© IDOSI Publications, 2010 Antagonisitic Potential of Soil Bacteria Against Food Borne Fungi (original) (raw)
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Archives of Applied Science Research, 2013
Bacteria have the ability to produce a wide variety of metabolites with antifungal capabilities. The present study was assessed in order to find out the antagonistic ability of eight different soil borne bacterial strains, Escherichia coli, Klebsiella ozaenae, Pseudomonas maltophila, Bacillus circulans, Bacillus sphaericus, Bacillus coagulans, Serratia marcescens and Streptococcus spp.against some plant pathogenic fungi , Alternaria porri, Fusarium oxysporum, Sclerotium rolfsii and Botryodiplodia theobromae which were isolated from disease specimen. All isolates were subjected to primary screening against test organisms and further carried out to secondary screening using agar disc assay and slide culture techniques. Most of the selected bacteria exhibited promising antagonistic activity against tested organisms. Out of eight bacterial species P.maltophila and B.circulans revealed effective biocontrol potential against all tested fungi. Whereas Streptococcus spp induced the vegetati...
Soil bacteria are able to synthesize a wide range of metabolites with fungicidal activity. Nine bacterial isolates were obtained from the botanical garden of university of Calabar. Preliminary examination of isolates was carried out using morphological characteristics and Gram's reaction. These isolates were designated with codes SB1, SB2, SB3, SB4, SB5, SB6, SB7, and SB8. Bacterial isolates were evaluated for their potential of antagonism against Aspergillus niger isolated from spoiled vegetables like tomatoes by using agar diffusion technique. Percentage inhibition of mycelial growth by these isolates recorded values as 27%, 0%, 66%, 40%, 97%, 0% and 23% respectively. Isolates were analyzed through several biochemical tests and were identified as Bacillus sp., Enterobacter spp., Pseudomonas spp., Proteus spp., Escherichia coli, Streptococcus spp. and Staphylococcus spp. respectively. These result indicated that bacterial species exhibited varying degree of antagonism against the fungus Aspergillus niger. Escherichia coli showed maximum inhibitory potential against tested fungus with reduction of up to 97% in their fungal Original Research Article Rao et al.; JAMB, 3(2): 1-7, 2017; Article no.JAMB.33320 2 growth. Pseudomonas spp. and Bacillus spp. followed with 66.7%. This result showed that Pseudomonas spp. and Bacillus spp. exhibited similar percentage of antagonism against Aspergillus niger. From the results obtained, it can be interpreted that test bacterial species can be used as fungal agents like Aspergillus niger.
Soil bacteria are able to synthesize a wide range of metabolites with fungicidal activity. Nine bacterial isolates were obtained from the botanical garden of University of Calabar. Preliminary examination of isolates was carried out using morphological characteristics and biochemical analysis. These isolates were designated with codes SB1, SB2, SB3, SB4, SB5, SB6, SB7, and SB8. Bacterial isolates were evaluated for their potentials of antagonism against Aspergillus niger isolated from spoiled vegetables like tomatoes by using agar diffusion technique. Percentage inhibition of mycelial growth by these isolates recorded values as 27%, 0%, 66%, 40%, 97%, 0% and 23% respectively. Isolates were analyzed through several biochemical tests and were identified as Bacillus sp., Enterobacter spp., Pseudomonas spp., Proteus spp., Escherichia coli, Streptococcus spp. and Staphylococcus spp. respectively. These result indicated that bacterial species exhibited varying degree of antagonism against the fungus Aspergillus niger. Escherichia coli showed maximum inhibitory potential against tested fungus with reduction of up to 97% in their mycelial fungal growth, followed by Pseudomonas spp. and Bacillus spp. with 66.7% reduction. From the results obtained, it is found that the bacterial species isolated from the soil samples are effective as antifungal agents against phyto-pathogenic fungi. Escherichia coli, Pseudomonas spp., Bacillus spp. had more antagonistic effect on vegetative growth of tested fungi (Aspergillus niger). These bacterial species showed higher levels of inhibitory effect on fungal spore germination. The presented data exhibit the antifungal activity of bacterial species and indicate the possibility of using these bacterial species as a biological agent to control the phyto pathogenic fungi.
Evaluation of Some Biocontrol Agents against Soil Pathogenic Fungi
Research Journal of Pharmaceutical, Biological and Chemical Sciences
The current study was aimed to screen of certain rhizospheric bacterial biocontrol agents against some pathogenic fungi. The obtained data revealed that among 116 bacterial isolates, nineteen bacterial isolates showed the highest inhibition percentage against Fusarium oxysporum, Rhizoctonia solani and Sclerotium rolfsii. Regarding the antifungal activities, results indicated that isolates B38 and B103 recorded the higher values of chitinase activity, catecholate-type siderophores and NH 3. Also data showed that isolate B103 was the highest producer for HCN followed by the isolates number B13 and B38. Concerning the production of volatile compounds, data indicated that isolates B103 and B38 showed considerable inhibition against pathogenic fungal growth. Data also showed that poly medium was the best medium for production of inhibitive substances for pathogenic fungi by the tested bacteria. Moreover, cultural filtrates of bacterial biocontrol agents with concentration of 10% showed t...
Antagonistic Potential of Soil Bacteria against Plant Pathogenic Fungi: Aspergillus niger
Aims: This study was carried out with the aim of assessing the antagonistic potentials of soil bacteria against the plant pathogenic fungi Aspergillus niger. Study Design: The complete Randomized Design was the experimental design for this study. Place and duration of study: This study took place in University of Calabar, Cross River State Nigeria within the pace of one month. Methodology: Standard microbiological methods were used to identify bacteria and obtain pure culture of fungi Results: Bacterial isolates were evaluated for their potential of antagonism against Aspergillus niger isolated from spoilt tomatoes. The percentage inhibition of mycelia growth by these isolates recorded values as 27%, 0%, 66%, 40%, 97%, 0% and 23% respectively. The isolates were analyzed and identified as Bacillus spp, Enterobacter spp., Pseudomonas spp., Proteus spp., Escherichia coli, Streptococcus spp. and Staphylococcus spp respectively. Conclusion: In the present work high levels of in vitro control of A. niger have been verified by E. coli isolates. However, in future investigations molecular studies should be carried out confirming that the isolates obtained from E. coli are not pathogenic to humans.
In vitro screening of soil bacteria for inhibiting phytopathogenic fungi
AFRICAN JOURNAL OF BIOTECHNOLOGY
At present, the greatest interest resides with the development and application of specific biocontrol agent for the control of diseases on plant and this form the focus of this work. Several soil bacteria were evaluated in vitro for their effectiveness on the basis of their ability to suppress fungi in plate inhibition assays. 51 strains of 12 bacterial species were performed against 12 strains of 10 phytopathogenic mould species. Almost all soil bacteria species; but about 50% of the bacteria strains, showed an antagonistic activity against at least one phytopathogenic fungus. Sphingomonans spp was the only specie that did not show any antagonistic effect to all fungi. Bradyrhizobium japonicum could highly inhibit the mycelial growth of five moulds (Botrytis cinerea, Phoma medicaginis, Fusarium verticilloides, Rhizoctonia solani and Phytophtora infestans) with a growth inhibition varying between 12.38 and 37.61%. 12 Bacillus strains and five Pseudomonas strains were antagonistic to the major phytopathogenic moulds used in this trial. Bacillus subtilis exhibited strong antagonism against fungi both from cultural medium and from sterile filtrate. Results show that bacterial suspension and bacterial supernatant did not operate in the same way. Supernatant from bacterial strains seemed to be efficient against phytopathogenic moulds. The mycelial growth of R. solani, P. medicaginis and F. verticilloides was inhibited by 12-fold dilution of the supernatant from B. japonicum. The latter draws a conclusion that bacteria isolated from soil are promising natural biocontrol agents and should be further studied and tested for the control of numerous plant diseases. Additional studies are required to definitively determine their mode of antifungal action, safety and biocompatibility.
Food Control, 2018
Toxigenic Aspergillus flavus and A. parasiticus fungal strains can contaminate a wide variety of food crops with the subsequent production of aflatoxins (AFs) resulting in severe economic losses and public health issues. Biological control is a promising approach to manage AFs contamination in pre-and postharvested crops. In the present study, the effect of soil-borne Bacillus spp. strains on aflatoxigenic A. parasiticus growth and AFs production was evaluated and the culture supernatant of the most effective strain was evaluated for the presence of antifungal lipopeptides. Six Bacillus spp. strains were able to reduce A. parasiticus growth rate significantly (p < 0.05). Bacillus spp. RC1A was able to inhibit fungal growth almost completely, reducing growth rate to 0.16 mm/h and increasing Lag phase duration (31.72 h) (p < 0.0001). RC1A could also reduce AFB 1 concentration produced by A. parasiticus (p < 0.0001). Organic solvent extraction and chromatographic analysis of RC1A culture supernatant showed the presence of bands corresponding to three of the main groups of lipopeptides (surfactin, iturin A and fengycin) at the expected retention factor (Rf) values; they were also confirmed by MALDI-MS analysis. These fractions were able to inhibit A. parasiticus growth and AFB 1 production to nondetectable levels when tested separately in liquid culture media. The further study of the antifungal compounds produced by these strains will determine their potential use to manage AFs contamination in crops and feeds.
Novel Ecofriendly Approaches for Controlling Soil Borne Fungal Pathogens: A Review
Agriculture Journal IJOEAR, 2021
The application of chemical fungicides for controlling soil borne plant pathogens is rapidly increasing due to their potential to deliver desirable results in a short span of time. However their rampant use has made many invasive plant pathogens resistant to any chemical control making them way harder to eradicate or eliminate as compared to the past days. The uncontrolled use of chemical fungicides is also causing soil toxicity and water pollution leading to several health hazards. The aim of the review article is to highlight the recent advancements in the field of eco-friendly disease management using the extracts obtained from natural resources and biologically active antagonistic organisms. The review article highlights the management of Black scurf disease (Rhizoctonia solani) in Potato using Bacillus subtilis V26 strain and by using a mixture of cattle manure and date palm compost. Biological control of Fusarium wilt of tomato (Fusarium oxysporum f.sp. lycopersici) by the application of endophytic bacterial isolates from Silver Leaf (Solanum elaeagnifolium) has been also mentioned. The review includes the management of Late blight of potato (Phytophthora infestans) using antagonistic Poplar (Populus nigra) bud extracts and peptide extracts obtained from Common Horsetail (Equisetum arvense). The review article also mentions the innovative method of management of Black shank disease of tobacco (Phytophthora parasitica var. nicotianae) by colonization of tobacco roots with Paenibacillus polymyxa C5 strain. As per the article, Foot rot of rice or rice bakanae (Fusarium moniliforme) can be effectively managed by the application of antifungal Surfactin-A extracted from Bacillus subtilis NH-100 and NH-217 strains. The article highlights the potential of the Bacillus subtilis RH5 strain as a bioformulation for controlling Sheath blight of rice (Rhizoctonia solani). The extracts and the antagonistic biocontrol agents can be used in the effective management of some economically important soil-borne plant diseases as a novel, innovative and environmentally safe approach.
Antagonistic activity of some bacterial species against other microorganisms isolated from the soil
2020
Executive manager at Metalab diagnostic laboratories Fall 2019 pathogenic microorganisms in which klebsiella had not antagonistic activity or was not able to be antifungal agent against Aspergillus Niger. Whereas Escherichia coli , Bacillus spp., Staphylococcus spp. had varies effects as antifungal growth agents according to the difference in the production of pathogenic fungal cell wall lytic enzymes.
Isolation and characterization of fungal strains as biocontrol agents
Agriculture is the back-bone of country and Indian economy (K Kabir). Plant pathogenic bacteria and fungi are considered economically important around the world (Carson 1962; Houeto et al. 1995) due to cause many serious diseases of plants (Vidhyasekaran 2002). Modern agronomy, pesticides and fertilizers have sharply increased yields from cultivation, but also caused widespread ecological damage and negative human health effects (EPA 2006). So, there is a need to replace conventional pesticides and fertilizers. Microorganisms with ability to suppress disease causing fungi, bacteria and insect-pests are potentially important alternatives to chemical pesticides and have been reported by many researchers. With the above facts the present study entitled “Isolation and Characterization of Fungal Strains as Biocontrol Agents.” In the study Fungal strains namely Trichoderma viride, Acrimonium strictum, Aspergillus terreus, Aspergillus oryzae, Aspergillus niger, Paecilomyces variotii, Aspergillus fumigates and Penicillium glabrum were found antibacterial active against 11 plant pathogenic bacterial strains. These fungi having antimicrobial activity can be used as biopesticides against broad range of pathogenic micro-organisms like bacteria & fungi. So the study will be helpful to improve crop yield as well as quality.