Whole cells of Bacillus subtilis AF 1 proved more effective than cell-free and chitinase-based formulations in biological control of citrus fruit rot and groundnut rust

2004 ◽  
Vol 50 (9) ◽  
pp. 737-744 ◽  
Author(s):  
K Manjula ◽  
G Krishna Kishore ◽  
A R Podile
Keyword(s):  
Bacillus Subtilis ◽  
Hydrolytic Enzymes ◽  
Citrus Fruit ◽  
Pathogenic Fungi ◽  
Soft Rot ◽  
Fruit Rot ◽  
Test Plant ◽  
Active Metabolites ◽  
Antagonistic Microorganisms

In foliar and postharvest biocontrol systems, the use of active metabolites produced by antagonistic microorganisms is advantageous compared with the use of living microorganisms. Chitinases, a major group of hydrolytic enzymes produced by biocontrol agents, are involved in the lysis of cell walls of pathogenic fungi. In the present study, an attempt was made to test the partially purified β-1,4-N-acetylglucosaminidase (NAGase) of a biocontrol strain Bacillus subtilis AF 1 for control of rust in groundnut (caused by Puccinia arachidis) and soft rot in lemons (caused by Aspergillus niger). Four proteins of molecular mass 67, 40, 37, and 32 kDa were isolated from the culture filtrates of AF 1 by affinity chromatography, of which the 67-kDa protein has detectable chitinolytic ability. This protein (NAGase) effectively inhibited the in vitro growth of A. niger in microtitre plates. In the presence of NAGase, germination of urediniospores of P. arachidis was reduced by 96% compared with the control. In a detached leaf bioassay, NAGase reduced the rust lesion frequency by >60%. NAGase significantly reduced the incidence of soft rot in harvested lemon fruits. However, fresh cells and (or) alginate formulation of AF 1 were more effective than NAGase in control of both of the test plant – pathogen systems.Key words: chitinase, peanut rust, lemon fruit rot, biocontrol.

scholarly journals Biocontrol potential of Streptomyces sp. CACIS-1.5CA against phytopathogenic fungi causing postharvest fruit diseases

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Zahaed Evangelista-Martínez ◽  
Erika Anahí Contreras-Leal ◽  
Luis Fernando Corona-Pedraza ◽  
Élida Gastélum-Martínez
Keyword(s):  
Pathogenic Fungi ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Fruit Rot ◽  
Main Body ◽  
Type I ◽  
Tropical Fruit ◽  
Habanero Pepper ◽  
Antagonistic Microorganisms

Abstract Background Fungi are one of the microorganisms that cause most damage to fruits worldwide, affecting their quality and consumption. Chemical controls with pesticides are used to diminish postharvest losses of fruits. However, biological control with microorganisms or natural compounds is an increasing alternative to protect fruits and vegetables. In this study, the antifungal effect of Streptomyces sp. CACIS-1.5CA on phytopathogenic fungi that cause postharvest tropical fruit rot was investigated. Main body Antagonistic activity was evaluated in vitro by the dual confrontation over fungal isolates obtained from grape, mango, tomato, habanero pepper, papaya, sweet orange, and banana. The results showed that antagonistic activity of the isolate CACIS-1.5CA was similar to the commercial strain Streptomyces lydicus WYEC 108 against the pathogenic fungi Colletotrichum sp., Alternaria sp., Aspergillus sp., Botrytis sp., Rhizoctonia sp., and Rhizopus sp. with percentages ranging from 30 to 63%. The bioactive extract obtained from CACIS-1.5 showed a strong inhibition of fungal spore germination, with percentages ranging from 92 to 100%. Morphological effects as irregular membrane border, deformation, shrinkage, and collapsed conidia were observed on the conidia. Molecularly, the biosynthetic clusters of genes for the polyketide synthase (PKS) type I, PKS type II, and NRPS were detected in the genome of Streptomyces sp. CACIS-1.5CA. Conclusions This study presented a novel Streptomyces strain as a natural alternative to the use of synthetic fungicides or other commercial products having antagonistic microorganisms that were used in the postharvest control of phytopathogenic fungi affecting fruits.

Improved Production of Two Anti-Candida Lipopeptide Homologues Co- Produced by the Wild-Type Bacillus subtilis RLID 12.1 under Optimized Conditions

2020 ◽  
Vol 21 (5) ◽  
pp. 438-450
Author(s):  
Ramya Ramchandran ◽  
Swetha Ramesh ◽  
Anviksha A ◽  
RamLal Thakur ◽  
Arunaloke Chakrabarti ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Pathogenic Fungi ◽  
Fold Increase ◽  
Production Yield ◽  
Yield Enhancement ◽  
Bioactive Metabolites ◽  
Candida Auris ◽  
Media Formulation ◽  
Static Conditions

Background:: Antifungal cyclic lipopeptides, bioactive metabolites produced by many species of the genus Bacillus, are promising alternatives to synthetic fungicides and antibiotics for the biocontrol of human pathogenic fungi. In a previous study, the co- production of five antifungal lipopeptides homologues (designated as AF1, AF2, AF3, AF4 and AF5) by the producer strain Bacillus subtilis RLID 12.1 using unoptimized medium was reported; though the two homologues AF3 and AF5 differed by 14 Da and in fatty acid chain length were found effective in antifungal action, the production/ yield rate of these two lipopeptides determined by High-Performance Liquid Chromatography was less in the unoptimized media. Methods:: In this study, the production/yield enhancement of the two compounds AF3 and AF5 was specifically targeted. Following the statistical optimization (Plackett-Burman and Box-Behnken designs) of media formulation, temperature and growth conditions, the production of AF3 and AF5 was improved by about 25.8- and 7.4-folds, respectively under static conditions. Results:: To boost the production of these two homologous lipopeptides in the optimized media, heat-inactivated Candida albicans cells were used as a supplement resulting in 34- and 14-fold increase of AF3 and AF5, respectively. Four clinical Candida auris isolates had AF3 and AF5 MICs (100 % inhibition) ranging between 4 and 16 μg/ml indicating the lipopeptide’s clinical potential. To determine the in vitro pharmacodynamic potential of AF3 and AF5, time-kill assays were conducted which showed that AF3 (at 4X and 8X concentrations) at 48h exhibited mean log reductions of 2.31 and 3.14 CFU/ml of C. albicans SC 5314, respectively whereas AF5 at 8X concentration showed a mean log reduction of 2.14 CFU/ml. Conclusion:: With the increasing threat of multidrug-resistant yeasts and fungi, these antifungal lipopeptides produced by optimized method promise to aid in the development of novel antifungal that targets disease-causing fungi with improved efficacy.

scholarly journals Developing Penicillium digitatum Management Strategies on Post-Harvest Citrus Fruits with Metabolic Components and Colonization of Bacillus subtilis L1-21

2022 ◽  
Vol 8 (1) ◽  
pp. 80
Author(s):  
Yongmei Li ◽  
Mengyuan Xia ◽  
Pengbo He ◽  
Qiaoming Yang ◽  
Yixin Wu ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Culture Filtrate ◽  
Management Strategies ◽  
Citrus Fruit ◽  
Inhibition Zone ◽  
Penicillium Digitatum ◽  
Antifungal Compounds ◽  
Fruit Peel ◽  
Post Harvest

Citrus is among the most important plants in the fruit industry severely infected with pathogens. Citrus green mold caused by Penicillium digitatum is one of the most devastating diseases during post-harvest stages of citrus fruit. In this study, a potential endophyte Bacillus subtilis L1-21, isolated from healthy citrus plants, was assessed for its biocontrol activity against the pathogen P. digitatum. Based on an in vitro crosstalk assay, we suggested that B. subtilis L1-21 inhibits the pathogen with an inhibition zone of 3.51 ± 0.08 cm. Biocontrol efficacy was highest for the fermented culture filtrate of B. subtilis L1-21. Additionally, using GC-MS analysis, 13 compounds were detected in the extract of this endophyte. The culture filtrate in Landy medium could enlarge and deform pathogen spores and prevent them from developing into normal mycelium. Accordingly, the Landy culture filtrate of B. subtilis L1-21 was stable in the temperature range of 4–90 °C and pH of 3–11. Further, MALDI-TOF-MS for B. subtilis L1-21 detected surfactin, fengycin, bacillaene and bacilysin as potential antifungal compounds. GFP-tagged B. subtilis L1-21 easily colonized in citrus fruit peel and pulp, suggesting its role in eliminating the fungal pathogen. Altogether, it is highly expected that the production of antifungal compounds, and the colonization potential of B. subtilis L1-21 are required against the post-harvest P. digitatum pathogen on citrus fruit.

scholarly journals Identification and Predictions Regarding the Biosynthesis Pathway of Polyene Macrolides Produced by Streptomyces roseoflavus Men-myco-93-63

2021 ◽  
Vol 87 (10) ◽  
Author(s):  
Xing Han ◽  
Jiao Wang ◽  
Lianna Liu ◽  
Fengying Shen ◽  
Qingfang Meng ◽  
...  
Keyword(s):  
Fermentation Broth ◽  
Pathogenic Fungi ◽  
Biosynthetic Gene Cluster ◽  
Inhibitory Effect ◽  
Plant Diseases ◽  
Active Metabolites ◽  
Content Type ◽  
Polyene Macrolides ◽  
Alternative Agent

ABSTRACT A group of polyene macrolides mainly composed of two constituents was isolated from the fermentation broth of Streptomyces roseoflavus Men-myco-93-63, which was isolated from soil where potato scabs were repressed naturally. One of these macrolides was roflamycoin, which was first reported in 1968, and the other was a novel compound named Men-myco-A, which had one methylene unit more than roflamycoin. Together, they were designated RM. This group of antibiotics exhibited broad-spectrum antifungal activities in vitro against 17 plant-pathogenic fungi, with 50% effective concentrations (EC50) of 2.05 to 7.09 μg/ml and 90% effective concentrations (EC90) of 4.32 to 54.45 μg/ml, which indicates their potential use in plant disease control. Furthermore, their biosynthetic gene cluster was identified, and the associated biosynthetic assembly line was proposed based on a module and domain analysis of polyketide synthases (PKSs), supported by findings from gene inactivation experiments. IMPORTANCE Streptomyces roseoflavus Men-myco-93-63 is a biocontrol strain that has been studied in our laboratory for many years and exhibits a good inhibitory effect in many crop diseases. Therefore, the identification of antimicrobial metabolites is necessary and our main objective. In this work, chemical, bioinformatic, and molecular biological methods were combined to identify the structures and biosynthesis of the active metabolites. This work provides a new alternative agent for the biological control of plant diseases and is helpful for improving both the properties and yield of the antibiotics via genetic engineering.

Bacillus subtilis BS 107 as an antagonist of potato blackleg and soft rot bacteria

1998 ◽  
Vol 44 (8) ◽  
pp. 777-783 ◽  
Author(s):  
B M Sharga ◽  
G D Lyon
Keyword(s):  
Bacillus Subtilis ◽  
Erwinia Carotovora ◽  
Soft Rot ◽  
Defined Medium ◽  
Alkaline Solutions ◽  
Water Mixture ◽  
Potato Blackleg ◽  
Antimicrobial Substances

Antimicrobial substances were produced by Bacillus subtilis BS 107 in a defined medium and isolated from culture filtrate by precipitation at pH 2.5. Active fractions were extracted in ethyl acetate, acetone, and 80% ethanol and purified by thin-layer chromatography (TLC) on silica gel plates developed with an ethanol-water mixture (2:1, v/v). In each case, a band with a Rf of 0.75 formed an inhibitory zone when the TLC plates were placed in contact with agar seeded with test cultures of the Erwinia spp. The antibiotic was released into the culture medium during early stages of growth of Bacillus subtilis BS 107 but higher amounts were released in older cultures. The antibiotic was resistant to the action of nucleases, proteases, and lipase. It was stable when autoclaved twice for 35 min at 2 atm (1 atm = 101.325 kPa) in acidic, neutral, and alkaline solutions. It remained active over the pH range of 1-14 during 1 month of observation and exhibited no loss of antimicrobial activity when stored at 4°C for over 1 year. Bacillus subtilis BS 107 showed activity in vitro and in vivo against Erwinia carotovora subsp. atroseptica and Erwinia carotovora subsp. carotovora, the causal agents of potato blackleg and tuber soft rot. The application of an antagonist or its antibiotic to cut potato tissues prevented or reduced symptoms of the diseases. The antibiotic was active in vitro against a broad spectrum of bacterial and fungal species.Key words: antagonist, Bacillus subtilis BS 107, Erwinia carotovora, potato.

scholarly journals Diffusible and volatile compounds produced by an antagonistic Bacillus subtilis strain cause structural deformations in pathogenic fungi in vitro

2005 ◽  
Vol 160 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Bhaskar Chaurasia ◽  
Anita Pandey ◽  
Lok Man S. Palni ◽  
Pankaj Trivedi ◽  
Bhavesh Kumar ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Volatile Compounds ◽  
Pathogenic Fungi ◽  
Subtilis Strain ◽  
Structural Deformations

ISOLATION, IDENTIFICATION AND CHARACTERIZATION OF BACTERIAL ANTAGONISTS OF THE DRAGON FRUIT FUNGAL PATHOGEN Neoscytalidium dimidiatum

2021 ◽  
Vol 44 (02) ◽  
Author(s):  
NGUYEN NGOC AN ◽  
HUA HUYNH MINH THAO ◽  
HO NGUYEN HOANG YEN ◽  
NGUYEN THI DIEU HANH ◽  
NGUYEN LE HIEN HOA ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Pathogenic Fungi ◽  
Fungal Spore ◽  
Stem Canker ◽  
Antagonistic Effect ◽  
Fruit Rot ◽  
Economic Losses ◽  
Neoscytalidium Dimidiatum ◽  
Dragon Fruit

Dragon fruit or pitahaya (Hylocereus spp.) are famous for their nutrient-rich favourable taste, which brings high economic value to subtropical and tropical countries. However, dragon fruit cultivation all over the world is threatened by fungal pathogens and among them, Neoscytalidium dimidiatum has recently been shown to be responsible for stem canker and fruit rot which cause big economic losses. In order to find an environmentally friendly way to control this pathogen, five out of sixty-nine bacterial isolates used in a screening test for antifungal activity were selected. All five strains appeared to be aerobic Gram positive spore forming bacteria suggesting that they all belong to the Bacillus genus. Cell-free culture supernatants of these strains were found to strongly inhibit both fungal spore germination and mycelia growth in vitro for at least 5 days. The strain D19 which possessed the highest antagonistic effect was further identified to be Bacillus amyloliquefaciens, a well-known species shown to have antifungal effect against several other pathogenic fungi. Thus, the results of this study opened a new promising perspective to prevent Neoscytalidium dimidiatum infection during cultivation of dragon fruit.

scholarly journals The Iturin-like Lipopeptides Are Essential Components in the Biological Control Arsenal of Bacillus subtilis Against Bacterial Diseases of Cucurbits

2011 ◽  
Vol 24 (12) ◽  
pp. 1540-1552 ◽  
Author(s):  
Houda Zeriouh ◽  
Diego Romero ◽  
Laura García-Gutiérrez ◽  
Francisco M. Cazorla ◽  
Antonio de Vicente ◽  
...  
Keyword(s):  
Biological Control ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Xanthomonas Campestris ◽  
Soft Rot ◽  
Bacterial Diseases ◽  
Chromatography Analysis ◽  
Essential Components ◽  
Bacillus Spp

The antibacterial potential of four strains of Bacillus subtilis, UMAF6614, UMAF6619, UMAF6639, and UMAF8561, previously selected on the basis of their antifungal activity and efficacy against cucurbit powdery mildew, was examined. Among these strains, UMAF6614 and UMAF6639 showed the highest antibacterial activity in vitro, especially against Xanthomonas campestris pv. cucurbitae and Pectobacterium carotovorum subsp. carotovorum. These strains produced the three families of lipopeptide antibiotics known in Bacillus spp.: surfactins, iturins, and fengycins. Using thin-layer chromatography analysis and direct bioautography, the antibacterial activity could be associated with iturin lipopeptides. This result was confirmed by mutagenesis analysis using lipopeptide-defective mutants. The antibacterial activity was practically abolished in iturin-deficient mutants, whereas the fengycin mutants retained certain inhibitory capabilities. Analyses by fluorescence and transmission electron microscopy revealed the cytotoxic effect of these compounds at the bacterial plasma membrane level. Finally, biological control assays on detached melon leaves demonstrated the ability of UMAF6614 and UMAF6639 to suppress bacterial leaf spot and soft rot; accordingly, the biocontrol activity was practically abolished in mutants deficient in iturin biosynthesis. Taken together, our results highlight the potential of these B. subtilis strains as biocontrol agents against fungal and bacterial diseases of cucurbits and the versatility of iturins as antifungal and antibacterial compounds.

Fusarihexins A and B: Novel Cyclic Hexadepsipeptides from the Mangrove Endophytic Fungus Fusarium sp. R5 with Antifungal Activities

Planta Medica ◽  
2018 ◽  
Vol 84 (18) ◽  
pp. 1355-1362 ◽  
Author(s):  
Xinwei Zhu ◽  
Yu Zhong ◽  
Zihui Xie ◽  
Manlin Wu ◽  
Zhibo Hu ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Fruits And Vegetables ◽  
Pathogenic Fungi ◽  
Crown Rot ◽  
Fruit Rot ◽  
Chemical Structures ◽  
Mangrove Endophytic Fungus ◽  
Fusarium Sp ◽  
Colletotrichum Musae

AbstractTwo novel cyclic hexadepsipeptides, fusarihexin A (1) and fusarihexin B (2), and two known compounds, cyclo-(L-Leu–L-Leu–D-Leu–L-Leu–L-Val) (3) and cyclo-(L-Leu–L-Leu–D-Leu–L-Leu–L-Ile) (4), were isolated from the marine mangrove endophytic fungus Fusarium sp. R5. Their chemical structures were elucidated on the basis of spectroscopic data and Marfeyʼs analysis. In an in vitro bioassay, fusarihexin A (1) remarkably inhibited three plant pathogenic fungi: Colletotrichum gloeosporioides (Penz.) Sacc., which causes anthracnose in many fruits and vegetables, Colletotrichum musae (Berk. and M. A. Curtis) Arx, which causes crown rot and anthracnose in bananas, and Fusarium oxysporum Schlecht. f. sp. lycopersici (Sacc.) W. C. Snyder et H. N. Hansen, which causes Fusarium wilt and fruit rot in tomatoes. Fusarihexin B (2) strongly inhibited C. gloeosporioides and C. musae. The compounds were more potent than carbendazim, which is widely used as an agricultural and horticultural fungicide worldwide.

scholarly journals Phenotypic and Molecular Characterization of Endophytic Bacteria Isolated from Banana

2019 ◽  
pp. 1-10
Author(s):  
G. Ragavi ◽  
M. Muthamilan ◽  
S. Nakkeeran ◽  
N. Kumaravadivel ◽  
U. Sivakumar ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Endophytic Bacteria ◽  
Soft Rot ◽  
Achromobacter Xylosoxidans ◽  
Rrna Gene ◽  
Banana Plant ◽  
Urease Test ◽  
Carotovorum Subsp ◽  
Biocontrol Potential

Several species of endophytic bacteria has been reported from various plants. In the present study, samples of roots, rhizome, pseudostem, petiole and leaves of healthy Banana plant were collected from variety Yangambi km5 (AAA). In total, 38 endophytic bacteria were isolated. Amongst 16 isolates were selected based on compatibility by cross streak method. The 16 strains tested by paper disc method, Lf4, Lf5, Lf10, Pt4 and Ps7 showed inhibitory effects against Pectobaterium carotovorum subsp. carotovorum under in vitro conditions. The Lf4 and Lf5 showed similar results for the biochemical characteristics studied. The isolate Lf10 showed a slight difference with regard to oxidase test, Methyl red, Urease test and H2S production. The isolates Pt4 and Ps7 showed similar result except nitrate reduction, KOH test and Pigment production. Bacillus subtilis (Bs) strain (culture collected from Department of Plant pathology, TNAU) was used as reference culture. The total DNA extracted from selected five isolates was identified by partial sequencing of the 16S rRNA gene and phylogenetic tree was constructed using MEGA 6.0. The results confirmed that isolates Lf4 and Lf5 were Bacillus subtilis, isolate Lf10 was an Ochrobactrum daejeonense, isolate Pt4 was an Achromobacter xylosoxidans and Ps7 was a Pseudomonas aeruginosa. The study revealed that all the five strains have biocontrol potential against soft rot pathogen.

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