scholarly journals BACTERICIDAL ACTIVITY OF WILD AND HYBRID VARIETIES OF SYZIGIUM CUMINI L. AGAINST A FEW PLANT PATHOGENS

Author(s):  
HERIN SHEEBA GRACELIN D

Objective: The objective of the present study was to analyze the antibacterial activity of seeds of wild and hybrid varieties of Syzygium cumini against plant pathogens such as Erwinia herbicola, Pseudomonas syringae, and Xanthomonas campestris. Methods: The phytochemicals from the wild and hybrid varieties of S. cumini seeds collected from the Tirunelveli region (Tamil Nadu) were extracted by cold methanol method. Antibacterial activity of the methanol extract of seeds has been tested against E. herbicola, P. syringae, and X. campestris by disc diffusion assay. Results: The seed extract of wild variety revealed more effective antimicrobial activity than a hybrid variety with minimum inhibitory concentration ranging from 8 μg/ml to 128 μg/ml. The highest inhibition zone was exhibited by wild seed extract against X. campestris (16.3 mm). Conclusions: This result showed that the wild variety of S. cumini seeds may be the best antibacterial agent against plant pathogens.

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 613
Author(s):  
Alfredo Ambrico ◽  
Mario Trupo ◽  
Rosaria Magarelli ◽  
Roberto Balducchi ◽  
Angelo Ferraro ◽  
...  

Several bacteria pathogens are responsible for plant diseases causing significant economic losses. The antibacterial activity of Dunaliella salina microalgae extracts were investigated in vitro and in vivo. First, biomass composition was chemically characterized and subjected to extraction using polar/non-polar solvents. The highest extraction yield was obtained using chloroform:methanol (1:1 v/v) equal to 170 mg g−1 followed by ethanol (88 mg g−1) and hexane (61 mg g−1). In vitro examination of hexane extracts of Dunaliella salina demonstrated antibacterial activity against all tested bacteria. The hexane extract showed the highest amount of β-carotene with respect to the others, so it was selected for subsequent analyses. In vivo studies were also carried out using hexane extracts of D. salina against Pseudomonas syringae pv. tomato and Pectobacterium carotovorum subsp. carotovorum on young tomato plants and fruits of tomato and zucchini, respectively. The treated young tomato plants exhibited a reduction of 65.7% incidence and 77.0% severity of bacterial speck spot disease. Similarly, a reduction of soft rot symptoms was observed in treated tomato and zucchini fruits with a disease incidence of 5.3% and 12.6% with respect to 90.6% and 100%, respectively, for the positive control.


2021 ◽  
Vol 16 (3) ◽  
pp. 91-95
Author(s):  
Surachai Rattanasuk ◽  
Rujirek Boongapim ◽  
Tannatorn Phiwthong

The aim of this study was to determine the antibacterial activity of Cathormion umbellatum extracts against seven antibiotic-resistant bacteria. The pods, leaves and branches of C. umbellatum were extracted with ethanol and methanol. The disc diffusion assay was used to screen the antibacterial activity and broth microdilution and colorimetric assay were used to measure the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. The result indicated that the highest inhibition zone (11 mm) was presented in ethanolic pods extract against multidrug resistance Klebsiella pneumoniae. The lowest MIC value of 0.05 mg/mL was obtained from branch extracted with ethanol against colistin resistant Pseudomonas aeruginosa. The lowest MBC values of 1.56 mg/mL were obtained when using C. umbellatum leaves extracted with methanol against all test antibiotic-resistant bacteria. This is the first report presented C. umbellatum extracts have the potential to eliminate antibiotic-resistant bacteria in patients. These findings show the antibacterial effect of C. umbellatum.


Author(s):  
Yori Turu Toja ◽  
Eddy Suprayitno ◽  
Aulanni’am ◽  
Uun Yanuhar

Indonesia has many local plants with potential as herbal antibacterial properties, one of which is the local black fruit of Wandama. The objective of this study is to determine the antibacterial activity of the extract of black fruit seed against A. Hydrophila by in vitro and FTIR by Tilapia. The benefit of this research is to make black fruit seed extract as a natural remedy against tilapia attacked by Aeromonas Hydrophila. The antibacterial activity of black fruit seed extract against A. Hydrophila is investigated in vitro and using FTIR on tilapia in this research. The aim of this study is to establish black fruit seed extract as a natural treatment for tilapia infected with Aeromonas Hydrophila. The disc approach was used to conduct the in vitro research. Agar medium was poured into a sterile petri dish, and 2 drops of bacteria from the liquid medium were uniformly distributed and cooled. On the press, disc paper with black fruit seed extract was put and incubated for 18-24 hours at 35 C. An FTS 1000 version spectrophotometer system was used for the FTIR test. For the FT-IR study, a fraction of dried black fruit seeds was used. For clear preparation, 100 mg of dry extract is condensed in KBr pellets. A specimen of loaded black fruit seed samples was analyzed using FT-IR spectroscopy with a scanning range of 400-4000 cm-1 and a resolution of 4 cm-1. The results showed that the ethyl acetate fraction produced an inhibition zone (13.65 mm), the water fraction produced an inhibition zone (11.21 mm), and the n-hexane fraction produced the weakest inhibition zone (11.21 mm) (5.31mm). The concentration test results from 125 ppm, 250 ppm, 500 ppm and 1000 ppm obtained a large inhibition zone at a concentration of 1000 ppm with an inhibition zone area of 11.43 + 0.02. The absorbance value of black fruit seed extract in ethyl acetate solvent at 3430 cm-1 revealed the absorption band with the strongest vibration of the hydroxylate (-OH) functional group, according to FTIR research. Final thoughts with an average value of 13.65 + 0.06, black fruit seed extract using ethyl acetate can inhibit A. Hydrophila bacteria.


2013 ◽  
Vol 76 (4) ◽  
pp. 719-722 ◽  
Author(s):  
MICHAEL MAHOVIC ◽  
GANYU GU ◽  
STEVEN RIDEOUT

Overhead spray applications of in-field tomato treatments dissolved in aqueous solutions have specific pest targets (fungal, bacterial, insect, or other). Any organism present in the solution or on treated plant surfaces that is not a specific target of the application is unlikely inactivated and can instead be spread through the phyllosphere. In this laboratory study, commercially labeled pesticides (including Actigard 50WG, Bravo Weather Stik 6F, Cabrio 20EG, Kasumin, Kocide 3000 46WG, Oxidate 27L, Penncozeb 75DF, ProPhyt 54.5L, Stimplex 100L, Firewall, 22.4WP, and Tanos 50DF) in common use in commercial tomato production fields of the Eastern Shore of Virginia were investigated for activity against in vitro bacterial contamination of pesticide application waters. Pesticides of interest were tank mixed individually with one of the plant pathogens Ralstonia solanacearum, Xanthomonas campestris pv. vesicatoria, Pseudomonas syringae pv. tomato, Erwinia carotovora subsp. carotovora, or one of two serovars (Newport and Montevideo) of the human pathogen Salmonella enterica to assess reduction values during the average time between mixing and initial application. Observations suggested that while some treatments had a noticeable effect on population levels, only the oxidizer, peroxyacetic acid, showed significant and consistent levels of suppression against all bacteria investigated, at levels that could have practical implications.


2006 ◽  
Vol 57 (5) ◽  
pp. 511 ◽  
Author(s):  
Leeto Nteso ◽  
Johan C. Pretorius

The antimicrobial properties of crude methanol extracts of above- and below-soil parts of Tulbaghia violacea were quantified by means of an agar diffusion method against 6 plant pathogenic bacteria and 7 fungi. The growth of 3 out of the 6 bacteria, Clavibacter michiganensis, Ralstonia solanacearum, and Xanthomonas campestris, was significantly inhibited by crude extracts of both below-soil and aerial parts of T. violacea, whereas the growth of Pseudomonas syringae, Erwinia carotovora, and Agrobacterium tumefaciens was unaffectedl. Compared with the standard fungicide, both the aerial and below-soil extracts of T. violacea significantly inhibited the mycelial growth of 6 of the 7 test fungi, Botrytis cinerea, Sclerotium rolfsii, Rhizoctonia solani, Mycosphaerella pinodes, Botryosphaeria dothidea, and P. ultimum, whereas only the below-soil extract inhibited the mycelial growth of Fusarium oxysporum significantly. The broad-spectrum antifungal activity shown by the crude T. violaceae extracts supplied a rationale for a further investigation into the in vivo activity of the extracts under glasshouse and field conditions.


2020 ◽  
Vol 16 ◽  
Author(s):  
Mohanasrinivasan V. ◽  
Mounika Ranga ◽  
Jannatul Firdous Siddique ◽  
Nivetha Anbalagan ◽  
Subathradevi C.

Abstract:: Bacteriocins are antimicrobial peptides synthesized ribosomally which can be used as bio-preservative reducing the risk of chemical preservative’s effect and also replacing the thermal treatments. This study aims to isolate, purify the an-tibacterial protein from Lactobacillus plantarum KY449289 and to assess its bio preservative potential. In this study, twenty strains were isolated from a yogurt sample and preliminary characterization was carried out, such as morphological, bio-chemical, and molecular levels as a preliminary assay. The characterized strains were assessed for the antibacterial activity by well diffusion assay, whereas all twenty strains were shown to have a antibacterial activity against foodborne pathogens, among which two strains VITMM04 and VITMM05 shows the highest zone of inhibition of 15 mm and 10 mm respectively against Listeria monocytogenes. The potent isolate VITMM05 solely showed a broad spectrum antibacterial activity against the pathogens. These strains were further subjected to optimization, purification, and application studies. A high increase in the inhibition zone was recorded with an optimum temperature of 35°C and its activity was found to be stable up to 85°C, optimum pH 6, and 5 mM of EDTA as an enhancer surfactant. On subjected to RP-HPLC, the purified sample showed a dis-tinct peak at 2.192 min corresponding to the peak at 2.192 min for standard bacteriocin The six-fold purified bacteriocin was effective in controlling 87% of the microbial population with 20mm zone of inhibiton against the Listeria monocytogenes and this shows the effective role of purified bacteriocin in inhibiting bacterial growth in a greater extent.


1998 ◽  
Vol 44 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Yoav Bashan

Six strains of Azospirillum belonging to five species of plant growth-promoting bacteria (A. brasilense, A. lipoferum, A. amazonense, A. irakense, and A. halopraeference) did not cause visible disease symptoms on the roots or leaves of tomato, pepper, cotton, and wheat, failed to inhibit seed germination, and did not reduce plant dry weight when seven standard techniques for the inoculation of plant pathogens were used. Similar inoculation conditions with plant pathogens (Pseudomonas syringae pv. tomato, Xanthomonas campestris pv. vesicatoria, Xanthomonas campestris pv. translucens, and Xanthomonas campestris pv. malvacearum) induced typical disease symptoms. None of Azospirillum strains caused the hypersensitive reaction on eggplant, whereas all pathogens did. All Azospirillum strains increased phytoalexin production in all disease-resistant plant species to moderate levels, but the levels were significantly lower than those induced by the compatible pathogens. The various phytoalexins produced in plants had the capacity to inhibit growth of all Azospirillum strains. Azospirillum amazonense, A. irakense, and A. halopraeference had no apparent effect on plant growth, while A. brasilense and A. lipoferum increased the dry weight of all plant species. Under partial mist conditions, all Azospirillum strains were capable of colonizing leaf surfaces (103-107 cfu/g dry weight) regardless of the plant species. These results provide experimental evidence that Azospirillum sp. might be considered safe for the inoculation of several plant species.Key words: Azospirillum, beneficial bacteria, environmental protection, plant inoculation, plant growth-promoting bacteria.


2018 ◽  
Vol 56 (1) ◽  
pp. 161-180 ◽  
Author(s):  
George W. Sundin ◽  
Nian Wang

Antibiotics have been used for the management of relatively few bacterial plant diseases and are largely restricted to high-value fruit crops because of the expense involved. Antibiotic resistance in plant-pathogenic bacteria has become a problem in pathosystems where these antibiotics have been used for many years. Where the genetic basis for resistance has been examined, antibiotic resistance in plant pathogens has most often evolved through the acquisition of a resistance determinant via horizontal gene transfer. For example, the strAB streptomycin-resistance genes occur in Erwinia amylovora, Pseudomonas syringae, and Xanthomonas campestris, and these genes have presumably been acquired from nonpathogenic epiphytic bacteria colocated on plant hosts under antibiotic selection. We currently lack knowledge of the effect of the microbiome of commensal organisms on the potential of plant pathogens to evolve antibiotic resistance. Such knowledge is critical to the development of robust resistance management strategies to ensure the safe and effective continued use of antibiotics in the management of critically important diseases.


Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2395
Author(s):  
Muhammad Akbar ◽  
Usman Ali ◽  
Tayyaba Khalil ◽  
Muhammad Sajjad Iqbal ◽  
Awais Amin ◽  
...  

In the present study, the antibacterial activity of Cornus macrophylla was examined. Organic solvent extracts of leaves were prepared using methanol, n-hexane, chloroform, and ethyl acetate. Antibacterial activity was examined by using a 100 mg/mL extract concentration. Penicillin was kept as a positive control while dimethyl sulfoxide was taken as a negative control. Methanolic extract exhibited a 21.5, 36.3, 25.3, and 23.7 mm inhibition zone diameter (IZD); n-hexane showed a 33, 40, 32.8, and 28.7 mm IZD; chloroform showed a 18.8, 29, 22.3, and 21.6 mm IZD; and ethyl acetate showed a 23.5, 30.2, 30, and 22.3 mm IZD against Erwinia carotovora, Pseudomonas syringae, Ralstonia solanacearum, and Xanthomonas axonopodis, respectively. The n-hexane extract revealed high antibacterial activity against all bacterial species as compared with methanolic, chloroform, and ethyl acetate extract. Gas Chromatography Mass Spectrometry (GC/MS) analysis of n-hexane extract depicted the presence of 55 compounds. Out of these compounds, one compound, identified as α-amyrin (Mol. wt = 426), exhibited the maximum peak area (32.64%), followed by A’-Neogammacer-22(29)-en-3-ol, acetate, (3.beta.,21.beta.)- (Mol. wt = 468) and β-amyrin (Mol. wt = 426) having peak areas of 25.97 and 6.77%, respectively. It was concluded that the antibacterial activity observed during the present investigation may be due to these compounds.


2000 ◽  
Vol 90 (3) ◽  
pp. 208-213 ◽  
Author(s):  
N. W. Schaad ◽  
A. K. Vidaver ◽  
G. H. Lacy ◽  
K. Rudolph ◽  
J. B. Jones

In 1980, over 90% of all plant-pathogenic pseudomonads and xanthomonads were lumped into Pseudomonas syringae and Xanthomonas campestris, respectively, as pathovars. The term “pathovar” was created to preserve the name of plant pathogens, but has no official standing in nomenclature. Proposals to elevate and rename several pathovars of the genera Pseudomonas and Xanthomonas to the rank of species has caused great confusion in the literature. We believe the following changes have merit and expect to adopt them for publication in a future American Phytopathological Society Laboratory Guide for Identification of Plant Pathogenic Bacteria. Upon review of published data and the Rules of The International Code of Nomenclature of Bacteria, we make the following recommendations. We reject the proposal to change the name of P. syringae pvs. phaseolicola and glycinea to P. savastanoi pvs. phaseolicola and glycinea, respectively, because both pathogens are easily differentiated phenotypically from pv. savastanoi and convincing genetic data to support such a change are lacking. We accept the elevation of P. syringae pv. savastanoi to the rank of species. We accept the reinstatement of X. oryzae to the rank of species with the inclusion of X. oryzicola as a pathovar of X. oryzae and we accept the species X. populi. We agree with the elevation of the pvs. cassavae, cucurbitae, hyacinthi, pisi, and translucens to the rank of species but not pvs. melonis, theicola, and vesicatoria type B. We recommend that all type A X. vesicatoria be retained as X. campestris pv. vesicatoria and all type B X. vesicatoria be named X. exitiosa. We reject the newly proposed epithets arboricola, bromi, codiaei (poinsettiicola type B), hortorum, sacchari, and vasicola and the transfer of many pathovars of X. campestris to X. axonopodis. The proposed pathovars of X. axonopodis should be retained as pathovars of X. campestris.


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