scholarly journals Enumeration, Antagonism and Enzymatic Activities of Microorganisms Isolated from Railway Station Soil

2018 ◽  
Author(s):  
Megha Sharma ◽  
Prashant Kaushik ◽  
Pawan Chaturvedi
Keyword(s):  
Plant Pathogens ◽  
Antagonistic Activity ◽  
Soil Sampling ◽  
Microbial Count ◽  
Bacillus Sp ◽  
Bacterial Isolates ◽  
Gradual Reduction ◽  
Railway Station ◽  
Mucor Species ◽  
Rainy Days

AbstractSoil is the well-known hotspot for microbial diversity. Therefore, for our investigation, we isolated, characterized, and identified microorganisms from railway station soil. Sampling was done subsequently after every 15 days interval, and from two different soil depths i.e. 0-15 cm and below during March to May of 2013. Further, soil isolates were examined for their antagonistic activity, against four soil born plant pathogens namely,Rhizoctonia solani, Aspergillus niger, Fusarium f sp pisi, andSclerotinia sclerotiorum. Subsequently, isolates were screened for the presence of amylases, proteases, lipases and cellulases. For each interval of soil sampling, a gradual reduction in the microbial count was noticed from month March to May. Mucor species was observed only in the rainy days. The most promising enzymes producers wereBacillus sp., Aspergillus and Penicillium sp. Overall, the fungal isolates were better producers of enzymes as compared to bacterial isolates.

scholarly journals Lytic Exoenzymes of Soil Strains of Bacillus Representatives and Manifestations of their Biological Activity

2021 ◽  
Vol 83 (4) ◽  
pp. 54-62
Author(s):  
Yu.V. Korzh ◽  
◽  
I.V. Dragovoz ◽  
L.V. Avdeeva ◽  
◽  
...  
Keyword(s):  
Biological Activity ◽  
Soil Bacteria ◽  
Antagonistic Activity ◽  
Lytic Activity ◽  
Bacillus Sp ◽  
Genus Bacillus ◽  
Phytopathogenic Bacteria ◽  
Petri Dishes ◽  
Bacillus Strains ◽  
Test Cultures

Bacteria of the genus Bacillus make up a significant (8–12%) part of the soil microbiome. Manifestation of their biological activity, in particular, the antagonistic and lytic activity against other microorganisms directly depends on their exometabolites. According to the literature, such properties of soil bacteria of the genus Bacillus thus can be related to their various lytic exoenzymes. Aim. To evaluate the role of lytic exoenzymes of the studied soil bacteria strains of the genus Bacillus in the manifestation of their biological (antagonistic, lysing) activity. Methods. The antagonistic activity of bacteria strains of the genus Bacillus against phytopathogenic micromycetes was determined by the method of double culture in Petri dishes on potato-glucose agar. For qualitative analysis of the presence of extracellular enzymes, strains of bacteria of the genus Bacillus were plated on Petri dishes with solid mineral-salt medium and a suitable substrate inducer. The ratio of the diameter of substrate hydrolysis zone to the diameter of the colony was taken as the relative enzymatic activity of the culture. Bacteriolytic activity of the studied strains was determined by the change in optical density of living cells of phytopathogenic bacteria suspension at 540 nm. Results. Six strains of bacteria of the genus Bacillus were selected by the results of preliminary screening, with at least five types of lytic activity, namely proteolytic, chitinase, amylolytic, cellulase, and xylanase of different levels (low, average, high). Analysis of the antagonistic activity of the selected strains of bacteria of the genus Bacillus to the main groups of phytopathogenic bacteria (six test cultures) singled out the strain Bacillus sp. 41 for a careful study of the nature and spectrum of its antagonism. Analysis of the level of antagonistic activity of the selected Bacillus strains against the phytopathogenic micromycetes showed that the minimum decrease of antagonism (the decrease of growth inhibition zones) during the observation period (at the 3rd and 7th days) was in Bacillus sp. 41 strain. Therefore, only this strain showed a stable and relatively wide range of antagonistic activity against phytopathogens of bacterial and fungal etiology. The nature of this antagonism is probably complex and conditioned by the participation of various biochemical mechanisms, in particular, the synthesis of a complex of lytic exoenzymes. To assess the lysing activity of Bacillus strains, three strains with the highest proteolytic and cellulolytic activity of exoenzymes were taken from the six previously chosen. Only Bacillus sp.1913 strain showed high (70%) lytic activity against gram-negative polyphagous phytopathogen Pseudomonas syringae pv. syringae UCM B-1027T. Such activity of the strain did not manifest against the rest of the phytopathogenic test cultures. The high lytic activity of Bacillus sp. 1913 strain may be associated with high activity of exogenous proteases and cellulases of the lytic complex, which is quite consistent with the literature data on the lytic activity of bacteria of the genus Bacillus. Conclusions. The spectrum and activity of lytic exoenzymes of strains of the studied soil bacteria of the genus Bacillus indicate the indirect participation of these enzymes in the manifestation of biological activity (antagonistic and lytic).

scholarly journals Searching for Antagonistic Activity of Bacterial Isolates Derived from Food Processing Environments on Some Food-Borne Pathogenic Bacteria

2020 ◽  
Vol 49 (4) ◽  
pp. 415-423
Author(s):  
B. Baráti-Deák ◽  
Cs. Mohácsi-Farkas ◽  
Á. Belák
Keyword(s):  
Escherichia Coli ◽  
Food Processing ◽  
Pathogenic Bacteria ◽  
Inhibitory Effect ◽  
Antagonistic Activity ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Food Borne ◽  
Time Period ◽  
Growth Decline

Bacterial strains with inhibitory effect on Salmonella Hartford, Listeria monocytogenes, Yersinia enterocolitica, and Escherichia coli, respectively, were isolated. Out of the 64 bacteria originated from food processing environments, 20 could inhibit at least one of the tested pathogens, and it was proved that growth decline of the pathogenic bacteria was more remarkable by co-culturing than by using cell-free supernatants of the isolates. Seven different genera (Pseudomonas, Bacillus, Paenibacillus, Macrococcus, Staphylococcus, Serratia, and Rothia) reduced the pathogens’ growth during the time period of analysis, and the strongest inhibitory effect was observed after 24 h between 15 and 30 °C. Sensitivity of the tested human pathogenic bacteria against the inhibitory strains was distinct, as Y. enterocolitica could be inhibited by numerous isolates, while S. Hartford proved to be the most resistant. Our results reveal that the isolated bacteria or their excreted metabolites could hinder pathogen growth when used in sufficient quantities.

Isolation, Characterization and Application of Protease Enzyme from Marine Bacteria

2021 ◽  
pp. 4236-4240
Author(s):  
Sneha S ◽  
Mrunal Palsokar ◽  
Vemula Sai Jahnavi ◽  
Anwesha Sarkar ◽  
K. V. Bhaskara Rao
Keyword(s):  
Marine Bacteria ◽  
Peptide Bond ◽  
Mangrove Sediment ◽  
Bacillus Sp ◽  
Bacterial Isolates ◽  
Sediment Samples ◽  
Protease Enzyme ◽  
Stain Removal ◽  
Marine Sediment Sample ◽  
Protease Assay

Protease constitutes the major group of catalytic enzymes which is involved in hydrolyzing peptide bond of proteins. Marine sediment sample were collected and protease producing bacterial isolates were identified by using casein as a substrate. The organisms were characterized by biochemical test and identified as Bacillus sp. In order to check for the production of protease enzyme, quantitative protease assay and Lowry’s method of protein estimation was carried out. The crude extract of protease was subjected for blood stain removal activity and the enzyme proved to be efficient which removed the stain in 15 min. The purpose of the current study is to isolate, identify, characterize and to carry out applications of protease enzyme from marine bacteria isolated from mangrove sediment samples.

Physiological and molecular characterization of compost bacteria antagonistic to soil-borne plant pathogens

2017 ◽  
Vol 63 (5) ◽  
pp. 411-426 ◽  
Author(s):  
Rowida Mohamed ◽  
Emma Groulx ◽  
Stefanie Defilippi ◽  
Tamara Erak ◽  
James T. Tambong ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Antagonistic Activity ◽  
Antagonistic Bacteria ◽  
Antimicrobial Compounds ◽  
Fusarium Sambucinum ◽  
Inhibitory Compounds ◽  
Antimicrobial Lipopeptides ◽  
Chemical Pesticides ◽  
Insight Into

Disease suppressive composts have the potential to mitigate the risks associated with chemical pesticides. One of the main characteristics responsible for the suppressive nature of composts is their microbiological populations. To gain insight into the determinants responsible for their suppressive effects, we assayed composts to (i) isolate and identify beneficial antagonistic bacteria, (ii) quantify their antifungal and anti-oomycetal activities, (iii) extract inhibitory compounds produced by the bacteria, and (iv) identify antimicrobial lipopeptides produced by these bacteria. The antagonistic bacteria belonged to the genera Arthrobacter, Pseudomonas, Bacillus, Brevibacillus, Paenibacillus, and Rummeliibacillus and had the ability to antagonise the growth of Fusarium sambucinum, Verticillium dahliae, and (or) Pythium sulcatum. These bacteria produced antimicrobial compounds that affected the mycelial growth and (or) conidial germination of the pathogens. Mass spectrometry analyses showed the presence of various antimicrobial lipopeptides in Bacillus and Bacillus-related spp. extracts, demonstrating that they are responsible, at least in part, for the antagonistic activity of the bacteria. Results from this work provide greater insight into some of the biological, biochemical, and physiological determinants of suppressiveness in composts involved in the control of plant pathogens.

scholarly journals A Rare Thioquinolobactin Siderophore Present in a Bioactive Pseudomonas sp. DTU12.1

2019 ◽  
Vol 11 (12) ◽  
pp. 3529-3533
Author(s):  
Pavelas Sazinas ◽  
Morten Lindqvist Hansen ◽  
May Iren Aune ◽  
Marie Højmark Fischer ◽  
Lars Jelsbak
Keyword(s):  
Gene Cluster ◽  
Secondary Metabolite ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Plant Pathogens ◽  
Gene Clusters ◽  
Fungal Species ◽  
Antagonistic Activity ◽  
Evolutionary Origins

Abstract Many of the soil-dwelling Pseudomonas species are known to produce secondary metabolite compounds, which can have antagonistic activity against other microorganisms, including important plant pathogens. It is thus of importance to isolate new strains of Pseudomonas and discover novel or rare gene clusters encoding bioactive products. In an effort to accomplish this, we have isolated a bioactive Pseudomonas strain DTU12.1 from leaf-covered soil in Denmark. Following genome sequencing with Illumina and Oxford Nanopore technologies, we generated a complete genome sequence with the length of 5,943,629 base pairs. The DTU12.1 strain contained a complete gene cluster for a rare thioquinolobactin siderophore, which was previously described as possessing bioactivity against oomycetes and several fungal species. We placed the DTU12.1 strain within Pseudomonas gessardii subgroup of fluorescent pseudomonads, where it formed a distinct clade with other Pseudomonas strains, most of which also contained a complete thioquinolobactin gene cluster. Only two other Pseudomonas strains were found to contain the gene cluster, though they were present in a different phylogenetic clade and were missing a transcriptional regulator of the whole cluster. We show that having the complete genome sequence and establishing phylogenetic relationships with other strains can enable us to start evaluating the distribution and evolutionary origins of secondary metabolite clusters.

Screening of new bacterial isolates with antifungal activity and application of selected Bacillus sp. cultures for biocontrol of Fusarium graminearum under field conditions

2018 ◽  
Vol 113 ◽  
pp. 22-28 ◽  
Author(s):  
Karina Stumbriene ◽  
Renata Gudiukaite ◽  
Roma Semaskiene ◽  
Povilas Svegzda ◽  
Akvile Jonaviciene ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Fusarium Graminearum ◽  
Field Conditions ◽  
Bacillus Sp ◽  
Bacterial Isolates

scholarly journals Antifungal activity of indigenous Bacillus spp. isolated from soil

2017 ◽  
pp. 261-269 ◽  
Author(s):  
Dragana Bjelic ◽  
Maja Ignjatov ◽  
Jelena Marinkovic ◽  
Nemanja Spremo ◽  
Maja Karaman ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Fusarium Verticillioides ◽  
Fungal Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Fungal Species ◽  
Antagonistic Activity ◽  
Antagonistic Effect ◽  
Plant Diseases ◽  
Bacterial Isolates ◽  
Bacillus Spp

Biocontrol using plant growth-promoting rhizobacteria (PGPR) represents an alternative approach to disease management, since PGPR are known to promote growth and reduce diseases in various crops. Among the different PGPR, members of the genus Bacillus are prefered for most biotechnological uses due to their capability to form extremely resistant spores and produce a wide variety of metabolites with antimicrobial activity. The objective of this research was to identify antagonistic bacteria for management of the plant diseases. Eleven isolates of Bacillus spp. were obtained from the soil samples collected from different localities in the Province of Vojvodina. The antifungal activity of bacterial isolates against five fungal species was examined using a dual plate assay. Bacillus isolates exhibited the highest antifungal activity against Fusarium proliferatum, Fusarium oxysporum f. sp. cepae and Alternaria padwickii, while they had the least antagonistic effect on Fusarium verticillioides and Fusarium graminearum. Molecular identification showed that effective bacterial isolates were identified as Bacillus safensis (B2), Bacillus pumilus (B3, B11), Bacillus subtilis (B5, B7) and Bacillus megaterium (B8, B9). The highest antagonistic activity was exhibited by isolates B5 (from 39% to 62% reduction in fungal growth) and B7 (from 40% to 71% reduction in fungal growth). These isolates of B. subtilis could be used as potential biocontrol agents of plant diseases.

scholarly journals Screening and Potential Uses of Contaminated Spent Mushroom (Pleurotus spp.)

2021 ◽  
Author(s):  
Mathipriya Shanmugavelu ◽  
Ganesan Sevugaperumal
Keyword(s):  
Pathogenic Fungi ◽  
Dry Weight ◽  
Antagonistic Activity ◽  
Pseudomonas Sp ◽  
Bacillus Sp ◽  
Bacterial Strains ◽  
Mushroom Compost ◽  
Plant Growth Promoting Activities ◽  
Shoot Weight ◽  
Aspergillus Sp

The commercial production of mushrooms generates a co-product, a virtually inexhaustible supply of spent mushroom substrate (SMS). It represents an ideal growth medium for plants and plant disease suppressive quality. Here we discussed about the contaminated microbial flora of SMS, potential antifungal and plant growth promoting activities, the results of these findings were also discussed in relation to the usage of SMS as a potential product for organic farming. SMS contained moisture content 72%, EC 1.75 mmho.cm−1 and had pH of 6.1. The cellulose and hemicellulose content of paddy straw substrate were 30.25%, 23.18% and 15.31% dry weight respectively. Growth in terms of root and shoot weight of the seedlings of green gram, black gram, tomato and chili were significantly higher when grown in 60% SMS amended soil. Spent mushroom compost from Pleurotus eous used in this study harbored bacterial population including, Bacillus sp., Clostridium sp., Pseudomonas sp. and E. coli. Bacterial isolate B1 was identified as Bacillus sp., isolate B2 was identified as Clostridium sp., isolate B3 as Pseudomonas sp. and B4 as Escherichia coli. These bacterial strains showed significant antagonistic activity against soil borne pathogenic fungi viz., Fusarium sp., Alternaria sp., Phytophthora sp. and Aspergillus sp.

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