Search Results (333)

Essential oils (EOs) have gained recognition as promising alternatives to antibiotics due to their positive effects on bird growth performance, enhanced meat quality, and improved overall health, without producing the negative consequences associated with antibiotics. This study evaluated the effects of dietary supplementation of tea tree (TTEO) and thyme (TEO) EOs, individually or in combination with the probiotic BioPlus 2b (Bacillus subtilis and Bacillus licheniformis), on poultry broiler performance, including the meat quality. A total of 240 ROSS 308 broilers were assigned to eight dietary treatments over a 35-day trial. Parameters such as body weight (BW), feed conversion ratio (FCR), carcass portion, drip loss, and meat pH were evaluated. TTEO had a significant (p ≤ 0.05) impact on final carcass and breast portion, while in combination with probiotics, specifically TTEO with BioPlus significantly (p ≤ 0.05) reduced meat drip loss. GC-MS analysis identified terpinen-4-ol and γ-terpinene as the major constituents of TTEO, and thymol and carvacrol as the major constituents of TEO. In conclusion, combinations of TTEO, TEO, and probiotics can have beneficial effects on chicken raw meat quality, providing a complementary benefit to the industry and representing a viable alternative to conventional agents. Full article

The stability of spore-forming soil bacteria is crucial for their effective use in agricultural biopreparations. This study evaluated the long-term survivability of selected strains (Paenibacillus amylolyticus, Priestia megaterium, Bacillus velezensis, Bacillus subtilis, and Bacillus licheniformis) with potential applications in biopreparations for crop residue decomposition. The effects of different storage and preservation conditions on vegetative cells and bacterial spores were studied over 12 months. Bacteria were stored at different temperatures (15 °C, 21 °C, 30 °C), pH levels (5, 9, and post-cultivation liquid pH), and osmotic pressures (2%, 5%, and 10% of carbamide, calcium chloride, and multicomponent fertilizer). Additionally, freeze-drying, spray-drying and freezing were performed using cryoprotectants (skimmed milk, trehalose, and glycerol). The results showed that bacterial stability depended on both the strain and storage conditions. Vegetative cells of P. amylolyticus and B. velezensis were most sensitive to temperatures of 30 °C, whereas the spores of most strains demonstrated high temperature resistance. The tested strains exhibited better survivability at pH 5 than pH 9. The addition of calcium chloride, carbamide, or multicomponent fertilizer proved beneficial for maintaining viability, especially increasing spore numbers. Trehalose and skimmed milk were the most effective cryoprotectants overall, though efficacy varied by strain and cell form. These findings provide insight into the optimal conditions for preserving the bacterial viability of spore-producing bacteria in bioformulations, which is crucial for maintaining their effectiveness in agricultural applications. Full article

Using Bacillus licheniformis H107 as the initial strain, a novel complementary synbiotics production method was developed through comprehensive metabolic engineering strategies. Key modifications included the systematic analysis and reconstruction of the central carbon metabolism pathway through precise gene editing, targeting the deletion of pflB, alsS, ydaP, and pycA genes while disrupting ganA1 and ganA2 to block galactooligosaccharide (GOS) metabolism. Additionally, heterologous expression of the L-lactate dehydrogenase gene (BcoaLDH) was implemented, resulting in the engineered strain H107-06A. Shake-flask fermentation under anaerobic conditions with 20 g/L glucose yielded L-lactic acid production of 4.45 g/L, representing a 15.3-fold increase compared to the wild type. In a 5 L fermenter using GOS syrup as the carbon source, the engineered system synergistically produced complementary synbiotics, comprising L-lactic acid (42.56 g/L), GOS (141.89 g/L, accounting for 75.09% of total sugars), and viable cells (3.82 g/L). These findings provide a foundation for developing innovative and functional fermentation products. Full article

This study was conducted in two phases: first, to assess the impact of microbial fermentation on enhancing the nutritional quality of fish by-products, and second, to evaluate the effects of replacing fishmeal with these fermented by-products in the diet of Nile tilapia (Oreochromis niloticus) on growth performance, blood parameters, antioxidant indices, immunity, digestive enzyme activity, and carcass composition. In the initial phase, proteolytic activity of five bacterial strains including Bacillus subtilis (ATCC: 6051), B. licheniformis (IBRCM: 10204), Lactiplantibacillus plantarum (PTCCs: 1058 and 1745), and Lactobacillus casei (PTCC: 1608) was evaluated using growth assays in skimmed milk culture media and analyzed using Image-J software. B. licheniformis exhibited the highest proteolytic activity and was selected for fermentation. Resulting hydrolyzed proteins were characterized by peptides with molecular weights below 11 kDa. In the second phase, fishmeal was replaced with fermented by-products at five levels (0 (control), 25, 50, 75, and 100%). Two hundred ten Nile tilapia with an average weight of 2.83 ± 0.05 g were stocked in fifteen 200 L plastic tanks at three replicates, with 14 fish per tank, and fed daily at a rate of 7% of their body weight for 63 days. With increasing levels of fishmeal replacement (25% to 75%), significant improvements (p < 0.05) were observed in final weight gain, body weight gain, specific growth rate, protein production value, and protein efficiency ratio. Additionally, blood plasma concentrations of hormones T₃ and T₄, immunoglobulin level, the activities of complement (ACH₅₀), and antioxidant enzymes (catalase and superoxide dismutase) increased significantly in fish fed the diets with fermented by-products compared to those of the control diet (p < 0.05). The optimal replacement levels for specific growth rate and feed conversion ratio were identified as 86.28% and 83.91%, respectively. Full article

Biosurfactants are environmentally friendly alternatives for chemical surfactants and have a broad spectrum of applications in different industries such as cosmetics, oleochemistry, pharmaceuticals, and detergents. It has been established that Bacillus licheniformis produces several lipopeptide-type biosurfactants, including lichenysin and iturin. However, in order to enhance the biosurfactant production by Bacillus licheniformis, it is necessary to either extend the already performed media optimization to circumvent the current limitations or defeat the product inhibition. Cyclic oligosaccharides made of glucose monomers called cyclodextrins (CD) have been shown to improve the biomass synthesis of other microorganisms, which may also increase the output of biosurfactants. The efficient fermentative production of biosurfactants is often limited by the inhibitory/toxic effect of the product on the producer cells itself. Therefore, in this work, we demonstrated that CDs may entrap biosurfactants from the broth, decreasing product inhibition. Thus, we also tested the media supplementation with three different types of cyclodextrins including alpha-, beta-, and gamma-CD and a derivative (dimethyl-beta-cyclodextrin, DIMEB); notably, DIMEB at 2.0 g/L enhanced biosurfactant production by up to 41.43% and specific product formation (g product/g cells) by 79,6% compared to the control, while mitigating the growth inhibition observed at lower concentrations. This study demonstrates, for the first time, the distinct advantage of DIMEB over native CDs in reducing product toxicity and boosting biosurfactant yields, highlighting its potential as a simple additive strategy for improving sustainable bioprocesses. Full article

Food processing environments are prone to microbial contamination, where biofilm formation by persistent bacteria reduces hygiene and food safety. In this study, 27 biofilm-forming bacterial strains were isolated from processing equipment surfaces, with the dominant strains identified as B. cereus LE3, B. cereus YJBR3, and P. cibi F25. An environmental isolate, B. licheniformis YJE5, exhibited no hemolytic activity and demonstrated strong enzymatic potential. Intracellular substances (ICS) extracted from B. licheniformis YJE5, isolated from a food processing environment, significantly inhibited biofilm formation by B. cereus LE3, B. cereus YJBR3, and P. cibi F25 by 47–53% and degraded pre-formed biofilms by 37–44%. Light and confocal laser scanning microscopy confirmed pronounced structural degradation of biofilms following ICS treatment. API ZYM analysis further revealed multiple hydrolytic enzymes, indicating that enzymatic hydrolysis is central to biofilm degradation. Whole-genome sequencing showed a 4.3 Mbp chromosome with diverse metabolic pathways but no antibiotic resistance and virulence genes, confirming the strain’s safety. These findings suggest that B. licheniformis YJE5 represents a safe and eco-friendly candidate for controlling biofilm-associated contamination in food processing facilities. Full article

Azaleas (Ericaceae) are among the most diverse ornamental plants, celebrated for their cultural and economic significance. R. simsii has been extensively utilized in horticulture as a parent species for both “pot azalea” cultivars and various cultivars grown in the warmer regions of China. From 2021 to 2023, approximately 15% of R. simsii in nurseries situated in the Xuanwu District, Nanjing, exhibited symptoms of wilting and chlorosis. Investigations revealed that these symptoms were caused by a pathogen responsible for crown and root rot. Strains were isolated from the roots of affected plants. The morphology of the colonies was predominantly radial to stellate, characterized by intercalary and terminal hyphal swelling. The sporangia appeared spherical, pyriform, or ovoid with a single papillae. For accurate identification, the 28S rDNA gene (Large subunit, LSU), cytochrome oxidase subunit I (COXI), and cytochrome oxidase subunit II (COXII) genes were amplified through PCR and then sequenced. The species was identified as P. vexans after completing the phylogenetic analysis. Healthy R. simsii plants were infected with zoospores and developed symptoms similar to those of natural infection. Furthermore, the morphological characteristics of the isolates from the experimentally infected plants were similar to those of the original inoculated strains. This study identified P. vexans as the pathogen causing root rot in R. simsii. During the sampling process, several strains were isolated from the rhizosphere soil of healthy rhododendron plants. Based on this, research was immediately initiated to explore whether there are specific bacterial species in the soil that have the potential to inhibit the occurrence of root rot. Additionally, an endophytic bacterial strain BL1 was isolated from rhizosphere soil and subjected to Whole-Genome Shotgun (WGS) sequencing, thus constructing a bacterial genome framework for this isolate. The strain BL1 was identified as Bacillus licheniformis. To our knowledge, this is the first report of the occurrence of P. vexans causing crown and root rot of R. simsii in China. In this study, we also focused on exploring the potential of biological control agents against P. vexans. The isolation and identification of the endophytic bacterial strain BL1 (Bacillus licheniformis) from the rhizosphere soil of healthy soil show strong in vitro antagonism, identifying it as a promising candidate for future biological control studies of root rot in R. simsii. The genomic component analysis and coding gene annotation of BL1 provide insights into its genetic makeup and potential mechanisms of action against pathogens. However, these findings are based on in vitro assays. Therefore, further research, including in planta experiments, is essential to confirm the efficacy of BL1 in controlling P. vexans infections in R. simsii and to evaluate its potential for practical application. Full article

Tiliacora triandra (Yanang) leaf contains polyphenols, flavonoids, and mucilage polysaccharides with antioxidant and prebiotic functions, making it a promising substrate for probiotic fermentation. This study aimed to optimize Yanang extraction and sterilization to preserve bioactive mucilage and support probiotic survivability during freeze-drying–based encapsulation, and evaluate antimicrobial activity against poultry pathogens. Yanang extract was prepared under different leaf processing conditions and used as a substrate for Pediococcus acidilactici V202, Lactiplantibacillus plantarum TISTR 926, Streptococcus thermophilus TISTR 894, Bacillus subtilis RP4-18, and Bacillus licheniformis 46-2. Fermentation at 37 °C for 24 h revealed that lactic acid bacteria (P. acidilactici V202, L. plantarum TISTR 926, S. thermophilus TISTR 894) reduced pH (<4.10, p < 0.001) while maintaining high viable counts (>8.67 log CFU/mL, p < 0.01), whereas Bacillus strains (B. subtilis RP4-18, B. licheniformis 46-2) retained a higher pH (>5.00) and lower viability (<8.50 log CFU/mL). Total soluble solids decreased across treatments, with the lowest observed for B. subtilis RP4-18 (1.97 °Brix, p = 0.007). Freeze-dried probiotics encapsulated in enzyme-extracted rice bran carriers had comparable physicochemical properties (p > 0.05), while compared with Bacillus strains (p < 0.01), lactic acid bacteria had superior tolerance to simulated gastrointestinal and thermal stress. Supernatant from Yanang extract inhibited B. cereus WU22001, S. aureus ATCC25923, Escherichia coli ATCC25922, and Salmonella typhimurium WU241001 (MIC/MBC 25–50% v/v). These results indicate that Yanang extract supports effective probiotic fermentation, and rice bran encapsulation enhances survivability and antimicrobial functionality for potential functional feed applications. Full article

Cyclic lipopeptides (CLPs), produced by beneficial rhizobacteria such as Bacillus and Pseudomonas species, are specialized metabolites retaining key functions for the plant protective activity of the producers, which shows their potential as biocontrol agents in agriculture. Beyond their strong antimicrobial properties, CLPs can act as potent elicitors of plant immunity and systemic resistance. However, the molecular mechanisms underlying these immune-modulatory effects and the role of CLPs’ structural diversity remain poorly understood. Here, we demonstrate that specific structural features of surfactin-type CLPs critically influence their ability to trigger early immune responses in plants, including reactive oxygen species bursts, nitric oxide (NO) production, calcium fluxes, and systemic resistance. In Arabidopsis thaliana roots, we show that surfactin-induced NO generation requires calcium signaling. Moreover, we reveal that contrasting immune effects of CLPs may stem from the ecological lifestyles of their microbial producers, shedding light on the evolutionary basis of plant–microbe interactions. Altogether, our findings underscore the importance of CLP structural variation in shaping plant defense responses and highlight the potential for structure-informed design of next-generation biosourced small molecules with broad-spectrum efficacy as plant protectants. Full article

The aim of this study was to evaluate two proteases (P1 and P2) on the apparent and standardized ileal digestibility (AID and SID, respectively), of crude protein (CP) and amino acids (AAs) and apparent total tract digestibility (ATTD) of nutrients and gross energy (GE) of corn and soybean meal, with 46% and 48% CP, in pigs by the index method. Ninety crossbred castrated male piglets (13.52 ± 1.96 kg body weight) were fed a nitrogen-free diet, or diets containing corn or soybean meal as the sole sources of CP and AAs, supplemented or not with 0.05% of P1 or 0.01% of P2, an acid protease. Treatment differences were considered statistically significant at p < 0.05. The inclusion of proteases in corn and of P1 in soybean meal diets did not improve the digestibility of nutrients and energy. Otherwise, the addition of P2, an acid protease, in soybean meal diets increased (p < 0.05) the AID and SID of Lys, Met, Phe, Ala, Cys, and Glu, and the respective digestible AA values, from 7.5% to 22%, compared to soybean meal without proteases. The use of the acid protease can be an important tool to enhance the digestibility of the AAs of soybean meal in piglets. Full article

This research reports ruminal and fecal microbiota composition of lactating dairy cows enrolled in a study aimed at investigating the effects of a fermentation extract derived from Bacillus licheniformis (BLFE), monensin (Rumensin^®; R), and their interactions on feed efficiency (FE, FE = milk yield/DMI). In a completely randomized design, 48 Holstein cows at 108 ± 35 days in milk were matched for parity and assigned to monensin (0 or 17.6 g/kg of DM) and BLFE (0 or 166 mg/kg of DM) in a 2 × 2 factorial arrangement. Treatments were fed daily for 63 d, including a 21 d adaptation period followed by a 42 d measurement period (P2). On d 38 and d 39 of P2, rumen-fluid (RF) and fecal samples were collected. DNA from RF and feces was sequenced using 16S rRNA gene-amplicon sequencing on an Illumina MiSeq platform. Fecal and RF volatile fatty acid (VFA) concentrations were analyzed, and propionate/acetate (P: A) was determined. The BLFE increased milk yield (3.3 kg/d) and FE (1.20 to 1.28), when fed alone rather than with monensin, while monensin increased energy-corrected milk yield (2.5 kg/d, p < 0.05), regardless of the BLFE in the diet. The BLFE tended to increase ruminal Firmicutes/Bacteroidetes (F: B) when fed alone, while alpha and beta diversities remained unmodified. The BLFE increased the abundances of Bifidobacterium (p = 0.02) and Erysipelotrichaceae_UCG-002 (p = 0.01) in RF, whereas monensin increased and decreased the abundances of Oscillospirales_ge (p = 0.02) and an unclassified Clostridia genus (p = 0.03), respectively. The monensin-suppressed Clostridia were negatively associated with ruminal P: A (r = −0.66; p < 0.01) and feed efficiency (r = −0.30; p = 0.04). The BLFE and monensin interactively affected several fecal genera (p < 0.05), but they had negligible or weak correlations with fecal P: A and FE. Overall, the results showed the ability of dietary supplementations of monensin and BLFE to increase milk production performance and FE by modulating ruminal rather than lower-gut microbiota composition, this is predominantly attributed to the ratio between the Firmicutes and Bacteroidetes abundances in lactating dairy cows. Full article

In recent years, as the number of cats has increased, the intestinal health of cats has receied increasing amounts of attention. Probiotics have positive effects on maintaining intestinal homeostasis. This study was conducted to investigate the effects of probiotics Bacillus licheniformis (B. licheniformis) and Bacillus subtilis (B. subtilis) on cat immunity, inflammation, antioxidants, intestinal barrier and microbiota, and serum metabolites. Thirty-six cats (over one year old, 3.48 ± 0.71 kg) were randomly divided into 3 groups and fed with a basal diet (CON group), a basal diet + B. licheniformis (BL group), and a basal diet + B. subtilis (BS Group). The experiment lasted 35 days. Fecal scoring indicates that B. licheniformis and B. subtilis can improve fecal scores. Serum analysis indicated that the addition of both substances increased levels of IgA, IgM, T-AOC, and SOD, while reducing levels of the pro-inflammatory factor TNF-α. Moreover, 16S rRNA gene sequencing revealed that B. licheniformis and B. subtilis altered the fecal microbiota composition, characterized by the elevated abundance of Bacillus. Adding B. licheniformis to the diet increased the level of Faecalibacterium and decreased the level of Mogibacterium. Serum metabolomics revealed that levels of L-Glycine and Sn-Glycero-3-phosphocholine exhibited marked elevation in both the BL and BS groups, respectively. Furthermore, the study demonstrated that differential metabolites in the BL group were mainly enriched in amino acid metabolism pathways, while those in the BS group were chiefly concentrated in lipid metabolism pathways. However, this study acknowledges the limitations of its exclusive use of Ragdoll cats and its 35-day intervention period. It highlights the need for future research involving diverse breeds and longer durations. Overall, the data highlight B. licheniformis and B. subtilis as cat nutritional supplements that improve immunity and maintain intestinal health. Full article

To address the limitations of traditional chemical flooding—such as high cost, environmental impact, and formation damage—and the challenges of standalone microbial flooding—including preferential channeling, microbial loss, and limited sweep efficiency—this study develops a novel composite system for a high-permeability heavy oil reservoir. The system integrates a 3% scleroglucan + 1% phenolic resin gel (ICRG) with Bacillus licheniformis (ZY-1) and a surfactant. Core flooding and two-dimensional physical simulation experiments reveal a synergistic mechanism: The robust and biocompatible ICRG gel effectively plugs dominant flow paths, increasing displacement pressure fourfold to divert subsequent fluids. The injected strain ZY-1 then metabolizes hydrocarbons, producing biosurfactants that reduce oil–water interfacial tension by 61.9% and crude oil viscosity by 65%, thereby enhancing oil mobility. This combined approach of conformance control and enhanced oil displacement resulted in a significant increase in ultimate oil recovery, achieving 15% and 20% in one-dimensional and two-dimensional models, respectively, demonstrating its substantial potential for improving heavy oil production. Full article

Lignin, as one of the three primary components of renewable lignocellulosic biomass, can be converted into aromatic platform chemicals and holds significant potential for high-value applications. p-Hydroxybenzaldehyde is a compound derived from lignin. In this study, the mutant Δ60 of the glycosyltransferase UGT_BL1 derived from Bacillus licheniformis was adopted to catalyze the glycosylation reaction of p-hydroxybenzaldehyde, producing a bioactive compound Helicid analogue (p-hydroxybenzaldehyde β-glucoside). Truncation mutations targeting loop regions may reduce local flexibility, thereby facilitating enhanced access of p-hydroxybenzaldehyde to the active site pocket and promoting relative activity. Under optimal conditions (35 °C, pH 7.5, and glucose 200 mM), a high yield of 97.8% for p-hydroxybenzaldehyde β-glucoside was achieved from 2 mM p-hydroxybenzaldehyde within 10 h. The conversion of 3 mM p-hydroxybenzaldehyde (366.4 mg/L) yielded up to 2.7 mM (767.5 mg/L) of p-hydroxybenzaldehyde β-glucoside within 48 h. According to the molecular docking results, the CDOCKER energy value of mutant Δ60 was lower than that of the wild-type, at −16.0 kcal/mol. To our knowledge, this is the first example of an efficient and environmentally sustainable approach for the synthesis of p-hydroxybenzaldehyde β-glucoside, providing a new insight for the valorization of lignin into valuable biobased chemicals. Full article

Biosurfactants are amphiphilic compounds synthesized by microorganisms, providing environmentally sustainable alternatives to synthetic surfactants owing to their biodegradability and minimal toxicity. This review examines bacterial origins of biosurfactants, with a focus on surfactin derived from Bacillus species including B. subtilis, B. amyloliquefaciens, B. licheniformis, and B. pumilus. The cyclic lipopeptide structure of surfactin, which consists of a heptapeptide attached to a β-hydroxy fatty acid chain, imparts remarkable surface-active characteristics, such as a reduced surface tension of 27 mN/m and a low critical micelle concentration of 20 µM. In medical applications, surfactin demonstrates antimicrobial, antiviral, and anticancer properties through mechanisms such as apoptosis induction and metastasis inhibition, as well as promoting wound healing by enhancing angiogenesis and decreasing fibrosis. In the realm of food processing, it functions as a natural antimicrobial agent against pathogens such as Listeria and Salmonella, improves emulsion stability in products like mayonnaise, prolongs shelf life, and influences gut microbiota composition. The safety profiles correspond with the Generally Recognized as Safe (GRAS) status for compounds derived from Bacillus; however, it is essential to optimize dosing to reduce the risks associated with hemolysis. Challenges encompass production expenses, scalability issues, and regulatory obstacles, with genetic engineering suggested as a means to achieve improved yields. Surfactin demonstrates potential as a sustainable bioactive component within the food and health industries. Full article