Pectinolytic enzymes that catalyze the breakdown of substrates containing pectin are widespread. Pectinases have potential applications in various industries, including food, animal feed, textile, paper, and fuel. In this study, one hundred bacterial isolates were collected from Marand city farmlands (Azarbaijan-E-Sharqi, Iran) and screened by MP medium on the base of pectinase activity considering the significance of pectinases. The results depicted that three isolates showed the most pectinase activity (more massive halo). The biochemical and molecular test results showed that the three screened bacteria were Enterobacter and named Enterobacter sp. MF41, Enterobacter sp. MF84, and Enterobacter sp. MF90. Enterobacter sp. MF84 had the largest halo, so this strain was selected for the study of its produced pectinase. The results exhibited that the produced enzyme has optimum temperature and pH for activity at 30 °C and in 9, respectively. Finally, the enzyme production by Enterobacter sp. MF84 is optimized using response surface methodology (RSM) considering four factors (NH4Cl, K2HPO4, pectin, and incubation time) as variables. The results showed that the optimization procedure increased the enzyme production up to 12 times (from 1.16 to 14.16 U/mg). The Pareto analysis revealed that ammonium chloride has a significant role in decreasing the enzyme production, probably by inducing the nitrification pathway enzymes in the presence of organic nitrogen in Enterobacter sp. MF84.
- MeSH
- Bacteria klasifikace genetika izolace a purifikace metabolismus MeSH
- bakteriální proteiny metabolismus MeSH
- Enterobacter klasifikace genetika izolace a purifikace metabolismus MeSH
- farmy MeSH
- fermentace MeSH
- fylogeneze MeSH
- koncentrace vodíkových iontů MeSH
- kultivační média chemie MeSH
- pektiny analýza metabolismus MeSH
- polygalakturonasa metabolismus MeSH
- půdní mikrobiologie MeSH
- RNA ribozomální 16S genetika MeSH
- statistické modely MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Írán MeSH
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
Bacteriophages are ubiquitous in nature and represent a vast repository of genetic diversity, which is driven by the endless coevolution cycle with a diversified group of bacterial hosts. Studying phage-host interactions is important to gain novel insights into their dynamic adaptation. In this study, we isolated 12 phages infecting species of the Acinetobacter baumannii-Acinetobacter calcoaceticus complex which exhibited a narrow host range and similar morphological features (podoviruses with short tails of 9-12 nm and isometric heads of 50-60 nm). Notably, the alignment of the newly sequenced phage genomes (40-41 kb of DNA length) and all Acinetobacter podoviruses deposited in Genbank has shown high synteny, regardless of the date and source of isolation that spans from America to Europe and Asia. Interestingly, the C-terminal pectate lyase domain of these phage tail fibres is often the only difference found among these viral genomes, demonstrating a very specific genomic variation during the course of their evolution. We proved that the pectate lyase domain is responsible for phage depolymerase activity and binding to specific Acinetobacter bacterial capsules. We discuss how this mechanism of phage-host co-evolution impacts the tail specificity apparatus of Acinetobacter podoviruses.
- MeSH
- Acinetobacter baumannii virologie MeSH
- Acinetobacter calcoaceticus virologie MeSH
- genom virový genetika MeSH
- hostitelská specificita fyziologie MeSH
- Podoviridae klasifikace genetika metabolismus MeSH
- polygalakturonasa metabolismus MeSH
- polysacharid-lyasy metabolismus MeSH
- proteinové domény fyziologie MeSH
- sekvence nukleotidů MeSH
- virion genetika MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Asie MeSH
- Evropa MeSH
A thermotolerant fungus identified as Aspergillus niveus was isolated from decomposing materials and it has produced excellent levels of hydrolytic enzymes that degrade plant cell walls. A. niveus germinated faster at 40 °C, presenting protein levels almost twofold higher than at 25 °C. The crude extract of the A. niveus culture was purified by diethylaminoethyl (DEAE)-cellulose, followed by Biogel P-100 column. Polygalacturonase (PG) is a glycoprotein with 37.7 % carbohydrate, molecular mass of 102.6 kDa, and isoelectric point of 5.4. The optimum temperature and pH were 50 °C and 4.0-6.5, respectively. The enzyme was stable at pH 3.0 to 9.0 for 24 h. The DEAE-cellulose derivative was about sixfold more stable at 60 °C than the free enzyme. Moreover, the monoaminoethyl-N-aminoethyl-agarose derivative was tenfold more stable than the free enzyme. PG was 232 % activated by Mn(2+). The hydrolysis product of sodium polypectate corresponded at monogalacturonic acid, which classifies the enzyme as an exo-PG. The K m, V max, K cat, and K cat/K m values were 6.7 mg/ml, 230 U/mg, 393.3/s, and 58.7 mg/ml/s, respectively. The N-terminal amino acid sequence presented 80 % identity with PglB1, PglA2, and PglA3 putative exo-PG of Aspergillus fumigatus and an exo-PG Neosartorya fischeri.
- MeSH
- aktivátory enzymů metabolismus MeSH
- Aspergillus enzymologie růst a vývoj izolace a purifikace MeSH
- fylogeneze MeSH
- izoelektrický bod MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- kyseliny hexuronové metabolismus MeSH
- mangan metabolismus MeSH
- mikrobiologie životního prostředí MeSH
- molekulová hmotnost MeSH
- polygalakturonasa chemie izolace a purifikace metabolismus MeSH
- sekvenční homologie aminokyselin MeSH
- shluková analýza MeSH
- stabilita enzymů MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Pseudomonas chlororaphis strain 449 isolated from the rhizosphere of maize suppresses numerous plant pathogens in vitro. The strain produces phenazine antibiotics and synthesizes at least three types of quorum sensing signaling molecules, N-acylhomoserine lactones. Here we have shown that the rhizospheric P. chlororaphis strains 449, well known strain 30-84 as well as two other P. chlororaphis strains exhibit polygalacturonase activity. Using mini-Tn5 transposon mutagenesis, four independent mutants of strain P. chlororaphis 449 with insertion of mini-Tn5 Km2 in gene gacS of two-component GacA-GacS system of global regulation were selected. All these mutant strains were deficient in production of extracellular proteinase(s), phenazines, N-acylhomoserine lactones synthesis, and did not inhibit the growth of G(+) bacteria in comparison with the wild type strain. The P. chlororaphis 449-06 gacS (-) mutant studied in greater detail was deficient in polygalacturonase, pectin methylesterase activities, swarming motility and antifungal activity. It is the first time the involvement of GacA-GacS system in the regulation of enzymes of pectin metabolism, polygalacturonase and pectin methylesterase, was demonstrated in fluorescent pseudomonads.
- MeSH
- antibióza MeSH
- bakteriální proteiny genetika metabolismus MeSH
- houby fyziologie MeSH
- karboxylesterhydrolasy genetika metabolismus MeSH
- laktony metabolismus MeSH
- mutace MeSH
- polygalakturonasa genetika metabolismus MeSH
- Pseudomonas enzymologie fyziologie genetika MeSH
- půdní mikrobiologie MeSH
- regulace genové exprese u bakterií MeSH
- transkripční faktory genetika metabolismus MeSH
- vývojová regulace genové exprese MeSH
- MeSH
- Bacteroides metabolismus MeSH
- finanční podpora výzkumu jako téma MeSH
- glukosa metabolismus MeSH
- králíci MeSH
- pektiny metabolismus MeSH
- polygalakturonasa metabolismus MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
