Microbial Efficiency Research Articles

Role of Stockyard Litter Amendment in the Short-Term Restoration of Soil Microbial Efficiency in a Lowland Paddy

Role of Stockyard Litter Amendment in the Short-Term Restoration of Soil Microbial Efficiency in a Lowland Paddy

AI-driven monitoring systems for bioremediation: real-time data analysis and predictive modelling

Artificial Intelligence (AI) and Machine Learning (ML) are transforming the field of bioremediation by enabling real-time monitoring and optimization of environmental cleanup processes. This paper explores the integration of AI-driven monitoring systems with bioremediation techniques, focusing on how real-time data analysis and predictive modelling can enhance the effectiveness of pollutant degradation. These AI systems continuously collect data from contaminated sites, such as soil and water, and analyse variables like microbial activity, pollutant concentration, and environmental conditions. By processing this data, AI models can optimize the bioremediation environment, adjusting factors such as pH, temperature, and nutrient levels to maximize microbial efficiency. Predictive modelling plays a crucial role in forecasting remediation outcomes, allowing for proactive adjustments to improve the speed and success of the process. The study also highlights the potential of AI in reducing operational costs by automating data collection and analysis, minimizing the need for manual intervention. Furthermore, it discusses challenges related to data quality, system integration, and the scalability of AI applications in real-world bioremediation projects. By leveraging AI's capability to provide real-time insights and predictive analytics, this research demonstrates its potential to significantly enhance the precision and sustainability of bioremediation efforts, paving the way for smarter environmental management.

Effects of Formaldehyde-Treated Feed on Rumen Metabolism and Blood Biochemistry in Lambs: A Review

This review evaluates the impact of formaldehyde treatment on feed for lambs, focusing on its effects on rumen metabolism and blood biochemical indicators. Formaldehyde is commonly used as a feed additive to improve nutritional efficiency and preserve feed quality. This review synthesizes data from various studies to assess how formaldehyde-treated feed influences rumen fermentation parameters, including volatile fatty acid (VFA) production, rumen pH, and microbial activity. Additionally, the review examines the effects of formaldehyde treatment on key blood biochemical markers such as glucose, urea nitrogen, and liver enzymes. Studies indicate that formaldehyde treatment can enhance the stability and digestibility of feed, potentially improving nutrient utilization and overall animal performance. The preservation of protein and reduction in feed spoilage are highlighted as significant benefits, contributing to more consistent rumen function and metabolic efficiency. However, the impact on rumen microbial populations and VFA profiles shows mixed results, with some studies reporting improved microbial efficiency and others noting minimal changes. The review also discusses potential adverse effects, including alterations in blood biochemical parameters. While formaldehyde treatment generally maintains or improves key indicators like blood glucose and protein levels, excessive use may lead to concerns such as elevated urea nitrogen levels and potential liver enzyme disruptions, the review concludes that formaldehyde-treated feed can be a valuable tool in optimizing feed efficiency and lamb health, provided it is used judiciously. Future research is recommended to further elucidate the long-term effects on rumen microbiota and metabolic processes, ensuring balanced benefits without compromising animal welfare.

179 Charting the evolution of rumen microbial models from past to present

Abstract This review delves into the intricate realm of ruminal microbes, shedding light on their complexity beyond previously recognized dimensions. Existing publications have probed the essential facets of these microorganisms on a finer scale than previously acknowledged. Mathematical models have emerged to simulate the behavior of approximately 200 distinct bacterial species, 25 genera of ciliate protozoa, and five genera of anaerobic fungi, constituting about 10% of the total viable bacteria in the rumen. However, the expansive diversity and density of rumen microbes challenge the complete characterization of species or genera in relation to substrates or end products. Consequently, continuous revision and re-engineering of mathematical models become imperative. In the context of ruminants, prevalent models often categorize bacteria into fiber-fermenting and nonfiber-fermenting groups. An additional subgroup featuring hyper-ammonia-producing bacteria has been proposed, but its explicit integration into nutrition models remains unexplored. Furthermore, incorporating a more mechanistic evaluation of protozoa and fungal growth may be warranted to improve nutrition models. The time horizon and intervals at which models are constructed present another critical consideration, with feed efficiency variations among ruminants believed to be closely tied to differences in the ruminal microbiota. Addressing immediate concerns, this review underscores the need for a comprehensive exploration of factors influencing microbial growth in the rumen. Several indices have been suggested and adopted to predict microbial efficiencies, but they may provide simplification for practical application. Thus, a mechanistic approach should be considered to remove dependencies between estimates and improve predictive accuracy and precision. While artificial intelligence holds promise in elucidating gaps within empirical and mechanistic models, the generation of accurate, vetted datasets is paramount. Furthermore, this review posits that factors such as recycled nitrogen, endotoxins, and microbial population dynamics (i.e., cross-feeding and competition) may be limiting our understanding of microbial growth, suggesting the necessity of modeling these intricacies concurrently to achieve a more nuanced comprehension. This multifaceted approach aims to propel the understanding of ruminal microbial dynamics into new frontiers, paving the way for more informed and effective modeling in the future.

Inhibiting methanogenesis by targeting thermodynamics and enzymatic reactions in mixed cultures of rumen microbes in vitro.

Mitigation of enteric methane (CH4) emissions from ruminant livestock represents an opportunity to improve the sustainability, productivity, and profitability of beef and dairy production. Ruminal methanogenesis can be mitigated via two primary strategies: (1) alternative electron acceptors and (2) enzymatic inhibition of methanogenic pathways. The former utilizes the thermodynamic favorability of certain reactions such as nitrate/nitrite reduction to ammonia (NH3) while the latter targets specific enzymes using structural analogs of CH4 and methanogenic cofactors such as bromochloromethane (BCM). In this study, we investigated the effects of four additives and their combinations on CH4 production by rumen microbes in batch culture. Sodium nitrate (NaNO3), sodium sulfate (Na2SO4), and 3-nitro-1-propionate (3NPA) were included as thermodynamic inhibitors, whereas BCM was included as a enzymatic inhibitor. Individual additives were evaluated at three levels of inclusion in experiments 1 and 2. Highest level of each additive was used to determine the combined effect of NaNO3 + Na2SO4 (NS), NS + 3NPA (NSP), and NSP + BCM (NSPB) in experiments 3 and 4. Experimental diets were high, medium, and low forage diets (HF, MF, and LF, respectively) and consisted of alfalfa hay and a concentrate mix formulated to obtain the following forage to concentrate ratios: 70:30, 50:50, and 30:70, respectively. Diets with additives were placed in fermentation culture bottles and incubated in a water bath (39°C) for 6, 12, or 24h. Microbial DNA was extracted for 16S rRNA and ITS gene amplicon sequencing. In experiments 1 and 2, CH4 concentrations in control cultures decreased in the order of LF, MF, and HF diets, whereas in experiments 3 and 4, CH4 was highest in MF diet followed by HF and LF diets. Culture pH and NH3 in the control decreased in the order of HF, MF, to LF as expected. NaNO3 decreased (p < 0.001) CH4 and butyrate and increased acetate and propionate (p < 0.03 and 0.003, respectively). Cultures receiving NaNO3 had an enrichment of microorganisms capable of nitrate and nitrite reduction. 3NPA also decreased CH4 at 6h with no further decrease at 24 h (p < 0.001). BCM significantly inhibited methanogenesis regardless of inclusion levels as well as in the presence of the thermodynamic inhibitors (p < 0.001) while enriching succinate producers and assimilators as well as propionate producers (p adj < 0.05). However, individual inclusion of BCM decreased total short chain fatty acid (SCFA) concentrations (p < 0.002). Inhibition of methanogenesis with BCM individually and in combination with the other additives increased gaseous H2 concentrations (p < 0.001 individually and 0.028 in combination) while decreasing acetate to propionate ratio (p < 0.001). Only the cultures treated with BCM in combination with other additives significantly (padj < 0.05) decreased the abundance of Methanobrevibacter expressed as log fold change. Overall, the combination of thermodynamic and enzymatic inhibitors presented a promising effect on ruminal fermentation in-vitro, inhibiting methanogenesis while optimizing the other fermentation parameters such as pH, NH3, and SCFAs. Here, we provide a proof of concept that the combination of an electron acceptor and a methane analog may be exploited to improve microbial efficiency via methanogenesis inhibition.

Synergetic effect of biochar and intermittent electricity stimulation on mitigating the adverse effects of tannic acid on anaerobic granular sludge in wastewater

Tannic acid (TA), a common industrial contaminant in sectors such as papermaking and leather production, affects the anaerobic treatment of wastewater by forming complexes with proteins in sludge granules, thereby inhibiting microbial efficiency and promoting sludge deflocculation. Although techniques such as intermittent electricity can promote microbial growth, they do not effectively resolve sludge deflocculation. Additionally, although biochar (BC) enhances the abundance of microbes, it does not significantly improve microbial activity or treatment performance. This study aimed to alleviate the adverse effects of TA on anaerobic granular sludge (AnGS) by synergistically applying intermittent electrical stimulation and BC. Co-treatment with 1 h-on/off intermittent electricity and 3 g/L BC notably reduced granular sludge deflocculation. Consequently, the chemical oxygen demand (COD) removal efficiency in wastewater reached 91.73 %, with a maximum methane production per cycle of 230.59 mL/g COD, 16.95 % higher than that of the control reactor (197.17 mL/g COD). This improvement was attributed to the synergistic action of intermittent electricity and BC, which enriched the functional microorganisms and stimulated their activity, thereby facilitating direct interspecies electron transfer. Additionally, enhancing the polysaccharide and protein levels in extracellular polymeric substances improved the stability of granular sludge, ultimately mitigating the adverse effects of TA on AnGS.

Qualitative investigation and screening of antimicrobial activity of stem extract in Clerodendrum infortunatum plant

Clerodendrum infortunatum is known as hill glory bower and a plant which is widely distributed throughout the whole world. Up to now, many species of C. infortunatum have been described in various indigenous systems of medicine that are used in preparation of folklore medicines for the treatment of various life-threatening diseases, and much of this plant have been very well studied for their chemical constituents and biological activities. It also is used in Unani, Ayurveda, and siddha system of medicine for many years. From Clerodendrum infortunatum many compounds, including mono-turpentine and its derivatives, sesquiterpene, diterpenoids, tri-terpentine, flavonoid, quercetin, acacetin, gallic acid, sterol and flavonoid glycoside, phenylethanoid glycoside, steroids and steroid glycosides, cyclohexylethanoids, anthraqunine, cyanogenic glycolsides, and others have been isolated and identified. In the present study, Chloroform, pet. ether, and water stem extract of Clerodendrum infortunatum obtained by Soxhlet extraction was screened to detect the presence or absence of several bioactive compounds which are reported to cure different diseases. Anti-microbial analysis of stem extract was carried out against lactobacillus, E.coli and staphylococcus aureus organisms by agar well diffusion method. It was observed that the zone was recorded against this organism. The results indicate that the chloroform, pet.ether and water extracts of C. infortunatum are having anti- microbial efficiency in controlling the microorganisms. So, Clerodendrum infortunatum is the plant which are beneficial on human health.

Mild alkaline conditions affect digester performance and community dynamics during long-term exposure

This paper examines the adaptive responses of microbial communities to gradual shifts in pH toward the mild alkaline range in anaerobic digestion (AD) systems. The results indicate that a pH of 8.0 serves as a critical upper limit for stable AD operation, beyond which microbial efficiency declines, underscoring the importance of microbial resilience against elevated pH stress. Specifically, hydrolysis genera, e.g. Eubacterium and Anaerobacterium, and syntrophic bacteria were crucial for reactor stability. Fibrobacter had also been shown to play a key role in the accumulation of propionate, thus leading to its dominance in the volatile fatty acid profile throughout the experimental phases. Overall, this investigation revealed the potential adaptability of microbial communities in AD systems to mild alkaline pH shifts, emphasizing the hydrolysis bacteria and syntrophic bacteria as key factors for maintaining metabolic function in elevated pH conditions.

INFLUENCE OF LIVE WEIGHT ON STARCH AND N DIGESTION OF CORN-BASED (DRY-ROLLED OR STEAM-FLAKED) FINISHING DIETS FOR HOLSTEIN STEERS

&lt;p&gt;&lt;strong&gt;Background&lt;/strong&gt;. A possible effect of live weight on digestion capacity and starch and nitrogen utilization in cattle has been suggested, however, to our knowledge, this effect has not been evaluated by direct testing. This becomes especially relevant when finishing diets are used, which are characterized by their high percentages of starch and nitrogen &lt;strong&gt;Objective: &lt;/strong&gt;To study the possible effect of live weight (BW) on digestion and utilization of two treatments corn, dry rolled (DR) and steam-flaked (SF). &lt;strong&gt;Results&lt;/strong&gt;. Microbial N and microbial efficiency were not affected by the live weight by corn processing interaction. PV decreased linearly (P&amp;lt;0.01) rumen starch digestion in response to dry-rolled corn, whereas with steamed corn, PV had an opposite effect by linearly (P&amp;lt;0.01) increasing rumen starch digestion. &lt;strong&gt;Implications.&lt;/strong&gt; Attention should not be paid to the live weight of the animals when choosing the type of grain processing. &lt;strong&gt;Conclusions. &lt;/strong&gt;It is concluded that live weight does not have a significant effect on the digestion of corn starch, but there is a quadratic effect on the nitrogen efficiency; however, the direction of this effect (increase or decrease in digestion as PV increases) depends on the type of grain processing.&lt;/p&gt;

Effects of different concentrate levels in AGRI-002E sorghum silage-based diets on nutrient intake and digestibility, ruminal pH and ammonia concentration, ruminal degradability, and microbial efficiency in beef cattle

This study aimed to evaluate the effect of increasing concentrate levels in AGRI-002E sorghum silage (SS)-based diets on nutrient intake and digestibility, ruminal pH and ammonia concentration, Nitrogen (N) balance, efficiency of microbial protein synthesis, and in situ degradability of complete diets. Five rumen-cannulated Nellore bulls (age = 8 ± 1.0 months; initial BW = 242 ± 5 kg) received five dietary treatments in a 5×5 Latin square experimental design. The dietary treatments consisted of five concentrate levels (0, 200, 400, 600, and 800 g of concentrate/kg on a DM basis) in SS-based diets. The experiment lasted 120 d, with five periods of 24 d. Each period consisted of 17 d for dietary adaptation, and 7 d for data collection. In situ degradability assays were conducted to estimate ruminal degradability. Total feces and urine collection were performed to estimate nutrient intake and digestibility and estimate N balance. Omasal and ruminal digesta collection were performed to estimate ruminal digestibility and ruminal parameters. Increasing concentrate levels in SS-based diets led to linear increases (P<0.001) in the intake of dry matter (DM), organic matter (OM), crude protein (CP), and ether extract (EE). Neutral detergent fiber corrected for ash and protein contamination (apNDF) and starch intake showed quadratic responses (P≤0.008). Ruminal digestibility of DM, OM and CP responded quadratically (P≤0.040), while apNDF exhibited linear decrease (P=0.003). Starch ruminal digestibility exhibited a cubic effect (P=0.016). Apparent total-tract digestibility of DM, OM, and EE increased linearly (P≤0.001), whereas apNDF, and CP digestibility decreased linearly (P≤0.012), and starch presented a quadratic effect (P=0.029). In situ ruminal degradation parameters increased linearly with higher concentrate levels (P<0.001). Ruminal pH exhibited a quadratic pattern (P=0.006), ammonia concentration linearly decreased (P=0.003). Total volatile fatty acids, and butyrate showed linear increases (P<0.001), acetate and propionate had quadratic effects (P<0.001), while the ratio Acetate to Propionate decreased linearly (P<0.001). N intake, fecal N excretion, retained N, total digestible nutrients, digestible organic matter, and microbial production increased linearly (P<0.001), although urine N excretion, urinary urea, and blood urea concentration decreased linearly (P<0.028). Therefore, increasing concentrate levels in AGRI-002E sorghum silage-based diets improve TDN intake, microbial protein synthesis efficiency, in situ ruminal degradability parameters, and nitrogen utilization. Moreover, our findings indicate that AGRI-002E sorghum silage demonstrates potential as a fiber source for high-concentrate diets. However, its effectiveness is limited without concentrate supplementation, emphasizing the importance of balanced dietary composition for optimal utilization in beef cattle.

Timing of High-Energy Supplementation to Early-Season-Pasture-Forage Fed Continuous Culture

A continuous culture study was conducted duplicating the daily meal pattern of pasture-grazed cattle and evaluating the time of two supplements differing in their composition (one complex: SUPP A and one simplistic: SUPP B) on their effects on nutrient digestion and metabolism of ruminal microorganisms. SUPP A contained ingredients containing substantial amounts of both structural and non-structural carbohydrates (NSC), fat, and protein, all having fractions with differing rates of availability. SUPP B’s predominate organic matter ingredients were only corn grain and soybean meal and contained approximately 3% less crude protein than SUPP A. All treatments were fed forage at five distinct times, mimicking forage intake on pasture, with supplements being fed at either a morning (AM) or evening (PM) feeding. The treatments were a) SUPP A fed AM, b) SUPP B fed AM, c) SUPP A fed PM, and d) Supp B fed PM. The results showed that dry matter, organic matter, and NSC digestibility’s were unaffected by supplement type or time of feeding. Supplement A showed greater fiber digestion than SUPP B, regardless of time of supplementation. The PM feeding decreased the digestion of both neutral detergent fiber and acid detergent fiber in SUPP B with no effect on fiber digestion in SUPP A. Culture pH remained more stable over the 24-hour day with SUPP B feeding than it did with SUPP A feeding while average pH was not affected by supplement or time of feeding. Total volatile fatty acid flow was unaffected by treatment, as were flows of acetic and propionic acids. Butyric acid flow decreased significantly on both supplements with the PM feeding. As expected, there were fewer total branch chain volatile fatty acids generated with SUPP B. Microbial growth measured in g microbial N flow/day increased for both supplements at the PM feeding. Flow of by-pass feed nitrogen was unaffected by supplement but was lower with PM feeding. Microbial efficiency was increased as a result of the PM feedings. The timing of a large amount of supplementation relative to the timing of daily forage meals can alter the effects seen in continuous culture work and may translate to effects in-vivo systems as well.

Comprehensive Analysis of Clean Energy Generation Mechanisms in Microbial Fuel Cells

This paper reviews the current state of microbial fuel cell (MFC) technology for energy generation. It begins by exploring clean energy alternatives, focusing on waste‐to‐energy solutions, and introduces the concept, applications, and advantages of MFCs. The biochemical processes within MFCs are explained, highlighting how microorganisms metabolize substrates through glycolysis, the Krebs cycle, and the electron transport chain to generate electrons. These electrons flow through an external circuit and combine with protons and oxygen at the cathode to produce water or reduced forms of nitrogen and sulfur. This paper also analyzes 10 key parameters affecting MFC performance: coulombic efficiency, pH, temperature, substrates, organic loading rate, electrode potential, open circuit voltage, treatment efficiency, organic removal rate, and hydraulic retention time. Recent advancements in MFC technology are also discussed, including innovations in reactor configuration and scaling, the development of new membrane materials like earthen and ceramic, and improvements in wastewater treatment methods. The advancements also extend to genetic engineering techniques to enhance microbial efficiency and component modifications, such as the use of carbon‐based nanomaterials and metal catalysts for improved performance, innovations in proton transfer membranes, and mediator‐less MFCs utilizing metal‐reducing bacteria. Challenges facing MFC technology, such as cost, scalability, and environmental sensitivity, are mentioned. The paper concludes with future directions, including the use of advanced materials, integration with wastewater treatment infrastructure, and the potential for nutrient recovery and chemical synthesis. This comprehensive review aims to provide knowledge into optimizing MFCs for sustainable energy generation and environmental benefits.

Effect of neutral detergent-soluble carbohydrate profile on digestive parameters of dairy goats

ABSTRACTThe aim of the present study was to evaluate the effect of diets with high concentrations of different neutral detergent-soluble carbohydrates on the ruminal degradability and total digestibility, digestive parameters, and microbial efficiency of dairy goats. Five non-lactating goats and rumen and abomasum cannulas were arranged in a 5 × 5 Latin square design. The diets were the ratio between starch associated with soluble sugar (StSS) to NDSF (StSS:NDSF): 0.82; 1.3; 1.63; 2.94; and 5.35. Starch intake increased (P < 0.001) linearly with the increase of StSS:NDSF ratios in the diet. There was a linear decrease (P < 0.001) in the intake of soluble carbohydrates and neutral detergent soluble fiber (NDF). The ruminal degradability of dry matter (DM), crude protein, NDF, and NDSC decreased linearly (P < 0.05) with the increase of StSS:NDSF ratios in the diet. Total nitrogen flow, microbial nitrogen flow (MNF), and microbial efficiency increased (P < 0.05) with the increment of StSS:NDSF ratios in the diet. The increases in StSS:NDSF ratios in the diet affected only butyric (P < 0.001), valeric (P < 0.001), and isovaleric (P = 0.004) acids, as well as pH (P < 0.001). High StSS:NDSF ratio diets do not affect DM and NDF intake but reduce DM and NDF ruminal degradability, increasing MNF and, consequently, microbial efficiency in dairy goats.

Tithonia diversifolia Improves In Vitro Rumen Microbial Synthesis of Sheep Diets without Changes in Total Gas and Methane Production

Among the alternatives identified as capable of making livestock farming a more efficient activity and reducing its environmental impact, the use of feeds with high digestibility and the use of non-conventional fodder species can be highlighted. Tithonia diversifolia (Hemsl.) A. Gray (TD) has already gained attention as a feed for ruminants. Nonetheless, there has been little discussion about the impacts of this plant on the rumen dynamics that lead to better animal performance. The aim of this study was to assess how increasing levels of TD could affect ruminal microbial biomass synthesis, degradability, and in vitro gas production (IVGP) of diets. Four diets were evaluated: a control diet (TD0: 400 g kg−1 soybean meal and maize grain, and 600 g kg−1 Tifton 85 hay (Cynodon spp.)) and three increasing levels of TD (TD9: 90, TD27: 270, and TD45: 450 g kg−1–dry matter basis) as a replacement for dietary roughage. A 96 h IVGP assay was carried out and five incubation times (2, 4, 10, 24, and 96 h) were used for degradability determination. Gas produced, methane (CH4), degradability of organic matter (IVDOM), short-chained fatty acid (SCFA) production, partitioning factor (PF), and microbial biomass (MB) were evaluated among treatments. There was no significant effect (p &gt; 0.05) between TD inclusion and IVGP at most incubation times; only at 6 h of incubation did gas production increase linearly with TD inclusion (R2 = 0.19; p &lt; 0.05). TD inclusion had no effects on CH4. IVDOM increased linearly with TD inclusion at 6 and 10 h, with TD45 being more degradable than the control diet at 6 h only. There was a positive linear relationship (R2 = 0.20; p &lt; 0.05) between TD inclusion and PF. TD45 had significantly higher PF values than the control. MB also increased linearly (R2 = 0.30; p &lt; 0.05) with TD inclusion, and all diets with TD had significantly more MB than the control diet. The inclusion of TD at the levels used in this work was revealed to have a positive impact on microbial protein synthesis, which could be related to the higher microbial efficiency of increased substrate quality.

Does vitamin blends supplementation affect the animal performance, carcass traits, and nutrient digestibility of young Nellore finishing bulls?

This study was realized to evaluate the effects of supplementation with blends of water and fat-soluble vitamins on animal performance and carcass traits of young Nellore bulls. Forty-three Nellore bulls, with an initial weight of 261±27.3 kg and a mean age of 8±1.0 months, were used. Five animals were slaughtered at the beginning of the experiment (reference group), to determine the initial empty body weight of the bulls that remained in the experiment. The remaining 38 bulls were fed ad libitum and distributed in a completely randomized design in a 2×2 factorial scheme, with or without supplementation of water-soluble (B-blend+ or B-blend-) and fat-soluble (ADE+ or ADE-) vitamin blends. Diets were isonitrogenous (120 g of crude protein/kg dry matter [DM] of total mixed ration) and consisted of a roughage:concentrate rate of 30:70 based on total DM of diet. The experiment lasted 170 days, with 30 days of adaptation and 140 days for data collection. At the beginning and end of the experimental period, the bulls were weighed to determine the average daily gain. To estimate the apparent digestibility of nutrients and microbial efficiency, spot collections of feces and urine were performed for five consecutive days. DM, ashes, organic matter, crude protein, ethereal extract, neutral detergent fiber corrected for residual ash and residual nitrogenous, and N intake and apparent digestibility were not influenced by vitamin supplementation, but total digestible nutrients intake and non-fibrous carbohydrates digestibility were influenced by B complex vitamin supplementation. Nitrogen balance, microbial efficiency, and performance data were not influenced (p>0.05) by vitamin supplementation. Vitamin supplementation (a blend of water-soluble and fat-soluble vitamins or their combinations) does not influence the animal performance and carcass traits of young Nellore bulls.

Soil microbial community composition and functions are disrupted by fire and land use in a Mediterranean woodland

The intersection of fire, land use transformations, and climate change is putting Mediterranean climate-type ecosystems at risk of soil degradation and loss of ecosystem services. Ondik et al. (2022b) showed that in a Mediterranean dry sclerophyll woodland of South Australia, high severity fire and clearing and grazing practices impacted both physicochemical and biological soil quality indicators. Building upon the work of Ondik et al. (2022b) this study aims to 1) identify soil physicochemical properties impacted by fire and land management that are indirect drivers of changes to soil microbial community composition and 2) determine whether the observed changes to soil microbial community composition affect soil microbial functions. Via a redundancy analysis, we identified fire and management-induced changes to pH, soil water repellency, nutrient stoichiometry, and total nutrient content as significant drivers of the composition of soil microbial communities. We then measured basal respiration, substrate induced respiration, and the carbon mineralisation quotient, and calculated functional trait distributions among microbial communities by linking 16S and 18S rRNA sequences to respiration modes and functional guilds, respectively. We found that fire reduced soil microbial respiration and the relative abundance (RA) of microbial symbionts, anaerobic bacteria, and microaerophilic bacteria, while increasing the RA of aerobic bacteria. Furthermore, management increased the RA of post-fire ectomycorrhizal fungi and may have reduced pathogenic load, microbial efficiency, and wood saprotrophs, while increasing litter, soil, and other saprotrophic species that are adapted to grasslands. This study shows that, through changes to microbial community composition, high severity wildfire and land management affected soil respiration rates, bacterial modes of respiration, prevalence of symbiotic bacteria and fungi, and microbial substrate preference. Having identified the main physicochemical drivers of changes to microbial community composition, we provide valuable insights into how fire and land management can impact soils in Mediterranean woodland.

Effect of substituting maize silage with fresh or ensiled sugar beets on nutrient digestibility, rumen fermentation and microbial synthesis, and enteric methane emission in dairy cows

This study aimed to 1) examine nutrient digestibility, rumen fermentation and microbial synthesis, and enteric methane emission when feeding diets high in sugar content provided as freshly stored or ensiled sugar beets to dairy cows, and 2) to evaluate the methane mitigation potential of ensiled sugar beets with different nutrient composition (sugar vs. alcohol) by use of an additive during ensiling. Four rumen, duodenal and ileal fistulated Danish Holstein dairy cows were used in a 4 × 4 Latin square design with 21-d periods. Maize silage was included in the control diet (CON) and was partially replaced in the experimental diets with either freshly stored sugar beets (SBF), ensiled beets with ensiling additive (SBE+), or ensiled beets without ensiling additive (SBE−) at 196 g/kg dietary dry matter (DM) content. Cows adapted to the diets for 11 d, after which rumen liquid and digesta were collected over 5 d, and gas exchange was measured in respiration chambers over the next 5 d. Dry matter intake (DMI), daily methane production, and methane per kg organic matter (OM) intake, rumen digested OM, and energy-corrected milk (ECM) yield were unaffected by diet. Methane per kg DMI (tendency) and per kg OM intake was lower for SBE– compared to SBF. Nutrient digestibility of DM, OM, starch, and neutral detergent fibre in different sections of the digestive tract were unaffected by diet. Molar proportion of acetate in rumen liquid decreased for ensiled sugar beet diets relative to CON, while molar proportions of propionate and acetate-to-propionate ratio remained unaffected. Molar proportion of butyrate was higher for SBE+ than CON. Microbial crude protein synthesis and microbial efficiency were unaffected by diet. Milk yield and ECM yield (tendency) were lower for SBE+ than CON. In conclusion, freshly stored sugar beets and sugar beets ensiled with or without additive, can replace maize silage in dairy cattle rations without adverse effects on DMI, rumen fermentation, and nutrient digestibility, and without altering most expressions of methane emissions, but methane per kg of OM intake was lower for beets ensiled without additive compared to freshly stored beets. The ECM yield, however, tends to be lowered for ensiled beets with additive.

A bucket sand filter and Moringa Oleifera drinking water treatment hybrid system for rural households

The Bucket filter (BF) is a modification of the conventional BioSand filter (CBSF) meant to make it more adaptable for use in rural communities. Unfortunately, it has a low microbial efficiency compared to the CBSF. This paper explored the potential of integrating Moringa Oleifera with the bucket filter by creating a hybrid system that would work as efficiently as the CBSF but lower in cost and lighter in weight. Four filters, including BF, CBSF, Moringa High dose (125 mg/l) bucket filter (MUBFHigh) and Moringa Low dose (75 mg/l) bucket filter (MUBFLow) were set up. For 91 days, they were evaluated for turbidity, pH, organic matter and E. coli. Results indicate that the MUBFHigh system had an E. coli removal efficiency of 81–98%, which was comparable to the CBSF. MUBFHigh also yielded water that met the WHO guidelines for turbidity, organic matter and pH although the pH was slightly lower than the initial water. The MUBFHigh also weighed between 15 and 20 kg compared to 230 kg for the CBSF. The initial cost of the CBSF was more than double the cost of the MUBFHigh system. Although more work is needed to operationalize the filter, this study provides a baseline for future research.

Oily waste to biosurfactant: A path towards carbon neutrality and environmental sustainability

Tons of oily waste accumulating worldwide has led to severe environmental problems and an increase in carbon footprint. The oily waste is rich in carbon and therefore its utilization as a substrate for the production of value-added products can aid in the concept of carbon neutrality. Oils can be directly utilized as substrate and microorganisms can catabolize them to produce biosurfactants. Biosurfactants being biodegradable and less toxic than synthetic surfactants are the molecules of the 21st century and are preferred candidates. Also, several fungal species can bio-transform oils to produce biosurfactants. Therefore, this study comprehensively summarizes different categories of oily waste generated worldwide, their sources, and environmental toxicity. The microbial efficiency towards oily waste utilization for the production of biosurfactants is reviewed. Following this, advance techniques including metabolic engineering, and omics approaches for biosurfactant production from this waste have been presented. Their global market and future perspective have been discussed to further emphasize the requirement for biosurfactants. The state-of-the-art information provided in various sections of this manuscript may aid the researchers to understand the relationship of oily waste utilization with carbon footprint generation. This directs attention and warrants future research towards the development of improved pathways/processes in oil waste based biorefineries.

Effects of non-protein nitrogen on buffel grass fiber and ruminal bacterial composition in sheep

This study aimed to evaluate different concentrations of non-protein nitrogen (NPN) ruminal infusion in sheep fed buffel grass hay on nutrient intake and digestibility, ruminal parameters, nitrogen balance, and rumen bacterial composition. Five rumen-fistulated adult wethers, weighing 58 ± 5.1 kg were distributed according to a 5 × 5 Latin square design. The control treatment consisted of a 5.5% crude protein (CP) buffel grass hay basal diet only, while the other four treatments consisted of the addition, via ruminal infusion, of increasing amounts of NPN to gradually raise the level of CP in the basal diet (7.44, 9.39, 11.33 and 13.27% CP). There was a quadratic effect for the intake of dry matter (DM), organic matter (OM), CP, ether extract (EE) and neutral detergent fiber (NDF). Values of pH, volatile fatty acids, microbial protein, microbial efficiency and digestibility coefficients were not affected by CP levels in basal diet. On the other hand, there was a linear effect for the concentrations of ammonia nitrogen (NNH3) and nitrogen (N) in urine, and a quadratic effect for ingested and excreted N in feces, as well as for N balance. There was no effect of the different CP levels on the ruminal microbial composition. While the 5.5% CP basal diet provided sufficient NPN supply for the maintenance of ruminal bacterial activity, increased CP concentrations from 7.34 to 8.66% by means of ruminal infusion with NPM optimized the utilization of buffel grass nutrients by sheep.