Immobilized Recombinant Chitinase and its Inhibition Effect on Botrytis Cinerea

2014 ◽  
Vol 936 ◽  
pp. 674-680
Author(s):  
Na Zhang ◽  
Rui Xiang Yan ◽  
Wen Qiang Guan

To isolate recombinant chitinase quickly and boost its anti-fungi activities in vitro, functional magnetic nanometer carrier was used to immobilize recombinant chitinase from the crude enzyme solution and immobilized recombinant chitinase was applied to test whether it would inhibit the growth of gray mold from fruits. In this study, the carboxyl magnetic carrier was produced by solvent thermal reduction method and characterized by scanning electron microscope (SEM) and fourier transform infrared spectrometer (FTIR). Then, the carboxyl magnetic carrier activated by EDC/NHS was applied to immobilize recombinant chitinase and the immobilization efficiency was investigated by quantitative analysis. To obtain the highest immobilization efficiency, reaction conditions were optimized through combining different pH, temperature and reaction period. The results show that the surface of magnetic carrier was successfully carboxyl and the average diameter was 200nm. The immobilization efdiciency could reach the peak 64.43% after 7h reaction at the condition of pH 6 and 25°C. It also shows that immobilized recombinant chitinase can significantly inhibit the growth of gray mold isolated from table grape compared with the enzyme without immobilization with magnetic nanometer carrier.

2021 ◽  
Vol 7 (6) ◽  
pp. 428
Author(s):  
Men Thi Ngo ◽  
Minh Van Nguyen ◽  
Jae Woo Han ◽  
Myung Soo Park ◽  
Hun Kim ◽  
...  

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of Trichoderma longibrachiatum SFC100166 effectively suppressed the development of tomato gray mold, rice blast, and tomato late blight. The culture filtrate was then successively extracted with ethyl acetate and n-butanol to identify the fungicidal metabolites. Consequently, a new compound, spirosorbicillinol D (1), and a new natural compound, 2′,3′-dihydro-epoxysorbicillinol (2), together with 11 known compounds (3–13), were obtained from the solvent extracts. The chemical structures were determined by spectroscopic analyses and comparison with literature values. The results of the in vitro antifungal assay showed that of the tested fungal pathogens, Phytophthora infestans was the fungus most sensitive to the isolated compounds, with MIC values ranging from 6.3 to 400 µg/mL, except for trichotetronine (9) and trichodimerol (10). When tomato plants were treated with the representative compounds (4, 6, 7, and 11), bisvertinolone (6) strongly reduced the development of tomato late blight disease compared to the untreated control. Taken together, our results revealed that the culture filtrate of T. longibrachiatum SFC100166 and its metabolites could be useful sources for the development of new natural agents to control late blight caused by P. infestans.


Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1991-1997 ◽  
Author(s):  
Xiaoxue Ji ◽  
Jingjing Li ◽  
Zhen Meng ◽  
Shouan Zhang ◽  
Bei Dong ◽  
...  

Gray mold caused by Botrytis cinerea can be a severe disease of tomato infecting leaves and fruits of tomato plants. Chemical control is currently the most effective and reliable method; however, application of fungicides has many drawbacks. The combination of biological control agents with newly developed fungicides may be a practicable method to control B. cinerea. Fluopimomide is a newly developed fungicide with a novel mode of action. Bacillus methylotrophicus TA-1, isolated from rhizosphere soil of tomato, is a bacterial strain with a broad spectrum of antimicrobial activities. Little information is currently available about the effect of fluopimomide and its integrated effect on B. cinerea. Therefore, laboratory, pot, and field experiments were carried out to determine the effects of fluopimomide alone and in combination with B. methylotrophicus TA-1 against gray mold on tomato. The in vitro growth of B. methylotrophicus TA-1 was unaffected by 100 mg liter−1 fluopimomide. Inhibition of B. cinerea mycelial growth was significantly increased under combined treatment of fluopimomide and B. methylotrophicus TA-1. In greenhouse experiments, efficacy against gray mold was significantly greater by an integration of fluopimomide and B. methylotrophicus TA-1 than by either alone; control efficacy of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 at 108 colony-forming units (cfu) ml−1 reached 70.16 and 69.32%, respectively, compared with the untreated control. In both field trials during 2017 and 2018, control efficacy was significantly higher for the combination of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 than for either treatment alone. The results from this study indicated that integration of the new fungicide fluopimomide with the biocontrol agent B. methylotrophicus TA-1 synergistically increased control efficacy of the fungicide against gray mold of tomato.


1977 ◽  
Vol 55 (15) ◽  
pp. 2122-2136 ◽  
Author(s):  
H. W. J. Ragetli ◽  
M. Elder

An unknown virus was isolated from a young red clover plant (Trifolium pratense) with a bright yellow leaf mottle and subsequently was isolated from five other field clover plants with milder symptoms growing in three locations. In the laboratory, red clover became systemically infected by the virus only when the plants were kept between 10 and 16 °C after inoculation, and symptoms were mild. Crimson clover (T. incarnatum) was readily invaded at room temperature, and survivors of the initial shock reaction were severely mottled. White clover (T. repens) and Alsike clover (T. hybridum) did not become systemically infected under either temperature regime. The symptom common to all four species, necrotic spots in the inoculated primary leaves, suggested the name clover primary leaf necrosis virus. Among the nine leguminous and six non-leguminous host species, bean (Phaseolus vulgaris) was best suited for virus propagation, and cucumber (Cucumis sativus) was best suited for quantitative assay and detection.The virus was characterized by a single sedimenting species of spherical nucleoprotein particles with a sedimentation value, S20.w, of 136–137, an average diameter of 36 nm, and a specific extinction, E260 nm1%, 1 cm, of 58.15. The nucleic acid was of the ribose type and constituted 21% of the weight of the virion. Activity was lost from crude juice at 65 °C and from purified suspensions at 85 °C, with about 10% activity persisting between 60–70 °C. Two electrophoretic components were isolated from purified preparations. They induced identical symptoms in three hosts, but one replicated both components in bean and had more antigenic determinants than the other, which replicated itself only. The virus was weakly antigenic inducing an antiserum with titer of 128. Some of its in vitro properties were similar to those of carnation ringspot virus, but the two viruses were serologically unrelated. Nor was this virus serologically related to any of 15 other spherical viruses tested.


1985 ◽  
Vol 5 (3) ◽  
pp. 554-562 ◽  
Author(s):  
K G Miller ◽  
J Tower ◽  
B Sollner-Webb

To determine the size and location of the mouse rDNA promoter, we constructed systematic series of deletion mutants approaching the initiation site from the 5' and 3' directions. These templates were transcribed in vitro under various conditions with S-100 and whole-cell extracts. Surprisingly, the size of the rDNA region that determines the level of transcription differed markedly, depending on the reaction conditions. In both kinds of cell extracts, the apparent 5' border of the promoter was at residue ca. -27 under optimal transcription conditions, but as reaction conditions became less favorable, the 5' border moved progressively out to residues -35, -39, and -45. The complete promoter, however, extends considerably further, for under other nonoptimal conditions, we observed major effects of promoter domains extending in the 5' direction to positions ca. -100 and -140. In contrast, the apparent 3' border of the mouse rDNA promoter was at residue ca. +9 under all conditions examined. We also show that the subcloned rDNA region from -39 to +9 contains sufficient information to initiate accurately and that the region between +2 and +9 can influence the specificity of initiation. These data indicate that, although the polymerase I transcription factors recognize and accurately initiate with only the sequences downstream of residue -40, sequences extending out to residue -140 greatly favor the initiation reaction; presumably, this entire region is involved in rRNA transcription in vivo.


2017 ◽  
Vol 107 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Wayne M. Jurick ◽  
Otilia Macarisin ◽  
Verneta L. Gaskins ◽  
Eunhee Park ◽  
Jiujiang Yu ◽  
...  

Botrytis cinerea causes gray mold and is an economically important postharvest pathogen of fruit, vegetables, and ornamentals. Fludioxonil-sensitive B. cinerea isolates were collected in 2011 and 2013 from commercial storage in Pennsylvania. Eight isolates had values for effective concentrations for inhibiting 50% of mycelial growth of 0.0004 to 0.0038 μg/ml for fludioxonil and were dual resistant to pyrimethanil and thiabendazole. Resistance was generated in vitro, following exposure to a sublethal dose of fludioxonil, in seven of eight dual-resistant B. cinerea isolates. Three vigorously growing B. cinerea isolates with multiresistance to postharvest fungicides were further characterized and found to be osmosensitive and retained resistance in the absence of selection pressure. A representative multiresistant B. cinerea strain caused decay on apple fruit treated with postharvest fungicides, which confirmed the in vitro results. The R632I mutation in the Mrr1 gene, associated with fludioxonil resistance in B. cinerea, was not detected in multipostharvest fungicide-resistant B. cinerea isolates, suggesting that the fungus may be using additional mechanisms to mediate resistance. Results from this study show for the first time that B. cinerea with dual resistance to pyrimethanil and thiabendazole can also rapidly develop resistance to fludioxonil, which may pose control challenges in the packinghouse environment and during long-term storage.


Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 236
Author(s):  
Vanessa Mendes ◽  
Flávia Franco Veiga ◽  
Lidiane Vizioli de Castro-Hoshino ◽  
Francielle Sato ◽  
Mauro Luciano Baesso ◽  
...  

We evaluated a hydroalcoholic extract of Sapindus saponaria L. pericarps (ETHOSS), as a candidate to a topical antifungal medicine for onychomycosis. ETHOSS was produced by extracting the crushed fruits in ethanol. The saponin contents were identified and characterized by electrospray ionization mass spectrometry. We measured the in vitro antifungal activity against three dermatophyte fungi, isolated from onychomycosis: Trichophyton rubrum, T. mentagrophytes, and T. interdigitale, using broth microdilution tests. The minimum fungicide concentration of ETHOSS ranged from 195.31 to 781.25 μg/mL. The cytotoxicity of the crude extract was tested on the HeLa cell line, and its ability to permeate into healthy human nails by photoacoustic spectroscopy and Fourier transformation infrared spectrometer (FTIR) spectroscopy by attenuated total reflection. Besides its strong antifungal activity, ETHOSS showed low cytotoxicity in human cells. It was able to permeate and reach the full thickness of the nail in one hour, without the aid of facilitating vehicles, and remained there for at least 24 h. These results suggest that ETHOSS has great potential for treating onychomycosis.


2021 ◽  
Author(s):  
Xiaoping Chen ◽  
Jiaqi Fu ◽  
Jiangang Li ◽  
Bohong Chen ◽  
Lei Yang ◽  
...  

In this work, submicron copper powder with narrow particle distribution was synthesized via a simple methanol thermal reduction method without using any surfactants. Smaller copper powder with narrower particle size...


2021 ◽  
Vol 17 (10) ◽  
pp. 1939-1950
Author(s):  
Beibei Lin ◽  
Xuegu Xu ◽  
Xiaobi Zhang ◽  
Yinfei Yu ◽  
Xiaoling Wang

We prepared poly(lactide-co-glycolide) (PLGA) encapsulated with chlorin e6 (Ce6) in an effort to increase the stability and efficiency of photosensitizers for photodynamic therapy (PDT). We determined that Ce6-loaded PLGA nanoparticles (PLGA-Ce6 NPs) had drug-loading efficiency of 5%. The efficiency of encapsulation was 82%, the zeta potential was- 25 mV, and the average diameter was 130 nm. The encapsulation of Ce6 in PLGA nanoparticles showed excellent stability. The nanoparticles exhibited sustained Ce6 release profiles with 50% released at the end of 3 days, whereas free Ce6 showed rapid release within 1 day. Ce6 release patterns were controlled by encapsulation into PLGA. The uptake of PLGA-Ce6 NPs was significantly enhanced by endocytosis in the first 8 hours in the HCT-116 cell line. An intracellular reactive oxygen species assay revealed the enhanced uptake of the nanoparticles. An in vitro anti-tumor activity assay showed that the PLGA-Ce6 NPs exhibited enhanced phototoxicity toward HCT-116 cells and a slightly lower IC50 value in HCT-116 cells than Ce6 solution alone. Exposure of HCT-116 cell spheroids to PLGA-Ce6 NPs penetrated more profoundly and had better phototoxicity than pure drugs. These findings suggest that PLGA-Ce6 NPs might serve as PDT for colorectal cancer.


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