Insect fungal symbionts: a promising source of detoxifying enzymes. J Ind Microbiol 9:149-161

Journal of Industrial Microbiology and Biotechnology (Impact Factor: 2.44). 04/1992; 9(3):149-161. DOI: 10.1007/BF01569619
Source: OAI


Many species of insects cultivate, inoculate, or contain symbiotic fungi. Insects feed on plant materials that contain plant-produced defensive toxins, or are exposed to insecticides or other pesticides when they become economically important pests. Therefore, it is likely that the symbiotic fungi are also exposed to these toxins and may actually contribute to detoxification of these compounds. Fungi associated with bark beetles, ambrosia beetles, termites, leaf-cutting ants, long-horned beetles, wood wasps, and drug store beetles can variously metabolize/detoxify tannins, lignins, terpenes, esters, chlorinated hydrocarbons, and other toxins. The fungi (Attamyces) cultivated by the ants and the yeast (Symbiotaphrina) contained in the cigarette beetle gut appear to have broad-spectrum detoxifying abilities. The present limiting factor for using many of these fungi for large scale detoxification of, for example, contaminated soils or agricultural commodities is their slow growth rate, but conventional strain selection techniques or biotechnological approaches should overcome this problem.

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    • "The identification of Rep-like sequences most closely related to gemycircularviruses in fungal genomes provides some support that gemycircularviruses may in fact be mycoviruses. There have been previous reports of interactions of fungi with both insects and faecal matter, suggesting there could be an association (Aanen et al., 2002; Davies et al., 1993; Dowd, 1992; Hajek and St. Leger, 1994). All the viruses currently grouped as gemycircularviruses (all $2200 nts) are bi-directionally transcribed and encode Reps in the complementary sense and CPs in the virion sense. "
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    ABSTRACT: Next generation sequencing and metagenomic approaches are commonly used for the identification of circular replication associated protein (Rep)-encoding single stranded (CRESS) DNA viruses circulating in various environments. These approaches have enabled the discovery of some CRESS DNA viruses associated with insects. In this study we identified and recovered 31 viral genomes which represent 24 distinct CRESS DNA viruses from seven dragonfly species (Rhionaeschna multicolor, Erythemis simplicicollis, Erythrodiplax fusca, Libellula quadrimaculata, Libellula saturata, Pachydiplax longipennis, and Pantala hymenaea) and two damselfly species (Ischnura posita, Ischnura ramburii) sampled in various locations in the states of Arizona and Oklahoma of the United States of America (USA). We also identified Sclerotinia sclerotiorum hypovirulence-associated DNA virus-1 (SsHADV-1) in P. hymenaea, E. simplicicollis and I. ramburii sampled in Oklahoma, which is the first report of SsHADV-1 in the New World. The genome architectures of the CRESS DNA viruses recovered vary, but they all have at least two major open reading frames (ORFs) that have either a bidirectional or unidirectional arrangement. Four of the viral genomes recovered, in addition to the three isolates of SsHADV-1, show similarities to viruses of the proposed gemycircularvirus group. Analysis of the Rep encoded by the remaining 24 viral genomes reveals that these are highly diverse and allude to the fact that they represent novel CRESS DNA viruses. Copyright © 2015. Published by Elsevier B.V.
    Full-text · Article · Jan 2015 · Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases
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    • "Association with microorganisms beneÞt xylophagous insects through degradation of plant defensive com - pounds , digestion of recalcitrant plant polymers and through synthesis or assimilation of essential nutrients ( Dowd 1992 , Klepzig et al . 2009 ) . "
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    ABSTRACT: Wood-feeding insects face a host of physical, chemical, and nutritional barriers in their food resource. Wood-boring Hymenoptera in the family Siricidae are associated with mutualistic basidiomycete wood-rot fungi, which assist colonization and provide nutrition for their insect partner, though functional properties of this symbiosis are poorly described. In this study, we document the behavioral and morphological adaptations of the globally invasive woodwasp, Sirex noctilio F., for foraging using its fungal symbiont Amylostereum areolatum (Chaillet ex Fries) Boidin. Larvae concentrated foraging near the border of fungal symbiont growth in pine xylem. Foraging larvae do not ingest bulk xylem tissue, but rather use specialized asymmetric mandibles to press xylem shavings and extract liquid fractions. Fluids drain toward the oral cavity via a sulcus on the occlusal surface of the left mandible. Processed shavings are expelled from the oral cavity without ingestion and passed along the underside of the larvae via peristaltic undulation to the rear of the feeding gallery. Larval midguts lack elaborated chambers typical in insects reliant on microbial fermentation of cellulose, and no xylem tissue was recovered from gut dissections. Larval behavior and functional morphology indicate larval S. noctilio do not ingest xylem, but instead use the fungus as an external gut for digestion of recalcitrant lignocellulosic compounds.
    Full-text · Article · Mar 2014 · Annals of the Entomological Society of America
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    • "Similar symbiotic associations have been extensively reported among microbial associates and wood-boring beetles (Cardoza et al. 2006, Adams et al. 2011, Six et al. 2011, Sun et al. 2013). For example, mycangial symbiotic fungi enhance the diet of Dendroctonus frontalis larvae by contributing to the acquisition of N and P (Ayres et al. 2000); the yeasts isolated from Phoracantha semipunctata feeding on Eucalyptus could degrade saccharose, maltose, amidon, and pectin (Dowd 1992). Additionally, the complex interactions among host pine and a symbiotic fungi vectored by an invasive bark beetle were driven by a host chemical compound 3- carene (Lu et al. 2010, Sun et al. 2013). "
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    ABSTRACT: Invasive pathogen-insect symbioses have been extensively studied in many different ecological niches. Whether the damage of symbioses in different introduced regions might be influenced by other microorganisms has, however, received little attention. Eight years of field data showed that the varied levels of the nematode and beetle populations and infested trees of the invasive Bursaphelenchus xylophilus--Monochamus alternatus symbiosis were correlated with patterns in the isolation frequencies of ophiostomatoid fungi at six sites, while the laboratory experiments showed that the nematode produced greater numbers of offspring with a female-biased sex ratio and developed faster in the presence of one native symbiotic ophiostomatoid fungus, Sporothrix sp. 1. Diacetone alcohol (DAA) from xylem inoculated with Sporothrix sp. 1 induced B. xylophilus to produce greater numbers of offspring. Its presence also significantly increased the growth and survival rate of M. alternatus, and possibly explains the prevalence of the nematode-vector symbiosis when Sporothrix sp. 1 was dominant in the fungal communities. Studying the means by which multispecies interactions contributed to biogeographical dynamics allowed us to better understand the varied levels of damage caused by biological invasion across the invaded range.
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