In vitro Antagonistic Activity of Diverse Bacillus Species Against Cochliobolus sativus (Common Root Rot) of Barley

Antagonistic microorganisms have been used as biological control agents to reduce the use of chemical fungicides in the control of crop diseases. The present work was conducted to determine the antagonistic potential of Bacillus sp. isolates against the soil-borne fungus Cochliobolus sativus, the causal agent of barley common root (CRR) disease. Out of 525 isolates, 40 were showed in vitro antagonistic activity against the virulent C. sativus isolate CRR16. On the basis of 16S rRNA gene sequencing Bacillus sp. isolates are identified as B. atrophaeus, B. subtilis, Paenibacillus polymyxa, B. amyloliquefaciens, B. simplex and B. tequilensis. Results showed that Bacillus sp. had significant (P<0.05) antagonistic activities against the C. sativus where the percentage of radial growth inhibition of the fungi colonies ranged from 59 to 92%, compared to the untreated control. The B. subtilis isolate SY41B had the highest inhibition effect on the vegetative growth zones as compared with the other species isolates. In view of these, our results indicate that the antagonistic effect of the Bacillus sp. isolates may be important contributors as a biocontrol approach that could be employed as a part of integrated CRR management system.

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Potentials of Indigenous Bacillus thuringiensis Isolates from the soil in controlling Fusarium wilt of Cucumber cause by Fusarium oxysporum f.sp cucumerinum

Nigerian Journal of Biotechnology ◽

10.4314/njb.v37i1.14 ◽

2020 ◽

Vol 37 (1) ◽

pp. 129-137

Author(s):

P.O. Akintokun ◽

A.O. Okuwa ◽

A.R. Oloyede ◽

S.O. Adebajo ◽

A.K. Akintokun

Keyword(s):

Bacillus Thuringiensis ◽

16S Rrna ◽

16S Rrna Gene ◽

Fusarium Wilt ◽

16S Rrna Gene Sequencing ◽

Antagonistic Activity ◽

Rrna Gene ◽

Rrna Gene Sequencing ◽

Screen House

Cucumber (Cucumis sativus L.) production is generally low in Nigeria due to continuous soil nutrient limitation and diseases. However, the persistence in the use of agrochemicals for cucumber production in Nigeria is associated with high cost and deleterious effects on man, animal and the environment. This study was conducted to investigate the potentials of indigenous Bacillus thuringiensis (Bt), a spore-forming bacterium known for its insecticidal properties in controlling Fusarium wilt of cucumber. Bacillus thuringiensis strains were isolated from soil samples collected from different farm sites in Abeokuta, Nigeria, and identified phenotypically and molecularly. The in-vitro antagonistic activity of B. thuringiensis strains on F. oxysporum f.sp. cucumerinum was evaluated by dual culture method, followed by pot experiment in the screen house. 16S rRNA gene sequencing was performed on the antagonistic B. thuringiensis to confirm Bt species. The results of the in-vitro antagonistic activity revealed that most indigenous B. thuringiensis strains showed significant growth inhibition of Fusarium oxysporium f. sp. cucumerinum. Similarly, application of B. thuringiensis A and C isolates significantly suppressed the incidence of Fusarium wilt of cucumber in the screen house when compared to the control. The 16S rRNA gene sequencing technique identified the isolates A and C as Bacillus thuringiensis strain LTS-209 and Bacillus thuringiensis strain VITSJ-01, respectively. Hence, indigenous B. thuringiensis A and C isolates should be incorporated into cucumber cultivation for controlling Fusarium wilt disease of cucumber. Keywords: Cucumber, Bacillus thuringiensis, Fusarium wilt, 16S rRNA gene

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In Vitro Antagonistic Activity of Diverse Bacillus Species Against Fusarium culmorum and F. solani Pathogens

The Open Agriculture Journal ◽

10.2174/1874331502014010157 ◽

2020 ◽

Vol 14 (1) ◽

pp. 157-163

Author(s):

M. Harba ◽

M. Jawhar ◽

M.I.E. Arabi

Keyword(s):

Fungal Pathogens ◽

Fusarium Culmorum ◽

Antagonistic Activity ◽

Broth Culture ◽

Bacillus Species ◽

Rrna Gene ◽

Antagonistic Effects ◽

Biological Potential ◽

Potential Activity

Background: Fusarium culmorum and Fusarium solani are economically important fungal pathogens of many plant species causing significant yield losses worldwide. Frequent uses of fungicides are hazardous to humans and the environment. Therefore, in vitro antagonistic activity of diverse Bacillus species isolates with biological potential activity to control these both pathogens should be investigated. Objective: The objectives were to isolate and identify the Bacillus spp., which are potential controls of F. culmorum and F. solani, and to characterize molecularly, at the species level, those isolates that have potential as biocontroller of the pathogens. Methods: The in vitro antagonistic potential of 40 Bacillus isolates against F. culmorum and F. solani was evaluated on the basis of fungal growth inhibition on nutrient broth culture. The colony morphology and the 16S rRNA gene sequencing of Bacillus spp. were used to identify the isolates. Results: Bacillus sp. isolates were identified as B. atrophaeus, B. subtilis, Paenibacillus polymxa, B. amyloliquefaciens, B. simplex and B. tequilensis. They had significant (P<0.05) antagonistic activities against F. culmorum and F. solani isolates as compared to the untreated control. The antagonistic effects varied depending on the Fusarium sp. The bacterial B. subtilis isolates SY116C and SY SY118C provided the most noteworthy result as both strongly inhibited mycelial growth of F. solani by 97.2%, while the B. tequilensis isolate SY145D was the most effective in the formation of inhibition zones against F. culmorum by 75%. Conclusion: It is apparent that Bacillus sp. isolates play an important role in the inhibition of growth of F. culmorum and F. solani, and that the B. subtilis isolates SY116C and SY118C had the highest biological potential activity against these fungi. These antagonistic effects may be important contributors as a biocontrol approach that could be employed as a part of integrated soil pathogen management system.

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Effect of the endophytic plant growth promoting Enterobacter ludwigii EB4B on tomato growth

Hellenic Plant Protection Journal ◽

10.2478/hppj-2020-0006 ◽

2020 ◽

Vol 13 (2) ◽

pp. 54-65 ◽

Cited By ~ 1

Author(s):

M.E.A. Bendaha ◽

H.A. Belaouni

Keyword(s):

Root Length ◽

Biocontrol Agent ◽

Growth Promotion ◽

Dry Weight ◽

Antagonistic Activity ◽

Rrna Gene ◽

Plant Growth Promoting ◽

Enterobacter Ludwigii ◽

Tomato Growth

SummaryThis study aims to develop a biocontrol agent against Fusarium oxysporum f.sp. radicis-lycopersici (FORL) in tomato. For this, a set of 23 bacterial endophytic isolates has been screened for their ability to inhibit in vitro the growth of FORL using the dual plate assay. Three isolates with the most sound antagonistic activity to FORL have been qualitatively screened for siderophore production, phosphates solubilization and indolic acetic acid (IAA) synthesis as growth promotion traits. Antagonistic values of the three candidates against FORL were respectively: 51.51 % (EB4B), 51.18 % (EB22K) and 41.40 % (EB2A). Based on 16S rRNA gene sequence analysis, the isolates EB4B and EB22K were closely related to Enterobacter ludwigii EN-119, while the strain EB2A has been assigned to Leclercia adecarboxylata NBRC 102595. The promotion of tomato growth has been assessed in vitro using the strains EB2A, EB4B and EB22K in presence of the phytopathogen FORL. The treatments with the selected isolates increased significantly the root length and dry weight. Best results were observed in isolate EB4B in terms of growth promotion in the absence of FORL, improving 326.60 % of the root length and 142.70 % of plant dry weight if compared with untreated controls. In the presence of FORL, the strain EB4B improved both root length (180.81 %) and plant dry weight (202.15 %). These results encourage further characterization of the observed beneficial effect of Enterobacter sp. EB4B for a possible use as biofertilizer and biocontrol agent against FORL.

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The growth response of rice (Oryza sativa L. var. FARO 44) in vitro after inoculation with bacterial isolates from a typical ferruginous ultisol

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00528-8 ◽

2021 ◽

Vol 45 (1) ◽

Author(s):

Musa Saheed Ibrahim ◽

Beckley Ikhajiagbe

Keyword(s):

16S Rrna ◽

Bacillus Cereus ◽

Proteus Mirabilis ◽

Growth Response ◽

Gene Sequencing ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Rice Seedlings ◽

Rrna Gene Sequencing

Abstract Background Rice forms a significant portion of food consumed in most household worldwide. Rice production has been hampered by soil factors such as ferruginousity which has limited phosphorus availability; an important mineral component for the growth and yield of rice. The presence of phosphate-solubilizing bacteria (PSB) in soils has been reported to enhance phosphate availability. In view of this, the present study employed three bacteria species (BCAC2, EMBF2 and BCAF1) that were previously isolated and proved P solubilization capacities as inocula to investigate the growth response of rice germinants in an in vitro setup. The bacteria isolates were first identified using 16S rRNA gene sequencing and then applied as inoculum. The inolula were prepared in three concentrations (10, 7.5 and 5.0 ml) following McFarland standard. Viable rice (var. FARO 44) seeds were sown in petri dishes and then inoculated with the three inocula at the different concentrations. The setup was studied for 28 days. Results 16S rRNA gene sequencing identified the isolates as: isolate BCAC2= Bacillus cereus strain GGBSU-1, isolate BCAF1= Proteus mirabilis strain TL14-1 and isolate EMBF2= Klebsiella variicola strain AUH-KAM-9. Significant improvement in rice germination, morphology, physiology and biomass parameters in the bacteria-inoculated setups was observed compared to the control. Germination percentage after 4 days was 100 % in the inoculated rice germinants compared to 65% in the control (NiS). Similarly, inoculation with the test isolates enhanced water-use efficiency by over 40%. The rice seedlings inoculated with Bacillus cereus strain GGBSU-1 (BiS) showed no signs of chlorosis and necrosis throughout the study period as against those inoculated with Proteus mirabilis strain TL14-1 (PiS) and Klebsiella variicola strain AUH-KAM-9 (KiS). Significant increase in chlorophyll-a, chlorophyll-b and alpha amylase was observed in the rice seedlings inoculated with BiS as against the NiS. Conclusion Inoculating rice seeds with Bacillus cereus strain GGBSU-1, Proteus mirabilis strain TL14-1 and Klebsiella variicola strain AUH-KAM-9 in an in vitro media significantly improved growth parameters of the test plant. Bacillus cereus strain GGBSU-1 showed higher efficiency due to a more improved growth properties observed.

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Bacterial endosymbiont inhabiting Leucaena leucocephala leaves and their antioxidant and antidiabetic potential

Journal of Complementary and Integrative Medicine ◽

10.1515/jcim-2020-0203 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Sridevi Chigurupati ◽

Shantini Vijayabalan ◽

Kesavanarayanan Krishnan Selvarajan ◽

Ahmad Alhowail ◽

Fatema Kauser

Keyword(s):

Free Radical ◽

Crude Extract ◽

Leucaena Leucocephala ◽

Endophytic Bacteria ◽

Radical Scavenging ◽

16S Rrna Gene Sequencing ◽

Free Radical Scavenging ◽

Rrna Gene ◽

Standard Drug

AbstractObjectivesResearch on endosymbionts is emerging globally and is considered as a potential source of bioactive phytochemicals. The present study examines the antioxidant and antidiabetic of the endophytic crude extract isolated from Leucaena leucocephala leaves.MethodsEndophytic bacteria were isolated from the leaves of L. leucocephala and 16S rRNA gene sequencing was used to establish their identity. The in vitro antioxidant effect of endophytic crude extract (LL) was evaluated using 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) free radical scavenging methods. The in vitro antidiabetic properties of LL were evaluated using α-amylase and α-glucosidase enzyme inhibition assay.ResultsThe isolated endophytic bacteria were identified as Cronobacter sakazakii. LL displayed potent free radical scavenging effect against ABTS and DPPH radicals with an inhibitory concentration 50% (IC50) value of 17.49 ± 0.06 and 11.3 ± 0.1 μg/mL respectively. LL exhibited α-amylase and α-glucosidase inhibition with an IC50 value of 23.3 ± 0.08 and 23.4 ± 0.1 μg/mL respectively compared to the standard drug (acarbose). Both glucose loaded normoglycemic rats and STZ induced diabetic rats treated with LL (200 mg/kg) exhibited a considerable reduction in blood glucose levels p<0.01 after 8 h of treatment when compared to normal and diabetic control rats respectively.ConclusionsThus, the study shows that LL has a wellspring of natural source of antioxidants, and antidiabetic agents and phytoconstituents present in endophytes could be the rich source for bioactive compounds.

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

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-020-00319-9 ◽

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.

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Live Bacillus subtilis natto Promotes Rumen Fermentation by Modulating Rumen Microbiota In Vitro

Animals ◽

10.3390/ani11061519 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1519

Author(s):

Meinan Chang ◽

Fengtao Ma ◽

Jingya Wei ◽

Junhao Liu ◽

Xuemei Nan ◽

...

Keyword(s):

Bacillus Subtilis ◽

16S Rrna ◽

Rumen Fluid ◽

Gene Sequencing ◽

16S Rrna Gene Sequencing ◽

Rumen Fermentation ◽

Rrna Gene ◽

Bacillus Subtilis Natto ◽

Rrna Gene Sequencing

Previous studies have shown that Bacillus subtilis natto affects rumen fermentation and rumen microbial community structure, which are limited to detect a few microbial abundances using traditional methods. However, the regulation of B. subtilis natto on rumen microorganisms and the mechanisms of microbiota that affect rumen fermentation is still unclear. This study explored the effects of live and autoclaved B. subtilis natto on ruminal microbial composition and diversity in vitro using 16S rRNA gene sequencing and the underlying mechanisms. Rumen fluid was collected, allocated to thirty-six bottles, and divided into three treatments: CTR, blank control group without B. subtilis natto; LBS, CTR with 109 cfu of live B. subtilis natto; and ABS, CTR with 109 cfu of autoclaved B. subtilis natto. The rumen fluid was collected after 0, 6, 12, and 24 h of fermentation, and pH, ammonia nitrogen (NH3-N), microbial protein (MCP), and volatile fatty acids (VFAs) were determined. The diversity and composition of rumen microbiota were assessed by 16S rRNA gene sequencing. The results revealed LBS affected the concentrations of NH3-N, MCP, and VFAs (p < 0.05), especially after 12 h, which might be attributed to changes in 18 genera. Whereas ABS only enhanced pH and NH3-N concentration compared with the CTR group (p < 0.05), which might be associated with changes in six genera. Supplementation with live B. subtilis natto improved ruminal NH3-N and propionate concentrations, indicating that live bacteria were better than autoclaved ones. This study advances our understanding of B. subtilis natto in promoting ruminal fermentation, providing a new perspective for the precise utilization of B. subtilis natto in dairy rations.

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Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

The Scientific World JOURNAL ◽

10.1100/2012/723293 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

M. M. Rahman ◽

M. E. Ali ◽

A. A. Khan ◽

A. M. Akanda ◽

Md. Kamal Uddin ◽

...

Keyword(s):

Biological Control ◽

Biological Control Agent ◽

Erwinia Carotovora ◽

Soft Rot ◽

Control Agent ◽

Antagonistic Activity ◽

Antagonistic Effect ◽

Antagonistic Bacteria ◽

And Storage

A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacteriumErwinia carotovorasubsp.carotovora(Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was testedin vitroagainst the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited thein vitrogrowth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genusBacillusand the isolate E-45 asLactobacillussp. The stronger antagonistic activity against Ecc P-138 was found in E-65in vitroscreening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

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Antifungal activity of several isolates of Trichoderma against Cladosporium and Botrytis

Ukrainian Journal of Ecology ◽

10.15421/2018_191 ◽

2018 ◽

Vol 8 (1) ◽

pp. 88-91 ◽

Cited By ~ 1

Author(s):

M. Skaptsov ◽

S. Smirnov ◽

M. Kutsev ◽

O. Uvarova ◽

T. Sinitsyna ◽

...

Keyword(s):

Antifungal Activity ◽

Trichoderma Harzianum ◽

Its Region ◽

Botanical Garden ◽

Antagonistic Activity ◽

Antagonistic Effect ◽

Soil Samples ◽

Morphological Observation ◽

The South

Trichoderma isolates (SSBGT07, SSBGT08, SSBGT09, SSBGT10) were isolated from the soil samples of the South-Siberian Botanical Garden and identified using morphological observation and ITS region analysis as Trichoderma harzianum, T. asperellum, T. ghanense, and T. longibranchiatum. Antagonistic activity against Cladosporium sp. and Botrytis sp. was evaluated in vitro. All isolates showed antagonistic effect by competition against Cladosporium sp. T. asperellum and T. longibranchiatum showed antagonism against Botrytis sp. All isolates showed hyper sporulation on the sclerotia of Botrytis sp. (except the T. ghanense) and colonies of the Cladosporium sp. Our study provides new isolates that affect the Cladosporium sp. and Botrytis sp.

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Potential of Trichosporon asahii against Alternaria sp. and mechanisms of actions

Summa Phytopathologica ◽

10.1590/0100-5405/220861 ◽

2020 ◽

Vol 46 (1) ◽

pp. 20-25

Author(s):

Ariane Silva Bosqueiro ◽

Rodolfo Bizarria Júnior ◽

Márcia Maria Rosa-Magri

Keyword(s):

Antagonistic Activity ◽

Mechanisms Of Action ◽

Antagonistic Effect ◽

Production Chain ◽

Trichosporon Asahii ◽

Modern Agriculture ◽

Killer Toxins ◽

Alternaria Sp ◽

Mycelial Development

ABSTRACT Alternaria sp. is a fungus that causes rot in several crops, causing damage to the agricultural production chain. Biological control agents constitute an alternative to reduce the use of pesticides in the crops, a social demand for modern agriculture. The aim of the present study is to demonstrate the antagonistic effect of the yeast Trichosporon asahii (3S44) on the mycelial development of Alternaria sp. and some in vitro mechanisms of action. Trichosporon asahii showed antagonistic activity towards Alternaria sp., presenting mycelial inhibition (57.47%). The assays indicated production of volatile organic compounds (VOCs), competition for nutrients, biofilm formation, production of killer toxins and β-1,3-glucanase as mechanisms of action of T. asahii. Collectively, our results showed the potential of T. asahii to control the mycelial development of Alternaria sp. and some mechanisms of action of this yeast for future biotechnological studies.

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