Thuricin 4AJ1, produced by Bacillus thuringiensis strain 4AJ1, showed inhibition activity against Bacillus cereus 0938 and ATCC 10987. It began to appear in the stationary phase and reached its maximum activity level of 209.958 U at 18 h against B. cereus 0938 and 285.689 U at 24 h against B. cereus ATCC 10987. Tricine-SDS-PAGE results showed that the partly purified thuricin 4AJ1 was about 6.5 kDa. The molecular weights of the known B. thuringiensis bacteriocins and the ones obtained by the two mainstream websites for predicting bacteriocins were inconsistent with the size of the thuricin 4AJ1, indicating that the bacteriocin obtained in this study may have a novel structure. Based on the biochemical properties, the thuricin 4AJ1 activities increased after treatment with proteinase K and lipase II, and were not affected by a-amylase, catalase, α-chymotrypsin VII and α-chymotrypsin II. It was heat tolerant, being active up to 90º C. In the pH 3-10 range, it maintained most of its activity. Finally, the sensitivity of the strain 4AJ1 to commonly used antibiotics was tested. In view of its stability and antibacterial activity, thuricin 4AJ1 may be applied as a food biopreservative.
- MeSH
- antibakteriální látky farmakologie MeSH
- Bacillus cereus účinky léků MeSH
- Bacillus thuringiensis chemie metabolismus MeSH
- bakteriociny chemie izolace a purifikace farmakologie MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- molekulová hmotnost MeSH
- potravinářská mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
Bacillus thuringiensis (Bt) is efficient, strongly specific, and avirulent to humans, making it one of the most popular biopesticides in the world. Bt LLP29 is a mosquitocidal strain that was first isolated from Magnolia denudata. To understand its molecular mechanism against mosquitoes, the genome of Bt LLP29 was sequenced and annotated in this study. The LLP29 genome was found to have a total length of 5.99 Mb, with an average G + C content of 35.21%. A total of 6107 coding sequences were also detected, together with 42 rRNAs and 124 tRNAs and 135 other RNAs. With the help of annotation databases, including GO, COG, KEGG, Nr and Swiss-Prot, most unigene functions were identified. At the same time, a collinear analysis was performed on the genome of LLP29. There were also some virulence genes detected, including cry, chitinase, zwittermicin and vip.
Pectinase is widely used in numerous industrial fields, including the food, wine, and paper industries. In this work, seven bacteria were isolated from orange peel and their pectinase production activity was assayed. One bacterium (OR-B2) identified as a Bacillus sp. showed the highest enzyme activity towards others. A gene encoding a pectate lyase designed as PelB-B2 in this work was amplified and heterogeneous expressed in E.coli. PelB-B2 was defined as a member of the PelB pectate lyase family after phylogenic tree analysis. 3D model of PelB-B2 was constructed by SWISS-MODEL and PelB-B2 showed conserved para-β structure. After inducing culture and purified by Ni-affinity chromatography, the properties of the purified PelB-B2 were assayed. Optimal pH and temperature for PelB-B2 was pH 8.0 and 50 °C, respectively. PelB-B2 showed excellent pH stability and thermostability. It was stable within pH range 3.0-11.0 and retained more than 51% activity after incubation at 40 °C, 50 °C, or 60 °C for 1 h. Furthermore, we determined that PelB-B2 was a Ca2+-dependent pectinase and the pectin extracted from citrus was the benefit substrate for PelB-B2. The Km and Vmax of PelB-B2 were 1.64 g/L and 232.56 mol/(L min), respectively. The OR-B2 can be a new resource for pectinase production and the PelB-B2 has potential for industrial application. 7 bacteria were isolated from orange peel, namely OR-B1 to OR-B7 and their pectinase activities were assayed. One pectate lyase belongs to PelB family was cloned from OR-B2 and heterogeneous expressed in E. coli. Purified PelB-B2 was further studied with its properties. Effects of pH, temperature, chemicals, substrate on the enzyme activity were assayed and the enzyme kinetic was also measured.
- MeSH
- Bacillus enzymologie genetika metabolismus MeSH
- Citrus metabolismus MeSH
- Escherichia coli genetika metabolismus MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- pektiny metabolismus MeSH
- polygalakturonasa biosyntéza metabolismus MeSH
- polysacharid-lyasy metabolismus MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
A novel Bacillus thuringiensis (Bt) bacteriocin BtCspB, active against a food-borne pathogen Bacillus cereus, was identified and purified by a traditional four-step chromatographic process with low yield (44.5 µg/L) in our lab previously. The aim of this study was to dramatically increase its yield by heterologous expression of BtCspB. The BtCspB gene from Bt BRC-ZYR2 was successfully heterologously expressed in Escherichia coli BL21 (DE3). Affinity chromatography was used to obtain the pure BtCspB up to 20 mg/L. The purified BtCspB showed a MIC value of 12.5 µg/mL and a MBC value of 50.0 µg/mL against Bacillus cereus ATCC 10987. The bacteriocin activity of BtCspB against B. cereus ATCC 10987 was further directly detected in a gel-overlay assay. The anti-B. cereus activity, however, was lower than the bacteriocin purified by the traditional four-step chromatographic process probably because of structural modifications. Compared with the traditional method, the yield of the bacteriocin by heterologous expression increased by 449 times, and the purification step was dramatically simplified, which laying a foundation for the industrial production of this novel cold-shock protein-like bacteriocin BtCspB active against B. cereus.
- MeSH
- Bacillus cereus účinky léků MeSH
- Bacillus thuringiensis genetika metabolismus MeSH
- bakteriální proteiny genetika izolace a purifikace farmakologie MeSH
- bakteriociny farmakologie MeSH
- Escherichia coli genetika růst a vývoj MeSH
- mikrobiální testy citlivosti MeSH
- Publikační typ
- časopisecké články MeSH
Ectropis oblique Prout (Lepidoptera: Geometridae) is one of the main pests that damages the tea crop in Southeast Asia. To understand the molecular mechanisms of its feeding biology, transcriptomes of the alimentary tract (AT) and of the body minus the AT of E. oblique were successfully sequenced and analyzed in this study. A total of 36,950 unigenes from de novo sequences were assembled. After analysis using six annotation databases (e.g., Gene Ontology, Kyoto Encyclopedia of Genes and Genome, and NCBI nr), a series of putative genes were found for this insect species that were related to digestion, detoxification, the immune system, and Bacillus thuringiensis (Bt) receptors. From this series of genes, 21 were randomly selected to verify the relative expression levels of transcripts using quantitative real-time polymerase chain reaction. These results will provide an invaluable genomic resource for future studies on the molecular mechanisms of E. oblique, which will be useful in developing biological control strategies for this pest.
Persistence of Bacillus thuringiensis is an important factor in determining the success of this product as a pest control agent. In this report we present the development of a highly active mosquitocidal formulation with high resistance to UV. LLP29-M19 strain of Bt, selected by repeated exposure to UV was found to be highly resistant to UV. The product was optimized and the methods used were statistically analyzed. Using single-factor experiments it was determined that the optimal concentration of sodium alginate, CaCl2 and hollow glass beads in the formulation were 1.0%, 2.0% and 3.5%, respectively. Plackett-Burman design was used to screen the interaction of the three factors, CaCl2, sodium alginate and hollow glass beads in the sustained-release formulation. The best combined concentration and mutual effects of the three factors were optimized by response surface methodology. The results showed that the most favorable composition was sodium alginate 0.78%, CaCl2 4.52%, hollow glass bead 3.12%, bacterial powder 3.0%, melanin 0.015%, sodium benzoate 0.2%, and mouse feed 0.5%, resulting in the immobilization time of 4.5 h, at which time the corrected sustained-release virulence rose 2391.67 fold, which was 6.07-fold higher than the basic formulation and deviated only 5.0% from the value predicted by RSM.
- MeSH
- algináty farmakologie MeSH
- Bacillus thuringiensis fyziologie MeSH
- bakteriální proteiny farmakologie MeSH
- biologická kontrola škůdců metody MeSH
- biologická ochrana farmakologie MeSH
- chemie farmaceutická metody MeSH
- Culicidae účinky léků MeSH
- kyselina glukuronová farmakologie MeSH
- kyseliny hexuronové farmakologie MeSH
- larva účinky léků MeSH
- léky s prodlouženým účinkem farmakologie MeSH
- moskyti - kontrola metody MeSH
- ultrafialové záření MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Gene expression profiles are important data to reveal the functions of genes putatively involved in crucial biological processes. RNA arbitrarily primed polymerase chain reaction (RAP-PCR) and specifically primed reverse transcription polymerase chain reaction (RT-PCR) were combined to screen differentially expressed genes following development of a commercial Bacillus thuringiensis subsp. kurstaki strain 8010 (serotype 3a3b). Six differentially expressed transcripts (RAP1 to RAP6) were obtained. RAP1 encoded a putative triple helix repeat-containing collagen or an exosporium protein H related to spore pathogenicity. RAP2 was homologous to a ClpX protease and an ATP-dependent protease La (LonB), which likely acted as virulence factors. RAP3 was homologous to a beta subunit of propionyl-CoA carboxylase required for the development of Myxococcus xanthus. RAP4 had homology to a quinone oxidoreductase involved in electron transport and ATP formation. RAP5 showed significant homology to a uridine kinase that mediates phosphorylation of uridine and azauridine. RAP6 shared high sequence identity with 3-methyl-2-oxobutanoate-hydroxymethyltransferase (also known as ketopantoate hydroxymethyltransferase or PanB) involved in the operation of the tricarboxylic acid cycle. The findings described here would help to elucidate the molecular mechanisms underlying the differentiation process of B. thuringiensis and unravel novel pathogenic genes.
- MeSH
- Bacillus thuringiensis klasifikace genetika růst a vývoj izolace a purifikace MeSH
- bakteriální proteiny genetika metabolismus MeSH
- DNA fingerprinting metody MeSH
- polymerázová řetězová reakce s reverzní transkripcí metody MeSH
- regulace genové exprese u bakterií MeSH
- spory bakteriální klasifikace genetika růst a vývoj metabolismus MeSH
- vývojová regulace genové exprese MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
An understanding of how climate variables drive seasonal dynamics of mosquito populations is critical to mitigating negative impacts of potential outbreaks, including both nuisance effects and risk of mosquito-borne infectious disease. Here, we identify climate variables most affecting seasonal dynamics of two major floodwater mosquitoes, Aedes vexans (Meigen, 1830) and Aedes sticticus (Meigen, 1838) (Diptera: Culicidae), along the lower courses of the Dyje River, at the border between the Czech Republic and Austria. Monthly trap counts of both floodwater mosquitoes varied both across sites and years. Despite this variability, both models used to fit the observed data at all sites (and especially that for Ae. sticticus) and site-specific models fitted the observed data quite well. The most important climate variables we identified-temperature and especially flooding-were driving seasonal dynamics of both Aedes species. We suggest that flooding determines seasonal peaks in the monthly mosquito trap counts while temperature modulates seasonality in these counts. Hence, floodwater mosquitoes indeed appear worthy of their name. Moreover, the climate variables we considered for modeling were able reasonably to predict mosquito trap counts in the month ahead. Our study can help in planning flood management; timely notification of people, given that these mosquitoes are a real nuisance in this region; public health policy management to mitigate risk from such mosquito-borne diseases as that caused in humans by the Tahyna virus; and anticipating negative consequences of climate change, which are expected only to worsen unless floods, or the mosquitoes themselves, are satisfactorily managed.
- MeSH
- Culicidae * MeSH
- hmyz - vektory MeSH
- moskyti - kontrola MeSH
- podnebí MeSH
- populační dynamika MeSH
- statistické modely MeSH
- záplavy * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- validační studie MeSH
- Geografické názvy
- Rakousko MeSH
- východní Evropa MeSH
- Publikační typ
- abstrakt z konference MeSH
