Potato Soft Rot Research Articles

Isolation and characterization of pectolytic bacterial pathogens infecting potatoes in Nakuru County, Kenya.

Isolation and characterization of pectolytic bacteria associated with soft rot disease of potatoes in Nakuru, Kenya, to provide the basis for the development of disease control measures. Potato tubers showing symptoms of soft rot were collected from different farms in Molo and Mau Narok regions within Nakuru county. Isolation was done using crystal violet pectate medium (CVPM). Out of the 71 isolates that showed growth on CVPM, pathogenicity tests revealed that 36 of them had the ability to macerate tissues of potato tubers. All the isolates yielded a fragment of approximately 1500bp after 16S rDNA amplification. Using the BIOLOG microbial identification system, 20 bacterial isolates were identified as Pectobacterium carotovorum subsp. carotovorum, 7 were Pseudomonas fluorescens B while 9 were Ps. fluorescens A. Y1/Y2 primers successfully amplified pectate lyase-encoding (pel) gene, approximately 434bp, in all the 20 P. carotovorum species. The virulence of the isolated strains to cause disease, according to pectinolytic tests, varied with change in incubation temperature of the test samples. Pectobacterium carotovorum strains were the most virulent at 30°C while disease severity due to infection by Ps. fluorescens A strains was high at 20°C compared to the other isolates. This study reveals the identity of pectolytic bacterial species from two genera, Pectobacterium and Pseudomonas, as causative agents of potato soft rot in Nakuru, Kenya. Research findings from this study will aid in developing suitable risk mitigation methods for adoption by farmers to prevent losses due to soft rot.

Pectobacterium carotovorum subsp. brasiliense and Pectobacterium carotovorum subsp. carotovorum as causal agents of potato soft rot in Algeria

During surveys carried out in 2014 and 2015 in Algerian potato fields, severe bacterial tuber soft rot was observed. Twenty-one Gram-negative pectinolytic bacterial isolates were obtained from diseased potato tubers. These induced a hypersensitive reaction and soft rot symptoms when inoculated in tobacco leaves and potato tubers, respectively. PCR amplification using the Y1/Y2 primers demonstrated that all of the bacterial isolates belonged to the genus Pectobacterium. Phylogenetic analysis using partial malate dehydrogenase (mdh) gene sequences revealed that six and 15 isolates grouped with Pectobacterium carotovorum subsp. brasiliense and Pectobacterium carotovorum subsp. carotovorum reference strains, respectively. Multilocus sequence analysis of concatenated partial sequences of the acnA, atpD, gyrB and infB genes carried out on selected bacterial isolates confirmed the results obtained with the mdh gene sequences. PCR amplification with the BR1f/L1r primers that are specific for P. carotovorum subsp. brasiliense confirmed that six of the Algerian isolates belonged to this taxon.

Comparison of Different Sets of Primers Used in Detection and Identification of Potato Soft Rot Pectobacteriumcarotovorum subsp. carotovorum (DYE1969)

Comparison of Different Sets of Primers Used in Detection and Identification of Potato Soft Rot Pectobacteriumcarotovorum subsp. carotovorum (DYE1969)

The use of an electronic nose to detect early signs of soft-rot infection in potatoes

In this paper we report on the detection of soft-rot in potatoes caused by the bacterium Pectobacterium carotovorum through the use of an array of low cost gas sensors. This disease results in significant crop losses in store (circa 5%) with associated negative financial impacts. At present, there is no commercial technological solution for soft rot detection in such stores, with store managers having to regularly inspect large volumes of potatoes. As soft-rot is associated with a strong odour and there is forced air movement through potato stores, our aim was to investigate the potential of an array of low-cost gas sensors to detect the disease. In laboratory conditions, 80 potatoes with and without soft rot (evenly split) were analysed by an array of 11 different gas sensors. These were tested at both pre-symptomatic and symptomatic time points. Results indicated that 100% detection accuracy could be achieved at both time points with only 3 sensors. The identified sensors therefore offer promise for an automated in-store monitoring system.

Detection and Identification of Potato Soft Rot <i>Pectobacterium carotovorum</i> Subspecies <i>carotovorum</i> by PCR Analysis of 16S rDNA in Jordan

Various bacterial species are known to be agents causing soft rot of potatoes. The results of this study showed that potato soft rot is widely spread in different potato planting areas in Jordan. A survey was conducted through the years 2013-2015 to detect potato soft rot disease in Jordan, two hundred and four rotted potato samples were collected from different potato growing areas through different potato growing seasons. One hundred and thirty one bacterial isolates were isolated, purified on selective media and identified as Pectobacterium carotovorum subspecies carotovorum (Pcc) by different biochemical and physiological tests. Furthermore, 131 Pcc Jordanian (Jo) isolates were identified by PCR analysis of total DNA extracted from isolates that were biochemically identified as Pcc using universal primer Fd1/Rd1. Cloning and sequencing of representative PCR products, amplifying the 16S rDNA region were done. Phylogenetic analysis of the Pcc Jo-isolates revealed other than 90% similarity with different reference Pcc strains available at the GenBank. Different rot causal agents also were detected by PCR amplification and further sequences. The sequencing data revealed similarities to Pseudomonas fluorescence, Enterobacteriaceae genera such as Enterobacter spp., Serratia spp. and Klebsiella spp., in addition to Pectobacterium carotovorum subsp. carotovorum. This study indicated that using molecular techniques such as amplification of 16S rDNA region is a sensitive and specific method for detecting Pcc as potato soft rot causal agent. So far this is the first study where Pcc has been identified by using PCR and sequencing approaches in Jordan.

Isolation and Characterization of Two Bacteriophages Infecting Kosakonia sacchari Bacterium Causing Potato Soft Rot Disease

Potato crop is one of the most economically important crops, and is considered as the fourth main food crop in the world. One of the most important serious diseases of potato is bacterial soft rot disease. In our study, soil samples were collected from potato rhizosphere from a potato cultivated field in Giza, Egypt. Two bacteriophages were isolated on Kosakonia sacchari as a host, causing potato soft rot disease. Based on the genome characterization and electron microscopy, the two phages were named as vB_KsaM-C1 belonging to Myoviridae and vB_KsaO-C2 belonging to Microviridae. Both phages sustained their activity more than 20 months with a remarkable decrease in phage titre. In addition both recorded the same TIP at 65°C and showed the optimum activity at pH 7. The DEP of vB_KsaM-C1 was 10-7, while that of phage vB_KsaO-C2 was 10-9. A small scale application of the two isolated bacteriophages on infected potato tubers discs, in the lab, successfully inhibited bacterial soft rot caused by Kosakonia sacchari.

Bacterial Infection Potato Tuber Soft Rot Disease Detection Based on Electronic Nose

AbstractSoft rot is a severe bacterial disease of potatoes, and soft rot infection can cause significant economic losses during the storage period of potatoes. In this study, potato soft rot was selected as the research object, and a type of potato tuber soft rot disease early detection method based on the electronic nose technology was proposed. An optimized bionic electronic nose gas chamber and a scientific and reasonable sampling device were designed to detect a change in volatile substances of the infected soft rot disease of potato tuber. The infection of soft rot disease in potato tuber samples was detected and identified by using the RBF NN algorithm and SVM algorithm. The results revealed that the proposed bionic electronic nose system can be utilized for early detection of potato tuber soft rot disease. Through comparison and analysis, the recognition rate using the SVM algorithm reached up to 89.7%, and the results were superior to the RBF NN algorithm.

Soft rot of potatoes caused by Bacillus amyloliquefaciens in Guangdong province, China

Potato tubers exhibiting symptoms of soft rot were observed in a field in Baiyun District, Guangzhou, Guangdong Province, China, in March 2016. Bacteria were isolated from the diseased potato tubers. Using morphological and molecular (16S rDNA and gyrB) characterization and pathogenicity tests, a representative isolate of the bacterium was identified as Bacillus amyloliquefaciens. Inoculating the isolate onto healthy potato tubers led to soft rot with the same symptoms as displayed in the field, which confirmed Bacillus amyloliquefaciens as the causal agent. Further testing of the bacterial isolate on other hosts showed that it could also cause soft rot on tomato, onion and pepper. To our knowledge, this is the first report of soft rot of potato tubers caused by Bacillus amyloliquefaciens in the field.

Evaluation of the antagonistic potential of Bacillus strains against Pectobacterium carotovorum subsp. carotovorum and their role in the induction of resistance to potato soft rot infection

In the present study, a collection of 235 Bacillus strains, which had been isolated from the potato rhizosphere, was screened with the aim of controlling Pectobacterium carotovorum subsp. carotovorum (Pcc), a dominant potato pathogen known for causing soft rot in Iran. Fifteen strains inhibited the known Pcc strains in vitro and these were chosen for further studies. The maceration capacity of Pcc strains was decreased by the antagonistic strains in the range of 1.6–4 times. Based on 16S rRNA sequencing, five Bacillus species were characterized. Conducting various supplementary tests, the current work evaluated all antagonistic strains for biosurfactant production, mobility, enzymatic activities, production and inactivation of acyl-homoserine lactones, and the ability to produce auxin. Among the five antimicrobial peptide biosynthetic genes tested, bmyB was the less frequent gene, while three genes, namely srfAA, fenD, and ituC, were the most distributed genes. In addition, the interaction of four promising Bacillus species in the potato-Pcc system was studied. Along with its discussion of the potency for the biocontrol of Pcc by B. pumilus IrB8 and B. amyloliquefaciens IrB12, the present study’s test results also indicated these two suppressed tuber maceration by 63.7 and 47.8% respectively. The high levels of phenylalanine ammonia-lyase, polyphenol oxidase, peroxidase and total phenols were obtained in a single application of IrB8 or IrB12 after 8 h. In addition, the discontinuous usage of Bacillus and Pcc strains was achieved in comparison to other treatments. Consequently, the current work’s findings show that IrB8 and IrB12 strains have the potential to be used for potato soft rot control.

Newly Isolated Bacteriophages from the Podoviridae, Siphoviridae, and Myoviridae Families Have Variable Effects on Putative Novel Dickeya spp.

Soft rot pathogenic bacteria from the genus Dickeya cause severe economic losses in orchid nurseries worldwide, and there is no effective control currently available. In the last decade, the genus Dickeya has undergone multiple changes as multiple new taxa have been described, and just recently a new putative Dickeya species was reported. This study reports the isolation of three bacteriophages active against putative novel Dickeya spp. isolates from commercially produced infected orchids that show variable host-range profiles. Bacteriophages were isolated through enrichment from Dickeya-infected orchid tissue. Convective interaction media monolith chromatography was used to isolate bacteriophages from wastewaters, demonstrating its suitability for the isolation of infective bacteriophages from natural sources. Based on bacteriophage morphology, all isolated bacteriophages were classified as being in the order Caudovirales, belonging to three different families, Podoviridae, Myoviridae, and Siphoviridae. The presence of three different groups of bacteriophages was confirmed by analyzing the bacteriophage specificity of bacterial hosts, restriction fragment length polymorphism and plaque morphology. Bacteriophage BF25/12, the first reported Podoviridae bacteriophage effective against Dickeya spp., was selected for further characterization. Its genome sequence determined by next-generation sequencing showed limited similarity to other characterized Podoviridae bacteriophages. Interactions among the bacteriophages and Dickeya spp. were examined using transmission electron microscopy, which revealed degradation of electron-dense granules in response to bacteriophage infection in some Dickeya strains. The temperature stability of the chosen Podoviridae bacteriophage monitored over 1 year showed a substantial decrease in the survival of bacteriophages stored at -20°C over longer periods. It showed susceptibility to low pH and UV radiation but was stable in neutral and alkaline pH. Furthermore, the stability of the tested bacteriophage was also connected to the incubation medium and bacteriophage concentration at certain pH values. Finally, the emergence of bacteriophage-resistant bacterial colonies is highly connected to the concentration of bacteriophages in the bacterial environment. This is the first report on bacteriophages against Dickeya from the Podoviridae family to expand on potential bacteriophages to include in bacteriophage cocktails as biocontrol agents. Some of these bacteriophage isolates also showed activity against Dickeya solani, an aggressive strain that causes the soft rot of potatoes, which indicates their broad potential as biocontrol agents.

English

Potato soft rot is one of the major destructive diseases affecting potato plants throughout the world. In a survey of different potato growing seasons in different regions of Jordan, samples of rotten potato tubers were collected and 131 isolates identified biochemically as Pectobacterium carotovorum subsp. carotovorum (Pcc). The PCR primer pair (EXPCCR/EXPCCF) was used to detect these Jordanian isolates. The primer set amplified a single fragment of 550 bp in size from the total genomic DNA, which was extracted independently from 67 Pcc strains. In a nested PCR, the primer set (INPCCR/INPCCF) amplified the expected single fragment of 400 bp from the PCR product of first PCR amplification. The use of these primers was not reliable in detecting all isolates identified biochemically as Pcc. Different rots causal agents were detected by PCR amplification and further sequenced. The sequencing data revealed similarities to different genera; Pseudomonas, Enterobacteriaceae genera such as Enterobacter spp., Serratia spp. and Klebsiella spp., in addition to P. carotovorum subsp. carotovorum. So far this is the first study where Pcc has been identified by using PCR and sequencing approaches in Jordan.   Key words: Pectobacterium carotovorum subsp. carotovorum, specific primers, nested PCR, sequencing. &nbsp

FAIMS based volatile fingerprinting for real-time postharvest storage infections detection in stored potatoes and onions

Field asymmetric ion mobility spectrometry (FAIMS) was evaluated towards rapid and non-destructive detection of storage infections under varied storage conditions. Potato tubers and onion bulbs were inoculated with P. carotovorum subsp. carotovorum (causing soft rot) and B. cepacia (causing sour skin), respectively; and were incubated at room (around 25°C) and reduced temperature condition (4°C). Additional tubers and bulbs were inoculated with sterile water, which served as healthy controls. At room temperature, FAIMS could detect potato soft rot and onion sour skin pertinent volatile organic compounds (VOCs) as early as 1 and 3day(s) after inoculation (DAI) for potato tubers and onion bulbs, respectively. At a reduced temperature (4°C), the respective detection time frames were 11 and 16 DAI. Principal component analysis (PCA) based contribution analysis on FAIMS dispersion field data revealed a significant range of dispersion field (DF) intensity (52%–72%) and compensation voltage (CV) (−1.30V to −0.90V) that can potentially be used to train FAIMS for triggering an alarm during real-time monitoring of soft rot pertinent VOCs. This critical range was 47%–77% DF and −0.24V to 0.48V CV for sour skin pertinent VOCs. Naïve Bayes (NB) and linear discriminant analysis (LDA) classifiers tested on PCA datasets reported overall accuracies in the range of 71–100% and 69–100% for soft rot and 63–97% and 58–100% for sour skin, respectively. Higher accuracies were reported as days after inoculation progressed. Baseline sensing of different VOCs using FAIMS revealed that ethanol, acetone, 2-butanone and ethyl acetate were specifically contributing to P. carotovorum subsp. carotovorum caused soft rot peaks whereas pentane and 1-butanol were associated with healthy as well as inoculated tubers. Dimethyl disulfide, dipropyl disulfide, methyl propyl disulfide, undecane and 2-undecanone were found to be associated with healthy controls as well as with sour skin infected onion bulbs.

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

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 farmer’s level.Bangladesh J. Sci. Ind. Res. 52(2), 135-140, 2017

Chemical Composition and Bioactivity of Salvadora persica Extracts against Some Potato Bacterial Pathogens

Potent antibacterial activities of solvent extracts (methanol:n-hexane) from the branch, leaf, and root-wood of Salvadora persica were examined against potato phytopathogenic bacteria, namely Pectobacterium carotovorum subsp. carotovorum, Dickeya solani, Ralostonia solanacerum, Enterobacter cloacae, and Bacillus pumilus. The main chemical constituents analyzed by gas chromatography–mass spectrometry (GC/MS) in the branch extracts were N-benzylbenzamide (71.08%), decane (3.17%), stigmasterol (3.17%), 9-desoxo-9-x-acetoxy-3,8,12-tri-O-acetylingol (2.33%), and β-sitosterol (2.15%). The main components in the leaf extracts were 2,6-dimethyl-N-(2-methyl-α-phenylbenzyl)aniline (28.65%), spiculesporic acid (13.60%), homo-γ-linolenic acid (12.63%), and methyl hexadecanoate (11.01%). The root-wood extracts contained, as primary parts, benzeneacetonitrile (71.47%), 4-aminocarbonyl-5-fluoro-1-α-D-ribofuranosyl-imidazole (10.99%), and benzylisothiocyanate (5.05%). The extracts from the root-wood showed moderate antibacterial activity against the potato bacterial pathogens, which was followed by leaf and branch extracts. The results suggested that S. persica plant extracts could be used as bioagents against potato soft and brown rot bacterial pathogens.

Rapid and non–destructive detection of Pectobacterium carotovorum causing soft rot in stored potatoes through volatile biomarkers sensing

Early disease detection plays a significant role in the pre– and post–production management of specialty crops, that often are stored for several months prior to consumption. Potato is one of the most important specialty crops of the United States. However, soft rot in potatoes due to pathogenic infections during bulk storage, accounts for substantial losses to the industry. This study was aimed at assessing the applicability of an emerging technology, portable field asymmetric ion mobility spectrometry (FAIMS), towards early detection of soft rot in potatoes during bulk storage. The FAIMS senses mobility of ions pertinent to volatile organic compounds (VOCs) released from inoculated tubers. In this study, potato tubers, inoculated with Pectobacterium carotovorum causing soft rot, were analyzed using FAIMS over a 30–day period in storage. Sterile water inoculated tubers were considered as healthy controls. Results suggest that FAIMS can detect soft rot as early as two days after inoculation (DAI) by effectively capturing VOCs associated with rot progression. The activity of pathogen and associated VOCs release was maximum during the second week after inoculation. A principal component analysis showed a clear distinction between the healthy and P. carotovorum inoculated tubers. Classification models, quadratic discriminant analysis and Naïve Bayes with leave–one–out cross validation confirmed the validity of FAIMS response with accuracies between 83 and 100% for both healthy and P. carotovorum inoculated tubers.

PH-Dependent DNA Distortion and Repression of Gene Expression by Pectobacterium atrosepticum PecS

Transcriptional activity is exquisitely sensitive to changes in promoter DNA topology. Transcription factors may therefore control gene activity by modulating the relative positioning of -10 and -35 promoter elements. The plant pathogen Pectobacterium atrosepticum, which causes soft rot in potatoes, must alter gene expression patterns to ensure growth in planta. In the related soft-rot enterobacterium Dickeya dadantii, PecS functions as a master regulator of virulence gene expression. Here, we report that P. atrosepticum PecS controls gene activity by altering promoter DNA topology in response to pH. While PecS binds the pecS promoter with high affinity regardless of pH, it induces significant DNA distortion only at neutral pH, the pH at which the pecS promoter is repressed in vivo. At pH ∼8, DNA distortions are attenuated, and PecS no longer represses the pecS promoter. A specific histidine (H142) located in a crevice between the dimerization- and DNA-binding regions is required for pH-dependent changes in DNA distortion and repression of gene activity, and mutation of this histidine renders the mutant protein incapable of repressing the pecS promoter. We propose that protonated PecS induces a DNA conformation at neutral pH in which -10 and -35 promoter elements are suboptimally positioned for RNA polymerase binding; on deprotonation of PecS, binding is no longer associated with significant changes in DNA conformation, allowing gene expression. We suggest that this mode of gene regulation leads to differential expression of the PecS regulon in response to alkalinization of the plant apoplast.

Survey and Detection of Pectobacterium atrosepticum in Major Potato-Growing Areas in Central Java Province, Indonesia

Potato (Solanum tuberosum) is a seasonal shrub-tuber crop originated from sub-tropical area. Soft-rot is one of the most important diseases of potato. It can be caused by Pectobactorium atrosepticum, a pathogen within a status of quarantine plant pest A1 type I in Indonesia. The objective of this study was to know the incidence of potato soft rot disease and to detect P. atrosepticum in major potato-growing areas in Central Java Province by applying the serology method using DAS-ELISA technique. Survey of soft rot disease was carried out in some regencies in Central Java Province, i.e. Magelang, Banjarnegara, Wonosobo and Karanganyar. The field survey of potato plant in all the regencies indicated symptoms of stem rot which was black in color (blackleg) and foul-smelling, with disease incidence of about 10–90%. The laboratory testing showed that by applying DAS-ELISA method, P. atrosepticum was detected in samples collected from Pandean and Bagongan villages, district of Ngablak,Regency of Magelang, Central Java Province.

Pathogens Causing Soft Rot and Blackleg Symptoms in Potatoes in Peri-urban Harare Area

Aims: To identify, using standard biochemical tests, a polymerase chain reaction and sequencing, the soft rot species presumed to be the cause of potato soft rot and blackleg affecting potatoes in commercial farms around the Harare area in Zimbabwe. Study Design: Biochemical tests, a polymerase chain reaction and sequencing were conducted on the collected isolates. Place and Duration of Study: Samples were collected at potato commercial farms within a 60 km radius of Harare in May ‐ June 2012. Laboratory experiments were conducted at the University of Zimbabwe, Plant Pathology Laboratory. Methodology: 24 samples of infected potato tubers and stems were collected from eight farms. Eight representative isolates were selected for identification tests. A polymerase chain reaction using ADE 1/2 primers and sequencing using gyr B and rec A genes were carried out. Pathogenicity tests were conducted to further confirm the identity of the bacteria. Plants were observed for seven days for symptom development.

Efficacies of quorum sensing inhibitors, piericidin A and glucopiericidin A, produced by Streptomyces xanthocidicus KPP01532 for the control of potato soft rot caused by Erwinia carotovora subsp. atroseptica

To discover potential inhibitors of the quorum sensing (QS) system, a library of microbial culture extracts was screened with Chromobacterium violaceumCV026 strain. The culture extract of Streptomyces xanthocidicus KPP01532 contained quorum-sensing inhibitors (QSIs) of the CV026 strain. The active constituents of the culture extract of strain KPP01532 were purified using a series of chromatographic procedures, and based on data from NMR and mass spectroscopy, piericidin A and glucopiericidin A were identified. Erwinia carotovora subsp. atroseptica (Eca) is a plant pathogen that causes blackleg and soft rot diseases on potato stems and tubers. The virulence factors of Eca are regulated by QS. The expression of virulence genes (pelC, pehA, celV and nip) under the control of QS was monitored using quantitative real-time PCR (qRT-PCR). The transcription levels of the four genes were significantly lower when Eca was exposed to piericidin A or glucopiericidin A. These two compounds displayed similar control efficacies against soft rot caused by Eca in potato slices as furanone C-30. Therefore, piericidin A and glucopiericidin A are potential QSIs that suppress the expression of the virulence genes of Eca, suggesting that they could have potential use as control agents of soft rot disease on potato tubers.

Screening bactericidal effect of Pectobacterium carotovorum subsp. carotovorum strains against causal agent of potato soft rot.

This study focuses on the potential of Pectobacterium carotovorum subsp. carotovorum (Pcc) strains producing bacteriocin as a tool to control potato soft rot disease. Thirty out of 48 purified bacterial strains were characterized as Pcc using specific PCR and phenotypic tests. The pathogenicity and pectate degrading assays were recorded positive for 13 strains. Bacteriocin typing clustered producers into three groups according to their antimicrobial spectra. Majority of the producers except strains of group II showed antibacterial activity toward relative genus and the role of UV or mitomycin C was inductive. In addition, none of the distant genus was sensitive to Pcc bacteriocins except Rhizobium vitis. Molecular detection of four bacteriocins including carotovoricin, carosin S1, S2 and carosin D was performed. Overall, 54.5% of group I, 47.3 and 70% of groups II and III strains carried carotovoricin and four strains harbored gene corresponding to carosin S1. According to our data divers antimicrobial patterns obtained by Pcc strains and existence of new bateriocines could be possible. Moreover, our findings recommended that direct application of P29 or expression of corresponding genes of Pog22 or P21 in a nonpathogenic strain as a biocontrol agent may improve soft rot disease control.