Search Results (517)

Soil respiration (Rt), consisting of heterotrophic (Rh) and autotrophic respiration (Ra), plays a vital role in terrestrial carbon cycling and is sensitive to soil temperature and moisture. In dryland agriculture, plastic film mulching (PM) is widely used to regulate soil hydrothermal conditions, but its effects on Rt components and their temperature sensitivity (Q₁₀) across regions remain unclear. A two-year field study was conducted at two rain-fed maize sites: Anding (warmer, semi-arid) and Yuzhong (colder, drier). PM significantly increased Rt, Rh, and Ra, especially Ra, due to enhanced root biomass and improved microclimate. Yield increased by 33.6–165%. Peak respiration occurred earlier in Anding, aligned with maize growth and soil temperature. PM reduced Q₁₀ of Rt and Ra in Anding, but only Ra in Yuzhong. Rh Q₁₀ remained stable, indicating microbial respiration was less sensitive to temperature changes. Structural equation modeling revealed that Rt and Ra were mainly driven by soil temperature and root biomass, while Rh was more influenced by microbial biomass carbon (MBC) and dissolved organic carbon (DOC). Despite increased CO₂ emissions, PM improved carbon emission efficiency (CEE), particularly in Yuzhong (+67%). The application of PM is recommended to enhance yield while optimizing carbon efficiency in dryland farming systems. Full article

Wildfires can significantly alter soil physicochemical conditions and microbial communities in forest ecosystems. This study aimed to characterize the culturable soil fungal community and evaluate biological activity in Banco Totumo Bijibana, a protected dry tropical forest in Atlántico, Colombia, affected by a wildfire in 2014. Twenty soil samples were collected for microbiological (10 cm depth) and physicochemical (30 cm) analysis. Basal respiration was measured using Stotzky’s method, nitrogen mineralization via Rawls’ method, and fungal diversity through culture-based identification and colony-forming unit (CFU) counts. Diversity was assessed using Simpson, Shannon–Weaver, and ACE indices. The soils presented low organic matter (0.70%) and nitrogen content (0.035%), with reduced biological activity as indicated by basal respiration (0.12 kg C ha⁻¹ d⁻¹) and mineralized nitrogen (5.61 kg ha⁻¹). Four fungal morphotypes, likely from the genus Aspergillus, were identified. Simpson index indicated moderate dominance, while Shannon–Weaver values reflected low diversity. Correlation analysis showed Aspergillus-3 was positively associated with moisture, whereas Aspergillus-4 correlated negatively with pH and sand content. The species accumulation curve reached an asymptote, suggesting an adequate sampling effort. Although no control site was included, the findings provide a baseline characterization of post-fire soil microbial structure and function in a dry tropical ecosystem. Full article

The availability of detritus is a key factor influencing aquatic biota and can significantly affect decomposition processes. In this study, we investigated how varying quantities of surrounding detritus impact leaf litter decay rates. It was tested in flowing and still-water microcosms to highlight context-dependent effects of surrounding detritus on leaf litter decomposition. To isolate the effect of detritus amount, experiments were conducted in laboratory microcosms simulating lotic and lentic ecosystems, each containing leaf fragments for decomposition assessments. Four detritus quantities were tested, with invertebrates either allowed or restricted from moving among detritus patches. Leaf decomposition rates were influenced by the amount of surrounding detritus, with slower decay observed at higher detritus conditions, regardless of invertebrate mobility. Detritivore distribution responded to both detritus quantity and oxygen availability, showing a preference for high detritus conditions. Additionally, detritus quantity affected microbial activity with a quadratic response, as indicated by leaf respiration rates. Overall, our findings indicate that the amount of surrounding detritus modulates leaf litter decomposition independently of invertebrate density, by influencing oxygen dynamics and, consequently, the activity of biological decomposers. Full article

Utilizing edible films/coatings promises to extend the shelf life of fruits by controlling various physiological parameters (e.g., respiration and transpiration rates), maintaining firmness, and delaying fruit senescence. The influence of composite-based edible coatings made from sodium or calcium caseinate: carboxymethyl chitosan (75:25) on the postharvest quality of fresh blueberries was assessed over a 28-day storage period, on the basis of weight loss and changes in pH, firmness, color, titratable acidity, soluble solids content, mold and yeast count, and respiration rate. The pH of the blueberries increased over the period of storage, with significant differences observed between uncoated and coated (e.g., pH was 3.89, 3.17, and 3.62 at the end of the storage time for uncoated, Ca 75-1% SO, and Na 75-1% SO, respectively. Desirable lower pH values at the end of storage were obtained with the calcium caseinate formulations. Over the duration of storage, other quality parameters (e.g., firmness) were better retained in coated fruits compared to the uncoated (control) one. At the last storage day, the firmness of the uncoated sample was 0.67 N·mm⁻¹ while the sodium and calcium caseinate was 0.63 and 0.81 N.mm⁻¹, respectively. Moreover, the microbial growth was reduced in coated fruits, indicating the effectiveness of coatings in preserving fruit quality. The mold /yeast count was 1.4 and 2.3 log CFU/g for CaCa 75-1% SO and NaCa 75-1% SO compared with uncoated with 4.2 log CFU/g. Adding soybean oil to the caseinate–carboxymethyl chitosan composite edible coating has the potential to positively influence retention of various quality parameters of blueberries, thereby extending their shelf life and maintaining overall quality. Further research could explore the optimization of coating formulations and application methods to enhance their effectiveness in preserving fruit quality during storage. Full article

Odors from pet cats can negatively affect the quality of life of cat owners. The diverse bioactive compounds in plant extracts make them a promising candidate for effective odor reduction. This study evaluated twelve plant extracts for deodorizing efficacy via in vitro fermentation tests. Rosemary extract and licorice extract exhibited better deodorizing effects, with fractions of rosemary extract below 100 Da demonstrating the most effective deodorizing performance. Based on these findings, subsequent feeding trials were conducted using rosemary extract and its fractions below 100 Da. In the feeding trial, adult British Shorthair cats were divided into three groups (Control Check, RE, and RE100) and housed in a controlled-environment respiration chamber for 30 days. Measurements included odor emissions, fecal and blood physicochemical parameters, immune parameters, microbiota composition based on 16S rRNA sequencing, and metabolome analysis. The results of the feeding trial indicated that rosemary extract significantly reduced ammonia and hydrogen sulfide emissions (46.84%, 41.64%), while fractions below 100 Da of rosemary extract achieved even greater reductions (55.62%, 53.87%). Rosemary extract regulated the intestinal microbial community, significantly increasing the relative abundance of the intestinal probiotic Bifidobacterium (p < 0.05) and reducing the population of sulfate-reducing bacteria (p < 0.05). It also significantly reduced urease and uricase activities (p < 0.05) to reduce ammonia production and inhibited the degradation of sulfur-containing proteins and sulfate reduction to reduce hydrogen sulfide emissions. Furthermore, rosemary extract significantly enhanced the immune function of British Shorthair cats (p < 0.05). This study suggests that rosemary extract, particularly its fractions below 100 Da, is a highly promising pet deodorizer. Full article

Organohalide-respiring bacteria (OHRB) facilitate the reductive dehalogenation of toxic halogenated compounds in the environment, which supports their growth and proliferation. Research conducted on OHRB has achieved notable advancements. However, given the intricacy of the ecosystem and the methodologies employed for microbial isolation, numerous constraints persist. Further exploration is imperative to elucidate the physiological characteristics, ecological functions, and technological applications of OHRB. This study aimed to evaluate the outcomes and insights of prior research via a bibliometric analysis of three obligate OHRB genera—Dehalococcoides, Dehalobacter, and Dehalogenimonas—over a three-decade period from 1994 to 2024, based on the Web of Science (WOS) database. The results show that research on these three bacterial genera has advanced in sequence since the initiation of studies in this field. The research area encompasses the identification and isolation of novel OHRB species, the gene sequencing of related enzymes, and the role of microorganisms in the remediation of environmental pollutants, reflecting a gradual transition from individual investigations of OHRB to the applications of microorganisms in remediating complex environmental pollution. This study systematically reviewed the past research history of this field and conducted an in-depth analysis of research hotspots. The integration of this analysis with technological development trends and practical application requirements provides a theoretical basis and innovative concepts for future research directions in the field of ecological environment restoration. Full article

Broccoli stalks are considered an agro-industrial by-product that, in the context of fresh consumption, is undervalued, as only broccoli florets are typically marketed. This study evaluated the up-cycling of broccoli stalks into a value-added fresh-cut product through postharvest preservation strategies. Stalks were peeled, cut into sticks (8 × 8 mm × 50–100 mm), sanitised, packaged under modified atmosphere conditions, and stored at 5 °C. Treatments included (a) calcium ascorbate (CaAsc, 1% w/v), (b) trehalose (TREH, 5% w/v), (c) hot water treatment (HWT, 55 °C, 1 min), and several combinations of them. HWT alone was highly effective in reducing browning, a key factor for achieving an extended shelf-life, controlling microbial growth and respiration, and obtaining the highest sensory scores (appearance = 7.3 on day 11). However, it was less effective in preserving bioactive compounds. The HWT + CaAsc treatment proved to be the most effective at optimising quality and retaining health-promoting compounds. It increased vitamin C retention by 78%, antioxidant capacity by 68%, and total phenolic content by 65% compared to the control on day 11. This synergistic effect was attributed to the antioxidant action of ascorbic acid in CaAsc. TREH alone showed no preservative effect, inducing browning, elevated respiration, and microbial proliferation. Overall, combining mild thermal and antioxidant treatments offers a promising strategy to valorise broccoli stalks as fresh-cut snacks. An 11-day shelf-life at 5 °C was achieved, with increased content of health-promoting bioactive compounds, while supporting circular economy principles and contributing to food loss mitigation. Full article

The substrate-induced respiration-inhibition (SIRIN) method has been used to estimate fungi-derived N₂O emissions, but its contribution to soil N₂O emissions remains unclear. There is a need to quantify the fungal fraction of N₂O production more precisely. Here, using isotopocule analysis, we assessed the relative contribution of fungi to soil N₂O production potential under denitrifying conditions, where key limiting factors of denitrification (soil moisture, soil NO₃⁻, and electron donor) were removed. The result showed that the ratio of fungi-derived N₂O emissions (R_F) was 0.83~4.28% in paddy soils, 13.80~23.21% in vineyard soils, and 15.34~65.94% in vegetable field soils, respectively. This indicated that the bacteria were the dominator of soil N₂O production potential in most cases, but fungal pathways could be significant in vegetable field soils. The experiment with bactericide addition showed that inhibitors could affect non-target microorganisms in the SIRIN method. Our further analyses suggest that it is worth to explore the effect of soil organic carbon and microbial synergies on fungi-derived N₂O emissions. Full article

Soil degradation and declining fertility threaten sustainable agriculture and crop productivity. This study evaluates the effects of CFMI-8, a co-fermented microbial inoculant comprising eight bacterial strains selected through genomic and metabolic modeling, on soil health, nutrient availability, and corn performance. Conducted in a randomized complete block design at Findlay Farm, Wisconsin, the field trial assessed soil biological activity, nutrient cycling, and crop yield responses to CFMI-8 treatment. Treated soils exhibited significant increases in microbial organic carbon (+224.1%) and CO₂ respiration (+167.1%), indicating enhanced microbial activity and organic matter decomposition. Improvements in nitrate nitrogen (+20.2%), cation exchange capacity (+23.1%), and potassium (+27.3%) were also observed. Corn yield increased by 28.6%, with corresponding gains in silage yield (+9.6%) and nutritional quality. Leaf micronutrient concentrations, particularly iron, manganese, boron, and zinc, were significantly higher in treated plants. Correlation and Random Forest analyses identified microbial activity and nitrogen availability as key predictors of yield and nutrient uptake. These results demonstrate CFMI-8’s potential to enhance soil fertility, promote nutrient cycling, and improve crop productivity under field conditions. The findings support microbial inoculants as viable tools for regenerative agriculture and emphasize the need for long-term studies to assess sustainability impacts. Full article

This study presents an integrated approach to sustainable soil and crop management by evaluating the individual and combined effects of cow manure (CM), rice husk biochar (RHB), and potassium humate (KH)—three underutilized, low-cost organic amendments derived from agricultural byproducts. Uniquely, it investigates how these amendments simultaneously affect soil physical and chemical properties, plant growth, and the accumulation of bioactive compounds in sunflower sprouts, thereby linking soil health to crop nutritional quality. The application of 2% w/w KH alone resulted in the greatest increases in macroaggregation (+0.51), soil pH (from 6.8 to 8.6), and electrical conductivity (+298%). The combination of 1% w/w CM and 2% KH led to the highest increases in soil organic carbon (OC, +62.9%) and soil respiration (+56.4%). Nitrate and available phosphorus (P) peaked with 3% w/w RHB + 2% KH (+120%) and 1% w/w CM + 0.5% KH (+35.5%), respectively. For plant traits, 0.5% w/w KH increased the total leaf area by 61.9%, while 1% w/w CM enhanced shoot and root biomass by 60.8% and 79.0%, respectively. In contrast, 2% w/w KH reduced chlorophyll content (−43.6%). Regarding bioactive compounds, the highest total phenolic content (TPC) was observed with 1% w/w KH (+21.9%), while the strongest DPPH antioxidant activity was found under 1% w/w CM + 1% w/w KH (+72.6%). A correlation analysis revealed that biomass production and secondary metabolite accumulation are shaped by trade-offs arising from resource allocation under stress or nutrient limitations. Potassium, P, soil microbial respiration, and OC emerged as key integrators connecting soil structure, fertility, and plant metabolic responses. Overall, the combination of 1% w/w CM with 0.5–1% w/w KH proved to be the most effective strategy under the tested conditions. Full article

This study evaluated the effects of different types and rates of locally produced organic residues on soil organic matter (SOM) and soil health in highly degraded loamy soils of olive orchards in arid southern Tunisia. Three residues were tested: poultry manure, raw date palm waste, and composted date palm waste mixed with manure. A randomised field trial was conducted over three years. Two years after application, soil samples were analysed for physical and chemical properties, basal respiration, nitrogen mineralisation, microbial biomass, enzyme activities (dehydrogenase, phosphomonoesterase, β-glucosidase, urease, arylsulphatase), and community-level physiological profiles. All residues increased SOM and available phosphorus (Pi), with dose-dependent effects sustained over time, though significant increases were only observed at the highest application rates. The most notable improvements occurred in soils amended with composted date palm waste. In contrast, biological and biochemical parameters showed little response, even after remoistening to stimulate microbial activity. This limited response was attributed to the absence of vegetation and, consequently, of root exudates and plant residues. This will be further investigated by assessing changes in the same biological and biochemical properties following the implementation of an intercropping system, which is expected to enhance both SOM content and microbial activity in these soils. Full article

Acid deposition, a major environmental issue causing soil acidification and microbial suppression, impacts forest nutrient cycling. Meanwhile, nitrogen (N) fertilization is widely applied in subtropical forests, yet its interaction with acid deposition on litter decomposition is unclear. We conducted a field experiment using two common tree species, Cunninghamia lanceolata and Cinnamomum camphora, and applied three acid deposition levels (0, 0.25, and 0.50 g H⁺ m⁻² month⁻¹) and four N fertilization levels (0, 3, 6, and 9 g N m⁻² year⁻¹) in a factorial design. Our results showed that acid deposition alone significantly reduced litter decomposition rates, with maximum mass loss decreasing by 23.6% for Cunninghamia and 36.3% for Cinnamomum (p < 0.05). Urea fertilization alone also suppressed decomposition, reducing maximum mass loss by 27.3% for Cunninghamia and 37.3% for Cinnamomum (p < 0.05). However, when combined, urea fertilization mitigated the suppressive effect of acid deposition, particularly under severe acid conditions, where maximum mass loss increased by 18.5% for Cunninghamia and 43.1% for Cinnamomum (p < 0.05). Acid deposition reduced microbial respiration and enzyme activities related to carbon cycling, while urea fertilization showed both positive and negative effects depending on the acid levels (p < 0.05). Urea can enhance the litter layer’s acid-buffering capacity, offering potential management insights for acid deposition-affected forests. Further research on microbial mechanisms across ecosystems is recommended. Full article

Although the benefits of rational grazing by polygastric animals are well known, little is understood about how chicken grazing affects soil biological health and its capacity to store organic matter. This study aimed to assess the impact of long-term free-range chicken grazing in an olive grove on the soil chemical and biochemical properties, including the total organic carbon (TOC), total nitrogen (TN), microbial biomass (Cmic), basal respiration, and microbial community structure, as well as the soil’s capability to stock organic carbon and total nitrogen. A field experiment was conducted in an olive grove grazed by chickens for over 20 years, with the animal load decreasing with distance from the poultry houses. At 20 m, where the chicken density was highest, the soils showed reduced OC and TN contents and a decline in fungal biomass. This was mainly due to the loss of both aboveground vegetation and root biomass from intensive grazing. At 50 m, where grazing pressure was lower, the soil OC, TN, and microbial community size and activity were similar to those in a control, ungrazed area. These findings suggest that high chicken density can negatively affect soil health, while moderate grazing allows for the recovery of vegetation and soil organic matter. Rational management of free-range chicken grazing, particularly through the control of chicken density or managing grazing time and frequency, is therefore recommended to preserve soil functions and fertility. Full article

Postbiotics, which are non-viable microbial derivatives including short-chain fatty acids (SCFAs), microbial peptides, and cell wall components, are emerging as novel therapeutic agents for Inflammatory Bowel Disease (IBD). Unlike probiotics, postbiotics offer a safer, more stable alternative while retaining potent bioactivity. IBD, encompassing Crohn’s disease and ulcerative colitis, is characterized by chronic gastrointestinal inflammation, epithelial barrier dysfunction, and immune dysregulation. Recent evidence links mitochondrial dysfunction marked by impaired energy metabolism, oxidative stress, and apoptosis with the pathogenesis and persistence of IBD. Postbiotics have shown the ability to modulate mitochondrial health through multiple mechanisms. SCFAs such as butyrate serve as primary energy substrates for colonocytes, enhancing mitochondrial respiration and promoting biogenesis. They improve mitochondrial function and boost ATP production. Moreover, postbiotics reduce oxidative damage by regulating antioxidant defenses. These antioxidant actions limit epithelial apoptosis and preserve cellular integrity. In addition, postbiotics regulate mitophagy and help maintain mitochondrial quality and reduce inflammation. Structural components such as lipoteichoic acid and peptidoglycan have been shown to interact with mitochondrial pathways and modulate inflammatory responses. Collectively, this review explores the interplay between mitochondrial dysfunction, IBD, and preventive approach using postbiotics. Understanding the connections with postbiotics could open up new avenues for therapeutic interventions aimed at mitigating IBD severity in people with IBD. Full article

Drinking water biofilm ecosystems harbor complex and dynamic prokaryotic and eukaryotic microbial communities. However, little is known about the impact of copper corrosion on microbial community functions in metabolisms and resistance. This study was conducted to evaluate the impact of upstream Cu pipe materials on downstream viable community structures, pathogen populations, and metatranscriptomic responses of the microbial communities in drinking water biofilms. Randomly transcribed cDNA was generated and sequenced from downstream biofilm samples of either unplasticized polyvinylchloride (PVC) or Cu coupons. Diverse viable microbial organisms with enriched pathogen-like organisms and opportunistic pathogens were active in those biofilm samples. Cu-influenced tubing biofilms had a greater upregulation of genes associated with potassium (K) metabolic pathways (i.e., K-homeostasis, K-transporting ATPase, and transcriptional attenuator), and a major component of the cell wall of mycobacteria (mycolic acids) compared to tubing biofilms downstream of PVC. Other upregulated genes on Cu influenced biofilms included those associated with stress responses (various oxidative resistance genes), biofilm formation, and resistance to toxic compounds. Downregulated genes included those associated with membrane proteins responsible for ion interactions with potassium; respiration–electron-donating reactions; RNA metabolism in eukaryotes; nitrogen metabolism; virulence, disease, and defense; and antibiotic resistance genes. When combined with our previous identification of biofilm community differences, our studies reveal how microbial biofilms adapt to Cu plumbing conditions by fine-tuning gene expression, altering metabolic pathways, and optimizing their structural organization. This study offers new insights into how copper pipe materials affect the development and composition of biofilms in premise plumbing. Specifically, it highlights copper’s role in inhibiting the growth of many microbes while also contributing to the resistance of some microbes within the drinking water biofilm community. Full article