecological farming approach established by Masanobu Fukuoka (1913-2008). Natural farming, also known as ‘Prakritic Kheti’ is a climate resilient tool that can save humans and Agro-ecological system, Asha Rani et al. [1] advocated the natural farming in India. Krishi Vigyan Kendra, Sabour Bhagalpur, Bihar has started natural farming practices from 2018. We have organised awareness programme in 12 villages among 2000 farmers. KVK Sabour adopted a Village in Raipura, Goradih, where we have made a benchmark survey animal particularly Deshi cow. Bihar is an Agriculture based state. Focus of this survey was how many Deshi cow was existing their and what was the utility of cow dung and cow urine. Most of them are using cow-dung as fuel for making food and cow urine was drained out. We have organised off campus and on campus training programme for Raipura villagers, demonstrated the technology to make ‘Jivamrit, Bijamrit, Ghanjivamrit etc.’ The result of this awareness is that they have started the collection of cow urine and using cow dung to make ‘Ghanjivamrit, Jivamrit’ and different products. The purpose of this work was to conduct a simple survey and review the relevance of natural farming in the present day when the cattle number is in decline. Findings indicated natural farming to be impossible without desi cow, as every component is related to the species.

Can Nanoparticles Be Used to Boost Biogas Production?

Biogas is a type of gas that can be burnt to produce energy. It causes less harm to the environment than burning coal or oil, which is why it is called “green energy”. Biogas is produced by breaking down a plant or animal resource such as cow dung (poop) in an oxygen-free environment. Biogas is produced by special microorganisms that can survive and multiply without oxygen. Recently, nanoparticles have been used to make more biogas. Nanoparticles have unique features such as their extremely small size and their ability to easily react with substances. During biogas production, microorganisms can get a lot of nutrients from nanoparticles, which helps them to produce more biogas. Nanoparticles may also improve the interactions between biogas-producing microbes, further boosting biogas production. Although nanoparticles help to produce more biogas, the correct type of nanoparticles and the right amounts must be used to ensure that more biogas is produced.

EM4 Addition Effect with Eisenia foetida Worms on Compost Characteristics as a Soil Improver

A lot of fish waste is produced by the community, both from the marketing sector and the fisheries sector, which is caught by fishermen. Almost 35% of the fish waste produced is in the form of heads, bones, innards and also fish remains that are not the main catch which are thrown away directly. Vermicomposting is one of method to reduce the amount of fish waste. The adding of livestock manure in vermicomposting will increase the quality of compost. The purpose of this research is to analyze the compost quality with the mixture of fish waste and livestock manure. The results showed that The compost that has the best quality based on SNI 19-7030-2004 is B2 with 45% fish waste, 20% cow dung and 35% sawdust with a dose of EM4 10 ml, which has a final temperature of 29ºC, pH 7, water content 41%, C-organic 19.83%, nitrogen 1.34%, phosphorus 0.36%, potassium 1.15%, and C/N ratio 14.85. Then, after incubating the soil improvement, it was found that the addition of compost can improve the chemical characteristics of the soil according to the dose given. This indicates that compost application can affect soil quality. Soil quality that has C-organic and nitrogen content according to BPT in 2009 is with the addition of a dose of 5.2 grams of vermicompost. The shortcomings of this study are that the phosphorus and potassium levels are too high.

Pengaruh Kombinasi Pupuk Kandang Sapi dan Pupuk NPK terhadap Pertumbuhan dan Hasil Tanaman Kubis (Brassica oleraceae L.)

The use of organic and inorganic fertilizers is an alternative way to get good cabbage production, one of which is by using cow manure and NPK. This study aims to determine the good use of a combination of cow manure and NPK fertilizer on the growth and yield of cabbage (Brassica oleraceae L.). The research was carried out from October 2022 to January 2023. This study used a Randomized Block Design (RAK), namely with a combination of cow manure (PKS) and NPK fertilizer. With the following details: P0 = Control, P1 = PKS 200 g + NPK 5 g, P2 = PKS 400 g + NPK 10 g, P3 = PKS 600 g + NPK 15 g, P4 = PKS 800 g + NPK 20 g. The treatments were repeated 3 times so that there were 15 experimental units. Each experimental unit used 5 polybags and each polybag was planted with one plant so that the total cabbage plants used were 75 plants. The variables observed were leaf area, time of crop formation, crop weight, and crop volume and root volume. The results showed that the combination of cow manure and NPK fertilizer had a significant effect on the growth of leaf area, crop weight, and crop volume. However, it has not had a significant effect on the time of crop formation. Treatment of cow manure 800 g + NPK 20 g (P4) fertilizer increased crop weight and crop volume. Treatment of cow manure 400 g + NPK 10 g (P2) fertilizer increased cabbage leaf area.

Utilization of Liquid Organic Fertilizer from Cow and Chicken Manure, Indigofera on Hydroponic Lettuce, and Consumer Perception

Lettuce (Lactuca sativa L.) is a horticultural plant with high nutritional and economic value and good development prospects in Indonesia. However, the high costs of hydroponic fertilizers drive research to find more economical alternatives, such as substitution with Liquid Organic Fertilizer (LOF). This study aims to analyze consumer perceptions of hydroponic lettuce using LOF substitution and understand consumer responses and purchasing behavior toward these products to identify the attributes influencing purchasing decisions for hydroponic lettuce with LOF substitution. The study employs a survey method with purposive sampling, involving 35 regular customers and 15 supermarket shoppers from PT ABA to collect primary data through questionnaires regarding consumer interest in hydroponic lettuce with LOF substitution. Additionally, proximate analysis and nutrient content testing are conducted in the laboratory. Data analysis uses conjoint and discriminant analysis with SPSS Statistics 24 to evaluate consumer responses and the most preferred product model based on nutritional attributes, price, and weight. The study successfully analyzes consumer perceptions of hydroponic lettuce with LOF substitution and finds that consumers have a positive view of this product, mainly due to its better nutritional content and the plant's ability to absorb nutrients optimally. These factors significantly influence purchasing decisions, with the main attributes being price, weight, and nutritional content.

The Growth Dynamics of King Grass (Pennisetum purpureophoides) in The Application of Beef Cattle Dung Enriched Azolla microphylla

Research on the cultivation of king grass (Pennisetum purpureophoides) was conducted to obtain information on growth, productivity, and continuity in providing forage for a sustainablee ruminant farming business. One of the cultivation factors is fertilization using beef cow manure as a renewable, inexhaustible natural resource or organic fertilizer. Improving the quality beef manure is important for better stimulation of plant growth and production. Fertilizer can be enriched with Azolla microphylla as a good nitrogen contributor. This study used beef cow dung fertilizer at doses of 10, 20, 30 tons per hectare per defoliation, and Azolla microphylla enrichment by 0%, 10%, and 20 % as treatments in a completely randomized design (CRD). The observed variables were plant growth (plant height, stem diameter, number of plants, and number of leaves as production), every 14 days until harvesting on day 42. The data obtained were analyzed descriptively based on the dynamics of plant growth. The result showed that the growth dynamics of the king grass were strongly influenced by fertilizer and plant’s age but no interaction each other. In conclusion fertilizer made of beef cattle dung enriched with Azolla microphylla is a feasible nitrogen source. The optimum results were obtained from using 30 tons beef cattle dung enriched with 20% Azolla microphylla to fertilize per hectare per defoliation soil.

Seed dispersal effectiveness by greater one-horned rhinos and domestic bovids of a megafaunal fruit

The extinction of megafauna, such as rhinos, from tropical Asian forests may have detrimental effects on the regeneration of plant species that rely heavily on their dispersal services. Understanding the potential of other animals to substitute the ecological function of megafauna is important for predicting ecosystem change following declines or extirpation of megafauna. Anthropogenic activities have led to the presence of domestic bovids in many tropical habitats, and these animals could be capable of substituting seed dispersal roles of megafauna. Here, we conducted feeding trials, germination tests, and collected movement data on greater one-horned rhino (Rhinoceros unicornis) and domestic bovids (Bos primigenius; Bubalus bubalis) in the national parks of Chitwan and Shuklaphanta, Nepal. Our aim was to investigate whether domestic bovids can serve as effective substitutes for rhinos in dispersing the megafaunal-fruited Mallotus nudiflorus, which are specialized for rhino dispersal. Specifically, we assessed the long-distance seed dispersal capabilities of rhinos and bovids by combining gut passage times and movement patterns. Additionally, we compared the seed germination success rates among rhinos, bovids and other dispersal modes (e.g., deer and water dispersal). We found that rhinos dispersed 80 percent of seeds over distances greater than 1 km, with potential dispersal distances of up to approximately 5.4 km within their maximum gut passage time. In contrast, cattle dispersed 20 percent of seeds over 1 km, with a maximum distance of around 2.2 km, while buffaloes dispersed 15 percent of seeds over 1 km, with a maximum distance of around 1.4 km. Seeds consumed by rhinos exhibited similar or better germination rates compared to seeds retrieved from cattle and buffalo dung, as well as other dispersal modes. These findings indicate that rhinos provide a functionally unique dispersal service for this megafaunal fruit, especially in long-distance dispersal. While domestic bovids can partially substitute the seed dispersal functions of rhinos, they cannot fully compensate for the loss of seed dispersal that occurs with the disappearance of rhinos.

Estimation of Ammonia Emission Inventory Using Life Cycle Assessment Based on Livestock Manure Flow: A Case Study of the Manure Management Sector in Korea

Ammonia is one of the precursor gases in the formation of particulate matter (PM) that reacts with nitrogen oxides and sulfur oxides in the atmosphere. Based on the Clean Air Policy Support System (CAPSS) of Korea, the annual ammonia emissions amounted to 261,207 tons in 2020 and the agricultural source (manure management sector) contributes the highest proportion of the ammonia inventory. However, the methodology for the study of ammonia emissions in Korea has some limitations regarding the representativeness of the sites selected and the reliability of the measurement method. In this study, we aimed to recalculate the ammonia emissions from the livestock industry in Korea using the UK’s estimation method, which uses the life cycle assessment of livestock manure. Three major animal types, i.e., cattle (beef cattle and dairy cows), pigs and chickens, and three major processes based on the manure flow, i.e., housing, manure storage and treatment and land application processes, were considered. The total ammonia emissions were estimated to be approximately 33% higher than the official ammonia emissions stated by the CAPSS. For the manure flow, the ammonia emissions were the highest from land application processes. The ammonia emissions from dairy cow and poultry manure were much higher than those stated by the CAPSS, while the emissions from beef cattle and pig manure showed similar levels. The methodology used in this study can offer an alternative approach to the ammonia emission estimation of the manure management sector in the agriculture industry of Korea. Korean emission factors based on the manure flow should be developed and applied in the future.

Enhancing microplastics removal from soils using wheat straw and cow dung-derived biochars

Microplastics have attracted extensive public attention due to their harmful effects on environments and organisms, especially for small-size microplastics. Herein, six kinds of biochar were produced by wheat straw and cow dung at 500, 600 and 700 °C respectively for the removal of 1 μm polystyrene microplastics from soils. The removal efficiencies of microplastics exceeded 86% for all biochars. With increasing pyrolysis temperature, the removal performance of wheat straw biochars for microplastics gradually improved, while the removal efficiency of cow dung biochars decreased. Biochars effectively trapped microplastics within their channels, oxygen-containing functional groups (CO32− and COO−) on the surface of biochars facilitated the adsorption of microplastics. After seven cycles of biochars recycling, the removal performance of microplastics remained above 85%, the removal process was primarily governed by the adsorption sites rather than the porous structure of biochars. This article provided eco-friendly and recyclable biochar materials for microplastics removal and technical support for addressing soil microplastics pollution.

Castor Bean Meal Fertilizer Improves Peanut Yield and Quality by Regulating the Soil Physicochemical Environment and Soil Enzyme Activities

PurposeFertilization is important for improving crop yield and soil quality. Elucidation of the effects of castor bean meal (CBM) fertilizer on peanut yield and quality and soil fertility can lead to additional fertilization options for peanut and provide a theoretical reference for achieving a high-quality, high-yielding peanut.MethodsDuring 2022–2023, a two-year long-term field experiment was conducted in Tongliao city, Inner Mongolia, China. No fertilizer (CK) was used as the control, and the effects of different treatments, i.e., CBM fertilizer (B1: 2520 kg ha-1, B2: 5040 kg ha-1, and B3: 10,080 kg ha-1), chemical fertilizer alone (F1: 175 kg ha-1, F2: 350 kg ha-1, and F3: 700 kg ha-1), and cow manure alone (N1: 3724 kg ha-1, N2: 7448 kg ha-1, and N3: 14,896 kg ha-1) on peanut yield and quality and soil fertility were investigated.ResultsThe results showed that CBM fertilizer application improved soil ecology. Compared with other fertilization treatments, the soil pH of B3 treatment decreased by 8.5%, but significantly increased the contents of organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkali-hydrolyzed nitrogen (AN), basic phosphorus (AP) and rapidly available potassium (AK) in the soil, which increased by 86.4%, 64.6%, 70.5%, 11.3%, 75.8%, 150.1%, and 116.2%, respectively, compared with CK. Meanwhile, B1, B2, N1 and N2 treatments also led to the elevation of the above indexes. In addition, the activities of urease (URE), sucrase (SUC), phosphatase (PPL), catalase (CAT), amylase (AMY) and protease (PRO) in the B3 treatment were significantly greater than those in the other fertilization treatments, with increases of 256.4%, 248.4%, 68.2%, 96.8%, 267.3%, and 155.7%, respectively, compared with CK. The B3 treatment also significantly increased the rootlet length(PRL), number of branches(BN), plant height(PLH) and lateral branch length(LBL) of the peanut plants. Compared with the other treatments, the B3 treatment had a greater peanut yields, reaching 8059.5 kg ha-1 and 9935.7 kg ha-1 in 2022 and 2023, respectively. Compared with the other treatments, the B1 treatment significantly increased the contents of protein (Pro), fat (FAT), unsaturated fatty acid (UFA) and vitamin E (VE), which increased by 23.3%, 6.1%, 1.0%, 29.1%, respectively, compared with CK, but the total sugar (TS) content was reduced by 9.1%. Correlation analysis further confirmed that peanut yield and quality were significantly correlated with soil nutrients and enzyme activities.ConclusionsThis study showed that the application of CBM fertilizer has certain positive effects. For example, the B3 treatment has certain potential for increasing peanut yield, and the B1 treatment can be used for peanut quality improvement. Therefore, CBM fertilizer is recommended as a new type of organic fertilizer for improving the peanut quality and yield.

Study of synergistic behavior during bituminous coal-cow manure co-gasification: The role of intrinsic AAEM and organic matter

Co-thermal chemical conversion of coal and biomass is one of the important ways to realize efficient and clean utilization of coal. In this study, a typical Ningdong coal-Yangchangwan bituminous coal and cow manure were used to study the synergistic effect of intrinsic alkali, alkaline earth metals (AAEM) and organic matter on the co-gasification of coal and biomass by thermogravimetry analyzer (TG). The results showed that AAEM had obvious synergistic promotion effect on the gasification of a bituminous coal-cow manure mixture in the isothermal gasification (1000 ℃), whereas the organic matter will show the opposite effect on the process. To further investigate the effect of organic matter on the gasification process, the influence of organic matter on non-isothermal (25-1000 ℃) gasification reaction was investigated with heating rate of 10 ℃ /min, the kinetic parameters of the gasification reaction were obtained by Coats-Redfern method. The increase of biomass mass fraction in the sample facilitates the migration of alkali metals from the material to the solid phase. The possible mechanism of the synergistic effect of intrinsic AAEM/organic matter on the co-gasification process was proposed.

One–third substitution of nitrogen with cow manure or biochar greatly reduced N2O emission and carbon footprint in saline–alkali soils

The rapid expansion of farmland and long−term excessive nitrogen (N) application have caused huge environmental risks in fragile ecosystems facing global warming. Partially substituting N fertilizer with organic fertilizers offers an alternative field management strategy to alleviate the pressure of the ecological environment. To this end, the influence of one−third substitution of N fertilizer with cow manure or biochar field experiment was conducted under maize in Tarim River Basin since 2019. Five treatments with three replications were applied: CK (Fallow); no fertilization (0 N); conventional N fertilizer (N; N: 300 kg N ha−1, organic fertilizer: 0 kg N ha−1); one−third substitution of N with biochar (NB; N: 200 kg N ha−1, Biochar: 100 kg N ha−1) and one−third substitution of N with cow manure (NM; N: 200 kg N ha−1, Cow manure: 100 kg N ha−1) under maize season in saline−alkali soils. The greenhouse gas (GHG) emissions, net ecosystem carbon budget (NECB), soil organic carbon (SOC), maize yield, carbon footprint (CF), and yield carbon footprint (CFy) were analyzed from 2021 to 2022. The results showed that NB treatment decreased the average cumulative CO2 emissions by 21 %, while NM treatment showed no difference compared to N treatment. NB and NM treatments reduced the average cumulative N2O emissions (−61 %, −49 %), CF (−68 %, −10 %), CFy (−66 %, −19 %) and increased maize yield (+3 %, +2 %), SOC storage (+43 %, +6 %), NECB (+80 %, +24 %), and agronomic N use efficiency (ANUE) (+5 %, +3 %), compared to N treatment. NB treatment had the lowest emission factors (EF) (0.19 %) and the highest sustainability index (1.58) compared to NM treatment (0.26 %, 0.61) and N treatment (0.53 %, 0.84). To sum up, substituting one−third of N fertilizer with biochar or manure in saline−alkali soils was proved to be a multi−benefit strategy to increase yields and reduce GHG emissions and CF.

Optimizing Glutinous Corn Productivity through Demonstration Plots with the Application of Combined Organic Ameliorants

Sandy soil in Muncuk Karya, Ampenan, has low water retention and nutrient content, making it difficult for sticky rice farmers to meet their plants' water and nutrient needs. To overcome this challenge, research entitled "Optimizing Glutinous Corn Productivity through Demonstration Plots with the Application of Combined Organic Ameliorants" was carried out using an experimental methodology using a randomized block design involving five treatments and four replications, so that there were a total of 20 treatment plots. The treatments applied consisted of: A1 (50% cow manure + 50% mycorrhizal biofertilizer), A2 (50% compost + 50% mycorrhizal biofertilizer), A3 (50% fertile organic fertilizer + 50% mycorrhizal biofertilizer), A4 (50% rice husk charcoal + 50% mycorrhizal biofertilizer), and A5 (50% mixture of cow manure, compost, fertile organic fertilizer, and rice husk charcoal with a volume ratio of 1:1:1:1 + 50% mycorrhizal biofertilizer). The research results showed that the application of ameliorant, a combination of 50% cow manure and 50% mycorrhizal biofertilizer, was proven to be effective in increasing growth, plant productivity, soil nutrient concentration, plant nutrient uptake, and mycorrhizal development in the soil. To increase the productivity of sticky corn plants, soil fertility, plant nutrient uptake, and mycorrhiza development, it is recommended to use this combination ameliorant application.

Cultural practices and beliefs followed for new born care in Santhal pargana - A cross sectional study.

Newborn care practices and beliefs vary word-wide, country to country and region to region. These care practices play a vital role in morbidity and mortality of newborn. A descriptive cross-sectional study was conducted to assess the newborn care practices and beliefs of newborn care. Data was collected from 429 post-natal mothers, who delivered in selected government hospitals of Santhal parganas, Deoghar, Jharkhand. Convenience sampling technique was used to collect the data from February 2023 to April 2023. Findings of the study are, 86.9% mothers accepted that they massage the baby with oil before bath, 89.3% participants have given breastfeeding within one hour of delivery, 93.7% have given prelacteal feeds to the newborn. Applying Heeng (Asafoetida) over the umbilicus was found a common practice to cure the abdominal pain, 70.8% accepted that they apply ashes or powder or cow dung on the umbilical cord, and 88.3% rub the dough on baby's skin to remove excess hairs, 99.3% mothers had firm belief that hot and cold foods in their diet could harm the baby. In continuation 98.8% believed that tooth eruption is associated with diarrhoea, 95.6% are applying kajal in the eyes of new born. Majority 98.8% believed that baby's skin should be exposed to sunlight in case of jaundice and 94% avoid dressing of new born with yellow clothes. Continuous Health Education programs must be organized in Community to Educate the people about beneficial and harmful newborn care practices, which will help to reduce morbidity and mortality in newborn.

Pyrolysis temperature effect on biochar-derived cow manure: Physicochemical properties and adsorption behavior toward organic dyes

BackgroundThis study investigates the synthesis of biochar from cow manure at various pyrolysis temperatures and its effectiveness in dye adsorption, focusing on how temperature influences the adsorption capacities of biochar towards MB and MO. MethodsBiochar was produced at four pyrolysis temperatures (300, 500, 700, and 900 °C), labeled CMBC-x. Adsorption capacities for MB and MO were tested. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) identified functional groups involved in dye adsorption. FindingsBiochar produced at 900 °C (CMBC900) showed the highest adsorption capacities: 200 mg g-1 for MB and 147 mg g-1 for MO. For a dye mixture, CMBC900 adsorbed 104.5 mg g-1 of MB and 98.7 mg g-1 of MO, indicating efficient separation. CMBC900 maintained high efficiency after ten cycles, with 97.5 % for MB and 90.5 % for MO. These findings highlight the robustness and long-term potential of CMBC900 as an adsorbent. Converting agricultural waste into biochar offers an economically viable solution for waste management and environmental protection by removing harmful dyes from wastewater.

Continuous biogas production and ex-situ biomethanation in a trickling bed bioreactor under mesophilic and thermophilic conditions

The utilization of biogas as a renewable energy source necessitates a reduction in its CO2 content. "Ex-situ biomethanation" is employed to convert CO2 in biogas to CH4 through hydrogenotrophic methanogens. In this study, a biogas stream (32–36 % CO2) originating from cow manure digestion was subjected to treatment in a trickle bed bioreactor (4 liters). The presence of microorganisms on the packing material was confirmed by using a 16 S rRNA test and SEM images. This study stands out by considering all four combinations of thermophilic and mesophilic conditions, monitoring the transition and steady-state phases in a two-reactor series setup. The mesophilic-thermophilic mode yielded the highest purity (92 %) with an 86 % CO2 conversion rate and an energy density of 13,870 kJ/m3. Additionally, the performance consistency was also assessed using a larger TBB (8 liters). Extending the residence time, the thermophilic-thermophilic mode yielded the highest CH4 concentration at 98 %. The 16 S rRNA results revealed that, influenced by the designated growth conditions encompassing culture media, pH, temperature, and reactor retention time, an enrichment of hydrogenotrophic methanogens occurred. Furthermore, promising results in terms of CH4 concentration and process efficiency were demonstrated by the trickled bed bioreactor employing liquid-in-gas dispersion.

Utilization of local agro-industrial by-products based substrates to enhance production and dietary value of mushroom (P. ostreatus) in Ethiopia

Food insecurity and malnutrition are serious problems in many developing countries, including Ethiopia. This situation warrants an urgent need for the diversification of food sources with enhanced productivity. This study was aimed at contributing to the food security in Ethiopia through cultivation of Pleurotus ostreatus mushrooms using sustainable and locally available agro-industrial byproduct-based substrates in parallel with pollution control. Ten substrates were prepared using sugarcane bagasse, filter cake, trash, cotton seed hull and animal waste, namely cow dung and horse and chicken manure. The effect of each substrate (treatment) on the yields, biological efficiency, nutritional composition, and mineral contents of Pleurotus ostreatus mushroom species was evaluated at the Ethiopian Forest Products Innovation Center, Addis Ababa, Ethiopia. The results obtained indicate that a significantly higher (p < 0.05) yield and biological efficiency were recorded from the mushroom cultivated on S2 substrate containing a mixture of 80% sugarcane bagasse, 12% cow dung, and 8% cotton seed hull. Moreover, substrate containing sugarcane bagasse mixed with cotton seed hull, cow dung, and chicken manure significantly (p < 0.05) increased the yields and biological efficiency of the mushroom. The content of protein, crude fat, fiber, and carbohydrates of the mushroom cultivated from all the utilized substrates were in the range of 17.30–21.5, 1.77–2.52, 31.03–34.38, and 28.02–39.74%, respectively. The critical macro-elements are abundant in the mushroom in the order of potassium, magnesium, calcium, and sodium. The mushrooms cultivated on all the substrates were rich in essential micro-elements in the order of iron and zinc. It was found that substrate preparation and formulation significantly (p < 0.05) improved the yields, biological efficiency, nutritive values, and mineral contents of the mushroom. The use of these by-products as substrates is sustainable and environmentally friendly and allows the production of mushroom with high nutritional value on a sustainable basis in order to enhance food security in the country.

Dynamics of antibiotic resistance genes during manure composting: Reduction in herbivores manure and accumulation in carnivores

The elevated levels of antibiotic resistance genes (ARGs) in livestock manure represent a significant threat to both the environment and human health. Composting has been recognized as an effective strategy to mitigate the abundance of ARGs in manure. However, notable rebounds in ARGs abundance have been observed during this process. This study explored the changes in ARGs abundance and the underlying influencing factors during the composting of carnivore (chicken and pig) and herbivore (sheep and cow) manures, along with mushroom residues. The findings revealed that the total relative abundance of ARGs increased by 6.96 and 10.94 folds in chicken and pig manure composts, respectively, whereas it decreased by a remarkable 91.72% and 98.37% in sheep and cow manure composts. Nitrogen content emerged as the primary physicochemical factors governing the abundance of ARGs in chicken and pig manure composts. Conversely, carbon content played a pivotal role in determining ARGs abundance in chicken and pig manure composts. Furthermore, the presence of dominant hosts, such as Corynebacterium, Bacillus, and Clostridium, along with emerging bacteria like Thermobifida, Saccharomonospora, and Actinomadura, contributed significantly to the enrichment of total ARGs, including tetG, tetO, tetX, and sul2, in chicken and pig manure composts. The coexistence of these genes with mobile genetic elements and a plethora of host bacteria, coupled with their high abundance, renders them particularly high-risk ARGs. On the other hand, the observed decrease in the abundance of total ARGs in sheep and cow manure composts can be attributed to the decline in the population of host bacteria, specifically Atopostipes, Psychrobacter, and Corynebacterium. Collectively, these results provide crucial insights into the management of ARGs risks and offer essential theoretical support for enhancing the safe utilization of organic fertilizer in agriculture.

In-situ biomethanation of high CO content syngas in agricultural biogas digesters

To meet global energy demands, syngas with high CO content (>50 %) generated from hydrothermal gasification of agricultural residues or wood, could be utilized as a co-substrate in anaerobic digestion (AD) processes for conversion into CH4. This study investigated in-situ biomethanation using synthetic gas (55 % CO, 35 % H2, and 15 % CO2), mimicking wood gasification syngas, during AD of cow manure, the most abundant agricultural waste. A continuously stirred tank reactor (CSTR) served as a control and was fed only cow manure, while the other two reactors were fed syngas with or without gas recirculation at different gas loading rates (GLRs).In-situ syngas injection in AD of cow manure at GLRs ≤0.3 L LRV−1 d−1 improved overall CH4 productivity compared to the control (0.35 ± 0.1 vs. 0.29 ± 0.1 L LRV−1 d−1), though the CH4 content (45 ± 5 %) was lower than the control reactor (62 ± 3 %), indicating a need for biogas upgrading. Gas recirculation enabled higher CO and H2 conversion efficiencies of 99–100 % but considerably decreased CH4 productivity from cow manure. In-situ biomethanation enhanced the relative abundance of hydrogenotrophic methanogens, highlighting their role in syngas conversion to CH4.