Isolation and Characterization of a Novel Bacillus subtilis WD23 Exhibiting Laccase Activity from Forest Soil

2010 ◽  
Vol 113-116 ◽  
pp. 725-729 ◽  
Author(s):  
Chun Lei Wang ◽  
Min Zhao ◽  
De Bin Li ◽  
Dai Zong Cui ◽  
Hong Yi Yang ◽  
...  

The strain Bacillus sp. WD23 exhibiting laccase activity was screened from forest soil. The M9 medium containing Cu2+ was used for enriching and isolating bacterial strains capable of oxidizing syringaldazine (SGZ). One isolated strain was identified as Bacillus subtilis WD23 based on the results of physiological and biochemical tests and 16S rDNA sequence analysis. The strain WD23 could grow at temperatures ranging from 20 to 55°C and showed optimum growth temperature and pH at 25°C and 7.0, respectively. The sporulation rate of the strain clearly correlated well with the laccase activity. The temperature half-life of the spore laccase was 2.5 h at 80°C and the pH half-life was 15 d at pH 9.0. Its spore laccase could decolorized 50~90% of Remazol brilliant blue R (RBBR), alizarin red, congo red, methyl orange and methyl violet, which suggests the potential application of spore laccase in dyestuff treatment.

2011 ◽  
Vol 183-185 ◽  
pp. 773-777 ◽  
Author(s):  
Jun Bo Pan ◽  
Min Zhao ◽  
Lei Lu ◽  
Mei Hui Du ◽  
Guo Fu Li ◽  
...  

Bacterial strains exhibiting laccase activity were isolated from the forest soil. A strain LC02 with syringaldazine oxidation ability was obtained using enrichment medium supplemented with copper ions. The isolated strain was identified as Bacillus amyloliquefaciens using physiological and biochemical tests as well as 16S rDNA sequence analysis. The characterization of spore laccase activity was investigated. The result showed that the optimum pH and temperature of the enzyme was 6.6 and 70°C, respectively. A great thermostability was observed for the spore laccase at 70°C. Laccase activity was strongly inhibited by 0.1 mmol/L NaN3, dithiothreitol and cysteine.


2015 ◽  
Vol 77 (31) ◽  
Author(s):  
Suganthi Thevarajoo ◽  
Chitra Selvaratnam ◽  
Kian Mau Goh ◽  
Fazilah Abd. Manan ◽  
Zaharah Ibrahim ◽  
...  

Marine environment remained as largely unexplored source for researchers to discover marine microorganisms with novel properties. This study aims to isolate marine bacteria from the seashore of Desaru, Malaysia. Totally, six bacterial strains were successfully obtained and were identified by complete 16S rRNA sequencing. The characterizations of bacterial strains were performed based on morphological tests, Gram-staining, biochemical tests, and antibiotic sensitivity. The 16S rRNA sequence of D-2, D-4, D-7, D-15, D-31, and D-33 revealed a high identity of 97 to 99% with taxa belong to genera of Pseudomonas, Marinomonas, Exiquobacterium, Micrococcus, Pseudoalteromonas, and Shewanella respectively. Strain D-31 exhibited higher tolerance towards antibiotics kanamycin, ampicillin, and erythromycin while the growth of other strains were retarded by at least two of these antibiotics. We further characterized strain D-4 and D-31 that belonged to Marinomonas sp. and Pseudoalteromonas sp.. Both genera are interesting as earlier researchers have discovered new antibacterial substances, industrial enzymes and unique secondary metabolites.


2011 ◽  
Vol 183-185 ◽  
pp. 839-843
Author(s):  
Mei Hui Du ◽  
Min Zhao ◽  
Lei Lu ◽  
Tian Nv Wang ◽  
Tai Lun Li ◽  
...  

A newly isolated strain LS02 was estimated for its ability in dye decolorization. The LS02 strain was identified as Bacillus subtilis by the combination of physicochemical tests and 16S rDNA sequence analysis. The isolated strain could oxidize the laccase substrate syringaldazine, indicating the existence of laccase activity. B. subtilis LS02 grown well in the pH range of 5.0~9.0, and showed an optimum growth temperature at 37°C. Indigo carmine could be completely decolorized by B. subtilis LS02 after 4 days, whereas Remazol Brilliant Blue R, reactive black 5 and crystal violet were poorly decolorized. The result indicated that the laccase of B. subtilis LS02 may be suitable for the application in textile bleaching of indigo carmine.


Plant Disease ◽  
2005 ◽  
Vol 89 (12) ◽  
pp. 1273-1278 ◽  
Author(s):  
Lisa M. Keith ◽  
Kelvin T. Sewake ◽  
Francis T. Zee

Bacterial diseases of orchids continue to be serious problems. Bacterial strains were isolated from orchid plants exhibiting disease symptoms in Hawaii. Small to large leaf spots with or without water-soaking or soft rots were observed on various orchid genera, including Dendrobium, Oncidium, and Miltonia spp. and hybrids. Bacteria isolated and cultured from the lesions were tentatively identified using analytical profile index (API) strips and standard physiological and biochemical tests, and confirmed by species-specific polymerase chain reaction and sequencing of the 16S rRNA gene. The variation in pathogenic, morphological, cultural, and molecular characteristics of the orchid isolates also was evaluated. In our studies, a gramnegative, aerobic, rod-shaped bacterium that produced pale yellow, opaque, round colonies with entire margins on nutrient broth yeast extract agar (NBY) was isolated consistently from diseased orchid plants. On yeast dextrose calcium carbonate agar, the isolates produced brownishyellow, nonmucoid colonies, with the majority of the strains secreting a diffusible yellow or tan pigment into the media. The bacterium was identified as Burkholderia gladioli. Molecular analysis indicated very little diversity in the 16S rDNA gene. Testing B. gladioli isolates using media containing copper or streptomycin indicated varying levels of resistance (copper resistant = Cur; streptomycin resistant, Smr), with approximately 75% of the strains resistant to copper and 94% of the strains resistant to streptomycin. The minimum inhibitory concentration (MIC) of cupric sulfate among Cur strains ranged from 50 to 1,000 μg/ml and the MIC of streptomycin was 50 to 100 μg/ml for all Smr B. gladioli strains tested. Field and laboratory data suggest the frequent use of these chemicals in nurseries may have inadvertently resulted in the development of copper and streptomycin resistance in B. gladioli from orchids.


2017 ◽  
Vol 16 (1) ◽  
pp. 129-136 ◽  
Author(s):  
Kohinur Begum ◽  
Sultana Juhara Mannan ◽  
Refaya Rezwan ◽  
Md Mahinur Rahman ◽  
Md Shajidur Rahman ◽  
...  

We studied soil samples from Dhaka municipality area to isolate and characterize bacteria having potential biochemical and pharmacological importance. Total twenty five soil samples were collected from fish, vegetables and fruits dump area from Dhaka City. Bacterial population was sub-cultured in trypticase soya agar (TSA) plate. Nineteen colonies were isolated, cultured and characterized by gram staining and biochemical tests. Six isolates were found to be gram negative while thirteen were gram positive. All isolates were positive in oxidase, catalase, citrate, and protease tests. Eight isolates showed coagulase negative and nine were coagulase positive. It was found that all bacterial isolates were sensitive to tetracycline, chloramphenicol, gentamycin, ciprofloxacin, azithromycin and ceftriaxone. About 95% of the bacterial isolates were resistant to penicillin-G and ampicillin. About 89%, 26%, 21% and 11% of the bacterial isolates were resistant to amoxicillin, co-trimoxazole, nalidixic acid and erythromycin, respectively. It was found that bacterial isolates produce chemical(s) inhibitory to other bacterial strains including both gram positive and gram negative bacteria. Further studies are needed to characterize the potential antibacterial factor(s) and other bioactive compound (s) present in these bacterial isolates from soil samples.Dhaka Univ. J. Pharm. Sci. 16(1): 129-136, 2017 (June)


2018 ◽  
Vol 15 (2) ◽  
pp. 373-380
Author(s):  
Nguyễn Kim Thoa ◽  
Trần Thị Hoa ◽  
Trần Đình Mấn ◽  
Tạ Thị Thu Thuỷ

Binh Chau is famous for being a rare open-air hot spring with the highest mouth temperature in Vietnam. From water and sludge samples collected in Binh Chau hot spring, 64 aerobic thermophilic bacterial strains were isolated. Based on the identified characteristics of Bacillus genus, the optimum growth temperature as well as the ability to hydrolyze starch, 22 strains belonging to Geobacillus genus were selected for study on their α-amylase properties. Alpha-amylase from 11 of 22 strains showed pHopt ≥ 7. The optimum temperature of α–amylase ranged from 50oC to 90oC in different strains, of which seven strains showed the Topt of α–amylase at 90 oC. Thermostability of these strains at 90oC was identified, showing the half life of the three most prominent strains TĐ3.2, TG2.2, TG3.7 strains at 5.5 hours, 3.25 hours and 6.5 hours, respectively. Moreover, the addition of 5 mM Ca2+ resulted in improving α–amylase activity of 4 strains (TĐ3.2, TG2.2, TG3.1 and TG3.7) from 1,15 - 1,55 times, as well as in increasing thermostability of all enzymes produced by 7 strains with their new half life varied from 2-7 houts. Comparative analyses of sequences of 16S rRNA gene from the TĐ3.2, TG2.2, TG3.7 strains indicated that they were most closely related to G. caldoxilosilyticus, G. thermoglucosidasius, and G. stearothermophilus respectively (with the homology of 99%, 98% and 99%, respectively). Thus, it could be assumed that the genetic materials of microorganisms in Binh Chau hot spring are of great interest of exploitation in very near future.


2020 ◽  
Author(s):  
Rabia Saleem ◽  
Safia Ahmed

AbstractBeing a significant protein L-glutaminases discovers potential applications in various divisions running from nourishment industry to restorative and cure. It is generally disseminated in microbes, actinomycetes, yeast and organisms. Glutaminase is the principal enzyme that changes glutamine to glutamate. The samples were gathered from soil of Taxila, Wah Cantt and Quetta, Pakistan for the isolation of glutaminase producing bacteria. After primary screening, subordinate screening was done which includes multiple testification such as purification, observation of morphological characters and biochemical testing of bacterial strains along with 16S rRNA sequence homology testing. Five bacterial strains were selected showing glutaminase positive test in screening, enzyme production via fermentation and enzymatic and protein assays. Taxonomical characterization of the isolates identified them as Bacillus subtilis U1, Achromobacter xylosoxidans G1, Bacillus subtilis Q2, Stenotrophomonas maltophilia U3 and Alcaligenes faecalis S3. The optimization of different effectors such as incubation time, inducers, carbon source, pH, and nitrogen source were also put under consideration. There was slight difference among incubation of bacterial culture, overall, 36 hours of incubation time was the best for glutaminase production by all the strains. Optimal pH was around 9 in Achromobacter xylosoxidans G1 and Alcaligenes faecalis S3, pH 6 in Bacillus subtilis U1, pH 8 in Stenotrophomonas maltophilia U3, pH 6-8 in Bacillus subtilis Q2. Best glutaminase production was obtained at 37°C by Bacillus subtilis U1and Bacillus subtilis Q2, 30°C for Achromobacter xylosoxidans G1, Stenotrophomonas maltophilia U3 and 25°C by Alcaligenes faecalis S3. The carbon sources put fluctuated effects on activity of enzyme in such a way that glucose was the best carbon source for Bacillus subtilis U1and Bacillus subtilis Q2, Sorbitol for Achromobacter xylosoxidans G1 and Alcaligenes faecalis S3 while xylose was the best for Stenotrophomonas maltophilia U3. Yeast extract and Trypton were among good nitrogen sources for Achromobacter xylosoxidans G1 and of Bacillus subtilis U1 respectively. Glutamine was the best inducer for Bacillus subtilis Q2, Alcaligenes faecalis S3 and Stenotrophomonas maltophilia U3, while lysine for Achromobacter xylosoxidans G1 and glycine act as good inducer in case of Bacillus subtilis U1. After implementation of optimal conditions microbial L-glutaminase production can be achieved and the bacterial isolates have a great potential for production of glutaminase enzyme and their applications.


2021 ◽  
Vol 14 ◽  
pp. 117863612110242
Author(s):  
Sonal Suman ◽  
Tanuja

DDT is one of the most persistent pesticides among all the different types of organo-chlorine pesticides used. Among all the degradation methods, bacterial degradation of DDT is most effective. The present study was conducted to isolate different bacteria present in waste samples which have the ability to degrade DDT present in the soil in the minimum possible period of time and to observe the effect of different physical and chemical properties of the soil samples. Many pesticide degrading bacteria were isolated and identified through cultural, biochemical tests and further identified by 16S RNA sequencing method. The most potent strain DDT 1 growth in mineral salt medium supplemented with DDT as the only source of carbon (5-100 PPM) and was monitored at an optical density of 600 nm. The growth parameters at different physio-chemical conditions were further optimized. The result showed that Enterobacter cloacae had maximum growth in 15 days. FTIR analysis of the residual DDT after 15 days incubation showed that Enterobacter cloacae was able to degrade pesticide into its further metabolites of DDD, DDE, DDNU and other components can be used for biodegradation of DDT present in contaminated soil and water ecosystems.


Author(s):  
Tamara Popović ◽  
Jelena Menković ◽  
Anđelka Prokić ◽  
Nevena Zlatković ◽  
Aleksa Obradović

AbstractIn Montenegro, stone fruit species are grown on intensive and semi-intensive commercial plantations. However, almond production is mainly organized on family gardens and for household consumption. During two seasons (2017–2018), we surveyed apricot, peach, nectarine, sweet cherry, Japanese plum, and almond orchards for the presence of bacterial diseases at different geographical locations in Montenegro. From leaf, petiole and fruit lesions, branch or twig cankers, and necrotizing buds, a total of 29 isolates were obtained and subjected to identification based on their morphological, pathogenic, biochemical, and molecular characteristics. Pathogenicity of the isolates was confirmed by reproducing the symptoms on leaves, fruits, and twigs of the corresponding host plants. The biochemical tests indicated that the isolates belong to Pseudomonas syringae. However, isolates’ characterization showed variation in their phenotypic and molecular features. The presence of the syrB gene and ice nucleation activity grouped most of the isolates within pathovar syringae. The results of rep-PCR using the BOX primer revealed high genetic diversity of isolates. Multilocus sequence analysis (MLSA), using four housekeeping genes, showed that 27 isolates belong to the genomic species 1, P. syringae sensu stricto, corresponding to P. syringae phylogroup 2. However, isolates from the same phylogroup 2 did not form a monophyletic group. One strain isolated from apricot was most distinct and similar to members of genomic species 2, phylogroup 3. All tested isolates showed significant levels of resistance to copper sulfate and high level of sensitivity to streptomycin sulfate in vitro.


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