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This is the first report on the ascomycete Metschnikowia typographi from the adults and larvae of the great spruce bark beetle Dendroctonus micans in Turkey. In total, 910 of 1928 adults and 44 of 149 larvae investigated during the two years were infected by the pathogen. In a fresh smear the asci of the pathogen measure 18.5 +/- 2.05 microm (14.7-...
Citations
... Various microorganisms such as algae, yeast, bacteria, and fungi are able to accumulate lipids under specific culture conditions. Under certain conditions, microorganisms can produce large amounts of lipids, with their accumulation immediate occurrence on flowers, fruits, or cuticles of pollinating insects was proved [7,8]. Recently, Raman spectroscopy was used for the initial estimation of lipid production depending on the culture conditions. ...
... Biomass (g/L) 5.8 ± 0. 7 3.3 ± 0.1 2.7 ± 0.3 Lipid content (%) a 9.0 ± 0.7 8.3 ± 1.0 9.1 ± 0.8 ...
Oleogenic yeasts are characterized by the ability to accumulate increased amounts of lipids under certain conditions. These microbial lipids differ in their fatty acid composition, which allows them to be widely used in the biotechnology industry. The interest of biotechnologists is closely linked to the rising prices of fossil fuels in recent years. Their negative environmental impact is caused by significantly increased demand for biodiesel. The composition of microbial lipids is very similar to vegetable oils, which provides great potential for use in the production of biodiesel. In addition, some oleogenic microorganisms are capable of producing lipids with a high proportion of unsaturated fatty acids. The presented paper’s main aim was to study the production of lipids and lipid substances by yeasts of the genus Metschnikowia, to cultivate crude waste animal fat to study its utilization by yeasts, and to apply the idea of circular economy in the biotechnology of Metschnikowia yeasts. The work focuses on the influence of various stress factors in the cultivation process, such as reduced temperature or nutritional stress through the use of various waste substrates, together with manipulating the ratio of carbon and nitrogen sources in the medium. Yeast production properties were monitored by several instrumental techniques, including gas chromatography and Raman spectroscopy. The amount of lipids and in particular the fatty acid composition varied depending on the strains studied and the culture conditions used. The ability of yeast to produce significant amounts of unsaturated fatty acids was also demonstrated in the work. The most suitable substrate for lipid production was a medium containing glycerol, where the amount of accumulated lipids in the yeast M. pulcherrima 1232 was up to 36%. In our work, the crude animal fat was used for the production of high-value lipids, which to the best of our knowledge is a new result. Moreover, quantitative screening of lipase enzyme activity cultivated on animal fat substrate on selected yeasts of the genus Metschnikowia was performed. We found that for the yeast utilizing glycerol, animal fat seems to be an excellent source of carbon. Therefore, the yeast conversion of crude processed animal fat to value-added products is a valuable process for the biotechnology and food industry.
... An earlier study also found two sizes of M. bicuspidata spores infecting Daphnia magna and Daphnia pulex in southern England (Stirnadel and Ebert, 1997). In addition, a different Metschnikowia species, Metschnikowia typographi, that infects bark beetles also has different size morphs that may be specialized on different bark beetle species (Weiser et al., 2003;Yaman and Radek, 2008). More extensive sampling (both geographically and in terms of host species) and genotyping could help us to understand the evolutionary relationships between the genotypes documented in this study as well as the evolutionary history of M. bicuspidata spore size. ...
Genetic variation in parasites has important consequences for host–parasite interactions. Prior studies of the ecologically important parasite Metschnikowia bicuspidata have suggested low genetic variation in the species. Here, we collected M. bicuspidata from two host species (Daphnia dentifera and Ceriodaphnia dubia) and two regions (Michigan and Indiana, USA). Within a lake, outbreaks tended to occur in one host species but not the other. Using microsatellite markers, we identified six parasite genotypes grouped within three distinct clades, one of which was rare. Of the two main clades, one was generally associated with D. dentifera, with lakes in both regions containing a single genotype. The other M. bicuspidata clade was mainly associated with C. dubia, with a different genotype dominating in each region. Despite these associations, both D. dentifera- and C. dubia-associated genotypes were found infecting both hosts in lakes. However, in lab experiments, the D. dentifera-associated genotype infected both D. dentifera and C. dubia, but the C. dubia-associated genotype, which had spores that were approximately 30% smaller, did not infect D. dentifera. We hypothesize that variation in spore size might help explain patterns of cross-species transmission. Future studies exploring the causes and consequences of variation in spore size may help explain patterns of infection and the maintenance of genotypic diversity in this ecologically important system.
... Szczególną uwagę zwrócił on na charakterystyczne zarodniki w kształcie igieł, które jak później wykazano, stanowiły istotny element pasożytnictwa tych drożdży w organizmie rozwielitek Daphnia sp. [31,43,48,73]. W 1899 roku Kamienski zmienił nazwę rodzajową Monospora na Metschnikowia, ponie-waż pierwsza z nich była już stosowana w nazewnictwie glonów. ...
Metschnikowia spp. are extensively studied “non-conventional” yeasts. Strains belonging to these genera are considered as nonpathogenic and safe. The unique properties of Metschnikowia spp. allow us to look at these microorganisms as a promising subject for
evolutionary genetics, taxonomy, ecology, as well as a natural biocontrol agent in biotechnology. This article provides a synthesis of the systematics, morphology, ecology and physiology of Metschnikowia spp., with special attention to M. pulcherrima. These yeasts are able to produce a number of important metabolites, including organic acids, aroma compounds, oil or pulcherrimic acid. In addition, this review discusses possible applications of these non-conventional yeasts in biotechnology.
... Szczególną uwagę zwrócił on na charakterystyczne zarodniki w kształcie igieł, które jak później wykazano, stanowiły istotny element pasożytnictwa tych drożdży w organizmie rozwielitek Daphnia sp. [31,43,48,73]. W 1899 roku Kamienski zmienił nazwę rodzajową Monospora na Metschnikowia, ponie-waż pierwsza z nich była już stosowana w nazewnictwie glonów. ...
Metschnikowia spp. are extensively studied “non-conventional” yeasts. Strains belonging to these genera are considered as non-pathogenic and safe. The unique properties of Metschnikowia spp. allow us to look at these microorganisms as a promising subject for evolutionary genetics, taxonomy, ecology, as well as a natural biocontrol agent in biotechnology. This article provides a synthesis of the systematics, morphology, ecology and physiology of Metschnikowia spp., with special attention to M. pulcherrima . These yeasts are able to produce a number of important metabolites, including organic acids, aroma compounds, oil or pulcherrimic acid. In addition, this review discusses possible applications of these non-conventional yeasts in biotechnology.
1. Introduction. 2. Taxonomy. 3. Ecology. 4. Morphology and physiology. 5. Parasexual cycle. 6. Metschnikowia pulcherrima – biochemical activity and application potential. 7. Summary
... typographi was found in Ips sexdentatus (Börner) (Coleoptera, Curculionidae) from Austria (Wegensteiner et al., 2007). The same yeast was subsequently reported in I. sexdentatus (Unal et al., 2009) and Dendroctonus micans (Kugelann) (Yaman and Radek, 2008) in Turkey. Until now, all of these studies were based upon morphological data of the asci and have been mainly conducted by light microscopy, with the exception of one micrograph showing the ultrastructure of an early stage of M. typographi in I. sexdentatus (Unal et al., 2009). ...
... Until now, all of these studies were based upon morphological data of the asci and have been mainly conducted by light microscopy, with the exception of one micrograph showing the ultrastructure of an early stage of M. typographi in I. sexdentatus (Unal et al., 2009). Further micrographs of the ultrastructure of a Metschnikowia sp. in D. micans have been presented by Yaman and Radek (2008). M. typographi has been found in I. typographus in Georgia (Burjanadze et al., 2011) and in I. amitinus in Czech Republic (Lukášová et al., 2013), always in a very low number of beetles. ...
Ips sexdentatus (Six-spined engraver beetle) from Austria and Poland were dissected and examined for the presence of pathogens. Specimens collected in Austria were found to contain the ascomycetous fungus Metschnikowia cf. typographi. Infection rates ranged from 3.6% to 26.8% at different collection sites. M. cf. typographi infected midguts were investigated by histological, ultrastructural and molecular techniques. Extraordinary ultrastructural details are shown, such as ascospores with bilateral flattened flanks resembling alar rims at both sides of their attenuating tube-like ends. These have not yet been described in other yeast species. Molecular investigations showed a close phylogenetic relationship to the fungi Metschnikowia agaves and Candida wancherniae. Presence of the entomopathogenic fungus Beauveria bassiana found in Austria was confirmed both morphologically and molecularly. The eugregarine Gregarina typographi was diagnosed most frequently. Infection rates of all I. sexdentatus specimens ranged from 21.4% to 71.9% in Austria and 54.1% to 68.8% in Poland. Other entomopathogenic protists, bacteria, or viruses were not detected.
... In addition chemicals control mechanism has harmful effects on the ecosystem, especially natural enemies such as predators and parasitoids. Nowadays environmentalism is getting more popular hence latest studies have focused on using natural enemies in biological control (WEGENSTEINER 2004, YAMAN, RADEK 2005, YAMAN 2007, YAMAN, RADEK 2008. Most common biological control agent is microorganisms. ...
In present paper, an Entomopoxvirus of I. typographus (ItEPV) in Turkey is reported for first time. Ips typographus
Entomopoxvirus was found only in Artvin and the total infection rate was 14.7%. It was observed only
in the gut epithelium of the host. Spheroids (inclusion bodies) of the virus were rectangular and spherical. The
size of rectangular spheroids measured 4 to 10 x 5 to 15 μm and diameter of the spherical ones ranged from
7 to 12 μm. Ips typographus Entomopoxvirus infection was also confirmed with a Transmission Electron
Microscopy. Spherical to elipsoidal virions in spheroids measured 250 to 280 x 310 to 375 nm in size.
The occurrence and action of natural enemies of bark beetles (Coleoptera: Curculionidae, Scolytinae) are reviewed. Bark beetles have a diverse and important community of natural enemies. The community includes predators such as birds, beetles, flies, true bugs, and mites; parasitoids such as wasps and flies; pathogens such as viruses, bacteria, fungi, microsporidia, and protozoa; as well as nematodes. The general ecology of the various taxonomic groups is discussed and some of the species most relevant to biological control are treated in detail. Morphological descriptions and the biology of pathogens, field data on natural enemies’ prevalence and geographical distribution are presented. The role of these antagonistic agents in bark beetle population dynamics and their potential for use as biological control agents are evaluated based on literature, data from experiments, observations in the field, and from controlled laboratory experiments.
Sap-feeding insects harbor diverse microbial endosymbionts that play important roles in host ecology and evolution, including contributing to host pest status. The vine mealybug, Planococcus ficus, is a serious pest of grapevines, vectoring a number of pathogenic grape viruses. Previous studies have shown that virus transmission is abolished when mealybugs are raised in the laboratory on potato. To examine the possible role of microbial symbionts in virus transmission, the archaeal, bacterial, and fungal microbiota of field and laboratory P. ficus were characterized using molecular and classical microbiological methods. Lab and field colonies of P. ficus harbored different microbiota. While both were dominated by the bacterial obligate nutritional symbionts Moranella and Tremblaya, field samples also harbored a third bacterium that was allied with cluster L, a lineage of bacterial symbionts previously identified in aphids. Archaea were not found in any of the samples. Fungal communities in field-collected mealybugs were dominated by Metschnikowia and Cladosporium species, while those from laboratory-reared mealybugs were dominated by Alternaria and Cladosporium species. In conclusion, this study has identified a diverse set of microbes, most of which appear to be facultatively associated with P. ficus, depending on environmental conditions. The role of various members of the mealybug microbiome, as well as how the host plant affects microbial community structure, remains to be determined.
This study concerns a new neogregarine parasitic in the great spruce bark beetle Dendroctonus micans (Kugelann) (Curculionidae, Scolytinae). The rate of infection was high, reaching 27.3%. There was no difference in the rate of infection of male and female beetles. The life-cycle stages of the pathogen were described by light and electron microscopy. Each gametocyst of the neogregarine included 8-16 actinocephalid oocysts measuring 11.19 ± 0.42 × 4.99 ± 0.25 μm. The described pathogen has the typical characteristics of members of the genus Menzbieria within the order Neogregarinida and it was identified as Menzbieria chalcographi. This is the first record of an infection of D. micans by M. chalcographi. Possibly, this pathogen could be useful for the biological control of this destructive bark beetle.
