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Bacterial exopolysaccharides (EPS) are biopolymers of carbohydrates, often released from cells into the extracellular environment. Due to their distinctive physicochemical properties, biocompatibility, biodegradability, and non-toxicity, EPS finds applications in various industrial sectors. However, the need for alternative EPS has grown over the past few decades as lactic acid bacteria's (LAB) low-yield EPS is unable to meet the demand. In this case, rhizosphere bacteria with the diverse communities in soil leading to variations in composition and structure, are recognized as a potential source of EPS applicable in various industries. In addition, media components and cultivation conditions have an impact on EPS production, which ultimately affects the quantity, structure, and biological functions of the EPS. Therefore, scientists are currently working on manipulating bacterial EPS by developing cultures and applying abiotic and biotic stresses, so that better production of exopolysaccharides can be attained. This review highlights the composition, biosynthesis, and effects of environmental factors on EPS production along with the potential applications in different fields of industry. Ultimately, an overview of potential future paths and tactics for improving EPS implementation and commercialization is pointed out.
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Polissacarídeos Bacterianos , Rizosfera , Microbiologia do Solo , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/metabolismo , Bactérias/metabolismoRESUMO
BACKGROUND: Accurate detection of kidney damage is key to preventing renal failure, and identifying biomarkers is essential for this purpose. We aimed to assess the accuracy of miRNAs as diagnostic tools for chronic kidney disease (CKD). METHODS: We thoroughly searched five databases (MEDLINE, Web of Science, Embase, Scopus, and CENTRAL) and performed a meta-analysis using R software. We assessed the overall diagnostic potential using the pooled area under the curve (pAUC), sensitivity (SEN), and specificity (SPE) values and the risk of bias by using the QUADAS-2 tool. The study protocol was registered on PROSPERO (CRD42021282785). RESULTS: We analyzed data from 8351 CKD patients, 2989 healthy individuals, and 4331 people with chronic diseases. Among the single miRNAs, the pooled SEN was 0.82, and the SPE was 0.81 for diabetic nephropathy (DN) vs. diabetes mellitus (DM). The SEN and SPE were 0.91 and 0.89 for DN and healthy controls, respectively. miR-192 was the most frequently reported miRNA in DN patients, with a pAUC of 0.91 and SEN and SPE of 0.89 and 0.89, respectively, compared to those in healthy controls. The panel of miRNAs outperformed the single miRNAs (pAUC of 0.86 vs. 0.79, p < 0.05). The SEN and SPE of the panel miRNAs were 0.89 and 0.73, respectively, for DN vs. DM. In the lupus nephritis (LN) vs. systemic lupus erythematosus (SLE) cohorts, the SEN and SPE were 0.84 and 0.81, respectively. Urinary miRNAs tended to be more effective than blood miRNAs (p = 0.06). CONCLUSION: MiRNAs show promise as effective diagnostic markers for CKD. The detection of miRNAs in urine and the use of a panel of miRNAs allows more accurate diagnosis.
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Biomarcadores , MicroRNAs , Insuficiência Renal Crônica , Humanos , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/genética , Biomarcadores/sangue , Biomarcadores/urina , MicroRNAs/urina , MicroRNAs/sangue , Nefropatias Diabéticas/diagnóstico , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/urina , Nefrite Lúpica/genética , Nefrite Lúpica/diagnóstico , Nefrite Lúpica/urina , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/sangueRESUMO
Bacillus velezensis RB.IBE29 harbors two chitinases belonging to the glycoside hydrolase family 18 and exhibiting a novel domain structure. The roles of these chitinases in crop production have been reported; nevertheless, their contribution to controlling human pathogens is unknown. In this initial work, the chitinases A (BvChiA) and B (BvChiB) of strain RB.IBE29 were produced in recombinant Escherichia coli BL21-CodonPlus (DE3)-RIPL cells and subsequently purified using HisTrap FF column. The purified BvChiA and BvChiB exhibited the highest chitinase and binding activities against colloidal chitin. Combining both chitinases for the hydrolysis of powdered chitin increased the reducing sugar content by 88.7 %. Moreover, the purified chitinases remarkably suppressed the germination of Candida albicans VTCC 20568 (=JCM 2070) cells. These results indicated that the novel domain-structure-containing chitinases of strain RB.IBE29 have great potential and can be further developed as a novel therapeutic agent against human pathogenic C. albicans.
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This work aimed to isolate and characterize a novel chitin-degrading bacterium from Yok Don National Park, Vietnam, for crop production studies. Among the chitinolytic isolates, strain YSY-4.3 was selected, which grew rapidly and produced a large halo around the colony. 16S rDNA analysis indicated that the strain is a novel species in the genus paenibacillus, and an in vitro evaluation showed that the strain produced phytohormones (IAA, GA3, and zeatin), biofilms, and siderophores; possessed cellulase; and exerted antifungal activity. The whole genome of the strain was 5,628,400 bp with 49.3% GC content, 5056 coding sequences, 48 tRNA, and 1 rRNA. It shared the highest values of digital DNA-DNA hybridization (67.4%) and average nucleotide identity (89.54%) with those of Paenibacillus woosongensis B2_4 (CP126084.1), suggesting a novel species. Of the coding sequences, 4287 proteins were identified by COG, and 2561 were assigned by KEGG. The genome contained at least 51 genes involved in plant growth and resistance to heavy-metal toxicity and 359 carbohydrate-active enzymes. The chitinolytic system of the strain was composed of 15 enzymes, among them, PsChiC, which contained a GH18 catalytic domain and a GH5 catalytic domain, had not been previously reported. In addition, the genome possessed 15 gene clusters encoding antimicrobial metabolites, 10 of which are possible novel clusters. This study expands knowledge regarding novel chitinolytic bacteria from Yok Don National Park and provides a valuable gene resource for future studies.
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Introduction: The COVID-19 pandemic significantly impacted the mental health of individuals with chronic conditions such as Wilson's Disease (WD). This study investigates stress, anxiety, depression, quality of life, cognitive function, vaccination rates, infection rates, and perceptions related to the pandemic and vaccines among WD patients. Methods: The study analyzed COVID-19 perceptions and vaccine attitudes of 62 adult WD patients enrolled in the international multisite WD Registry. A subgroup of 33 participants completed a series of mental health scales. The effect of working essentially, income loss, wellness activity initiation, and infection of COVID-19 during the pandemic was observed. Results: Results indicate that, overall, the pandemic did not exacerbate anxiety or cognitive function in WD patients but did lead to increased depression among essential workers. Patients experiencing income loss exhibited higher levels of stress and anxiety. Despite these challenges, WD patients showed high vaccination rates and positive attitudes towards vaccines. Discussion: The findings underscore the significant impact of the pandemic on the mental health of WD patients.
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BACKGROUND: Despite medical advances, individuals with cerebral palsy (CP) face significant respiratory challenges, leading to heightened hospitalization rates and early mortality among this population. We hypothesize that integrating supplementary respiratory therapy into standard rehabilitation will result in significant improvements in pulmonary function, enhanced respiratory muscle strength, and an overall increase in the quality of life among pediatric patients with CP. METHODS: A systematic search of literature across five databases was conducted, and random-effects meta-analyses were performed to assess the impact of supplementary respiratory therapy on (a) pulmonary function: forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FVC/FEV1 ratio, peak expiratory flow (PEF), and (b) respiratory muscle strength: maximal inspiratory and expiratory pressure (MIP, MEP), and (c) quality of life. Certainty of evidence was determined by the GRADE assessment. RESULTS: Analysis of data from 11 eligible randomized controlled trials revealed clinically meaningful changes in pulmonary function. We found a relevant mean difference (MD) in absolute PEF of 0.50 L/s (95% confidence interval (CI): 0.19; 0.82 p = 0.0107). The certainty of the evidence ranged from moderate to high. CONCLUSIONS: This study presents current evidence on the impact of various supplementary respiratory therapies for CP patients classified under gross motor function classification level I-IV, demonstrating clinically meaningful improvements in pulmonary function and respiratory muscle strength. These improvements suggest the potential for an enhanced quality of life. Our findings hold the promise of serving as a foundational reference for potential revisions to conventional rehabilitation care, incorporating supplementary respiratory therapy.
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Bacillus velezensis RB.IBE29 is a chitinolytic bacterium originally isolated from the rhizospheric soil of black pepper grown in Vietnam. This bacterium is a strong biocontrol agent against plant pathogens and possesses a novel chitinase system. Genome sequences available in CAZy database revealed B. velezensis possesses one gene encoding xylanase belonging to glycoside hydrolase family 11; however, this enzyme has yet to be un-experimentally characterized. In this work, xyA gene was isolated from the genomic DNA of strain RB.IBE29 and cloned in Escherichia coli DH5α cells using the pUC19 vector. Sequencing analysis showed that the ORF of xyA contains 642 bp and encodes the deduced xylanase with 213 aa and 23.27 kDa. The domain structure of the enzyme has a signal peptide and a family 11 catalytic domain. xyA (without peptide sequence) was successfully expressed in E. coli BL21-CodonPlus (DE3)-RIPL cells using the pColdII vector and purified using the HisTrap FF column. Purified recombinant xylanase degraded xylan substrates, had the highest hydrolytic activity at 55°C in 20 mM sodium phosphate buffer (pH 6.0), and MgCl2, CoCl2, and MnCl2 enhanced the enzymatic activity. Nucleotide sequence of xyA was submitted to the DDBJ/GenBank/EMBL under accession number LC779040. This is the first data on the gene cloning, expression, purification, and characterization of the glycoside hydrolase family 11 from B. velezensis.
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Halophilic lactic acid bacteria have been widely found in various high-salt fermented foods. The distribution of these species in salt-fermented foods contributes significantly to the development of the product's flavor. Besides, these bacteria also have the ability to biosynthesize bioactive components which potentially apply to different areas. In this review, insights into the metabolic properties, salt stress responses, and potential applications of these bacteria have been have been elucidated. The purpose of this review highlights the important role of halophilic lactic acid bacteria in improving the quality and safety of salt-fermented products and explores the potential application of these bacteria.
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Alimentos Fermentados , Lactobacillales , Lactobacillales/metabolismo , Microbiologia de Alimentos , Fermentação , Indústria Alimentícia , Alimentos Fermentados/microbiologiaRESUMO
This study optimized the ultrasonic-assisted extraction (UAE) and microwave-assisted extraction (MAE) processes to acquire phenolics and flavonoids from passion fruit peels using a mixture of ethanol, acetone, and water. An augmented simplex-centroid design was employed to find the suitable volume ratio among solvent ingredients to attain the highest extraction yield of phenolics and flavonoids. One-factor experiments were conducted to investigate the influence of UAE and MAE parameters on the recovery yield of phenolics and flavonoids before the two processes were optimized using Box-Behnken Design (BBD) models. The optimal UAE conditions for recovering phenolics and flavonoids from passion fruit peel powder (PFP) were 28 mL/g of liquid-to-solid ratio (LSR), 608 W of ultrasonic power, and 63 °C for 20 min to acquire total phenolic content (TPC) and total flavonoid content (TFC) at 39.38 mg of gallic acid equivalents per gram of dried basis (mg GAE/g db) and 25.79 mg of rutin equivalents per gram of dried basis (mg RE/g db), respectively. MAE conditions for attaining phenolics and flavonoids from PFP were 26 mL/g of LSR and 606 W of microwave power for 2 min to recover TPC and TFC at 17.74 mg GAE/g db and 8.11 mg RE/g db, respectively. The second-order kinetic model was employed to determine the UAE and MAE mechanism of TPC and TFC and the thermodynamic parameters of the extraction processes. The antioxidant activities of passion fruit peel extracts at optimal conditions were examined to compare the efficiency of UAE and MAE. This study establishes an effective approach for obtaining phenolics and flavonoids from passion fruit peels.
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AIMS: This study focused on the isolation and characterization of chitinolytic bacteria from Yok Don National Park, Vietnam for future studies regarding biofertilizers and biocontrol agents. METHODS AND RESULTS: Chitinolytic bacteria were isolated from soils and chitin flakes soaked in river water at the National Park. On the basis of the halo zones caused by colloidal chitin degradation and colony morphologies, 12 chitinolytic strains were chosen from 15 700 isolates for various examinations. Findings from 16S rDNA analysis indicated that among these strains, 10 could be identified as different species, and the remaining 2 showed less identity to known species and genera. The 12 bacteria possess numerous properties concerning plant growth promotion and/or phytopathogenic biocontrol. Paenibacillus chitinolyticus YSY-3.1, which exhibited the highest chitinase activity and remarkable properties for plant growth, was chosen for sequencing and draft genome analysis. The results showed that the genome is 6571 781 bp in length with 6194 coding sequences, 52.2% G + C, and 96.53% ANI value. It harbors the chitinolytic system comprising 22 enzymes. Among these enzymes, PcChiQ has a loop structure different from that of known family 19 chitinases, PcChiA contains two GH18 catalytic domains rarely found in microorganisms, and PcChiF contains three GH18 catalytic domains that have never been reported. CONCLUSIONS: The 12 identified chitinolytic bacteria exhibit great potential for further studies on plant growth-promoting and/or biocontrol properties. Among these bacteria, two strains might be good candidates for next examinations concerning novel species and/or genera, and strain YSY-3.1 could possess a novel chitinolytic system.
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Quitinases , Parques Recreativos , Vietnã , Bactérias/genética , Bactérias/metabolismo , Quitinases/genética , Quitinases/metabolismo , Quitina/química , Quitina/metabolismoRESUMO
BACKGROUND: Wilson disease (WD) is a genetic disorder of copper metabolism that leads to copper accumulation in various organs, primarily the liver and brain, resulting in heterogenous hepatic, neurologic, and psychiatric symptoms. Diagnosis can occur at any age, requiring lifelong treatment, which can involve liver transplantation. This qualitative study aims to understand the wider patient and physician experience of the diagnosis and management of WD in the US. METHODS: Primary data were collected from 1:1 semi structured interviews with US-based patients and physicians and thematically analyzed with NVivo. RESULTS: Twelve WD patients and 7 specialist WD physicians (hepatologists and neurologists) were interviewed. Analysis of the interviews revealed 18 themes, which were organized into 5 overarching categories: (1) Diagnosis journey, (2) Multidisciplinary approach, (3) Medication, (4) The role of insurance, and (5) Education, awareness, and support. Patients who presented with psychiatric or neurological symptoms reported longer diagnostic journeys (range 1 to 16 years) than those presenting with hepatic symptoms or through genetic screening (range 2 weeks to 3 years). All were also affected by geographical proximity to WD specialists and access to comprehensive insurance. Exploratory testing was often burdensome for patients, but receipt of a definitive diagnosis led to relief for some. Physicians emphasized the importance of multidisciplinary teams beyond hepatology, neurology, and psychiatry and recommended a combination of chelation, zinc, and a low-copper diet; however, only half the patients in this sample were on a chelator, and some struggled to access prescription zinc due to insurance issues. Caregivers often advocated for and supported adolescents with their medication and dietary regimen. Patients and physicians recommended more education and awareness for the healthcare community. CONCLUSIONS: WD requires the coordination of care and medication among several specialists due to its complex nature, but many patients do not have access to multiple specialties due to geographical or insurance barriers. Because some patients cannot be treated in Centers of Excellence, easy access to reliable and up-to-date information is important to empower physicians, patients, and their caregivers in managing the condition, along with general community outreach programs.
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Degeneração Hepatolenticular , Médicos , Adolescente , Humanos , Degeneração Hepatolenticular/diagnóstico , Degeneração Hepatolenticular/terapia , Cobre/metabolismo , Doenças Raras/tratamento farmacológico , Zinco/uso terapêutico , AtençãoRESUMO
New essential oils (EOs) extracted from different parts of two Luvunga species (L. scandens and L. hongiaoensis) from Vietnam were investigated for their chemical composition, anti-inflammatory and cytotoxic activity. Sixty-nine total compounds were identified in the EOs by GC/MS. The major constituent of the leaf, fruit, and root EOs from L. scandens was ß-caryophyllene (71.5%, 63.0%, and 31.5% respectively). The main compounds in L. hongiaoensis EOs were ß-elemene (34.3% in leaf oil) and caryophyllene oxide (21.2% in root oil, 19.4% in stem oil). The EO from L. scandens fruits significantly inhibited nitric oxide production on LPS-induced RAW264.7 cells (IC50 = 37.95 ± 2.76 µg/mL). The EOs from L. hongiaoensis roots and L. scandens leaves and fruits exhibited cytotoxic activity against MCF-7, SK-LU-1, and HepG2 (IC50 from 49.74 ± 3.36 to 97.82 ± 8.61 µg/mL). This is the first report on L. hongiaoensis EOs and significantly complements the composition and bioactivity of L. scandens EOs.
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Two new sesquiterpene lactones, laurenolide A (1) and laurenolide B (2), along with six known compounds, palmitic acid (3), (R,R)-hexahydrofarnesyl acetone (4), trans-phytol acetate (5), cholesterol (6), cholesteryl acetate (7), cholesteryl heptadecanoate (8) were isolated from Palisada intermedia. The chemical structures of all compounds were elucidated by 1D and 2D-NMR spectroscopy and HR-ESI-MS analysis as well as compared with data in the literature. The petroleum ether, chloroform, ethyl acetate, methanol extracts and compounds 1, 2 were tested for the inhibition of two cancer cell lines MCF-7, NCI-H460 and they showed weak or none activities.
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BACKGROUND AND AIMS: Psychiatric symptoms are frequently reported in Wilson disease (WD); however, systematic assessments with validated measures are lacking. OBJECTIVE: We aim to report the prevalence and clinical correlates for major depressive disorder (MDD) as resulting from a multisite international WD registry. METHODS: All patients enrolled in the WD registry received structured psychiatric evaluations (Mini International Neuropsychiatric Interview, Patient Health Questionnaire-9, Generalized Anxiety Disorder-7 scale, Perceived Stress Scale), laboratory tests, hepatology, and neurological assessments. We present the analysis of the data collected at enrollment for the first 3 years (N = 62). RESULTS: Thirty-seven percent (23) had a lifetime history (MDD), and 6% (4) met the criteria for an active major depressive episode. Depression was self-reported in 30.51% (19) at WD diagnosis. Patients with MDD had worse mental health quality-of-life (QOL) scores (median 43 vs 53.6, P = 0.006), higher severe anxiety (13.04% vs 0), higher perceived stress (median 18 vs 9, P < 0.003), and higher levels of neuroticism (median 8 vs 5.0, P = 0.002). We found no significant difference in physical health QOL and severity of neurological or liver disease. There was no significant difference in copper parameters or liver tests in those with MDD and without. The limitations of our study consist of the small sample size, the cross-sectional report, and the lack of brain copper measurements. CONCLUSIONS: Lifetime MDD is highly prevalent in WD and associated with worse mental health QOL. We did not find a significant association among liver disease, neurological disease laboratory tests, and MDD. Screening for depression should be considered in patients with WD.
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Transtorno Depressivo Maior , Degeneração Hepatolenticular , Humanos , Transtorno Depressivo Maior/epidemiologia , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/psicologia , Qualidade de Vida/psicologia , Estudos Transversais , Degeneração Hepatolenticular/epidemiologia , Degeneração Hepatolenticular/complicações , CobreRESUMO
The Central Highlands region is considered as the center with the highest biodiversity in Vietnam because it has the majority of national parks such as Yok Don, Chu Yang Sin, Bidoup-Nui Ba, Ta Dung, Chu Mon Ray, and Kon Ka Kinh and nature reserves such as Ngoc Linh, Kon Chu Rang, Ea So, Nam Ka, and Nam Nung with different ecosystems [1]. Of the national parks and nature reserves, Yok Don has the most different ecosystem. Yok Don is the second biggest national park, and it is the only national park that conserves dry deciduous dipterocarp forests in Vietnam [2]. Presently, the decrease in forest area and global warming have led to the continuous reduction in microbial resources in this region. Thus, a dataset of the soil microbiome in this region has been established to explore microbial resources for conservation and further application in sustainable agricultural production in this region [3]; however, to the best of our knowledge, a dataset of water microbiome remains unknown. This work presented a microbiome dataset from surface water samples collected from Serepok River in Yok Don National Park, Vietnam. Metagenomic next-generation sequencing was used to characterize microbial communities in the sample. The raw sequence in this work was uploaded in Fastq format on NCBI, which can be accessed at https://www.ncbi.nlm.nih.gov/Traces/study/?acc=PRJNA853090. This metagenome dataset can provide valuable information on surface water microbial communities and their functionality. It can also be used for further studies on the conservation and application of indigenous microbial resources for sustainable crop production in this region.
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BACKGROUND: Medical students play important frontline roles in the prevention, early detection, and treatment of hepatitis C. This study investigated knowledge and attitudes toward hepatitis C among 5th- and 6th-year medical students and possible associated factors. METHODS: A cross-sectional survey was conducted among 2000 students from eight medical universities using a self-administered structured questionnaire. RESULTS: The mean knowledge and attitude scores for hepatitis C were 20.1 ± 4.0 (out of 26) and 10.6 ± 2.9 (out of 20), respectively. Approximately, three-quarters (74.4%) of the participants had a good knowledge score, but only a small proportion (3.1%) obtained a good attitude score. Although the participants had fairly high knowledge about the causes, consequences, and transmission routes of hepatitis C, there were important gaps in their knowledge about hepatitis C screening and treatment. In multivariate analysis, female students, 5th-year students, and students from the central provinces had significantly higher knowledge and attitude scores. There was a low positive correlation between knowledge and attitude scores. CONCLUSION: This study points out the need to update the medical training curriculum to improve the knowledge and attitude of students about hepatitis C infection.
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Hepatite C Crônica , Hepatite C , Estudantes de Medicina , Antivirais/uso terapêutico , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Hepacivirus , Hepatite C/tratamento farmacológico , Hepatite C/epidemiologia , Humanos , Inquéritos e Questionários , VietnãRESUMO
Vietnam is the most prominent black pepper producer and exporter in the world. In 2020, the cultivated area of black pepper in Vietnam was 132.000 hectares and its production was 270.000 tons, in which the Central Highlands region took about 70% of both the cultivated area and production [1]. Hence, this region is thought to be the capital of black pepper cultivation and production in Vietnam. Numerous researches have investigated biodiversity and collected various beneficial endophytic bacteria from this plant in this region; however, traditional methods only were used to isolate such bacteria [2], [3], [4], [5]. Therefore, these studies have a limitation to providing insight into the profiles of the endophytic microorganism dataset in the black pepper plant. Most recently, our work based on the 16S rRNA gene amplicon sequencing revealed an insight into profiles of microbial diversity and its functionality from the sample collected from a forest in this region; however, that work was just focused on soil microbiome dataset from the dry deciduous dipterocarp forest in Yok Don national park [6]. To our knowledge, a dataset of endophytic microbiome of black pepper plant cultivated in the Central Highlands remains unclear. This report presents a dataset of the endophytic microbiome from a representative sample combined from five different root samples of black pepper (Vinh Linh local variety) cultivated in the Central Highlands of Vietnam using 16S rRNA gene metagenomic next-generation sequencing. The dataset in this work can provide information on the endophytic microbial diversity and its functionality. It can also be useful for developing cultivation techniques by applying endophytic microbial genetic resources for sustainable black pepper production in the Central Highlands, Vietnam, towards the nutrient need in different stages of development and growth.
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To demonstrate that the amount of extracellular polymeric substances (EPS) and the freeze-dried viability of probiotics are correlated. Three strains of probiotics including Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Bifidobacterium bifidum were subjected to environmental challenges, such as temperature, pH, and carbon dioxide. The results indicated that the challenges could stimulate the EPS synthesis of the probiotics. The experimental correlation between the amount of synthesized EPS and the freeze-dried survival rate was also analyzed, and the viability of each of the three strains was represented by the following functions in which the equation of L. plantarum is y = - 0.0336x2 + 2.7059x - 14.849 with R2 = 0.9699, the B. bifidum's equation is y = - 0.0554x2 + 2.6243x - 13.654 with R2 = 0.9554, and the L. acidophilus's one was y = 0.0346x2 + 0.5862x - 9.1339 with R2 = 0.9733. This could be a new approach to determining the freeze-dried viability of probiotic strains based on the measured EPS content.
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Matriz Extracelular de Substâncias Poliméricas , Probióticos , Liofilização , Lactobacillus acidophilus , Taxa de SobrevidaRESUMO
BACKGROUND: Bacillus velezensis possesses numerous chitinolytic enzymes; however, not much is known about the role of its chitinase molecules. METHODS AND RESULTS: In this study, the chiA gene, which encodes a novel domain structure possessing family 18 chitinase from B. velezensis RB.IBE29, was expressed successfully in Escherichia coli BL21-CodonPlus (DE3)-RIPL using the pColdII expression vector. The recombinant protein, rBvChiA, was purified using the HisTrap FF column. Purified rBvChiA showed hydrolytic activity against insoluble chitin and bound to chitinous substrates. In addition, the purified recombinant enzyme displayed remarkable inhibition effects on the spore germination of Fusarium falciforme and the egg hatch of root-knot nematodes (Meloidogyne spp.), which are the main causes of black pepper diseases in the Central Highlands region, Vietnam. CONCLUSION: The current work results might enable further studies to develop novel chitinase A and strain RB.IBE29 as a natural fungicide and nematicide for sustainable black pepper production and other crops in the Central Highlands, Vietnam. This is the second report describing chitinase from B. velezensis based on the experimental data.