Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms

Azalea lace bug (Stephanitis pyrioides) is the most serious pest on azalea. Results of laboratory bioassays and field evaluations of 17 deciduous azalea taxa have identified three resistant taxa: R. canescens, R. periclymenoides, and R. prunifolium. Highly susceptible taxa are `Buttercup', `My Mary', R. oblongifolium, and the evergreen cultivar `Delaware Valley White'. To determine whether in vitro techniques would have potential value in screening or selecting for resistance, or for the identification of morphological or chemical factors related to resistance, an in-vitro screening assay was developed. In-vitro shoot proliferation was obtained using the medium and procedures of Economou and Read (1984). Shoots used in the bioassays were grown in culture tubes. Two assays were developed: one for nymphs and one for adult lace bugs. To assay for resistance to nymphs, `Delaware Valley White' leaves containing lace bug eggs were disinfested with 70% alcohol and 20% commercial bleach, and incubated in sterile petri plates with moistened filter paper until the nymphs hatched. Five nymphs were placed in each culture tube, and cultures were incubated for about 2 weeks, or until adults were observed. To assay for resistance to adults, five female lace bugs were placed in each culture tube and allowed to feed for 5 days. Data collected on survival and leaf damage was generally supportive of laboratory bioassays and field results. Adult lace bugs had a low rate of survival on resistant taxa. Survival of nymphs was somewhat reduced on resistant taxa.

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In Vitro Screening of Some Heterocyclic Compounds Against Human ABHD6 and ABHD12 Hydrolases

Letters in Drug Design & Discovery ◽

10.2174/1570180811666140313233940 ◽

2014 ◽

Vol 11 (7) ◽

pp. 944-952 ◽

Cited By ~ 1

Author(s):

Agnieszka Kaczor ◽

Antti Poso ◽

Monika Pitucha

Keyword(s):

Heterocyclic Compounds ◽

In Vitro Screening

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Multi-Trait Wheat Rhizobacteria from Calcareous Soil with Biocontrol Activity Promote Plant Growth and Mitigate Salinity Stress

Microorganisms ◽

10.3390/microorganisms9081588 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1588

Author(s):

Anastasia Venieraki ◽

Styliani N. Chorianopoulou ◽

Panagiotis Katinakis ◽

Dimitris L. Bouranis

Keyword(s):

Plant Growth ◽

Salinity Stress ◽

Calcareous Soil ◽

In Vitro Studies ◽

Pgp Traits ◽

Biocontrol Activity ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Microbial Fertilizers

Plant growth promoting rhizobacteria (PGPR) can be functional microbial fertilizers and/or biological control agents, contributing to an eco-spirit and safe solution for chemical replacement. Therefore, we have isolated rhizospheric arylsulfatase (ARS)-producing bacteria, belonging to Pseudomonas and Bacillus genus, from durum wheat crop grown on calcareous soil. These isolates harbouring plant growth promoting (PGP) traits were further evaluated in vitro for additional PGP traits, including indole compounds production and biocontrol activity against phytopathogens, limiting the group of multi-trait strains to eight. The selected bacterial strains were further evaluated for PGP attributes associated with biofilm formation, compatibility, salt tolerance ability and effect on plant growth. In vitro studies demonstrated that the multi-trait isolates, Bacillus (1.SG.7, 5.SG.3) and Pseudomonas (2.SG.20, 2.C.19) strains, enhanced the lateral roots abundance and shoots biomass, mitigated salinity stress, suggesting the utility of beneficial ARS-producing bacteria as potential microbial fertilizers. Furthermore, in vitro studies demonstrated that compatible combinations of multi-trait isolates, Bacillus sp. 1.SG.7 in a mixture coupled with 5.SG.3, and 2.C.19 with 5.SG.3 belonging to Bacillus and Pseudomonas, respectively, may enhance plant growth as compared to single inoculants.

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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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Thiosemicarbazole (Thiacetazone-Like) Compound with Activity against Mycobacterium avium in Mice

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.47.8.2685-2687.2003 ◽

2003 ◽

Vol 47 (8) ◽

pp. 2685-2687 ◽

Cited By ~ 27

Author(s):

Luiz E. Bermudez ◽

Robert Reynolds ◽

Peter Kolonoski ◽

Pricilla Aralar ◽

Clark B. Inderlied ◽

...

Keyword(s):

Mycobacterium Avium ◽

Significant Activity ◽

In Vitro Screening ◽

Single Drug ◽

Drug Regimens

ABSTRACT In vitro screening of thiacetazone derivatives indicated that two derivatives, SRI-286 and SRI-224, inhibited a panel of 25 Mycobacterium avium complex (MAC) isolates at concentrations of 2 μg/ml or lower. In mice, SRI-224 and thiacetazone had no significant activity against the MAC in livers and spleens, but treatment with SRI-286 resulted in significant reduction of bacterial loads in livers and spleens. A combination of SRI-286 and moxifloxacin was significantly more active than single drug regimens in liver and spleen.

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