scholarly journals TWO TRICHODERMA SPECIES AND BACILLUS SUBTILIS AS BIOCONTROL AGENTS AGAINST RHIZOCTONIA DISEASE AND THEIR INFLUENCE ON POTATO PRODUCTIVITY

2017 ◽  
Vol 95 (2) ◽  
pp. 527-541
Author(s):  
ABEER A. ALI ◽  
AHMED E. ABD EL-KADER ◽  
KHALED M. GHONEEM
Keyword(s):  
Bacillus Subtilis ◽  
Biocontrol Agents ◽  
Trichoderma Species ◽  
Rhizoctonia Disease

scholarly journals Phylogenetic Diversity of Trichoderma Strains and Their Antagonistic Potential against Soil-Borne Pathogens under Stress Conditions

Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 189
Author(s):  
Omar A. Hewedy ◽  
Khalid S. Abdel Lateif ◽  
Mahmoud F. Seleiman ◽  
Ashwag Shami ◽  
Fawziah M. Albarakaty ◽  
...  
Keyword(s):  
Trichoderma Harzianum ◽  
Phosphate Solubilization ◽  
Random Amplified Polymorphic Dna ◽  
Trichoderma Viride ◽  
Biocontrol Agents ◽  
Agricultural System ◽  
Dual Culture ◽  
In Planta ◽  
Trichoderma Species ◽  
Soil Borne Pathogens

Trichoderma species are known as excellent biocontrol agents against soil-borne pathogens that cause considerable crop losses. Eight strains of Trichoderma were isolated from five Egyptian regions. They identified based on translation elongation factor-1α (TEF1) sequencing as four different Trichoderma species: Trichoderma asperellum, Trichoderma harzianum, Trichoderma viride, and Trichoderma longibrachiatum. Optimal growth conditions (temperature and media), and the phosphate solubilization capability of Trichoderma strains were evaluated in vitro. Further, the ability of these strains to antagonize Fusarium solani, Macrophomina phaseolina, and Fusarium graminearum was also evaluated. The results revealed that Trichoderma harzianum (Th6) exhibited the highest antagonistic ability against F. solani, M. phaseolina and F. graminearum with inhibition rates of 71.42%, 72.97%, and 84.61%, respectively. Trichoderma viride (Tv8) exhibited the lowest antagonism against the same pathogens with inhibition rates of 50%, 64% and 69.23%, respectively. Simple-sequence repeats (SSRs) and random amplified polymorphic DNA (RAPD) markers were used to evaluate the genetic variability of the Trichoderma strains. The results revealed that of 45 RAPD amplified bands, 36 bands (80%) were polymorphic and of SSRs amplified 36 bands, 31 bands (86.11%) were polymorphic. The amplification of calmodulin and β-1,3-endoglucanase was noted at 500 bp and 230 bp, respectively. Data indicated that T. viride (Tv8) had the highest phosphate solubilization index (10.0 mm), while T. harzianum (Th6) had the lowest phosphate solubilization index (4.0 mm). In conclusion, T. harzianum (Th6) had the highest antagonistic activity in dual culture assay along with the growth rate; while T. viride (Tv8) had the highest phosphate solubilization activity. There are still gaps in obtaining new formulations, selecting potent Trichoderma strains to confirm disease control in planta. For improving Trichoderma recommendation in the organic agricultural system and sustaining the fertility of the soil, the field application of highly antagonistic biocontrol agents in different types of soil and plant species will be the first approach toward bio-pesticide treatments along with bio-fertilizer inoculation. Furthermore, secondary metabolites will be investigated for the most promising strains with the combination of different pathogens and application timing.

Influence of the bioherbicide phosphinothricin on interactions between phytopathogens and their antagonists

1995 ◽  
Vol 73 (11) ◽  
pp. 1750-1760 ◽  
Author(s):  
Iftikhar Ahmad ◽  
David Malloch ◽  
John Bissett
Keyword(s):  
Bacillus Subtilis ◽  
Pseudomonas Fluorescens ◽  
Pythium Aphanidermatum ◽  
Phytopathogenic Fungi ◽  
Growth Media ◽  
Trichoderma Species ◽  
Bacterium Bacillus Subtilis ◽  
The Media ◽  
Microbial Toxin ◽  
Bacterium Bacillus

Phosphinothricin is a microbial toxin currently under development as a selective weed killer in the cultivation of transgenic plants engineered to resist its presence. Here it is shown that phosphinothricin is inhibitory to antagonistic soil microorganisms including Bacillus subtilis, Pseudomonas flourescens, and many species of Trichoderma. Phosphinothricin was also inhibitory to the phytopathogenic fungi Rhizoctonia solani and Sclerotinia sclerotiorum. In contrast, phytopathogens Fusarium oxysporum and Pythium aphanidermatum were highly resistant to phosphinothricin. In pathogen–antagonist challenges, species of Trichoderma that parasitize F. oxysporum and P. aphanidermatum were eliminated when phosphinothricin was added to the growth media. Similarly, the ability of Pseudomonas fluorescens to exclude Pythium aphanidermatum was markedly affected by the presence of phosphinothricin in the media. The dominance equilibrium between Trichoderma species and the bacterium Bacillus subtilis was influenced in favor of the former at 0 and 5 mM concentrations of the herbicide and in favor of the latter at 1 mM concentrations. Pseudomonas fluorescens was unable to exclude Trichoderma species regardless of the phosphinothricin concentration in the media. Key words: phosphinothricin, pathogens, fungi, bacteria, antagonists, biocontrol.

scholarly journals Reclassification of the biocontrol agents Bacillus subtilis BY-2 and Tu-100 as Bacillus velezensis and insights into the genomic and specialized metabolite diversity of the species

Microbiology ◽  
2020 ◽  
Vol 166 (12) ◽  
pp. 1121-1128 ◽  
Author(s):  
Alex J. Mullins ◽  
Yinshui Li ◽  
Lu Qin ◽  
Xiaojia Hu ◽  
Lihua Xie ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Natural Product ◽  
Type Species ◽  
Bacterial Species ◽  
Gene Clusters ◽  
Core Gene ◽  
Biocontrol Agents ◽  
Bacillus Velezensis ◽  
Content Type ◽  
Link Type

The genomes of two historical Bacillus species strains isolated from the roots of oilseed rape and used routinely in PR China as biocontrol agents to suppress Sclerotinia disease were sequenced. Average nucleotide identity (ANI) and digital DNA–DNA hybridization analyses demonstrated that they were originally misclassified as Bacillus subtilis and now belong to the bacterial species Bacillus velezensis . A broader ANI analysis of available Bacillus genomes identified 292 B. velezensis genomes that were then subjected to core gene analysis and phylogenomics. Prediction and dereplication of specialized metabolite biosynthetic gene clusters (BGCs) defined the prevalence of multiple antimicrobial-associated BGCs and highlighted the natural product potential of B. velezensis . By defining the core and accessory antimicrobial biosynthetic capacity of the species, we offer an in-depth understanding of B. velezensis natural product capacity to facilitate the selection and testing of B. velezensis strains for use as biological control agents.

scholarly journals Bioactive Secondary Metabolites from Trichoderma spp. against Phytopathogenic Fungi

2020 ◽  
Vol 8 (6) ◽  
pp. 817 ◽  
Author(s):  
Raja Asad Ali Khan ◽  
Saba Najeeb ◽  
Shaukat Hussain ◽  
Bingyan Xie ◽  
Yan Li
Keyword(s):  
Secondary Metabolites ◽  
Management Strategies ◽  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Biocontrol Agents ◽  
Fungal Resistance ◽  
Comprehensive Overview ◽  
Trichoderma Spp ◽  
Trichoderma Species ◽  
Global Food Security

Phytopathogenic fungi, causing significant economic and production losses, are becoming a serious threat to global food security. Due to an increase in fungal resistance and the hazardous effects of chemical fungicides to human and environmental health, scientists are now engaged to explore alternate non-chemical and ecofriendly management strategies. The use of biocontrol agents and their secondary metabolites (SMs) is one of the potential approaches used today. Trichoderma spp. are well known biocontrol agents used globally. Many Trichoderma species are the most prominent producers of SMs with antimicrobial activity against phytopathogenic fungi. Detailed information about these secondary metabolites, when grouped together, enhances the understanding of their efficient utilization and further exploration of new bioactive compounds for the management of plant pathogenic fungi. The current literature provides the information about SMs of Trichoderma spp. in a different context. In this review, we summarize and group different antifungal SMs of Trichoderma spp. against phytopathogenic fungi along with a comprehensive overview of some aspects related to their chemistry and biosynthesis. Moreover, a brief overview of the biosynthesis pathway, action mechanism, and different approaches for the analysis of SMs and the factors affecting the regulation of SMs in Trichoderma is also discussed.

scholarly journals Biocontrol of collar rot on passion fruits via induction of apoptosis in the collar rot pathogen by Bacillus subtilis

2020 ◽  
Author(s):  
Yu-Hsuan Chen ◽  
Pei-Chun Lee ◽  
Tzu-Pi Huang
Keyword(s):  
Cell Death ◽  
Bacillus Subtilis ◽  
Membrane Potential ◽  
Energy Metabolism ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Chromatin Condensation ◽  
Passion Fruit ◽  
Biocontrol Agents ◽  
Collar Rot

The seedlings and fresh fruits of passion fruits are of high value in local and global trade. Fusarium solani is a main disease-causing agents affecting passion fruits. The objectives were to develop Bacillus-based biocontrol agents for the management of fusarium diseases on passion fruits and to investigate their putative control mechanisms. Our studies indicated Bacillus subtilis YBC and 151B1 showed antagonistic activity to F. solani PF7 from passion fruits and inhibited the conidial germination of strain PF7. The application of broth cultures from B. subtilis 151B1 and YBC in SYB medium reduced disease severity of fusarium wilt on the leaves of passion fruits, and enhanced the survival rates of passion fruit seedlings challenged with F. solani PF7. With regard to the putative mechanisms of disease control, the results indicated the treatments consisting of the respective culture filtrates from B. subtilis 151B1 and YBC broths caused aberrant conidial morphology and the loss of cell membrane integrity. Additionally, the treatments caused reductions in mitochondrial membrane potential and interfered with the energy metabolism of F. solani PF7. The treatments also enhanced reactive oxygen species accumulation, and resulted in the externalization of phosphatidylserine, chromatin condensation, and DNA fragmentation, suggesting their functions in triggering apoptotic-like cell death. In conclusion, B. subtilis 151B1 and YBC are potential biocontrol agents for passion fruit disease caused by F. solani. Their control efficacy may result from the produced surfactins to trigger apoptotic-like cell death, reducing the mitochondrial membrane potential and interfering with the energy metabolism of the pathogen.

scholarly journals CHARACTERIZATION OF SUPERNATANT EXTRACT AND VIABILITY OF BACILLUS SUBTILIS KM16 AND PSEUDOMONAS SPP. IN FISH FEED AS BIOCONTROL AGENTS AGAINST AQUACULTURE PATHOGENS

2021 ◽  
Vol 20 (1) ◽  
pp. 115-125
Author(s):  
Stella Magdalena ◽  
Brenda Kristanti ◽  
Yogiara Yogiara
Keyword(s):  
Bacillus Subtilis ◽  
Ethyl Acetate ◽  
Aquatic Organisms ◽  
Biocontrol Agents ◽  
Resistant Bacteria ◽  
Pseudomonas Sp ◽  
Aquatic Bacteria ◽  
Pseudomonas Spp ◽  
Minimum Inhibitory Concentrations ◽  
Ethyl Acetate Extracts

The use of biocontrol agent in aquaculture is being adapted as an effective alternative to antibiotics which can lead to the elaboration of antibiotic-resistant bacteria and confer unpleasant impacts to aquatic organisms. Aquatic bacteria have been discovered as biocontrol agents and potential probiotic candidates to improve the health of aquatic organisms, feed efficiency, and disease resistance to aquaculture pathogens. However, local isolate has not intensively been explored and used to increase aquaculture sector productivity. Therefore, this research aimed to determine minimum inhibitory concentrations of their antibacterial compounds against aquaculture pathogens and to characterize aquatic bacteria by their viability in the feed. Four isolates from several aquatic environments in Indonesia (Pseudomonas sp. S1.1, Pseudomonas sp. S1.2, Pseudomonas sp. SL1.1, and Bacillus subtilis KM16) were used to characterize of antibacterial compound and to determine the viability in feed. Ethyl acetate extracts from all isolates showed better antibacaterial activity against Aeromonas hydrophila and Vibrio vulnificus than chloroform and dichloromethane extracts, in which ethyl acetate extract from Bacillus subtilis KM16 showed the strongest antibacterial activity. Pseudomonas spp. were more effective against V. vulnificus (40 mg/mL) and Bacillus subtilis KM16 was more effective against A. hydrophila (20 mg/mL), as proved by the minimum inhibitory concentrations of their ethyl acetate extracts. In this research, Bacillus subtilis KM16 had stable viability in feed than Pseudomonas sp. isolates. 

scholarly journals Biological Control of the Artillery Fungus, Sphaerobolus stellatus, with Trichoderma harzianum and Bacillus subtilis

2001 ◽  
Vol 19 (1) ◽  
pp. 21-23 ◽  
Author(s):  
Elizabeth A. Brantley ◽  
Donald D. Davis ◽  
Larry J. Kuhns
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Trichoderma Harzianum ◽  
Biocontrol Agent ◽  
Biocontrol Agents ◽  
Biological Control Agents ◽  
Oatmeal Agar ◽  
Time Of Application ◽  
Bacterium Bacillus Subtilis ◽  
Bacterium Bacillus

Abstract Three strains of the fungus Trichoderma harzianum Rifai and two strains of the bacterium Bacillus subtilis (Ehrenberg) Cohn were evaluated for their ability to suppress colonization and sporulation of the artillery fungus (Sphaerobolus stellatus Tode:Pers.) on oatmeal agar. All five biological control agents inhibited growth of S. stellatus, but efficacy depended on time of application. Simultaneous inoculation of agar with S. stellatus and the biocontrol agents, as well as inoculation of biocontrol agents 14 days prior to S. stellatus, resulted in complete inhibition of S. stellatus. Inoculation of agar with biocontrol agents 14 days after inoculation with S. stellatus reduced, but did not completely suppress S. stellatus colonization and sporulation. In this experiment, gleba (spore masses) treated with all strains of T. harzianum and strain GBO3 of B. subtilis did not germinate, but 13% of gleba treated with strain MBI 600 of B. subtilis did germinate. Trichoderma harzianum was more effective than B. subtilis as a biocontrol agent.

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