Search Results (480)

This study aimed to isolate and identify fungi capable of producing xylanases and cellulases. Thirty-eight fungal strains were isolated from decaying water hyacinth (WH), and two were selected based on their superior enzyme production under solid-state fermentation (SSF). The strains were identified through morphological, cultural, and molecular analyses as Aspergillus austwickii B6 and Trichoderma harzianum M7. Their ribosomal ITS sequences were deposited in GenBank under accession numbers PQ142799.1 for A. austwickii B6 and PQ007458.1 for T. harzianum M7. Enzyme production was evaluated under SSF using eight culture medium variants prepared with natural or pretreated biomasses of WH and sugarcane bagasse (SCB), combined with either NaNO₃ or (NH₄)₂SO₄ as nitrogen sources. The maximum xylanase and cellulase activities were 752 and 65 U/g dry matter (DM), respectively, for A. austwickii B6, and 1724 and 152 U/g DM for T. harzianum M7, when cultivated on a low-cost medium composed of pretreated WH, (NH₄)₂SO₄, and a simple mineral salt solution. These findings highlight the potential of locally isolated fungal strains and lignocellulosic residues as cost-effective substrates and inducers of xylanase and cellulase production under SSF and underscore the importance of WH pretreatment to enhance substrate availability and maximize enzyme yields. Full article

Xylanase, an essential enzyme for breaking down xylan, faces limitations in its industrial applications due to the relatively low catalytic activity of the wild type. Directed evolution was used to enhance the catalytic efficiency of xylanase that originated from the Dickeya dadantii DCE-01. A xylanase variant (Xyn-ep) was obtained with improved catalytic activity by random mutant library employing two rounds of error-prone PCR. The results showed that the Xyn-ep demonstrated enzyme activity 1.6 times higher than that of wild-type xylanase. Sequencing analysis pinpointed key mutation sites at S159P, K212N, and N397S, respectively. Homology modeling was used to analyze the location of the mutation sites and to investigate the mechanism of the improved catalytic performance. The mutant Xyn-ep showed improved catalytic performance by error-prone PCR. Additionally, the increased flexibility of the loop of the mutant may contribute to the enhanced activity. These findings indicate that error-prone PCR is an effective method for enhancing enzyme activity and that the mutant Xyn-ep may be a new GH30 xylanase, being a potential candidate for industrial applications such as bast fiber bio-degumming, cotton bio-refinery, paper making, and so on. Full article

Water hyacinth is an invasive weed that can valorize through the production of hydrolytic enzymes via solid-state culture. This study explores the application of Trichoderma harzianum in producing xylanases and endoglucanases on water hyacinth beds. Laboratory-scale packed-bed column bioreactors (PBCBs) with a capacity of 8 grams of dry mass (g_dm) were used to evaluate the effects of temperature (28–36 °C) and initial moisture content (65–80%) on microbial growth and enzyme production. High yields of biomass and enzymes were produced at 30 °C. Moreover, xylanase activity was enhanced in cultures with a moisture content of 65% (~71.24 U/g_dm), and endoglucanase activity at 75–80% moisture (~20.13 U/g_dm). The operational conditions identified for xylanase production were applied to 6 L bench-scale cross-flow internally stirred bioreactors, packed to 40% capacity with 450 g_dm. Two stirring regimes were tested: intermittent and continuous. The results showed that continuous stirring promotes both microbial growth and xylanase activity. In fact, xylanase activity in continuous stirring conditions was comparable to that achieved in PBCBs. Consequently, continuous stirring enables a 56-fold increase in bioreactor capacity without compromising xylanase production. The approaches developed in this study can support the design of large-scale bioprocesses for the valorization of water hyacinth. Full article

Sustainable development requires implementation of eco-friendly practices and a circular approach in both agricultural and industrial systems. This study evaluated winery flotation wastewater (WFW) as a cultivation substrate for Bacillus sp. 10/R isolated from grapevine rhizosphere for sustainable biostimulant production. The bacterial isolate was characterized by 16S rRNA sequencing and biochemical tests, showing the highest similarity with Bacillus mojavensis and Bacillus halotolerans. Plant growth-promoting traits were assessed via assays for hydrolytic enzymes, ACC (1-aminocyclopropane-1-carboxylate) deaminase, and IAA (indole acetic acid) production, as well as for phosphate solubilization. The isolate was cultivated in WFW, including monitoring of biomass growth, enzymatic activity, and substrate composition changes. The resulting cultivation broths based on WFW (WFW-CB) and nutrient broth (NB-CB) were tested as barley seed treatment at five dosages, using sterile media and water as controls. The results have displayed strong pectinase (EAI–enzyme activity index 2.79) and cellulase activity (2.33), moderate xylanase (1.75) and ACC deaminase activity (growth zone 54.67 ± 0.58 mm), and moderate IAA production (9.66 µg/mL). Biomass content has increased by two log units within 48 h (up to 9.06 log CFU/mL), with stable pectinase activity (~2.2 U/mL). Germination assays revealed that 10% WFW-CB and 50% WFW enhanced germination indices and biomass, whereas undiluted WFW and WFW-CB inhibited germination. These results indicate that WFW is a suitable substrate for Bacillus sp. 10/R cultivation, linking industrial wastewater valorization with plant biostimulant production in a circular economy framework. Full article

In recent years, in response to the demand for the livestock industry to enhance cattle production performance, scholarly inquiries have centered on elucidating the underlying mechanisms by which feed additives modulate rumen microenvironment and metabolic efficacy, thereby facilitating nutrient absorption and augmenting production performance in cattle. This study was undertaken to evaluate the impacts of surfactant polyacrylamide (PAM) supplementation on digestive processes, metabolic dynamics, and ruminal digestive enzyme activities in cattle. Four ruminally cannulated crossbred cows (~3 years, 350 kg, non-pregnant/lactating) were utilized in a 4 × 4 Latin square design. The animals were fed a basal diet supplemented with polyacrylamide (PAM) at concentrations of 0, 1.0, 2.0, and 6.0 g/kg across four 22-day experimental periods, each consisting of a 16-day adaptation phase and a 6-day sampling phase. Supplementation with polyacrylamide (PAM) at levels ranging from 1.0 to 6.0 g/kg of diet significantly increased voluntary dry matter intake (VFI) in cattle by a maximum of 13.7% (p < 0.05), with peak effects at 2.0 g/kg. The digestibility of dry matter, crude protein, cellulose, and energy was significantly improved (p < 0.05 to p < 0.01), reaching maximum increases by 12.6%, 12.8%, 17.5%, and 11.7%, respectively. Nitrogen, calcium, and phosphorus retention increased substantially (p < 0.01 to p < 0.05), with calcium retention showing the highest improvement (55.7%). Rumen cellulase activities (endocellulase, exocellulase, cellobiase, and xylanase) were significantly enhanced (p < 0.01), peaking at 37.3% for cellobiase. However, pectase, amylase, and protease activities remained unaffected. Optimal benefits were observed at 2.0 g/kg PAM, highlighting its potential to improve feed efficiency and nutrient utilization in cattle. Full article

The resource utilization of peach wood as agricultural waste holds significant importance for the sustainable development of the edible fungi industry, yet its regulatory effects on the physiology and safety of Lentinula edodes (L. edodes) remain unclear. This study selected four L. edodes (F2, 0912, N5, and 215) and systematically analyzed their cultivation adaptability across five peach wood substrate proportions (0%, 20%, 40%, 60%, and 80%). Results indicated that while high peach wood proportions inhibited laccase activity and delayed mycelial growth, high carboxymethyl cellulase and xylanase activity formed a critical compensatory effect, ultimately enhancing total yield. Peach wood improved production through strain-specific mechanisms. F2 increased via single mushroom weight gain, while N5 relied on xylanase-driven primordia differentiation to boost mushroom numbers. Adding peach wood significantly increased crude protein, crude lipid, and total polysaccharide in F2, maintaining normal agronomic traits and increasing secondary mushroom proportion. Safety risks focused on arsenic accumulation, with 80% peach wood causing F2 to exceed control levels, albeit remaining far below the national standards. This study is among the first to elucidate peach wood’s temporal enzyme regulation for the maintenance of L. edodes yield. Future optimization through peach wood pretreatment and low arsenic strain selection could provide technical support for the high value utilization of agricultural waste. Full article

Calocybe gambosa (Fr.) Donk is an edible mushroom, highly appreciated especially in Italy. It forms fairy rings (FRs) characterized by a zone of dead vegetation corresponding to the underground-extending mycelial front, followed by a “greener belt” where vegetation is thriving. To better understand this particular phenomenon, the effect of C. gambosa mycelium on plants were studied both in situ, across different zones of FRs (external area—EX, fungal front—FF, greener belt—GB, internal area—IN) of three fairy rings, and ex situ on Poa trivialis L. Plant community analysis revealed significant changes in plant species composition across the zones, characterized by a decline in diversity and a vegetation shift, from dicotyledons to monocotyledons, progressing from the EX toward the IN, where vegetation gradually begins to reestablish its original composition. Molecular and morphological analyses showed the endophytic colonization of C. gambosa mycelium within the herbaceous plants growing at the FF. Ex situ studies indicated pathogenic behavior of C. gambosa. After root colonization, it caused growth reduction in P. trivialis plants (79% reduction in root length, 76% reduction in leaf length), leaf yellowing, decreased photosynthetic pigments, and root necrosis. The cellulase (endo-1,4-β-glucanase), xylanase, polygalacturonase, and polymethylgalacturonase enzymatic activities of C. gambosa support its pathogenic effects. Conversely, volatile organic compounds (VOCs) produced by C. gambosa mycelium stimulated shoot development in P. trivialis (17% increase in shoot length), which accounts for the formation of the flourishing vegetation zone behind the FF. In contrast, soluble substances produced by C. gambosa mycelium did not affect the growth of P. trivialis. Our results suggest that C. gambosa plays a dual ecological role in regulating plant community dynamics within FRs: it acts as a pathogen by colonizing herbaceous plant roots and, at the same time, promotes vegetation growth through VOC production. Full article

An experiment was conducted to evaluate the effects of mixed lactic acid bacteria (LAB) plus fibrolytic enzymes (xylanase + β-glucanase) on bacterial and fungal communities in terminal and aerobically exposed whole-plant corn silage ensiled in a temperate zone. Short-season corn forage was either uninoculated (C) or inoculated (I) with a mixture of LAB containing 1.5 × 10⁵ colony-forming units (cfu)/g Lentilactobacillus hilgardii, 1.5 × 10⁵ cfu/g of Lentilactobacillus buchneri, and 1.0 × 10⁵ cfu/g Pediococcus pentosaceus plus a combination of xylanase + β-glucanase. Silage samples were taken after ensiling in bag silos for 418 days (terminal silage; TS), with subsamples of TS subsequently exposed to air for 14 days (aerobically exposed silage; AS). Regardless of treatment, Firmicutes, Proteobacteria, Cyanobacteria, and Actinobacteria were the predominant phyla in the bacterial microbiome, whilst Ascomycota and Basidiomycota were the predominant phyla in the fungal microbiome in both TS and AS. Lactobacillus, Acetobacter, and Bacillus were the most abundant bacterial genera, whilst Candida, Aspergillus, Vishniacozyma, Pichia, and Issatchenkia were the most abundant fungal genera. Use of silage additive did not change bacterial or fungal alpha or beta diversity during ensiling or aerobic exposure, but decreased (p < 0.01) the relative abundance (RA) of Proteobacteria in both TS and AS, increased (p < 0.01) RA of Firmicutes in AS, but did not affect the RA of fungal phyla in either TS or AS. At the genus level, the additive significantly decreased (p < 0.01) RA of Acetobacter in both TS and AS. The silage additive used in this study significantly affected the composition of multiple microbial genera during ensiling and aerobic exposure by shifting bacterial communities towards enhanced aerobic stability. Full article

Native yeasts are a promising microbial resource for the development of sustainable biorefineries. In this study, we isolated 30 yeast strains from soil, decaying wood, and tree bark in a preserved Araucaria Forest in Southern Brazil and characterized them phenotypically and taxonomically. All strains were able to grow on glucose, xylose, and cellobiose, and 50% of them could metabolize arabinose. Several isolates showed high growth rates on xylose (up to 0.47 h⁻¹) and cellobiose (up to 0.45 h⁻¹). Notably, 19 strains (63% of the analyzed yeasts) exhibited xylanase activity at 50 °C (up to 156.84 U/mL), and four strains (13%) showed significant cellulase production. β-Glucosidase activities were particularly high in permeabilized cells of CHAP-258, CHAP-277, and CHAP-278 (up to 584.33 U/mg DCW), with kinetic parameters indicating high enzymatic performance. Twelve strains (40% of the total) were classified as oleaginous, and three (10%) displayed both lipogenic and esterase activity. Lipase activity against p-nitrophenyl palmitate (pNPP) reached 55.55 U/mL in CHAP-260. Taxonomic identification revealed representatives of seven genera, including Meyerozyma, Papiliotrema, Scheffersomyces, and Sugiyamaella, with potential for biotechnological use. Overall, the biochemical diversity observed highlights the value of native yeasts from Araucaria Forests as biocatalysts for lignocellulose-based bioprocesses, particularly due to their ability to grow on pentoses, secrete hydrolytic enzymes, and accumulate lipids. Full article

A 28-day study involving 448 male Ross 308 broilers aimed to determine the effect of dietary rice bran (RB) and xylanase (XYL) in maize- and wheat-based diets on chicken growth, N-corrected apparent metabolizable energy (AMEn), and nutrient availability. Two isonitrogenic and isocaloric maize- or wheat-based basal diets (BDs) were formulated matching breeding recommendations. Each diet was then split in four parts: two parts BD was substituted with 75 g/kg RB and then one of the RB substituted and one of the original parts was supplemented with 16,000 XYL units/kg, resulting in a total of eight experimental dietary treatments. Each diet was fed to seven pens of eight birds per pen following randomization. The data were analyzed by ANOVA using a 2 × 2 × 2 factorial design (cereal type × RB × XYL). Enzyme supplemented RB-free wheat-based diet had greater AMEn (p = 0.002) and fiber digestibility (p = 0.007) compared to the rest. Feeding RB reduced daily feed intake (p = 0.015) and weight gain (p < 0.001) of chicks. Birds fed wheat-based diets had greater feed efficiency, coupled with an increase in starch digestibility (SD) and energy conversion ratio (ECR). The observed differences in feed efficiency were explained only by SD and ECR. Full article

This study evaluates the effects of two Trichoderma reesei exogenous fibrolytic enzyme (EFE) preparations on the taxonomic profile, diversity, relative abundance, and population shifts of three ruminal bacteria fractions of lactating cows: free-floating (LIQ), weakly (AS), and tightly (SOL) feed-adhered. Three lactating cows were fed three EFE treatments in a 3 × 3 Latin square design: one control (CON) without enzymes, a cellulase/xylanase mix (MIX), and a high-xylanase treatment (XYL). Rumen contents were collected, and bacteria were extracted from the three ruminal content fractions for next-generation sequencing analysis. Alpha diversity was higher in XYL compared to CON. However, no EFE effect was observed on beta diversity. The relative abundance (RA) of the family Prevotellaceae increased, while that of Ruminococcaceae and Rikenellaceae decreased in XYL compared to MIX and CON. The bacterial community structure (beta diversity) of LIQ was differentiated from that of SOL and AS (p = 0.03), but no effects of fraction were observed on alpha diversity. Lachnospiraceae RA was greater in SOL, followed by AS, and lower in LIQ (p < 0.001), while Spirochaetaceae RA was greater in SOL and AS compared to LIQ (p = 0.003). The effects of EFE supplementation on rumen bacterial RA were independent of the ruminal content fraction. Full article

Microbial enzymes, due to their efficiency, specificity, and sustainability, are central to innovative biotechnological strategies aimed at optimizing industrial processes such as winemaking. In this study, the potential of Aureobasidium pullulans m11-2, a native dimorphic fungus from the wine ecosystem, was evaluated as a source of hydrolytic enzymes capable of degrading grape cell wall polysaccharides. The strain was identified at the molecular level and characterised in terms of its morphology. To maximise enzyme production, various culture media were tested. Among the concentrations tested, the optimal levels of glucose and pectin were 1 g L⁻¹ and 10 g L⁻¹, respectively. The partially constitutive and inducible nature of the various polysaccharidase activities (pectinases, cellulases, and xylanases) was confirmed. The effect of grape skins (a winemaking by-product) on microbial growth and enzyme synthesis was evaluated, achieving a pectinase activity of 0.622 U mL⁻¹ when combined with 1 g L⁻¹ of glucose. Maximum enzyme yields were detected during the exponential growth phase in both citrus pectin and grape skin media, suggesting favorable conditions for continuous bioprocessing. These results confirm that A. pullulans m11-2 is an interesting microbial option for producing polysaccharidases that can be adapted to sustainable production systems. Full article

The velvet complex is a master regulator of multiple physiological processes in filamentous fungi. In this study, we characterized the functions of velvet gene FpvelC in Fusarium proliferatum, which was the causative agent of rice spikelet rot disease. Compared with the wild-type Fp9 strain, deletion of FpvelC hindered conidiation, leading to a low level of trehalose content but excessive accumulation of chitin in conidia. Lack of FpvelC resulted in increased sensitivity to oxidative stress and decreased expression of antioxidant genes. Notably, ΔFpvelC exhibited attenuated pathogenicity on rice and maize, failure to produce invasive hyphae, and downregulation of genes encoding xylanases and xyloglucanases during infection processes. Nevertheless, disruption of FpvelC enhanced production of fumonisin B1 (FB1) and fusaric acid concomitantly; transcripts of the clustering genes responsible for the two mycotoxins’ biosynthesis were significantly increased. Additionally, the absence of FpvelC was displayed as more sensitive to rapamycin than the Fp9 strain, accompanied with less intracellular glutamine. Overall, FpvelC played versatile roles in conidiation, response to oxidative stress, pathogenicity and mycotoxins production in F. proliferatum. Full article

The use of exogenous enzymes in the nutrition of dairy cows is an innovative and efficient strategy to maximize productivity and milk quality, with positive applications in the economic and environmental aspects of dairy farming. Therefore, the objective of this study was to evaluate whether the addition of a blend of exogenous enzymes to the diet of lactating Jersey cows has a positive effect on productive performance, milk quality, animal health, ruminal environment, and digestibility. Twenty-one primiparous Jersey cows, with 210 days in lactation (DL), were used. The exogenous enzymes used were blends containing mainly protease, in addition to cellulase, xylanase, and beta-glucanase. The animals were divided into three groups with seven replicates per group (each animal being the experimental unit), as follows: Control (T-0), basal diet without enzyme addition; Treatment (T-80), animals fed enzymes in the diet at a daily dose of 80 mg per kg of dry matter (DM); Treatment (T-160), animals fed enzymes in the diet at a daily dose of 160 mg per kg of DM. The study lasted 84 days, during which higher milk production was observed in the treated groups (T-80 and T-160) compared to the control group (p = 0.04). When calculating feed efficiency from days 1 to 84, greater efficiency was observed in both groups that received the blend compared to the control (p = 0.05). In the centesimal composition of the milk, it was observed that the percentage of protein in the milk of the T-160 group was higher compared to the control group (p = 0.03). The effect of the enzymes was verified for butyric (p = 0.05) and palmitic (p = 0.05) fatty acids. We also observed the effect of the enzyme blend on the amount of volatile fatty acids (VFAs), which were higher in the ruminal fluid of cows that received the enzymes (p = 0.01). Cows that consumed enzymes showed a higher apparent digestibility coefficient of crude protein (p = 0.01). In vitro, the main result is related to lower gas production in 24 and 48 h at T-160. We concluded that the use of a blend of exogenous enzymes in the diet of lactating Jersey cows was able to increase milk production in these animals, resulting in greater feed efficiency and also an increase in milk protein content, positively modulating the fatty acid profile in the rumen and improving the apparent digestibility of nutrients. Full article

Using wheat flour milling (WFM) co-products in pig diets may reduce feed cost. Still, energy digestibility is lower for WFM co-products than for feed grains. Inadequate information exists about their fermentation characteristics and the relationship between digestible energy (DE) value and chemical characteristics or in vitro energy digestibility. The objectives were to (1) determine the chemical characteristics, in vitro and in vivo DE values, and energy digestibility of WFM co-products in growing pigs; (2) determine their in vitro microbial fermentation characteristics, and (3) establish relationships between in vivo DE value of WFM co-products and their chemical composition, fermentation characteristics, or in vitro digestibility values. Across Canada, 94 WFM co-products were sampled and characterized for their chemical composition and in vitro dry matter (DM) and energy digestibility using pepsin, pancreatin, and a multi-enzyme complex containing arabinase, β-glucanase, hemicellulase, xylanase, and cellulase. The in vivo energy, DM digestibility and DE value of 9 WFM co-products (2 shorts, 5 millrun, 1 middling, and 1 bran) were determined using a corn-based diet and 40 growing pigs in two periods to obtain 8 observations per diet. After in vitro digestion, the 9 WFM co-product samples were subjected to microbial fermentation using fresh fecal inoculum in a cumulative gas-production technique. The WFM co-products had a high content of crude fiber (up to 7.9% in shorts, 9.9% in millrun, 7.1% in middlings, and 12.0% in bran) and crude protein (CP; up to 27.8% in shorts, 20.0% in millrun, 22.1% in middlings, 15.9% in bran). The DE values ranged from 2.84 to 3.74 Mcal/kg DM among WFM co-products. Among chemical characteristics, neutral detergent fiber was the best predictor (R² = 0.81) for in vivo DE value, followed by crude fiber (R² = 0.78), and acid detergent fiber (R² = 0.72). The in vitro DE values predicted (R² = 0.80) in vivo DE values of 9 WFM co-products. Based on principal component analysis, total gas and short-chain fatty acid production varied among WFM co-products and was associated with the CP content of WFM co-products. In conclusion, WFM co-products contain high crude protein and have a high DE value for growing pigs but vary substantially in nutritional value. Full article