scholarly journals Characterization and Genome Study of Novel Lytic Bacteriophages against Prevailing Saprophytic Bacterial Microflora of Minimally Processed Plant-Based Food Products

2021 ◽  
Vol 22 (22) ◽  
pp. 12460
Author(s):  
Michał Wójcicki ◽  
Paulina Średnicka ◽  
Stanisław Błażejak ◽  
Iwona Gientka ◽  
Monika Kowalczyk ◽  
...  
Keyword(s):  
Biological Control ◽  
Genome Sequencing ◽  
Biological Control Agent ◽  
Antibiotic Resistance Genes ◽  
Food Products ◽  
Lytic Activity ◽  
Municipal Sewage ◽  
Bacterial Strains ◽  
Minimally Processed ◽  
Wide Range

The food industry is still searching for novel solutions to effectively ensure the microbiological safety of food, especially fresh and minimally processed food products. Nowadays, the use of bacteriophages as potential biological control agents in microbiological food safety and preservation is a promising strategy. The aim of the study was the isolation and comprehensive characterization of novel bacteriophages with lytic activity against saprophytic bacterial microflora of minimally processed plant-based food products, such as mixed leaf salads. From 43 phages isolated from municipal sewage, four phages, namely Enterobacter phage KKP 3263, Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 have lytic activity against Enterobacter ludwigii KKP 3083, Citrobacter freundii KKP 3655, Enterobacter cloacae KKP 3082, and Serratia fonticola KKP 3084 bacterial strains, respectively. Transmission electron microscopy (TEM) and whole-genome sequencing (WGS) identified Enterobacter phage KKP 3263 as an Autographiviridae, and Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 as members of the Myoviridae family. Genome sequencing revealed that these phages have linear double-stranded DNA (dsDNA) with sizes of 39,418 bp (KKP 3263), 61,608 bp (KKP 3664), 84,075 bp (KKP 3262), and 148,182 bp (KKP 3264). No antibiotic resistance genes, virulence factors, integrase, recombinase, or repressors, which are the main markers of lysogenic viruses,b were annotated in phage genomes. Serratia phage KKP 3264 showed the greatest growth inhibition of Serratia fonticola KKP 3084 strain. The use of MOI 1.0 caused an almost 5-fold decrease in the value of the specific growth rate coefficient. The phages retained their lytic activity in a wide range of temperatures (from –20 °C to 50 °C) and active acidity values (pH from 4 to 11). All phages retained at least 70% of lytic activity at 60 °C. At 80 °C, no lytic activity against tested bacterial strains was observed. Serratia phage KKP 3264 was the most resistant to chemical factors, by maintaining high lytic activity across a broader range of pH from 3 to 11. The results indicated that these phages could be a potential biological control agent against saprophytic bacterial microflora of minimally processed plant-based food products.

scholarly journals Application of a Broad Range Lytic Phage LPST94 for Biological Control of Salmonella in Foods

2020 ◽  
Vol 8 (2) ◽  
pp. 247 ◽  
Author(s):  
Md. Sharifull Islam ◽  
Yang Zhou ◽  
Lu Liang ◽  
Ishatur Nime ◽  
Ting Yan ◽  
...  
Keyword(s):  
Biological Control ◽  
Apple Juice ◽  
Biological Control Agent ◽  
Food Products ◽  
Control Agent ◽  
Chicken Breast ◽  
Lytic Phage ◽  
Wide Range ◽  
Significant Public Health ◽  
Different Temperatures

Salmonella, one of the most common food-borne pathogens, is a significant public health and economic burden worldwide. Lytic phages are viable alternatives to conventional technologies for pathogen biocontrol in food products. In this study, 40 Salmonella phages were isolated from environmentally sourced water samples. We characterized the lytic range against Salmonella and among all isolates, phage LPST94 showed the broadest lytic spectrum and the highest lytic activity. Electron microscopy and genome sequencing indicated that LPST94 belongs to the Ackermannviridae family. Further studies showed this phage is robust, tolerating a wide range of pH (4–12) and temperature (30–60 °C) over 60 min. The efficacy of phage LPST94 as a biological control agent was evaluated in various food products (milk, apple juice, chicken breast, and lettuce) inoculated with non-typhoidal Salmonella species at different temperatures. Interestingly, the anti-Salmonella efficacy of phage LPST94 was greater at 4 °C than 25 °C, although the efficacy varied between different food models. Adding phage LPST94 to Salmonella inoculated milk decreased the Salmonella count by 3 log10 CFU/mL at 4 °C and 0.84 to 2.56 log10 CFU/mL at 25 °C using an MOI of 1000 and 10000, respectively. In apple juice, chicken breast, and lettuce, the Salmonella count was decreased by 3 log10 CFU/mL at both 4 °C and 25 °C after applying phage LPST94 at an MOI of 1000 and 10,000, within a timescale of 48 h. The findings demonstrated that phage LPST94 is a promising candidate for biological control agents against pathogenic Salmonella and has the potential to be applied across different food matrices.

scholarly journals Streptomyces sp.: Characterization, Identification and Its Potential as a Ralstonia solanacearum Biological Control Agent in vitro

2019 ◽  
Vol 2 (3) ◽  
pp. 89-96 ◽  
Author(s):  
Rachmad Saputra ◽  
Triwidodo Arwiyanto ◽  
Arif Wibowo
Keyword(s):  
Biological Control ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Biological Control Agent ◽  
Wilt Disease ◽  
Molecular Characteristics ◽  
Streptomyces Sp ◽  
Bacterial Wilt Disease ◽  
Wide Range

Streptomyces sp. bacteria have the potential to produce antibiotic compounds, which are one of the mechanisms that are widely used in biological control. However, in general, biological control mechanisms also occur through competition, cell wall degradation and induced resistance. This study was aimed to determine the physiological, biochemical and molecular characteristics of two isolates of Streptomyces sp. (S-4 and S16 isolates) isolated from the tomatoes roots, and to find out their ability to control Ralstonia solanacearum, which causes bacterial wilt disease on a wide range of hosts. The results showed both Streptomyces sp. isolates had several different physiological and biochemical characteristics and had a different ability to inhibit R. solanacearum in vitro. Streptomyces sp. S-16 isolate had a high similarity with Streptomyces diastaticus subsp. ardesiacus strain NRRL B-1773T based on the molecular identification results. Further research needs to be done to see the potential inhibition of the two Streptomyces isolates in inhibiting the development of bacterial wilt disease in tomato plants caused by R. solanacearum.

The biology and host specificity of the Echium leaf miner Dialectica scalariella (Zeller) (Lepidoptera: Gracillariidae)

1977 ◽  
Vol 67 (4) ◽  
pp. 627-633 ◽  
Author(s):  
A. J. Wapshere ◽  
A. A. Kirk
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Close Relation ◽  
Control Agent ◽  
Leaf Miner ◽  
Cultivated Plants ◽  
High Fecundity ◽  
European Origin ◽  
Host Restriction ◽  
Wide Range

AbstractThe gracillariid leaf miner Dialectica scalariella (Zell.), which occurs in Mediterranean Europe, North Africa, the Middle East and the Canaries, is a potential biological control agent for the weed Echium plantagineum in Australia. The moth has a high fecundity and oviposits on the leaves of Echium spp. and other Boraginaceae. The larvae destroy the leaves by forming large bulbous blotch mines. There are 5-7 generations per year. Host restriction of D. scalariella to Boraginaceae was tested by exposing a wide range of cultivated plants considered to be most at risk from it because of their close relation to Boraginaceae, because they were of Australian or non-European origin, because they did not occur in the same ecoclimatic region as D. scalariella, because their entomological fauna was poorly known, and because they or related plants were known to be attacked by insects closely related to D. scalariella. The host restriction of the moth was confirmed as only boraginaceous plants were attacked. It was concluded that both in terms of effectiveness and specificity D. scalariella could serve as a biological control agent in Australia for E. plantagineum.

scholarly journals Lytic bacteriophages as a potential alternative to control Staphylococcus aureus

2019 ◽  
Vol 54 ◽  
Author(s):  
Juliana Almeida Leite ◽  
Hyago Passe Pereira ◽  
Cristiano Amâncio Vieira Borges ◽  
Bruna Rios Coelho Alves ◽  
Alessandra Isis Alves Pinheiro Ramos ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Biological Control Agent ◽  
Bovine Mastitis ◽  
Restriction Enzymes ◽  
Control Agent ◽  
Lytic Activity ◽  
Wide Range ◽  
Potential Alternative ◽  
Dna Fragment

Abstract: The objective of this work was to characterize autochthonous bacteriophages and to determine their lytic activity on Staphylococcus aureus. Six phages were isolated from dairy barn flush water through enrichment cultures with three S. aureus strains. All phages were characterized by DNA digestion by restriction enzymes and sequencing of the DNA fragment encoding endolysin. Each phage was tested against 100 S. aureus strains isolated from bovine mastitis and from dairy products using the lysis-plate method. The sequences of the endolysin gene were highly conserved, with nucleotide similarity higher than 99% among the isolated phages. Three domains involved in the recognition and lysis of the bacterial cell wall were identified. Two bacteriophages isolated from the dairy barns present high lytic activity on S. aureus, on a wide range of host strains, indicating their potential for studies on phage therapy in dairy cattle or as a biological control agent for dairy products.

scholarly journals Characterization of a Coliphage AS1 isolated from sewage effluent in Pakistan

2022 ◽  
Vol 82 ◽  
Author(s):  
A. Ullah ◽  
T. Qamash ◽  
F. A. Khan ◽  
A. Sultan ◽  
S. Ahmad ◽  
...  
Keyword(s):  
Control Agent ◽  
Lytic Activity ◽  
Sewage Effluent ◽  
Drug Resistant ◽  
Bacterial Strains ◽  
Wide Range ◽  
Maximum Stability ◽  
Conventional Antibiotics ◽  
Bacterial Control

Abstract The emergence of multi-drug resistant (MDR) bacterial strains, which are posing a global health threat has developed the interest of scientists to use bacteriophages instead of conventional antibiotics therapy. In light of an increased interest in the use of phage as a bacterial control agent, the study aimed to isolate and characterize lytic phages from sewage effluent. During the current study, bacteriophage AS1 was isolated from sewage effluent against E.coli S2. The lytic activity of phageAS1 was limited to E.coli S2 strain showing monovalent behavior. The calculated phage titer was 3.5×109 pfu/ml. PhageAS1 was stable at a wide range of pH and temperature. The maximum stability was recorded at 37ºC and pH 7.0, while showing its normal lytic activity at temperature 60ºC and from pH 5.0 to11.0 respectively. At temperature 70ºC, phage activity was somewhat reduced whereas, further increase in temperature and decrease or increase in pH completely inactivated the phage. From the current study, it was concluded that waste water is a best source for finding bacteriophages against multi-drug resistant bacterial strains and can be used as bacterial control agent.

scholarly journals Jekyll or Hyde? The genome (and more) of Nesidiocoris tenuis, a zoophytophagous predatory bug that is both a biological control agent and a pest

2020 ◽  
Author(s):  
K. B. Ferguson ◽  
S. Visser ◽  
M. Dalíková ◽  
I. Provazníková ◽  
A. Urbaneja ◽  
...  
Keyword(s):  
Biological Control ◽  
Genome Sequencing ◽  
Acyrthosiphon Pisum ◽  
Population Genomics ◽  
Biological Control Agent ◽  
Control Agent ◽  
Initial Assessment ◽  
Control Research ◽  
Nesidiocoris Tenuis ◽  
Sequencing Strategy

AbstractNesidiocoris tenuis (Reuter) is an efficient predatory biological control agent used throughout the Mediterranean Basin in tomato crops but regarded as a pest in northern European countries. Belonging to the family Miridae, it is an economically important insect yet very little is known in terms of genetic information – no published genome, population studies, or RNA transcripts. It is a relatively small and long-lived diploid insect, characteristics that complicate genome sequencing. Here, we circumvent these issues by using a linked-read sequencing strategy on a single female N. tenuis. From this, we assembled the 355 Mbp genome and delivered an ab initio, homology-based, and evidence-based annotation. Along the way, the bacterial “contamination” was removed from the assembly, which also revealed potential symbionts. Additionally, bacterial lateral gene transfer (LGT) candidates were detected in the N. tenuis genome. The complete gene set is composed of 24,688 genes; the associated proteins were compared to other hemipterans (Cimex lectularis, Halyomorpha halys, and Acyrthosiphon pisum), resulting in an initial assessment of unique and shared protein clusters. We visualised the genome using various cytogenetic techniques, such as karyotyping, CGH and GISH, indicating a karyotype of 2n=32 with a male-heterogametic XX/XY system. Additional analyses include the localization of 18S rDNA and unique satellite probes via FISH techniques. Finally, population genomics via pooled sequencing further showed the utility of this genome. This is one of the first mirid genomes to be released and the first of a mirid biological control agent, representing a step forward in integrating genome sequencing strategies with biological control research.

scholarly journals Evaluation of Strategies and Implementation of Biological Control of Fire Blight

1993 ◽  
Author(s):  
Steven E. Lindow ◽  
Shulamit Manulis ◽  
Dan Zutra ◽  
Dan Gaash
Keyword(s):  
Biological Control ◽  
Fire Blight ◽  
Biological Control Agent ◽  
Disease Incidence ◽  
Freezing Temperature ◽  
Plasmid Profile ◽  
Control Agent ◽  
Bacterial Strains ◽  
Antagonistic Microorganisms ◽  
Population Sizes

The main objective of this study was to develop data that would facilitate a consistently effective method of biological control of fire blight disease to be developed and to enable its implementation for disease control by ensuring its compatibility with variations in the biological, environmental, and chemical conditions present in pear orchards. As considerable information on the pathogen and biological control of fire blight was already gathered from studies in California and elsewhere, an emphasis was placed on investigating the genetics and ecology of Erwinia amylovora, the causal agent of fire blight in Israel. Studies of plasmid profile, virulence on several host, serological characteristics, as well as DNA fingerprints with selected primers all revealed E. amylovora strains in Israel to be homogeneous. Strains did vary in their resistance to streptomycin, with those from more northern locations being resistant while those in the southern costal plain were all sensitive to streptomycin. Resistance appeared to be conferred by chromosomal mutations as in streptomycin-resistant strains in California. The biological control agent Pseudomonas fluorescens strain A506 colonized flowers of both the Costia and Spodona pear cultivars in Israel as well as Bartlett pear in California. Flowers that were open at the time of spray inoculation of trees subsequently harbored from 105 to 107 cells of strain A506 per flower, while those that opened subsequent to spraying developed population sizes of about 105 cells/flower within 5 days. The incidence of fire blight infections were reduced about 3-fold in several trials in which moderate amounts of disease occurred in the plot areas; this degree of biological control is similar to that observed in California and elsewhere. On two occasions warm and moist weather that favored disease led to epidemics in which nearly all flowers became infected and which was so severe that neither P. fluorescens strain A506 nor chemical bactericides reduced disease incidence. A novel method for identifying antagonistic microorganisms for biological control of fire blight and other diseases was developed. A bacterial ice nucleation gene was introduced into E. amylovora to confer an Ice+ phenotype and the population sizes of this modified pathogen on flowers that had been pre-treated with potential control agents was estimated by measuring the freezing temperature of colonized flowers. Antagonistic strains that prevented the growth of E. amylovora in flowers were readily detected as those in which flowers froze at a low temperature. The method is both rapid and unbiased and several bacterial strains with substantial biological control potential have been identified using this method.

scholarly journals Predation of Glossiphonia weberi (Blanchard, 1897) on the invasive snail Physella acuta (Draparnaud, 1805) in the presence of an alternative prey

2021 ◽  
Vol 21 (4) ◽  
pp. 201-208
Author(s):  
Pranesh Paul ◽  
Rupsha Karmakar ◽  
Swagata Chatterjee ◽  
Ankita Barua ◽  
Sampa Banerjee ◽  
...  
Keyword(s):  
Biological Control ◽  
Negative Impact ◽  
Biological Control Agent ◽  
Freshwater Snail ◽  
Control Agent ◽  
Freshwater Ecosystems ◽  
Prey Preference ◽  
Alternative Prey ◽  
Wide Range ◽  
Physella Acuta

Abstract The North American freshwater snail Physella acuta has invaded and colonized a wide range of freshwater habitats, globally. Resembling other invasive species, P. acuta has several negative impacts on the invaded freshwater ecosystems, which calls for its regulation, preferably through biological control. The malacophagous leech Glossiphonia weberi, native to West Bengal, India, had been previously reported as a potential biocontrol agent of P. acuta. In this experiment, we observed the predation potential and prey preference of G. weberi on P. acuta in the presence of a native snail, Gyraulus convexiusculus. The results suggest that in all instances, G. weberi consumed less G. convexiusculus compared to P. acuta. In complex habitats, G. weberi showed significant prey preference to P. acuta except in the habitat characterized by the presence of pebbles. The complex habitats bear a significant (p < 0.05) negative impact only in the case of predation on P. acuta when present with conspecific but not in heterospecific prey conditions. Therefore, G. weberi qualifies as a useful biological control agent that can affect the colonization and expansion of the invasive snail P. acuta, even in the presence of alternative prey.

scholarly journals An Insight into the Role of Trissolcus mitsukurii as Biological Control Agent of Halyomorpha halys in Northeastern Italy

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 306 ◽  
Author(s):  
Davide Scaccini ◽  
Martina Falagiarda ◽  
Francesco Tortorici ◽  
Isabel Martinez-Sañudo ◽  
Paola Tirello ◽  
...  
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Field Performance ◽  
Egg Parasitoid ◽  
Control Agent ◽  
The Other ◽  
Invasive Pest ◽  
Halyomorpha Halys ◽  
Wide Range ◽  
Northeastern Italy

Sustainable strategies such as classical or augmentative biological control are currently being evaluated for the long-term management of the alien invasive pest Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). A three-year study carried out in northeastern Italy was performed to investigate the distribution and field performance of the H. halys egg parasitoid Trissolcus mitsukurii (Ashmead) (Hymenoptera: Scelionidae), in comparison with other parasitoid species. In the study area, adventive populations of T. mitsukurii were present since 2016, representing the earliest detection of this species in Europe. Trissolcus mitsukurii was the most abundant parasitoid and showed a higher “parasitoid impact” (i.e., number of parasitized eggs over the total number of field-collected eggs) compared to the other species, i.e., Anastatus bifasciatus (Geoffroy) (Hymenoptera: Eupelmidae), Trissolcus basalis (Wollaston) and Trissolcus kozlovi Rjachovskij (Hymenoptera: Scelionidae). The hyperparasitoid Acroclisoides sinicus (Huang and Liao) (Hymenoptera: Pteromalidae) was also recorded. Phylogenetic analysis of T. mitsukurii population distinguished two clades, one covering samples from Italy, Japan and China, the other from South Korea. The present study provides promising results for the biological control of a pest that is having a dramatic impact on a wide range of crops worldwide.

scholarly journals Association of L-form Bacteria with Plants and their Application in Biological Control of Phytopathogenic Fungi and Bacteria: A Review

2021 ◽  
pp. 77-86
Author(s):  
P. W. H. K. P. Daulagala
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Control Agent ◽  
Phytopathogenic Fungi ◽  
Plant Diseases ◽  
World Population ◽  
Wide Range ◽  
Rigid Cell Wall ◽  
Plant Disease Management ◽  
Phytopathogenic Fungi And Bacteria

L-form bacteria with modified or no cell walls are a special group of bacteria derived or induced from cell walled forms following suppression of their rigid cell wall. They have been used to establish non-pathogenic symbioses with a wide range of plants. These L-form-plant symbioses have been shown to confer resistance against the subsequent challenge of the associated plants by both fungal and bacterial pathogens. As the world population increases, the demand for food also increases and hence control of plant diseases is of paramount importance in producing enough agricultural crops to fulfil the food demand. Plant disease management using chemical fungicides and pesticides etc. is not an ecofriendly approach and hence researchers look for alternative options such as the use of biocontrol agents which are ecofriendly and sustainable. This review paper highlights the published information on the potential of applying L-form bacteria as a biological control agent in management of plant diseases caused by pathogenic microorganisms.

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