RESUMEN
In the present work, chemical and enzymatic assisted techniques were compared for protein extraction from lesser mealworm larvae (LM, Alphitobius diaperinus), recently approved as a novel food in the European Union. All extracts showed appreciable nutritional quality, with quantities of essential amino acids above the reference standard. Conventional alkali extraction allowed the isolation of only 73% of the protein, preserving the amino acid composition but potentially causing denaturation or racemisation. The "stepwise" method, following the Osborne fractionation, improved protein recovery to 91% by isolating four fractions with different solubility properties. Additionally, enzymatic hydrolysis using Bacillus licheniformis proteases was also tested, and it provided hydrolysates with an average degree of hydrolysis of 14%, making them a potential hypoallergenic solution. Overall, these findings indicate the ability to tailor the composition of LM protein to meet specific needs, offering promising prospects for the use of insect protein ingredients in various applications.
Asunto(s)
Proteínas de Insectos , Larva , Valor Nutritivo , Animales , Proteínas de Insectos/aislamiento & purificación , Proteínas de Insectos/química , Aminoácidos/análisis , Aminoácidos/química , Hidrólisis , Fraccionamiento Químico/métodos , Escarabajos/química , Escarabajos/metabolismo , Bacillus licheniformis/metabolismoRESUMEN
Synthetic textile dye malachite green (MG) and heavy metals present in industrial wastewater are hazardous to the ecosystem. Bioremediation of dyes and heavy metals using dry-biomasses has advantages over chemical methods. This study screened an acclimatized, heavy metal-resistant, and dye-degrading Gram positive Bacillus licheniformis AG3 strain from the textile wastewater near Kolkata, West Bengal. The EDXRF analysis of this colored wastewater effluent showed 36.33 mg/L lead, significantly higher than the WHO recommendation. Previously, Bag et al. showed bioremediation of synthetic dyes using dry-biomass of Bacillus cereus M116 from an aqueous solution (Bag et al. Arch Microbiol 203(7):3811-3823, 2021). Here, a consortium of dry-biomasses of B. licheniformis AG3 and B. cereus M116 strains (1:1 w/w ratio) was prepared for the simultaneous removal of lead and MG from wastewater. Statistical optimization determines that the pH, initial concentration of contaminants, and dry-biomass concentrations are critical for bioremediation under batch procedures. Further, optimization using the response surface methodology showed that 0.01% consortium dry-biomasses eliminated a maximum of 99.35% MG and 96.01% lead (II) within 6 h. SEM-EDS and FTIR confirmed a strong surface biosorption. Furthermore, a fixed-bed biofilter column of the consortium dry-biomasses was prepared, which was able to remove 98.1% MG and 98.5% lead at the 0.5-1 mL/min flow rate. Together, this study developed a biofilter with a consortium dry biomasses of B. licheniformis AG3 and B. cereus M116 for the simultaneous removal of MG and lead from wastewater.
Asunto(s)
Bacillus cereus , Bacillus licheniformis , Biodegradación Ambiental , Plomo , Colorantes de Rosanilina , Aguas Residuales , Contaminantes Químicos del Agua , Colorantes de Rosanilina/metabolismo , Colorantes de Rosanilina/química , Bacillus cereus/metabolismo , Bacillus cereus/aislamiento & purificación , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/análisis , Plomo/metabolismo , Aguas Residuales/química , Aguas Residuales/microbiología , Bacillus licheniformis/metabolismo , Biomasa , Purificación del Agua/métodos , Concentración de Iones de HidrógenoRESUMEN
The exopolymer (ESPp) was obtained from Bacillus licheniformis IDN-EC, composed of a polyglutamic acid and polyglycerol phosphate chain O-substituted with αGal moieties (αGal/αGlcNH2 3:1 molar ratio) and with a 5000 Da molecular weight. The cytotoxicity activity of EPSp was determined by reducing the MTT (3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium bromide) to formazan on HeLa cells. This EPS did not show cytotoxicity against the tested cell line. The ESPp presented great advantages as an antioxidant with free radical scavenging activities (1,1-diphenyl-2-picryl-hydrazyl radical (DPPH),hydroxyl radical (OH), and superoxide anion (O2-)) (65 ± 1.2%, 98.7 ± 1.9%, and 97 ± 1.7%), respectively. Moreover, EPSp increased the enzyme activity for catalase (CAT) and glutathione peroxidase (GSH-Px) in HeLa cells (CAT, 2.6 ± 0.24 U/mL; and GSH-Px, 0.75 ± 0.3 U/L). The presence of ESPp showed a significant protective effect against H2O2 in the cell line studied, showing great viability (91.8 ± 2.8, 89.9 ± 2.9, and 93.5 ± 3.6%). The EPSp presented good emulsifying activity, only for vegetable oils, olive oil (50 ± 2.1%) and sesame (72 ± 3%). Sesame was effective compared to commercials products, Triton X-100 (52.38 ± 1.6%), Tween 20 (14.29 ± 1.1%), and sodium dodecyl sulphate (SDS) (52.63 ± 1.6%). Furthermore, the EPS produced at 0.6 M has potential for environmental applications, such as the removal of hazardous materials by emulsification whilst resulting in positive health effects such as antioxidant activity and non-toxicity. EPSp is presented as a good exopolysaccharide for various applications.
Asunto(s)
Antioxidantes , Bacillus licheniformis , Humanos , Bacillus licheniformis/metabolismo , Células HeLa , Antioxidantes/farmacología , Antioxidantes/química , Emulsionantes/química , Emulsionantes/farmacología , Depuradores de Radicales Libres/farmacología , Depuradores de Radicales Libres/química , Catalasa/metabolismo , Glutatión Peroxidasa/metabolismoRESUMEN
Bacterial biofilms pose a significant threat to healthcare due to their recalcitrance to antibiotics and disinfectants. This study explores the anti-biofilm potential of Bacillus licheniformis cell-free culture supernatant (CFS) and its derived silver nanoparticles (bSNPs) against Staphylococcus aureus and Pseudomonas aeruginosa. The CFS exhibited potent anti-biofilm activity against both bacterial species, even at low concentrations, while devoid of significant bactericidal effects, mitigating resistance risks. Characterization studies revealed the non-proteinaceous nature and thermal stability of the CFS's anti-biofilm agent, suggesting a robust and heat-resistant structure. Green synthesis of bSNPs from CFS resulted in nanoparticles with significant anti-biofilm properties, particularly against P. aeruginosa, indicating differences in susceptibility between the bacterial species. Epifluorescence microscopy confirmed bSNPs' ability to inhibit and partially disrupt biofilm formation without inducing cellular lysis. The study highlights the potential of B. licheniformis CFS and bSNPs as promising biofilm control agents, offering insights into their mechanisms of action and broad-spectrum efficacy. Further research elucidating the underlying molecular mechanisms and identifying specific bioactive compounds is warranted for the translation of these findings into clinically relevant applications for combating biofilm-associated infections.
Asunto(s)
Antibacterianos , Bacillus licheniformis , Biopelículas , Nanopartículas del Metal , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa , Plata , Staphylococcus aureus , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Plata/farmacología , Plata/química , Nanopartículas del Metal/química , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Bacillus licheniformis/metabolismo , Bacillus licheniformis/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
Oxidative damage caused by the accumulation of reactive oxygen species (ROS) is one of the main obstacles to the improvement of microbial cell growth and fermentation characteristics under adverse environments. And the antioxidant capacity of cells will increase with the cell growth. Here, we found that a transition state transcription factor AbrB related to changes in cell growth status could regulate the accumulation of ROS and antioxidant capacity in Bacillus licheniformis. The results showed that the accumulation of intracellular ROS was reduced by 23.91â¯% and the cell survival rates were increased by 1.77-fold under 0.5â¯mM H2O2 when AbrB was knocked out. We further mapped regulatory target genes of AbrB related to ROS generation or clearance based on our previously analyzed transcriptome sequencing. It proved that AbrB could promote ROS generation via upregulating the synthesis of oxidase and siderophores, and negatively regulating the synthesis of iron chelators (pulcherriminic acid, and H2S). Additionally, AbrB could inhibit ROS clearance by negatively regulating the synthesis of antioxidase (superoxide dismutase, catalase, peroxidase, thioredoxin, thioredoxin reductase) and cysteine. Those results illustrated that the inactivation of AbrB during the stationary phase, along with its control over ROS generation and clearance, might represent a vital self-protection mechanism during cell evolution. Overall, the systematic investigation of the multi-pathway regulation network of ROS generation and clearance highlights the important function of AbrB in maintaining intracellular redox balance.
Asunto(s)
Antioxidantes , Bacillus licheniformis , Proteínas Bacterianas , Regulación Bacteriana de la Expresión Génica , Peróxido de Hidrógeno , Especies Reactivas de Oxígeno , Factores de Transcripción , Especies Reactivas de Oxígeno/metabolismo , Bacillus licheniformis/metabolismo , Bacillus licheniformis/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Peróxido de Hidrógeno/metabolismo , Antioxidantes/metabolismo , Estrés Oxidativo , Sideróforos/metabolismoRESUMEN
Plant growth-promoting rhizobacteria (PGPR) are known for their role in ameliorating plant stress, including alkaline stress, yet the mechanisms involved are not fully understood. This study investigates the impact of various inoculum doses of Bacillus licheniformis Jrh14-10 on Arabidopsis growth under alkaline stress and explores the underlying mechanisms of tolerance enhancement. We found that all tested doses improved the growth of NaHCO3-treated seedlings, with 109 cfu/mL being the most effective. Transcriptome analysis indicated downregulation of ethylene-related genes and an upregulation of polyamine biosynthesis genes following Jrh14-10 treatment under alkaline conditions. Further qRT-PCR analysis confirmed the suppression of ethylene biosynthesis and signaling genes, alongside the activation of polyamine biosynthesis genes in NaHCO3-stressed seedlings treated with Jrh14-10. Genetic analysis showed that ethylene signaling-deficient mutants (etr1-3 and ein3-1) exhibited greater tolerance to NaHCO3 than the wild type, and the growth-promoting effect of Jrh14-10 was significantly diminished in these mutants. Additionally, Jrh14-10 was found unable to produce 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, indicating it does not reduce the ethylene precursor ACC in Arabidopsis. However, Jrh14-10 treatment increased the levels of polyamines (putrescine, spermidine, and spermine) in stressed seedlings, with spermidine particularly effective in reducing H2O2 levels and enhancing Fv/Fm under NaHCO3 stress. These findings reveal a novel mechanism of PGPR-induced alkaline tolerance, highlighting the crosstalk between ethylene and polyamine pathways, and suggest a strategic redirection of S-adenosylmethionine towards polyamine biosynthesis to combat alkaline stress.
Asunto(s)
Arabidopsis , Bacillus licheniformis , Etilenos , Poliaminas , Arabidopsis/genética , Arabidopsis/efectos de los fármacos , Arabidopsis/metabolismo , Arabidopsis/microbiología , Arabidopsis/fisiología , Etilenos/metabolismo , Poliaminas/metabolismo , Bacillus licheniformis/metabolismo , Bacillus licheniformis/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Estrés Fisiológico , Plantones/efectos de los fármacos , Plantones/genética , Plantones/fisiología , Plantones/metabolismo , Álcalis/farmacología , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genéticaRESUMEN
Starch is an attractive feedstock in biorefinery processes, while the low natural conversion rate of most microorganisms limits its applications. Herein, starch metabolic pathway was systematically investigated using Bacillus licheniformis DW2 as the host organism. Initially, the effects of overexpressing amylolytic enzymes on starch hydrolysis were evaluated. Subsequently, the transmembrane transport system and intracellular degradation module were modified to accelerate the uptake of hydrolysates and their further conversion to glucose-6-phosphate. The DW2-derived strains exhibited robust growth in starch medium, and productivity of bacitracin and subtilisin were improved by 38.5% and 32.6%, with an 32.3% and 22.9% increase of starch conversion rate, respectively. Lastly, the employment of engineering strategies enabled another B. licheniformis WX-02 to produce poly-γ-glutamic acid from starch with a 2.1-fold increase of starch conversion rate. This study not only provided excellent B. licheniformis chassis for sustainable bioproduction from starch, but shed light on researches of substrate utilization.
Asunto(s)
Bacillus licheniformis , Almidón , Almidón/metabolismo , Bacillus licheniformis/metabolismo , Hidrólisis , Ácido Poliglutámico/análogos & derivados , Ácido Poliglutámico/biosíntesis , Microbiología Industrial/métodosRESUMEN
BACKGROUND: Selenium nanoparticles (SeNPs) are increasingly gaining attention due to its characteristics of low toxicity, high activity, and stability. Additionally, Bacillus licheniformis, as a probiotic, has achieved remarkable research outcomes in diverse fields such as medicine, feed processing, and pesticides, attracting widespread attention. Consequently, evaluating the activity of probiotics and SeNPs is paramount. The utilization of probiotics to synthesize SeNPs, achieving large-scale industrialization, is a current hotspot in the field of SeNPs synthesis and is currently the most promising synthetic method. To minimize production costs and maximize yield of SeNPs, this study selected agricultural by-products that are nutrient-rich, cost-effective, and readily available as culture medium components. This approach not only fulfills industrial production requirements but also mitigates the impact on downstream processes. RESULTS: The experimental findings revealed that SeNPs synthesized by B. licheniformis F1 exhibited a spherical morphology with diameters ranging from 110 to 170 nm and demonstrating high stability. Both the secondary metabolites of B. licheniformis F1 and the synthesized SeNPs possessed significant free radical scavenging ability. To provide a more robust foundation for acquiring large quantities of SeNPs via fermentation with B. licheniformis F1, key factors were identified through single-factor experiments and response surface methodology (RSM) include a 2% seed liquid inoculum, a temperature of 37 â, and agitation at 180 rpm. Additionally, critical factors during the optimization process were corn powder (11.18 g/L), soybean meal (10.34 g/L), and NaCl (10.68 g/L). Upon validating the optimized conditions and culture medium, B. licheniformis F1 can synthesize nearly 100.00% SeNPs from 5 mmol/L sodium selenite. Subsequently, pilot-scale verification in a 5 L fermentor using the optimized medium resulted in a shortened fermentation time, significantly reducing production costs. CONCLUSION: In this study, the efficient production of SeNPs by the probiotic B. licheniformis F1 was successfully achieved, leading to a significant reduction in fermentation costs. The exploration of the practical applications of this strain holds significant potential and provides valuable guidance for facilitating the industrial-scale implementation of microbial synthesis of SeNPs.
Asunto(s)
Bacillus licheniformis , Medios de Cultivo , Fermentación , Probióticos , Selenio , Bacillus licheniformis/metabolismo , Selenio/metabolismo , Medios de Cultivo/química , Probióticos/metabolismo , Nanopartículas/química , Nanopartículas del Metal/químicaRESUMEN
Drought stress is the main factor restricting maize yield. Poly-γ-glutamic acid (γ-PGA), as a water-retaining agent and fertilizer synergist, could significantly improve the drought resistance and yield of many crops. However, its high production costs and unclear long-term impact on soil ecology limit its large-scale application. In this study, an environmentally friendly green material γ-PGA was heterologous synthesized in maize for the first time using the synthetic biology method. The genes (PgsA, PgsB, PgsC) participated in γ-PGA synthesis were cloned from Bacillus licheniformis and transformed into maize to produce γ-PGA for the first time. Under drought stress, transgenic maize significantly increased the ear length, ear weight and grain weight by 50 % compared to the control, whereas the yield characteristic of ear weight, grain number per ear, grain weight per ear and 100-grain weight increased by 1.67 %-2.33 %, 3.78 %-13.06 %, 8.41 %-22.06 %, 6.03 %-19.28 %, and 11.85 %-18.36 %, respectively under normal growth conditions. γ-PGA was mainly expressed in the mesophyll cells of maize leaf rosette structure and improved drought resistance and yield by protecting and increasing the expression of genes for the photosynthetic and carbon fixation. This study is an important exploration for maize drought stress molecular breeding and building resource-saving agriculture.
Asunto(s)
Sequías , Plantas Modificadas Genéticamente , Ácido Poliglutámico , Zea mays , Zea mays/genética , Ácido Poliglutámico/análogos & derivados , Ácido Poliglutámico/biosíntesis , Plantas Modificadas Genéticamente/genética , Estrés Fisiológico/genética , Regulación de la Expresión Génica de las Plantas , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Hojas de la Planta/genética , Resistencia a la SequíaRESUMEN
Candida albicans, a significant human pathogenic fungus, employs hydrolytic proteases for host invasion. Conventional antifungal agents are reported with resistance issues from around the world. This study investigates the role of Bacillus licheniformis extracellular proteins (ECP) as effective antifungal peptides (AFPs). The aim was to identify and characterize the ECP of B. licheniformis through LC-MS/MS and bioinformatics analysis. LC-MS/MS analysis identified 326 proteins with 69 putative ECP, further analyzed in silico. Of these, 21 peptides exhibited antifungal properties revealed by classAMP tool and are predominantly anionic. Peptide-protein docking revealed interactions between AFPs like Peptide chain release factor 1 (Q65DV1_Seq1: SASEQLSDAK) and Putative carboxy peptidase (Q65IF0_Seq7: SDSSLEDQDFILESK) with C. albicans virulent SAP5 proteins (PDB ID 2QZX), forming hydrogen bonds and significant Pi-Pi interactions. The identification of B. licheniformis ECP is the novelty of the study that sheds light on their antifungal potential. The identified AFPs, particularly those interacting with bonafide pharmaceutical targets SAP5 of C. albicans represent promising avenues for the development of antifungal treatments with AFPs that could be the pursuit of a novel therapeutic strategy against C. albicans. SIGNIFICANCE OF STUDY: The purpose of this work was to carry out proteomic profiling of the secretome of B. licheniformis. Previously, the efficacy of Bacillus licheniformis extracellular proteins against Candida albicans was investigated and documented in a recently communicated manuscript, showcasing the antifungal activity of these proteins. In order to achieve high-throughput identification of ES (Excretory-secretory) proteins, the utilization of liquid chromatography tandem mass spectrometry (LC-MS) was utilized. There was a lack of comprehensive research on AFPs in B. licheniformis, nevertheless. The proteins secreted by B. licheniformis in liquid medium were initially discovered using liquid chromatography-tandem mass spectrometry (LC-MS) analysis and identification in order to immediately characterize the unidentified active metabolites in fermentation broth.
Asunto(s)
Antifúngicos , Bacillus licheniformis , Proteínas Bacterianas , Candida albicans , Espectrometría de Masas en Tándem , Candida albicans/efectos de los fármacos , Candida albicans/metabolismo , Antifúngicos/farmacología , Bacillus licheniformis/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Cromatografía Liquida , Humanos , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/química , Cromatografía Líquida con Espectrometría de MasasRESUMEN
Bacillus licheniformis and bacitracin have a huge application market and value in the fields of medicine, chemistry, aquaculture, agricultural, and sideline products. Therefore, the selection of B. licheniformis with high production of bacitracin is of great importance. In this experimental protocol, Bacillus with a high yield of bacitracin was isolated, purified, and identified from the fresh feces of healthy pigs. The inhibitory effect of secondary metabolite bacitracin on Micrococcus luteus was also tested. Thin-layer chromatography and high-performance liquid chromatography were used for the qualitative and quantitative detection of bacitracin. The physiological and biochemical characteristics of B. licheniformis were determined by relevant kits. The phylogenetic relationships of B. licheniformis were determined and constructed using gene sequence detection. This protocol describes and introduces the standard isolation, purification, and identification process of B. licheniformis from animal fresh feces from multiple perspectives, providing a method for the large-scale utilization of B. licheniformis and bacitracin in factories.
Asunto(s)
Bacillus licheniformis , Bacitracina , Heces , Animales , Bacitracina/farmacología , Heces/microbiología , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Bacillus licheniformis/aislamiento & purificación , PorcinosRESUMEN
Aflatoxin B1 (AFB1) contamination is a serious threat to nutritional safety and public health. The CotA-laccase from Bacillus licheniformis ANSB821 previously reported by our laboratory showed great potential to degrade AFB1 without redox mediators. However, the use of this CotA-laccase to remove AFB1 in animal feed is limited because of its low catalytic efficiency and low expression level. In order to make better use of this excellent enzyme to effectively degrade AFB1, twelve mutants of CotA-laccase were constructed by site-directed mutagenesis. Among these mutants, E186A and E186R showed the best degradation ability of AFB1, with degradation ratios of 82.2% and 91.8% within 12 h, which were 1.6- and 1.8-times higher than those of the wild-type CotA-laccase, respectively. The catalytic efficiencies (kcat/Km) of E186A and E186R were found to be 1.8- and 3.2-times higher, respectively, than those of the wild-type CotA-laccase. Then the expression vectors pPICZαA-N-E186A and pPICZαA-N-E186R with an optimized signal peptide were constructed and transformed into Pichia pastoris GS115. The optimized signal peptide improved the secretory expressions of E186A and E186R in P. pastoris GS115. Collectively, the current study provided ideal candidate CotA-laccase mutants for AFB1 detoxification in food and animal feed and a feasible protocol, which was desperately needed for the industrial production of CotA-laccases.
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Aflatoxina B1 , Bacillus licheniformis , Proteínas Bacterianas , Lacasa , Aflatoxina B1/metabolismo , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Bacillus licheniformis/enzimología , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Lacasa/metabolismo , Lacasa/genética , Mutagénesis Sitio-Dirigida , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , SaccharomycetalesRESUMEN
Cr(VI) and phenol commonly coexist in wastewater, posing a great threat to the environment and human health. However, it is still a challenge for microorganisms to degrade phenol under high Cr(VI) stress. In this study, the phenol-degrading strain Bacillus cereus ZWB3 was co-cultured with the Cr(VI)-reducing strain Bacillus licheniformis MZ-1 to enhance phenol biodegradation under Cr(â ¥) stress. Compared with phenol-degrading strain ZWB3, which has weak tolerance to Cr(â ¥), and Cr(â ¥)-reducing strain MZ-1, which has no phenol-degrading ability, the co-culture of two strains could significantly increase the degraded rate and capacity of phenol. In addition, the co-cultured strains exhibited phenol degradation ability over a wide pH range (7-10). The reduced content of intracellular proteins and polysaccharides produced by the co-cultured strains contributed to the enhancement of phenol degradation and Cr(â ¥) tolerance. The determination coefficients R2, RMSE, and MAPE showed that the BP-ANN model could predict the degradation of phenol under various conditions, which saved time and economic cost. The metabolic pathway of microbial degradation of phenol was deduced by metabolic analysis. This study provides a valuable strategy for wastewater treatment containing Cr(â ¥) and phenol.
Asunto(s)
Biodegradación Ambiental , Cromo , Aprendizaje Automático , Fenol , Fenol/metabolismo , Cromo/metabolismo , Bacillus cereus/metabolismo , Contaminantes Químicos del Agua/metabolismo , Bacillus licheniformis/metabolismoRESUMEN
BACKGROUND: The antibiotic resistance of microorganisms is escalating rapidly. Infections caused by opportunistic pathogens in immunocompromised individuals have prompted researchers to seek for potent and safe antibacterial agents. The purpose of this investigation was to explore the suppression of virulence gene expression, specifically the pga operon genes responsible in biofilm formation in Acinetobacter baumannii, through the utilization of metabolites obtained from probiotic bacteria. METHODS: To assess the antimicrobial properties, standard strains of five probiotic bacteria were tested against a standard strain of multidrug-resistant (MDR) A. baumannii employing the agar gel diffusion technique. Following the identification of the most potent probiotic strain (Bacillus licheniformis), the existence of its LanA and LanM genes was confirmed using the polymerase chain reaction (PCR) test. High-performance liquid chromatography (HPLC) and fourier-transform infrared spectroscopy (FTIR) techniques were employed to identify the intended metabolite, which was found to be a lipopeptide nature. The minimum inhibitory concentration (MIC) values and anti-biofilm activity of the targeted metabolite were determined using a dilution method in 96-well microplates and field emission scanning electron microscopy (FE-SEM). Real-time PCR (qPCR) was utilized for comparing the expression of pga operon genes, including pgaABCD, in A. baumannii pre- and post-exposure to the derived lipopeptide. RESULTS: The MIC results indicated that the probiotic product inhibited the growth of A. baumannii at concentrations lower than those needed for conventional antibiotics. Furthermore, it was observed that the desired genes' expression decreased due to the effect of this substance. CONCLUSIONS: This research concludes that the B. licheniformis probiotic product could be a viable alternative for combating drug resistance in A. baumannii.
Asunto(s)
Acinetobacter baumannii , Antibacterianos , Bacillus licheniformis , Biopelículas , Farmacorresistencia Bacteriana Múltiple , Lipopéptidos , Pruebas de Sensibilidad Microbiana , Probióticos , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/genética , Probióticos/farmacología , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Lipopéptidos/farmacología , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genéticaRESUMEN
Sericulture has become widespread globally, and the utilization of artificial diets produces a substantial quantity of silkworm excrement. Although silkworm excrement can be composted for environmentally friendly disposal, the potential utility of the resulting compost remains underexplored. The aim of this study was to assess the quality of this unique compost and screen for eco-beneficial microbes, providing a new perspective on microbial research in waste management, especially in sustainable agriculture. The low-concentration compost application exhibited a greater plant growth-promoting effect, which was attributed to an appropriate nutritional value (N, P, K, and dissolved organic matter) and the presence of plant growth-promoting bacteria (PGPB) within the compost. Encouraged by the "One Health" concept, the eco-benefits of potent PGPB, namely, Klebsiella pneumoniae and Bacillus licheniformis, in sericulture were further evaluated. For plants, K. pneumoniae and B. licheniformis increased plant weight by 152.44 % and 130.91 %, respectively. We also found that even a simple synthetic community composed of the two bacteria performed better than any single bacterium. For animals, K. pneumoniae significantly increased the silkworm (Qiufeng × Baiyu strain) cocoon shell weight by 111.94 %, which could increase sericulture profitability. We also elucidated the mechanism by which K. pneumoniae assisted silkworms in degrading tannic acid, a common plant-derived antifeedant, thereby increasing silkworm feed efficiency. Overall, these findings provide the first data revealing multiple beneficial interactions among silkworm excrement-derived microbes, plants, and animals, highlighting the importance of focusing on microbes in sustainable agriculture.
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Bombyx , Compostaje , Animales , Bombyx/microbiología , Compostaje/métodos , Klebsiella pneumoniae , Bacillus licheniformis/metabolismo , Microbiología del Suelo , Administración de Residuos/métodos , Heces/microbiologíaRESUMEN
Seriniquinone was isolated as a melanoma-selective anti-cancer agent from a culture broth of the marine-derived bacterium Serinicoccus marinus CNJ927 in 2014. It targets the unique small protein, dermcidin, which affects the drug resistance of cancer cells. Due to its significant activity against cancer cells, particularly melanoma, and its unique target, seriniquinone has been developed as a new pharmacophore. However, it has the disadvantage of poor solubility in drug discovery research, which needs to be resolved. A new seriniquinone glycoside (1) was synthesized by the biological transformation of seriniquinone using the deep sea-derived bacterium Bacillus licheniformis KDM612. Compound 1 exhibited selective anti-cancer activity against melanoma, similar to seriniquinone, and was 50-fold more soluble in DMSO than seriniquinone.
Asunto(s)
Antineoplásicos , Bacillus licheniformis , Glicósidos , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Línea Celular Tumoral , Glicósidos/farmacología , Glicósidos/química , Glicósidos/aislamiento & purificación , Bacillus licheniformis/metabolismo , Humanos , Biotransformación , Solubilidad , QuinonasRESUMEN
Anoxybacillus flavithermus, Geobacillus stearothermophilus and Bacillus licheniformis are the main contaminants found in dairy powders. These spore-forming thermophilic bacteria, rarely detected in raw milk, persist, and grow during the milk powder manufacturing process. Moreover, in the form of spores, these species resist and concentrate in the powders during the processes. The aim of this study was to determine the stages of the dairy powder manufacturing processes that are favorable to the growth of such contaminants. A total of 5 strains were selected for each species as a natural contaminant of dairy pipelines in order to determine the minimum and maximum growth enabling values for temperature, pH, and aw and their optimum growth rates in milk. These growth limits were combined with the environmental conditions of temperature, pH and aw encountered at each step of the manufacture of whole milk, skim milk and milk protein concentrate powders to estimate growth capacities using cardinal models and the Gamma concept. These simulations were used to theoretically calculate the population sizes reached for the different strains studied at each stage in between two successive cleaning in place procedures. This approach highlights the stages at which risk occurs for the development of spore-forming thermophilic bacterial species. During the first stages of production, i.e. pre-treatment, pasteurization, standardization and pre-heating before concentration, physico-chemical conditions encountered are suitable for the development and growth of A. flavithermus, G. stearothermophilus and B. licheniformis. During the pre-heating stage and during the first effects in the evaporators, the temperature conditions appear to be the most favorable for the growth of G. stearothermophilus. The temperatures in the evaporator during the last evaporator effects are favorable for the growth of B. licheniformis. In the evaporation stage, low water activity severely limits the development of A. flavithermus.
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Leche , Polvos , Esporas Bacterianas , Esporas Bacterianas/crecimiento & desarrollo , Leche/microbiología , Animales , Geobacillus stearothermophilus/crecimiento & desarrollo , Microbiología de Alimentos , Bacillus licheniformis/crecimiento & desarrollo , Bacillus licheniformis/metabolismo , Concentración de Iones de Hidrógeno , Anoxybacillus/crecimiento & desarrollo , Manipulación de Alimentos/métodos , Temperatura , Contaminación de Alimentos/análisis , Industria Lechera/métodos , Productos Lácteos/microbiologíaRESUMEN
The effect of barium ions on the biomineralization of calcium and magnesium ions is often overlooked when utilizing microbial-induced carbonate precipitation technology for removing barium, calcium, and magnesium ions from oilfield wastewater. In this study, Bacillus licheniformis was used to bio-precipitate calcium, magnesium, and barium ions. The effects of barium ions on the physiological and biochemical characteristics of bacteria, as well as the components of extracellular polymers and mineral characteristics, were also studied in systems containing coexisting barium, calcium, and magnesium ions. The results show that the increasing concentrations of barium ions decreased pH, carbonic anhydrase activity, and concentrations of bicarbonate and carbonate ions, while it increased the contents of humic acids, proteins, polysaccharides, and DNA in extracellular polymers in the systems containing all three types of ions. With increasing concentrations of barium ions, the content of magnesium within magnesium-rich calcite and the size of minerals precipitated decreased, while the full width at half maximum of magnesium-rich calcite, the content of O-C=O and N-C=O, and the diversity of protein secondary structures in the minerals increased in systems containing all three coexisting ions. Barium ions does inhibit the precipitation of calcium and magnesium ions, but the immobilized bacteria can mitigate the inhibitory effect. The precipitation ratios of calcium, magnesium, and barium ions reached 81-94%, 68-82%, and 90-97%. This research provides insights into the formation of barium-enriched carbonate minerals and offers improvements for treating oilfield wastewater.
Asunto(s)
Bacillus licheniformis , Bario , Biomineralización , Calcio , Magnesio , Magnesio/metabolismo , Bacillus licheniformis/metabolismo , Bario/metabolismo , Calcio/metabolismo , Aguas Residuales/microbiología , Aguas Residuales/química , Concentración de Iones de Hidrógeno , Iones , Anhidrasas Carbónicas/metabolismo , Carbonato de Calcio/metabolismoRESUMEN
Bacterial endophytes from plants harbor diverse metabolites that play major roles in biocontrol and improve plant growth. In this study, a total of 12 endophytic bacteria were isolated from the ginger rhizome. The strain K3 was highly effective in preventing mycelia growth of Pythium myriotylum (78.5 ± 1.5% inhibition) in dual culture. The cell-free extract (2.5%) of endophyte K3 inhibited 76.3 ± 4.8% mycelia growth, and 92.4 ± 4.2% inhibition was observed at a 5% sample concentration. The secondary metabolites produced by Bacillus licheniformis K3 showed maximum activity against Pseudomonas syringae (24 ± 1 mm zone of inhibition) and Xanthomonas campestris (28 ± 3 mm zone of inhibition). The strain K3 produced 28.3 ± 1.7 IU mL-1 protease, 28.3 ± 1.7 IU mL-1 cellulase, and 2.04 ± 0.13 IU mL-1 chitinase, respectively. The ginger rhizome treated with K3 in the greenhouse registered 53.8 ± 1.4% soft rot incidence, and the streptomycin-treated pot registered 78.3 ± 1.7% disease incidence. The selected endophyte K3 improved ascorbate peroxidase (1.37 ± 0.009 µmole ASC min-1 mg-1 protein), catalase (8.7 ± 0.28 µmole min-1 mg-1 protein), and phenylalanine ammonia-lyase (26.2 ± 0.99 Umg-1) in the greenhouse. In addition, K3 treatment in the field trial improved rhizome yield (730 ± 18.4 g) after 180 days (p < 0.01). The shoot length was 46 ± 8.3 cm in K3-treated plants, and it was about 31% higher than the control treatment (p < 0.01). The lytic enzyme-producing and growth-promoting endophyte is useful in sustainable crop production through the management of biotic stress.
Asunto(s)
Bacillus licheniformis , Endófitos , Enfermedades de las Plantas , Pythium , Zingiber officinale , Pythium/crecimiento & desarrollo , Endófitos/aislamiento & purificación , Endófitos/metabolismo , Endófitos/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Zingiber officinale/microbiología , Zingiber officinale/crecimiento & desarrollo , Bacillus licheniformis/crecimiento & desarrollo , Bacillus licheniformis/metabolismo , Rizoma/microbiología , Rizoma/crecimiento & desarrollo , Micelio/crecimiento & desarrollo , Antibiosis , Agentes de Control Biológico/farmacología , Metabolismo Secundario , Quitinasas/metabolismoRESUMEN
Glucosylation is a well-known approach to improve the solubility, pharmacological, and biological properties of flavonoids, making flavonoid glucosides a target for large-scale biosynthesis. However, the low yield of products coupled with the requirement of expensive UDP-sugars limits the application of enzymatic systems for large-scale. C. glutamicum is a Gram-positive and generally regarded as safe (GRAS) bacteria frequently employed for the large-scale production of amino acids and bio-fuels. Due to the versatility of its cell factory system and its non-endotoxin producing properties, it has become an attractive system for the industrial-scale biosynthesis of alternate products. Here, we explored the cell factory of C. glutamicum for efficient glucosylation of flavonoids using apigenin as a model flavonoid, with the heterologous expression of a promiscuous glycosyltransferase, YdhE from Bacillus licheniformis and the endogenous overexpression of C. glutamicum genes galU1 encoding UDP-glucose pyrophosphorylase and pgm encoding phosphoglucomutase involved in the synthesis of UDP-glucose to create a C. glutamicum cell factory system capable of efficiently glucosylation apigenin with a high yield of glucosides production. Consequently, the production of various apigenin glucosides was controlled under different temperatures yielding almost 4.2 mM of APG1(apigenin-4'-O-ß-glucoside) at 25°C, and 0.6 mM of APG2 (apigenin-7-O-ß-glucoside), 1.7 mM of APG3 (apigenin-4',7-O-ß-diglucoside) and 2.1 mM of APG4 (apigenin-4',5-O-ß-diglucoside) after 40 h of incubation with the supplementation of 5 mM of apigenin and 37°C. The cost-effective developed system could be used to modify a wide range of plant secondary metabolites with increased pharmacokinetic activities on a large scale without the use of expensive UDP-sugars.