Physiological properties of the entomopathogenic hyphomycete Paecilomyces farinosus in relation to its role in the forest ecosystem

1991 ◽  
Vol 69 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Sharon Harney ◽  
Paul Widden

Fifty-four strains of the entomopathogenic fungus Paecilomyces farinosus, half of which had been isolated from balsam fir litter and half of which had been isolated from naturally infected spruce budworm larvae, were evaluated for their use of a number of complex carbohydrates and other carbon sources, to determine their potential saprophytic ability. The fungi were also tested for (i) their ability to grow on and to decompose balsam fir litter, and (ii) their ability to survive desiccation, which is likely to occur in the tree canopy. The fungi produced a wide range of enzymes, including cellulases, chitinases, and proteases. They also grew on and decomposed balsam fir litter. A discriminant analysis showed a tendency for the strains isolated from spruce budworm to grow better on gelatin, whereas those from the litter grew better on cellulose. We conclude that P. farinosus is a versatile saprophyte, capable of opportunistically parasitizing spruce budworm larvae. These characteristics could be important when considering P. farinosus as a possible agent of biological control. Key words: Paecilomyces farinosus, entomopathogen, spruce budworm, saprophytic ability, hydrolases.

1991 ◽  
Vol 69 (3) ◽  
pp. 512-515 ◽  
Author(s):  
Sharon Harney ◽  
Paul Widden

The occurrence of Paecilomyces farinosus and other microfungi on litter was monitored in two balsam fir forests infested with spruce budworm to determine the possible role of this fungus as a saprophyte in these forests. The microfungi on the fir litter were similar to those found on other conifers. Paecilomyces farinosus, however, was very abundant, and its abundance increased on the litter after it fell to the ground. An apparent correlation between the abundance of the fungus and the population of spruce budworm suggests that opportunistic parasitism may positively affect the abundance of P. farinosus. Key words: Paecilomyces farinosus, entomopathogens, balsam fir, litter, microfungi.


1982 ◽  
Vol 60 (5) ◽  
pp. 958-961 ◽  
Author(s):  
Jean R. Finney ◽  
K. P. Lim ◽  
Gordon F. Bennett

Exposure of 4th, 5th, and 6th instar Choristoneura fumiferana to Heterorhabditis heliothidis (120 nemas per larva) resulted in 100% mortality within 48 h at 24 ± 1 °C. At 17 °C, 100% mortality was achieved within 120 h. Reduction of the dose to 15 nemas per 5th–6th instar larva caused 70% mortality at 24 ± 1 °C and 15% mortality at 17 °C within 120 h. At the higher temperature, mortalities of 80 and 73% were recorded for pupae exposed to 150 and 60 nemas per pupa, respectively. When 6th instar larvae on foliage of balsam fir or blue spruce were treated with the nematode suspension (120 nemas per larva) 100% mortality was obtained within 72 h at 24 ± 1 °C. The potential of using this nematode in biological control of spruce budworm is discussed.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4871
Author(s):  
Héctor M. Alvarez ◽  
Martín A. Hernández ◽  
Mariana P. Lanfranconi ◽  
Roxana A. Silva ◽  
María S. Villalba

Bacteria belonging to the Rhodococcus genus are frequent components of microbial communities in diverse natural environments. Some rhodococcal species exhibit the outstanding ability to produce significant amounts of triacylglycerols (TAG) (>20% of cellular dry weight) in the presence of an excess of the carbon source and limitation of the nitrogen source. For this reason, they can be considered as oleaginous microorganisms. As occurs as well in eukaryotic single-cell oil (SCO) producers, these bacteria possess specific physiological properties and molecular mechanisms that differentiate them from other microorganisms unable to synthesize TAG. In this review, we summarized several of the well-characterized molecular mechanisms that enable oleaginous rhodococci to produce significant amounts of SCO. Furthermore, we highlighted the ability of these microorganisms to degrade a wide range of carbon sources coupled to lipogenesis. The qualitative and quantitative oil production by rhodococci from diverse industrial wastes has also been included. Finally, we summarized the genetic and metabolic approaches applied to oleaginous rhodococci to improve SCO production. This review provides a comprehensive and integrating vision on the potential of oleaginous rhodococci to be considered as microbial biofactories for microbial oil production.


2008 ◽  
Vol 84 (1) ◽  
pp. 60-69 ◽  
Author(s):  
David A MacLean ◽  
Allison R Andersen

Nine 0.04-ha plots were established in 1956 (age 35 years) in a balsam fir (Abies balsamea [L.] Mill.) stand in northwestern New Brunswick, Canada to determine the impact of an uncontrolled spruce budworm (Choristoneura fumiferana [Clem.]) outbreak on stand development. The plots were measured annually from 1956 to 1961 and at five-year intervals from 1965 to 1995. Moderate to severe defoliation occurred from 1951 to 1957 and again in 1975 to 1977, 1981, and 1986 to 1988. Budworm-caused mortality from 1956 to 1961 (age 35 to 40 years) varied considerably among plots, reducing volume by 35 to 113 m3/ha (34%-84%), and resulting in a wide range of post-outbreak plot densities. Plots were grouped into three post-budworm outbreak (1965, age 45 years) basal area classes, of ≤ 20 m2/ha, 21 to 27 m2/ha, and ≥ 28 m2/ha, to examine stand recovery. Recovery of volume up to age 60 years ranged from 72 to 132 m3/ha, in the lowest to highest basal area classes, respectively. From age 60 to 75 years, five plots declined in volume due to the onset of stand break-up and four plots increased in volume. By age 60 years, survivor growth was greatest in the high basal area plots, ranging from 6.2 to 9.0 m3/ha/yr in seven plots, versus 2.6 to 3.2 m3/ha/yr in two low basal area plots. From age 60 to 75 years, survivor growth averaged only 2.8 to 5.2 m3/ha/yr, and the stand exhibited major decline, with 63%, 74%, and 78% mortality of fir ≤ 15 cm DBH in the low to high basal area plots, respectively. Budworm-caused "thinning" in the 1950s largely determined subsequent stand development and the rate of stand break-up 25 to 35 years later. The timing and rate of natural stand decline was strongly influenced by post-outbreak stand density. Key words: budworm-caused mortality, stand structure, stand development, growth, mortality, stand density


1999 ◽  
Vol 131 (6) ◽  
pp. 725-727 ◽  
Author(s):  
André J. Forté ◽  
Claude Guertin ◽  
Jean Cabana

The spruce budworm Choristoneura fumiferana (Clem.) is the most damaging insect of the balsam fir Abies balsema (L.) Mill. (Pinaceae) and the white spruce Picea glauca (Moench) Voss (Pinaceae) throughout eastern North America. In outbreak conditions, close to 100% tree mortality can occur in untreated mature fir stands (MacLean 1980). Bacillus thuringiensis var. kurstaki (Bacillaceae) is currently used to reduce spruce budworm damage (Van Frankenhuyzen and Payne 1993). Other possible biological control agents, such as baculoviruses, are also investigated to complement the use of B. thuringiensis. Baculoviruses are advantageous because they occur naturally in several insect species and are generally host specific (Federici 1993).


2012 ◽  
Vol 144 (3) ◽  
pp. 396-405 ◽  
Author(s):  
S.E. Holmes ◽  
E.G. Kettela ◽  
P.C. Nigam ◽  
S.B. Heard ◽  
R.C. Johns

AbstractSpruce budworm, Choristoneurafumiferana (Clemens) (Lepidoptera: Tortricidae), larvae can cause extensive defoliation in balsam fir (Abies balsamea [Linnaeus] Miller) and exhibit high temporal and spatial variability in individual behaviour. We gathered field data to determine the influence of daily and hourly variation in abiotic conditions on daytime activity patterns of late-instar budworm larvae on balsam fir. In both years of our study, less than 10% of larvae were observed feeding during the daytime. Most larvae observed were either resting, spinning silk, or roaming, although the proportion of individuals engaged in each activity varied between years, with more larvae in the first year roaming (48%) and in the second year either resting (38%) or spinning silk (42%). Daily and hourly variation in abiotic conditions had a limited influence on activity patterns. Our results indicate that in nature, mid- to late-instar budworm larvae maintain fairly consistent activity patterns across a wide range of abiotic conditions. We suggest that site-specific conditions such as variation in host-plant quality and/or budworm population density may be more important than weather in determining the relative frequencies of different larval activities in space and time.


2019 ◽  
Author(s):  
Michael Oschmann ◽  
Linus Johansson Holm ◽  
Oscar Verho

Benzofurans are everywhere in nature and they have been extensively studied by medicinal chemists over the years because of their chemotherapeutic and physiological properties. Herein, we describe a strategy that can be used to access elaborate benzo-2-carboxamide derivatives, which involves a synthetic sequence of 8-aminoquinoline directed C–H arylations followed by transamidations. For the directed C–H arylations, Pd catalysis was used to install a wide range of aryl and heteroaryl substituents at the C3 position of the benzofuran scaffold in high efficiency. Directing group cleavage and further diversification of the C3-arylated benzofuran products were then achieved in a single synthetic operation through the utilization of a two-step transamidation protocol. By bocylating the 8-aminoquinoline amide moiety of these products, it proved possible to activate them towards aminolysis with different amine nucleophiles. Interestingly, this aminolysis reaction was found to proceed efficiently without the need of any additional catalyst or additive. Given the high efficiency and modularity of this synthetic strategy, it constitute a very attractive approach for generating structurally-diverse collections of benzofuran derivatives for small molecule screening.


2020 ◽  
Vol 5 (1) ◽  
pp. 404-440 ◽  
Author(s):  
Mehrdad Alizadeh ◽  
Yalda Vasebi ◽  
Naser Safaie

AbstractThe purpose of this article was to give a comprehensive review of the published research works on biological control of different fungal, bacterial, and nematode plant diseases in Iran from 1992 to 2018. Plant pathogens cause economical loss in many agricultural products in Iran. In an attempt to prevent these serious losses, chemical control measures have usually been applied to reduce diseases in farms, gardens, and greenhouses. In recent decades, using the biological control against plant diseases has been considered as a beneficial and alternative method to chemical control due to its potential in integrated plant disease management as well as the increasing yield in an eco-friendly manner. Based on the reported studies, various species of Trichoderma, Pseudomonas, and Bacillus were the most common biocontrol agents with the ability to control the wide range of plant pathogens in Iran from lab to the greenhouse and field conditions.


2021 ◽  
Vol 496 ◽  
pp. 119408
Author(s):  
Djidjoho Julien Houndode ◽  
Cornelia Krause ◽  
Hubert Morin
Keyword(s):  

Author(s):  
Alif Chebbi ◽  
Massimiliano Tazzari ◽  
Cristiana Rizzi ◽  
Franco Hernan Gomez Tovar ◽  
Sara Villa ◽  
...  

Abstract Within the circular economy framework, our study aims to assess the rhamnolipid production from winery and olive oil residues as low-cost carbon sources by nonpathogenic strains. After evaluating various agricultural residues from those two sectors, Burkholderia thailandensis E264 was found to use the raw soluble fraction of nonfermented (white) grape marcs (NF), as the sole carbon and energy source, and simultaneously, reducing the surface tension to around 35 mN/m. Interestingly, this strain showed a rhamnolipid production up to 1070 mg/L (13.37 mg/g of NF), with a higher purity, on those grape marcs, predominately Rha-Rha C14-C14, in MSM medium. On olive oil residues, the rhamnolipid yield of using olive mill pomace (OMP) at 2% (w/v) was around 300 mg/L (15 mg/g of OMP) with a similar CMC of 500 mg/L. To the best of our knowledge, our study indicated for the first time that a nonpathogenic bacterium is able to produce long-chain rhamnolipids in MSM medium supplemented with winery residues, as sole carbon and energy source. Key points • Winery and olive oil residues are used for producing long-chain rhamnolipids (RLs). • Both higher RL yields and purity were obtained on nonfermented grape marcs as substrates. • Long-chain RLs revealed stabilities over a wide range of pH, temperatures, and salinities


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