Location: Natural Products Utilization ResearchTitle: Evaluation of the toxicity of Streptomyces aburaviensis (R9) towards various agricultural pests Author
Submitted to: Agricultural Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/27/2011
Publication Date: 11/17/2011
Citation: Saadoun, I., Bataineh, S., Ababneh, Q., Hameed, K., Schrader, K., Cantrell, C.L., Dayan, F.E., Wedge, D.E. 2011. Evaluation of the toxicity of Streptomyces aburaviensis (R9) towards various agricultural pests. Agricultural Sciences. 2(4):491-497. Interpretive Summary: Extract from a bacterial species that was isolated from a soil sample collected in Jordan was discovered to possess pesticidal activity. Specifically, the extract inhibited the growth of the type of blue-green algae that causes musty off-flavor in pond-raised channel catfish in Mississippi and was active against several species of plant pathogenic fungi that cause diseases in small fruits such as strawberries and muscadine grapes.
Technical Abstract: The culture filtrate fraction extracted with dichloromethane from Streptomyces aburaviensis -R9 strain grown on glucose-peptone-molasses (GPM) broth was bioassayed for its effect on phytopathogenic fungi (Colletotrichum acutatum, C. fragariae, C. gloeosoprioids, Botrytis cinerea, Fusarium oxysporum, Phomopsis viticola and P. obscurans), fish bacterial pathogens (Edwardsiella ictaluri and Flavobacterium columnare), a green alga (Selenastrum capricornutum), weed plant seeds [Bent grass (Agrostis spp) monocot and lettuce (Lactuca sativa) dicot] and 2-methylisoborneol (MIB)-producing cyanobacteria (Planktothrix perornata and Pseudanabaena spp.). The dichloromethane fraction showed selective antagonistic effect against the cyanobacteria (P. perornata) with a lowest-complete-inhibition concentration (LCIC) of 10 mg/L and lowest-observed-effect concentration (LOEC) of 10 mg/L. However such effect against the alga (S. capricornutum) was at 100 mg/L for the LCIC and LOEC. This fraction also showed slight meristematic cytogenic necrosis at 200 mg/L towards germinated seeds of both tested plants. The compounds were not very toxic towards the catfish pathogenic bacteria E. ictaluri and F. columnare. Evaluation of the extract on C. acutatum, C. fragariae and C. gloeosoprioids by TLC plates showed good activity. However, by using the microtiter plate bioassay, most of the activity was shown towards C. acutatum and C. fragariae and appears to have diminished at 72 hours and was moderately less active than the commercial fungicides azoxystrobin and captan comparing 1-100 mg/L levels at 48 hours.