In Vitro Efficacy of Bacterial Endophytes against Pythium sp. Causing Soft Rot of Ginger in Meghalaya

SummaryA total of 688 bacterial endophytes were isolated from both greenhouse and field-grown tomatoes in the Tehran and Alborz provinces, Iran in order to obtain effective bacterial endophytes against the fungus Verticillium dahliae. 128 bacterial isolates, with respect to their different phenotypic characteristics were further analysed. All bacteria with positive hypersensitivity reaction on tobacco and geranium leaves and potato soft rot were eliminated, and totally 39 isolates were selected for in vitro antagonism and greenhouse tests. The potential biocontrol isolates were evaluated using seed treatment and soil drench methods on two tomato cultivars. The results indicated that seven bacterial isolates had a high potential for the control of the fungus and reduced the severity disease to 95-98%. This reduction was coincided with an increase in some growth factors like plant dry weight, root dry weight, plant height, root length, root fresh weight and plant fresh weight ranged between 92-98%. The seven antagonists’ preliminary identification was confirmed using 16SrRNA gene sequencing analysis. The BLAST analysis was performed, and the bacteria were also identified as Bacillus pumilus (two isolates), Bacillus subtilis, Bacillus safensis, Enterobacter ludwigi, Serratia marcesens and Pseudomonas beatica. Biocontrol mechanisms examination indicated that protease production was positive for all isolates and differentiated isolates E. ludwigii and P. beatica as higher producers with protease levels up to 65%. The three bacteriocins producing isolates inhibited the phytopathogenic mycelium up to 70% in dual culture assay. Also, five of the isolates produced siderophores and P. baetica, S. marcesens and E. ludwigii produced remarkable amount of auxin hormone.

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Botanicals to Control Soft Rot Bacteria of Potato

The Scientific World JOURNAL ◽

10.1100/2012/796472 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

M. M. Rahman ◽

A. A. Khan ◽

M. E. Ali ◽

I. H. Mian ◽

A. M. Akanda ◽

...

Keyword(s):

Plant Extracts ◽

Curcuma Longa ◽

Soft Rot ◽

Storage Condition ◽

Storage Conditions ◽

Leaf Extracts ◽

Corchorus Capsularis ◽

Rot Disease ◽

And Storage

Extracts from eleven different plant species such as jute (Corchorus capsularisL.), cheerota (Swertia chiraitaHam.), chatim (Alstonia scholarisL.), mander (Erythrina variegata), bael (Aegle marmelosL.), marigold (Tagetes erecta), onion (Allium cepa), garlic (Allium sativumL.), neem (Azadiracta indica), lime (Citrus aurantifolia), and turmeric (Curcuma longaL.) were tested for antibacterial activity against potato soft rot bacteria,E. carotovorasubsp.carotovora (Ecc)P-138, underin vitroand storage conditions. Previously,EccP-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth ofEccP-138in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects onEcc-138 growth both inin vitroand storage experiments.

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Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

The Scientific World JOURNAL ◽

10.1100/2012/723293 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

M. M. Rahman ◽

M. E. Ali ◽

A. A. Khan ◽

A. M. Akanda ◽

Md. Kamal Uddin ◽

...

Keyword(s):

Biological Control ◽

Biological Control Agent ◽

Erwinia Carotovora ◽

Soft Rot ◽

Control Agent ◽

Antagonistic Activity ◽

Antagonistic Effect ◽

Antagonistic Bacteria ◽

And Storage

A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacteriumErwinia carotovorasubsp.carotovora(Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was testedin vitroagainst the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited thein vitrogrowth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genusBacillusand the isolate E-45 asLactobacillussp. The stronger antagonistic activity against Ecc P-138 was found in E-65in vitroscreening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

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Kemampuan Bakteri Endofit Akar dan Ubi Kentang untuk Menekan Penyakit Busuk Lunak (Erwinia carotovora pv. carotovora) pada Ubi

Agrikultura ◽

10.24198/agrikultura.v27i3.10880 ◽

2016 ◽

Vol 27 (3) ◽

Author(s):

Noor Istifadah ◽

Muhamad Salman Umar ◽

Sudarjat Sudarjat ◽

Luciana Djaya

Keyword(s):

Biological Control ◽

Potato Tuber ◽

Endophytic Bacteria ◽

Erwinia Carotovora ◽

Soft Rot ◽

Soft Rot Disease ◽

Post Harvest ◽

Rot Disease

ABSTRACTThe abilities of endophytic bacteria from potato roots and tubers to suppress soft rot disease (Erwinia carotovora pv. carotovora) in potato tuberSoft rot disease caused by Erwinia carotovora pv. carotovora is one of limiting factors in cultivation and post harvest of potato. The eco-friendly control measure that can be developed for controlling the diseases is biological control. Microbes that are potential as biological control agents include endophytic bacteria. This paper discussed the results of study examining the potential of endophytic bacteria isolated from roots and tubers of potato to inhibit the growth of E. carotovora pv. carotovora in vitro and suppress soft rot disease in potato tuber. The results showed that among 24 isolates examined, four isolates of endophytic bacteria (one isolate from potato tuber and three isolates from potato roots) inhibited the growth of E. carotovora pv. carotovora in vitro with inhibition zone 3.5-6.8 mm. In the in vivo test, the isolates inhibited the soft rot disease in potato tuber by 71.5-86.4%. The isolate that tended to show relatively better inhibition in vitro and in vivo was isolate from potato tuber which is CK U3 (Lysinibacillus sp.)Keywords: Biological control, Endophytic bacteria, Post-harvest, Potato, Soft rot diseaseABSTRAKPenyakit busuk lunak yang disebabkan bakteri Erwinia carotovora pv. carotovora, merupakan salah satu kendala dalam budidaya dan pascapanen kentang. Cara pengendalian ramah lingkungan yang dapat dikembangkan untuk menekan penyakit tersebut adalah pengendalian biologi. Kelompok mikroba yang berpotensi sebagi agens pengendali biologi adalah bakteri endofit. Artikel ini mendiskusikan potensi isolat bakteri endofit yang berasal dari ubi dan akar kentang untuk menghambat pertumbuhan bakteri E. carotovora pv. carotovora secara in vitro dan menekan perkembangan penyakit busuk lunak pada ubi kentang. Hasil percobaan menunjukkan bahwa diantara 24 isolat bakteri yang diuji, terdapat empat isolat bakteri endofit (satu isolat dari ubi kentang dan tiga isolat dari akar kentang) yang dapat menghambat pertumbuhan bakteri E. carotovora pv. carotovora secara in vitro dengan zona penghambatan sebesar 3,5-6,8 mm. Pada pengujian secara in vivo, isolat-isolat tersebut dapat menekan perkembangan penyakit busuk lunak pada ubi kentang sebesar 71,5-86,4%. Isolat yang cenderung menunjukkan penghambatan relatif lebih baik secara in vitro dan in vivo adalah isolat bakteri endofit asal ubi kentang yaitu isolat CK U3 (Lysinibacillus sp.).Kata Kunci: Pengendalian biologi, Bakteri endofit, Pascapanen, Kentang, Penyakit busuk basah

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Bacillus subtilis BS 107 as an antagonist of potato blackleg and soft rot bacteria

Canadian Journal of Microbiology ◽

10.1139/w98-064 ◽

1998 ◽

Vol 44 (8) ◽

pp. 777-783 ◽

Cited By ~ 12

Author(s):

B M Sharga ◽

G D Lyon

Keyword(s):

Bacillus Subtilis ◽

Erwinia Carotovora ◽

Soft Rot ◽

Defined Medium ◽

Alkaline Solutions ◽

Water Mixture ◽

Potato Blackleg ◽

Antimicrobial Substances

Antimicrobial substances were produced by Bacillus subtilis BS 107 in a defined medium and isolated from culture filtrate by precipitation at pH 2.5. Active fractions were extracted in ethyl acetate, acetone, and 80% ethanol and purified by thin-layer chromatography (TLC) on silica gel plates developed with an ethanol-water mixture (2:1, v/v). In each case, a band with a Rf of 0.75 formed an inhibitory zone when the TLC plates were placed in contact with agar seeded with test cultures of the Erwinia spp. The antibiotic was released into the culture medium during early stages of growth of Bacillus subtilis BS 107 but higher amounts were released in older cultures. The antibiotic was resistant to the action of nucleases, proteases, and lipase. It was stable when autoclaved twice for 35 min at 2 atm (1 atm = 101.325 kPa) in acidic, neutral, and alkaline solutions. It remained active over the pH range of 1-14 during 1 month of observation and exhibited no loss of antimicrobial activity when stored at 4°C for over 1 year. Bacillus subtilis BS 107 showed activity in vitro and in vivo against Erwinia carotovora subsp. atroseptica and Erwinia carotovora subsp. carotovora, the causal agents of potato blackleg and tuber soft rot. The application of an antagonist or its antibiotic to cut potato tissues prevented or reduced symptoms of the diseases. The antibiotic was active in vitro against a broad spectrum of bacterial and fungal species.Key words: antagonist, Bacillus subtilis BS 107, Erwinia carotovora, potato.

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In vitro efficacy of certain botanicals against bacterial soft rot of tomato (Solanum lycopersicum L.)

African Journal of Agricultural Research ◽

10.5897/ajar2015.9933 ◽

2017 ◽

Vol 12 (23) ◽

pp. 2049-2055

Author(s):

S. H. Adamu ◽

A. A. Lal ◽

S. Simon

Keyword(s):

Solanum Lycopersicum ◽

Soft Rot ◽

Bacterial Soft Rot ◽

Solanum Lycopersicum L

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Endophytic Actinomycetes: A Novel Source of Potential Acyl Homoserine Lactone Degrading Enzymes

BioMed Research International ◽

10.1155/2013/782847 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 21

Author(s):

Surang Chankhamhaengdecha ◽

Suphatra Hongvijit ◽

Akkaraphol Srichaisupakit ◽

Pattra Charnchai ◽

Watanalai Panbangred

Keyword(s):

Pathogenic Bacteria ◽

Sequence Similarity ◽

Soft Rot ◽

Quorum Quenching ◽

Homoserine Lactone ◽

Amide Bond ◽

Side Chain ◽

Signal Molecules ◽

Endophytic Actinomycetes

Several Gram-negative pathogenic bacteria employN-acyl-L-homoserine lactone (HSL) quorum sensing (QS) system to control their virulence traits. Degradation of acyl-HSL signal molecules by quorum quenching enzyme (QQE) results in a loss of pathogenicity in QS-dependent organisms. The QQE activity of actinomycetes in rhizospheric soil and inside plant tissue was explored in order to obtain novel strains with high HSL-degrading activity. Among 344 rhizospheric and 132 endophytic isolates, 127 (36.9%) and 68 (51.5%) of them, respectively, possessed the QQE activity. The highest HSL-degrading activity was at151.30±3.1 nmole/h/mL from an endophytic actinomycetes isolate, LPC029. The isolate was identified asStreptomycesbased on16S rRNAgene sequence similarity. The QQE from LPC029 revealed HSL-acylase activity that was able to cleave an amide bond of acyl-side chain in HSL substrate as determined by HPLC. LPC029 HSL-acylase showed broad substrate specificity from C6- to C12-HSL in which C10HSL is the most favorable substrate for this enzyme. In anin vitropathogenicity assay, the partially purified HSL-acylase efficiently suppressed soft rot of potato caused byPectobacterium carotovorumssp.carotovorumas demonstrated. To our knowledge, this is the first report of HSL-acylase activity derived from an endophyticStreptomyces.

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Biocontrol of the Potato Blackleg and Soft Rot Diseases Caused by Dickeya dianthicola

Applied and Environmental Microbiology ◽

10.1128/aem.02525-15 ◽

2015 ◽

Vol 82 (1) ◽

pp. 268-278 ◽

Cited By ~ 27

Author(s):

Yannick Raoul des Essarts ◽

Jérémy Cigna ◽

Angélique Quêtu-Laurent ◽

Aline Caron ◽

Euphrasie Munier ◽

...

Keyword(s):

Soft Rot ◽

Potato Production ◽

Biocontrol Agents ◽

Bacterial Isolates ◽

Potato Blackleg ◽

Content Type ◽

Potato Plants ◽

Potential Strategy

ABSTRACTDevelopment of protection tools targetingDickeyaspecies is an important issue in the potato production. Here, we present the identification and the characterization of novel biocontrol agents. Successive screenings of 10,000 bacterial isolates led us to retain 58 strains that exhibited growth inhibition properties against severalDickeyasp. and/orPectobacteriumsp. pathogens. Most of them belonged to thePseudomonasandBacillusgenera.In vitroassays revealed a fitness decrease of the testedDickeyasp. andPectobacteriumsp. pathogens in the presence of the biocontrol agents. In addition, four independent greenhouse assays performed to evaluate the biocontrol bacteria effect on potato plants artificially contaminated withDickeya dianthicolarevealed that a mix of three biocontrol agents, namely,Pseudomonas putidaPA14H7 andPseudomonas fluorescensPA3G8 and PA4C2, repeatedly decreased the severity of blackleg symptoms as well as the transmission ofD. dianthicolato the tuber progeny. This work highlights the use of a combination of biocontrol strains as a potential strategy to limit the soft rot and blackleg diseases caused byD. dianthicolaon potato plants and tubers.

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Effect of some chemicals on incidence of poato soft rot disease in Bangladesh

Bangladesh Journal of Scientific and Industrial Research ◽

10.3329/bjsir.v52i2.32936 ◽

2017 ◽

Vol 52 (2) ◽

pp. 135-140 ◽

Cited By ~ 1

Author(s):

MM Rahman ◽

AA Khan ◽

IH Mian ◽

AM Akanda ◽

MZ Alam

Keyword(s):

Acetic Acid ◽

Boric Acid ◽

Soft Rot ◽

Pectobacterium Carotovorum ◽

Potato Tubers ◽

Soft Rot Disease ◽

Bleaching Powder ◽

Carotovorum Subsp ◽

Rot Disease

Bactericidal effect was investigated by chemicals against potato soft rot bacteria in vitro and in storage. The chemicals were acetic acid, boric acid, bleaching powder, lactic acid, calcium hydroxide, calcium chloride, potassium chloride and sodium hypo-chloride. Among eight chemicals only three chemicals viz. acetic acid, boric acid and bleaching powder showed bactericidal activity against potato soft rot bacteria Pectobacterium carotovorum subsp. carotovorum (E. carotovora subsp. carotovora) P-138 in vitro. Based on the results of in vitro experiment three chemicals, acetic acid, boric acid and bleaching powder were used to control soft rot disease of potato in storage. Fresh potato tubers were dipped in 0.2% solution/suspensions of acetic acid, boric acid and bleaching powder for 30 min. Then soft rot bacteria Pectobacterium carotovorum subsp. carotovorum P-138 was inoculated on potato. Finally potatoes were stored for 22 weeks in net bags in sterilized condition. All the three chemicals significantly decreased the infection rate, loss in weight and increased percentage of disease reduction (PDR) of potato. Boric acid was the most effective in controlling the soft rot disease of potato in storage followed by acetic acid and bleaching powder. So these chemicals may be used for seed purpose storage of potato tubers for year round storage at farmers level.Bangladesh J. Sci. Ind. Res. 52(2), 135-140, 2017

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Bioactivity of Selected Phenolic Acids and Hexane Extracts from Bougainvilla spectabilis and Citharexylum spinosum on the Growth of Pectobacterium carotovorum and Dickeya solani Bacteria: An Opportunity to Save the Environment

Processes ◽

10.3390/pr8040482 ◽

2020 ◽

Vol 8 (4) ◽

pp. 482 ◽

Cited By ~ 1

Author(s):

Nader A. Ashmawy ◽

Said I. Behiry ◽

Asma A. Al-Huqail ◽

Hayssam M. Ali ◽

Mohamed Z. M. Salem

Keyword(s):

Phenolic Acids ◽

Tannic Acid ◽

Defense Mechanisms ◽

Pathogenic Bacteria ◽

Soft Rot ◽

Inhibition Zone ◽

Pectobacterium Carotovorum ◽

Bacterial Isolates ◽

Dickeya Solani

Phenolic acids and natural extracts, as ecofriendly environmental agents, can be used as bio bactericides against the growth of plant pathogenic bacteria. In this study, isolation trails from infected potato tubers and stems that showed soft rot symptoms in fields revealed two soft rot bacterial isolates and were initially identified through morphological, physiological, and pathogenicity tests. The molecular characterization of these isolates via PCR, based on the 16S rRNA region, was carried out by an analysis of the DNA sequence via BLAST and Genbank, and showed that the soft rot bacterial isolates belong to Pectobacterium carotovorum subsp. carotovorum (PCC1) and Dickeya solani (Ds1). The in vitro results of the tested phenolic acids against the cultured bacterial isolates proved that concentrations of 800, 1600, and 3200 μg/mL were the most effective. Ferulic acid was the potent suppressive phenolic acid tested against the Ds1 isolate, with an inhibition zone ranging from 6.00 to 25.75 mm at different concentrations (25–3200 μg/mL), but had no effect until reaching a concentration of 100 μg/mL in the PCC1 isolate, followed by tannic acid, which ranged from 7.00 to 25.50 mm. On the other hand, tannic acid resulted in a significant decrease in the growth rate of the PCC1 isolate with a mean of 9.11 mm. Chlorogenic acid was not as effective as the rest of the phenolic acids compared with the control. The n-hexane oily extract (HeOE) from Bougainvillea spectabilis bark showed the highest activity against PCC1 and Ds1, with inhibition zone values of 12 and 12.33 mm, respectively, at a concentration of 4000 μg/mL; while the HeOE from Citharexylum spinosum wood showed less activity. In the GC/MS analysis, nonanal, an oily liquid compound, was found ata percentage of 38.28%, followed by cis-2-nonenal (9.75%), which are the main compounds in B. spectabilis bark HeOE, and 2-undecenal (22.39%), trans-2-decenal (18.74%), and oleic acid (10.85%) were found, which are the main compounds in C. spinosum wood HeOE. In conclusion, the phenolic acids and plant HeOEs seem to raise the resistance of potato plants, improving their defense mechanisms against soft rot bacterial pathogens.

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