scholarly journals A Highly Thermostable Xylanase from Stenotrophomonas maltophilia: Purification and Partial Characterization

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Abhay Raj ◽  
Sharad Kumar ◽  
Sudheer Kumar Singh

Seven xylanolytic bacterial strains were isolated from saw-dust dump soil. The bacterial strain X6 was selected on the basis of the highest xylanase activity with no cellulase contamination. It was identified as Stenotrophomonas maltophilia by biochemical tests and 16S rRNA gene sequencing approach. Xylanase production studies by S. maltophilia on different commercial xylans and agro-industrial residues suggested that wheat bran was the best carbon source for xylanase production (26.4 ± 0.6 IU/mL). The studies with inorganic and organic nitrogen sources suggested yeast extract as the best support for xylanase production (25 ± 0.6 IU/mL). Maximum xylanase production was observed at initial medium pH = 8.0 (23.8 ± 0.4 IU/mL) with production at pH = 7.0 and pH = 9.0 being almost comparable. Xylanase produced by S. maltophilia was purified to homogeneity using ammonium sulfate precipitation, gel filtration, and ion exchange chromatography. The final purification was 5.43-fold with recovery of 19.18%. The molecular weight of the purified xylanase protein was ~142 kDa. Both crude and purified xylanase had good stability at pH = 9.0 and 80°C with activity retention greater than 90% after 30 min incubation. The enzyme stability at high temperature and alkaline pH make it potentially effective for industrial applications.

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Rajeeva Gaur ◽  
Soni Tiwari ◽  
Priyanka Rai ◽  
Versha Srivastava

Sixty bacterial strains isolated from the soils sample in the presence of organic solvent were screened for xylanase production. Among them, strain RSPP-15 showed the highest xylanase activity which was identified asBacillus vallismortis. The isolate showed maximum xylanase production (3768 U/mL) in the presence of birch wood xylan and beef extract at 55°C pH 7.0 within 48 h of incubation. The enzyme activity and stability were increased 181.5, 153.7, 147.2, 133.6, and 127.9% and 138.2, 119.3, 113.9, 109, and 104.5% in the presence of Co2+, Ca2+, Mg+2, Zn+2, and Fe+3ions (10 mM). Xylanase activity and stability were strongly inhibited in the presence of Hg and Cu ions. The enzyme was also stable in the presence of 30% ofn-dodecane, isooctane,n-decane, xylene, toluene,n-hexane,n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the xylanase stability, respectively. This isolate may be useful in several industrial applications owing to its thermotolerant and organic solvent resistance characteristics.


Author(s):  
P. Kämpfer ◽  
N. Lodders ◽  
E. Falsen

Three bacterial strains, designated CCUG 51397T, CCUG 53736 and CCUG 53920, isolated from water samples taken at different locations in southern Sweden were studied to determine their taxonomic position using a polyphasic approach. Comparative analysis of 16S rRNA gene sequences showed that these bacteria had <93 % sequence similarity to all described species of the genera Sediminibacterium, Lacibacter, Flavihumibacter, Flavisolibacter, Niabella, Niastella, Segetibacter, Parasegetibacter, Terrimonas, Ferruginibacter, Filimonas and Chitinophaga. The three organisms grouped most closely with Sediminibacterium salmoneum NJ-44T but showed only 92.5 % sequence similarity to this strain, the only recognized species of this genus. The fatty acid profiles showed large amounts of iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G with smaller amounts of iso-C15 : 0 3-OH, iso-C16 : 0 3-OH and other fatty acids, which differentiated the novel strains from related genera. Biochemical tests performed on strains CCUG 51397T, CCUG 53736 and CCUG 53920 also gave different results from those of Sediminibacterium salmoneum NJ-44T and other related genera. Based on this evidence, strains CCUG 51397T, CCUG 53736 and CCUG 53920 represent a novel species of a new genus, for which the name Hydrotalea flava gen. nov., sp. nov. is proposed. The type strain of Hydrotalea flava is CCUG 51397T (=CCM 7760T). A formal allocation of the genera Sediminibacterium, Lacibacter, Flavihumibacter, Flavisolibacter, Niabella, Niastella, Segetibacter, Parasegetibacter, Terrimonas, Ferruginibacter, Filimonas and Chitinophaga to the family Chitinophagaceae fam. nov. is also proposed.


2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Mohamed Ahmed ◽  
Md. Mohibul Alam Khan ◽  
Saleh M. S. Al-Garni ◽  
Roop Singh Bora ◽  
Saleh A. Kabli

Halophilic bacteria are a microorganism that grows optimally in the presence of the very high concentration of sodium chloride. Halophiles are vital sources of various enzymes including hydrolases, which are very stable and catalytically highly efficient at high salt concentration and other extreme conditions such as high temperature, pH and presence of organic solvents.  Several hydrolases such as amylases, proteases, and lipases have been obtained from halophilic bacteria and are commonly used for various industrial applications. We initiated a screening project to isolate and characterize the halophilic bacteria from the Red Sea, which is one of the saltiest bodies of water in the world. Water and soil samples, collected from the Red Sea coast, Jeddah, Saudi Arabia, were screened for isolation of halophilic bacteria. Ten bacterial isolates were obtained, which were characterized by biochemical tests and 16S rRNA gene sequencing. Hydrolase producing bacteria among the isolates were screened by plate assay on starch and gelatin agar plates for amylase and protease, respectively.  Two bacterial isolates i.e Bacillus haynesii and Enterobacter cloacae subsp. were found to possess significant amylase and protease activity. Further characterization of both the strains is in progress.


2005 ◽  
Vol 55 (6) ◽  
pp. 2309-2315 ◽  
Author(s):  
Yuichi Nogi ◽  
Hideto Takami ◽  
Koki Horikoshi

Twenty alkaliphilic bacterial strains from industrial applications or enzyme studies were subjected to a polyphasic taxonomic investigation, including 16S rRNA gene sequencing, determination of genomic DNA G+C content, DNA–DNA hybridization, fatty acid analysis and standard bacteriological characterization. By comparing the groupings obtained based on the genomic DNA G+C content and the construction of a phylogenetic tree based on the 16S rRNA gene sequence, 12 clusters of similar strains were recognized. DNA–DNA hybridization revealed that these clusters represented five novel genospecies. Further analysis supported the proposal of five novel species in the genus Bacillus: Bacillus wakoensis sp. nov. (type strain N-1T=JCM 9140T=DSM 2521T), Bacillus hemicellulosilyticus sp. nov. (type strain C-11T=JCM 9152T=DSM 16731T), Bacillus cellulosilyticus sp. nov. (type strain N-4T=JCM 9156T=DSM 2522T), Bacillus akibai sp. nov. (type strain 1139T=JCM 9157T=ATCC 43226T) and Bacillus mannanilyticus sp. nov. (type strain AM-001T=JCM 10596T=DSM 16130T).


2010 ◽  
Vol 60 (1) ◽  
pp. 229-233 ◽  
Author(s):  
Xuesong Luo ◽  
Zhang Wang ◽  
Jun Dai ◽  
Lei Zhang ◽  
Jun Li ◽  
...  

Two Gram-staining-negative, rod-shaped, non-spore-forming bacterial strains, 1-2T and 1-4 were isolated from dry riverbed soil collected from the Xietongmen area of Tibet, China. On the basis of 16S rRNA gene sequence similarity, the novel strains were shown to belong to the genus Pedobacter, sharing <95 % sequence similarity with all recognized species of the genus Pedobacter. The major respiratory quinone was MK-7 and the predominant cellular fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (comprising iso-C16 : 1 ω7c and/or C16 : 1 ω6c). The DNA G+C contents were 37.2–37.6 mol%. Chemotaxonomic data supported the affiliation of the two new isolates to the genus Pedobacter and the results of physiological and biochemical tests confirmed that the new strains differed significantly from the recognized species of the genus Pedobacter. Therefore, the new isolates represent a novel species within the genus Pedobacter, for which the name Pedobacter glucosidilyticus sp. nov. is proposed. The type strain is 1-2T (=CCTCC AB 206110T=KCTC 22438T).


Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 520
Author(s):  
Olga Nedashkovskaya ◽  
Nadezhda Otstavnykh ◽  
Natalia Zhukova ◽  
Konstantin Guzev ◽  
Viktoria Chausova ◽  
...  

Six Gram-stain-negative, aerobic, rod-shaped, and motile by gliding bacterial strains were isolated from Pacific green and red algae. Phylogenetic analysis based on 16S rRNA gene sequences placed the novel strains into the genus Zobellia as a distinct evolutionary lineage close to Zobellia nedashkovskayae Asnod2-B07-BT and Zobellia laminariae KMM 3676T sharing the highest similarity of 99.7% and 99.5%, respectively. The average nucleotide identity and the average amino acid identity values between strains 36-CHABK-3-33T and Z. nedashkovskayae Asnod2-B07-BT and Z. laminariae KMM 3676T were 89.7%/92.9% and 94.2%/95.8%, respectively. The digital DNA–DNA hybridization values based on the draft genomes between strains 36-CHABK-3-33T and Z. nedashovskayae Asnod2-B07-BT and Z. laminariae KMM 3676T were 39.5 ± 2.5% and 59.6 ± 2.7%, respectively. Multilocus sequence analysis based on house-keeping genes (dnaK, gyrB, pyrH, recA and topA) assigned the alga-associated isolates to the same species, which clustered separately from the recognized species of the genus Zobellia. The strains under study grew at 4–32 °C and with 0.5–8% NaCl and decomposed aesculin, gelatin, DNA, and Tweens 20 and 80, and weakly agar. The DNA G+C content was 36.7% calculated from genome sequence analysis for the strain 36-CHABK-3-33T. The predominant fatty acids of strain 36-CHABK-3-33T (> 5% of the total fatty acids) were iso-C17:0 3-OH, summed feature 3 (comprising C16:1 ω7c and/or iso-C15:0 2-OH fatty acids), iso-C15:0, iso-C15:1 G, and C15:0. The major polar lipids were phosphatidylethanolamine, three unidentified lipids, and two unidentified aminolipids. The only detected respiratory quinone was MK-6. The significant molecular distinctiveness between the novel isolates and their nearest neighbor was strongly supported by differences in physiological and biochemical tests. Therefore, the six novel strains represent a novel species of the genus Zobellia, for which the name Zobellia barbeyronii sp. nov. is proposed. The type strain is 36-CHABK-3-33T (= KACC 21790T = KMM 6746T).


2014 ◽  
Vol 80 (8) ◽  
pp. 2592-2601 ◽  
Author(s):  
Kundi Zhang ◽  
Xiaohua Chen ◽  
Wolfgang H. Schwarz ◽  
Fuli Li

ABSTRACTTwo cellulolytic thermophilic bacterial strains, CS-3-2 and CS-4-4, were isolated from decayed cornstalk by the addition of growth-supporting factors to the medium. According to 16S rRNA gene-sequencing results, these strains belonged to the genusClostridiumand showed 98.87% and 98.86% identity withClostridiumstercorariumsubsp.leptospartumATCC 35414TandClostridiumcellulosiAS 1.1777T, respectively. The endoglucanase and exoglucanase activities of strain CS-4-4 were approximately 3 to 5 times those of strain CS-3-2, whereas the β-glucosidase activity of strain CS-3-2 was 18 times higher than that of strain CS-4-4. The xylanase activity of strain CS-3-2 was 9 times that of strain CS-4-4, whereas the β-xylosidase activity of strain CS-4-4 was 27 times that of strain CS-3-2. The enzyme activities in spent cultures following cocultivation of the two strains with cornstalk as the substrate were much greater than those in pure cultures or an artificial mixture of samples, indicating synergism of glycoside hydrolase secretomes between the two strains. Quantitative measurement of the two strains in the cocultivation system indicated that strain CS-3-2 grew robustly during the initial stages, whereas strain CS-4-4 dominated the system in the late-exponential phase. Liquid chromatography-tandem mass spectrometry analysis of protein bands appearing in the native zymograms showed that ORF3880 and ORF3883 from strain CS-4-4 played key roles in the lignocellulose degradation process. Both these open reading frames (ORFs) exhibited endoglucanase and xylanase activities, but ORF3880 showed tighter adhesion to insoluble substrates at 4, 25, and 60°C owing to its five carbohydrate-binding modules (CBMs).


1991 ◽  
Vol 278 (2) ◽  
pp. 329-333 ◽  
Author(s):  
L Huang ◽  
T H Hseu ◽  
T T Wey

Trichoderma koningii G-39 produced xylanases in submerged culture using oat spelt xylan or crystalline cellulose, Avicel, as the sole carbon source. A low-Mr xylanase was purified from the culture filtrate by ion-exchange chromatography on SP-Trisacryl-M and gel filtration on Fractogel TSK HW-50F. It was homogeneous on SDS/PAGE and isoelectric focusing. A typical procedure provided about 11-fold purification with 4.5% protein yield and 50% activity recovery. The purified enzyme has an Mr value of about 21,500 and a pI of 8.9. Its specific activity was 6100 units/mg of protein, with optimal activity towards 0.5% xylan at about pH 5.5 and 60 degrees C. The purified enzyme had no activity against CM-cellulose with a degree of substitution of 0.63. It also showed no beta-xylosidase activity. The Km and Vmax. values, as determined with the soluble fraction of oat spelt xylan as substrate, were 0.70 mg/ml and 1.85 x 10(6) mumol/min per mg of enzyme respectively. Hg2+ (1 mM) and SDS (10 mM) completely inhibited xylanase activity, whereas Ca2+ showed no significant effect on the enzyme activity at 1 mM, but gave 80% inhibition at 10 mM. The enzyme contained about 4.4% carbohydrate and showed an immunological relationship to a cellobiohydrolase from the same fungal strain.


2006 ◽  
Vol 56 (2) ◽  
pp. 343-347 ◽  
Author(s):  
Yukiyo Fukunaga ◽  
Midori Kurahashi ◽  
Kenji Tanaka ◽  
Kensuke Yanagi ◽  
Akira Yokota ◽  
...  

Two bacterial strains, F423T and F10102, were isolated from two ascidians, Polycitor proliferus and Botryllidae sp., respectively, which were collected from a beach on the Boso peninsula in Japan. Cells of both isolates were motile, rod-shaped and formed star-shaped aggregates in the early stage of exponential growth, but were coccoid in stationary growth phase. The results of 16S rRNA gene sequence analysis, fatty acid analysis, DNA–DNA hybridization experiments and physiological and biochemical tests indicated that the two strains were members of a novel species of the genus Pseudovibrio for which the name Pseudovibrio ascidiaceicola sp. nov. is proposed. The type strain is F423T (=NBRC 100514T=IAM 15084T=DSM 16392T=KCTC 12308T).


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Rosa Acevedo-Barrios ◽  
Angela Bertel-Sevilla ◽  
Jose Alonso-Molina ◽  
Jesus Olivero-Verbel

Perchlorate (ClO4−) has several industrial applications and is frequently detected in environmental matrices at relevant concentrations to human health. Currently, perchlorate-degrading bacteria are promising strategies for bioremediation in polluted sites. The aim of this study was to isolate and characterize halophilic bacteria with the potential for perchlorate reduction. Ten bacterial strains were isolated from soils of Galerazamba-Bolivar, Manaure-Guajira, and Salamanca Island-Magdalena, Colombia. Isolates grew at concentrations up to 30% sodium chloride. The isolates tolerated pH variations ranging from 6.5 to 12.0 and perchlorate concentrations up to 10000 mg/L. Perchlorate was degraded by these bacteria on percentages between 25 and 10. 16S rRNA gene sequence analysis indicated that the strains were phylogenetically related toVibrio,Bacillus,Salinovibrio,Staphylococcus, andNesiotobactergenera. In conclusion, halophilic-isolated bacteria from hypersaline soils of the Colombian Caribbean are promising resources for the bioremediation of perchlorate contamination.


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