Role of the tissue free amino acids in adaptation of medicinal leeches <Emphasis Type="Italic">Hirudo medicinalis</Emphasis> L., 1758 to extreme climatic conditions

The first comparison of the spectra of free amino acids in tissues of the medicinal leeches H. medicinalis from different climatic and geographical Eurasian areas has been performed. Adaptation of H. medicinalis to extreme climatic conditions occurs via intensification of the amino acid metabolism resulting from a significant increase in the content of essential amino acids. Accumulation of arginine, histidine, and lysine (3.6-, 3.9-, and 2.0-fold increases, respectively) has proved to play a special protective role in adaptation of H. medicinalis to the low positive temperatures.     

Size structures and comparative phenology of syntopic populations of <Emphasis Type="Italic">Hirudo verbana</Emphasis> and <Emphasis Type="Italic">Hirudo medicinalis</Emphasis> in eastern Ukraine

Ranges of different species of medicinal leeches (Hirudo spp.) are nearly mutually exclusive with very few areas of overlapping. This biogeographical pattern suggests different ecological requirements for the two species. However, two habitats in Hungary and Ukraine where populations of H. verbana and H. medicinalis coexist were found. The aim of this research was to reveal differences in size structures and phenologies between the two species in a steppe pond with two populations. The study was conducted from March to September in 2009 and 2010 in Horila Dolyna, Kharkiv Region. Leeches were collected several times during the season, weighed and released. The abundance of H. verbana was always higher. The Mann-Whitney U-test and the Wilcoxon test were applied. Significant differences between sequential samples within the species were found. The large weight classes of H. verbana emerged by the end of summer and caused a higher variance in contrast to H. medicinalis. This suggests the higher growth rate and the more r-strategic biology of H. verbana in comparison with the largely K-strategic H. medicinalis.     

Detection of <Emphasis Type="Italic">Rickettsia</Emphasis> spp. in ticks parasitizing toads (<Emphasis Type="Italic">Rhinella marina</Emphasis>) in the northern Brazilian Amazon

This study evaluated rickettsial infection in ticks collected on toads from the northern Brazilian Amazon (Amapá state), where to our knowledge there are neither records of ticks from amphibians nor rickettsial infections in ticks. During 2016–2017, a total of 22 free-living toads were captured and identified as Rhinella marina. Overall, 12 (54.5%) toads were parasitized by a total of 97 ticks (6 males, 39 females, 31 nymphs, 21 larvae), giving a mean intensity of 8.1 ticks per infested toad. Two tick species were morphologically identified: Amblyomma rotundatum Koch (31 females, 14 nymphs), and Amblyomma dissimile Koch (6 males, 8 females, 17 nymphs). The 21 larvae were morphologically denoted as Amblyomma sp. Five toads were co-infested by A. rotundatum and A. dissimile. Morphological identifications were confirmed by nucleotide sequencing of fragments of the mitochondrial genes 16S rDNA, 12S rDNA and/or COX1. A total of 54 ticks were analyzed for the presence of rickettsial DNA. Eleven (9 females and 2 nymphs) out of 14 A. rotundatum ticks contained Rickettsia bellii. None of the 25 specimens of A. dissimile (6 males, 6 females, 13 nymphs) contained amplifiable rickettsial DNA. From 15 Amblyomma sp. larvae, a pool of 10 individuals contained Rickettsia sp. strain Colombianensi. Sequencing of the 16S rDNA amplicon derived from the positive pool yielded a sequence of A. dissimile. We detected Rickettsia sp. strain Colombianensi for the first time in Brazil. Prior records of this agent were restricted to Colombia and Honduras. In addition, we report the presence of A. rotundatum for the first time in the state of Amapá, where the only other record of A. dissimile was registered over 20 years ago.     

The fitness of the cotton mealybug <Emphasis Type="Italic">Phenacoccus solenopsis</Emphasis> (Tinsley) is reduced after feeding on virus-infected <Emphasis Type="Italic">Hibiscus rosa</Emphasis>-<Emphasis Type="Italic">sinensis</Emphasis>

The cotton mealybug Phenacoccus solenopsis (Tinsley) and Cotton leaf curl Multan virus (CLCuMV), serious threats to economic crops and garden plants, have invaded southern China and widely infected Hibiscus rosa-sinensis. Whether an inter-species connection has facilitated the invasion process is unclear. In this study the interaction between P. solenopsis and H. rosa-sinensis infected with CLCuMV was investigated in the laboratory. We observed that 1st and 2nd instar nymphs of P. solenopsis preferred to feed on healthy H. rosa-sinensis leaves, whereas 3rd instar nymphs and female adults had no preference between healthy and virus-infected H. rosa-sinensis leaves. The developmental time of each P. solenopsis developmental stage increased significantly after feeding on infected H. rosa-sinensis leaves (p < 0.05). In particular, the development time for 2nd instar female and male nymphs and 3rd instar female nymphs increased by approximately twofold. The generation time of female mealybugs increased from 25.84 d on healthy H. rosa-sinensis to 32.12 d when feeding on CLCuMV-infected H. rosa-sinensis, and the survival rate decreased from 71.04 % on healthy H. rosa-sinensis to 5.80 % on infected plants. Nymph survival was most affected by feeding on infected plants. Additionally, the fecundity of female mealybugs feeding on infected H. rosa-sinensis decreased by 47.8 %. Thus, feeding on CLCuMV-infected H. rosa-sinensis significantly decreased the biological fitness and invading and colonizing abilities of P. solenopsis.     

Adaptation or preadaptation: why are keelback snakes (<Emphasis Type="Italic">Tropidonophis mairii</Emphasis>) less vulnerable to invasive cane toads (<Emphasis Type="Italic">Bufo marinus</Emphasis>) than are other Australian snakes?

Biological invasions can expose native predators to novel prey which may be less nutritious or detrimental to predators. The introduction and subsequent spread of cane toads (Bufo marinus) through Australia has killed many anuran-eating snakes unable to survive the toad’s toxins. However, one native species, the keelback snake (Tropidonophis mairii), is relatively resistant to toad toxins and remains common in toad-infested areas. Is the keelback’s ability to coexist with toads a function of its ancestral Asian origins, or a consequence of rapid adaptation since cane toads arrived in Australia? And does the snake’s feeding preference for frogs rather than toads reflect an innate or learned behaviour? We compared keelback populations long sympatric with toads with a population that has encountered toads only recently. Unlike toad-vulnerable snake species, sympatry with toads has not affected keelback toxin tolerances or feeding responses: T. mairii from toad-sympatric and toad-naïve populations show a similar sensitivity to toad toxin, and a similar innate preference for frogs rather than toads. Feeding responses of neonatal keelbacks demonstrate that learning plays little or no role in the snake’s aversion to toads. Thus, behavioural aversion to B. marinus as prey, and physiological tolerance to toad toxins are pre-existing innate characteristics of Australian keelbacks rather than adaptations to the cane toad’s invasion of Australia. Such traits were most likely inherited from ancestral keelbacks that adapted to the presence of bufonids in Asia. Our results suggest that the impact of invasive species on native taxa may be strongly influenced by the biogeographic histories of the species involved.     

A PCR-based analysis of plant DNA reveals the feeding preferences of <Emphasis Type="Italic">Apolygus lucorum</Emphasis> (Heteroptera: Miridae)

The mirid bug Apolygus lucorum (Meyer-Dür) (Heteroptera: Miridae) is a severe pest of cotton and other crops in China. The feeding preferences of this pest are unclear due to its frequent movement among different host plants and the inconspicuous signs of its feeding. Here, we present results of a field trial that used direct observation of bug densities and a PCR-based molecular detection assay to detect plant DNA in bugs to explore relationships between A. lucorum population abundance and its feeding preference between two host plants, Humulus scandens (Loureiro) Merrill and Medicago sativa L. The field-plot samples showed that A. lucorum adults generally prefer flowering host plants. Its density was significantly higher on flowering H. scandens than on seedlings of M. sativa, and a similarly higher bug density was observed on flowering M. sativa than on seedlings of H. scandens. In the laboratory, we designed two pairs of species-specific primers targeting the trnL-F region for H. scandens and M. sativa, respectively. The detectability of plant DNA generally decreased with time post-feeding, and the half-life of plant DNA detection (DS₅₀) in the gut was estimated as 6.26 h for H. scandens and 3.79 h for M. sativa with significant differences between each other. In mirid bugs exposed to seedlings of H. scandens and flowering M. sativa, the detection rate of M. sativa DNA was significantly higher than that of H. scandens. Meanwhile, in mirid bugs exposed to seedlings of M. sativa and flowering H. scandens, a significantly higher detection rate of H. scandens DNA was found. We developed a useful tool to detect the remaining plant food species specifically from the gut of A. lucorum in the current study. We provided direct evidence of its feeding preference between H. scandens and M. sativa at different growth stages, which strongly supported a positive correlation between population abundance and feeding preference of A. lucorum on different plants under field conditions. The findings provide new insights into the understanding of A. lucorum’s feeding preference, and are helpful for developing the strategies to control this pest.     

Feeding behaviors of rice-ear bugs, <Emphasis Type="Italic">Trigonotylus caelestialium</Emphasis> and <Emphasis Type="Italic">Stenotus rubrovittatus</Emphasis> (Hemiptera: Miridae), in response to starch and its related substances

We investigated the feeding behavior-stimulating properties of starch and related substances, namely, rice starch, soluble starch, amylopectin, and d-glucose, in the mirid bugs Trigonotylus caelestialium (Kirkaldy) and Stenotus rubrovittatus (Matsumura). Using an electrical penetration graph, feeding behaviors were roughly categorized into three distinct processes: test probing, ingestion, and resting. Rice starch strongly stimulated the feeding behavior of S. rubrovittatus at all concentrations tested (10–50%), prompting an increase in ingestion behavior and a decrease in resting behavior. Rice starch stimulated the feeding behavior of T. caelestialium at a concentration of 10%. Soluble starch also elicited feeding-stimulant activity in S. rubrovittatus at all concentrations tested (10–30%), but did not stimulate feeding behavior at any concentration tested in T. caelestialium. Amylopectin, a main component of rice starch, showed feeding-stimulant activity in S. rubrovittatus only at a concentration of 10%. In T. caelestialium, amylopectin did not stimulate ingestion, but did decrease resting behavior. d-Glucose, the building block of amylopectin, stimulated feeding behavior in S. rubrovittatus, leading to an increase in the duration and frequency of ingestion at concentrations of 10% and 10–20%, respectively. These findings indicate that starch is one of the main feeding stimulants for rice-ear bugs, particularly S. rubrovittatus.     

Maternal care,larviparous and oviparous reproduction of <Emphasis Type="Italic">Hypoaspis larvicolus</Emphasis> (Acari: Laelapidae) feeding on astigmatid mites

Hypoaspis larvicolus (Acari: Laelapidae) (first report from Turkey) occurred together with Sancassania polyphyllae (Acari: Acaridae) on the larvae of the scarab beetle, Polyphylla fullo (Coleoptera: Scarabaeidae), that were feeding on the roots of strawberry in Aydin, Turkey. Laboratory studies were conducted to (1) observe whether H. larvicolus feeds and completes its life cycle on the various stages of S. polyphyllae or other astigmatid mites, such as Acarus siro, Carpoglyphus lactis and Tyrophagus putrescentiae (Acaridae), and to determine its population growth when feeding on these prey, and (2) to determine development periods, longevity and fecundity of H. larvicolus feeding on C. lactis. Hypoaspis larvicolus females did not feed on S. polyphyllae, but fed, developed and reproduced when A. siro, C. lactis or T. putrescentiae were provided as prey. Hypoaspis larvicolus is larviparous as well as oviparous. The female lays eggs or gives birth to larvae. If a female gives birth to a larva, it is attached under the female’s venter for 1–2 days, a phenomenon recorded for the first time in Hypoaspis; in fact, for the first time in mites. The results of the population growth experiments revealed that H. larvicolus feeding on C. lactis produced the highest number of eggs, juveniles and adults. The developmental periods of H. larvicolus feeding on C. lactis at life-cycle path I (larva to adult) and II (egg to adult) were 12.2?±?0.3 and 15.6?±?0.6 days (females) and 19.5?±?0.2 and 20.9?±?0.4 days (males), respectively. Longevity of females versus males of H. larvicolus was 120.6?±?7.2 versus 91.6?±?13.1 days (life cycle I) and 110.0?±?27.7 versus 118.3?±?10.9 days (life cycle II), respectively.     

Comparative study on intestinal bacterial communities of <Emphasis Type="Italic">Boleophthalmus pectinirostris</Emphasis> and <Emphasis Type="Italic">Periophthalmus magnuspinnatus</Emphasis> with different sexes and feeding strategies

Intertidal mudflats are unique, highly productive ecosystems. Boleophthalmus pectinirostris and Periophthalmus magnuspinnatus are common fish species that are distributed in the intertidal mudflats of the Yangtze Estuary in China. They perform important ecological functions and have different feeding strategies. Herein, we studied the intestinal microbial diversity and structure of wild B. pectinirostris and P. magnuspinnatus with different sexes and feeding strategies during their breeding season. Gut samples of B. pectinirostris and P. magnuspinnatus individuals (female:male ratio?=?1:1) were collected and subjected to high-throughput DNA sequencing. The results showed Proteobacteria was the most dominant phylum in all the four sample groups: 73.5% in the males and 52.6% in the females of B. pectinirostris and 40.2% in the males and 40.9% in the females of P. magnuspinnatus. Aeromonas, Shewanella, Halomonas, and Acinetobacter of the phylum Proteobacteria were dominant genera in all the sample groups and accounted for 62.13% of the ten dominant genera. The diversity of the intestinal microflora in the omnivorous P. magnuspinnatus was significantly higher (P?<?0.05) than that in the herbivorous B. pectinirostris. Beta diversity, including PCoA and UPGMA of unweighted UniFrac distances, showed that B. pectinirostris samples were clustered together, and P. magnuspinnatus samples were clustered together, implying the effect of the feeding habits on the microbial community structure is more considerable than that of sex.     

New record of the fish leech <Emphasis Type="Italic">Piscicola pojmanskae</Emphasis> (Annelida: Hirudinida: Piscicolidae) - DNA barcoding and phylogeny

The aim of this study was to confirm the taxonomic status of Piscicola pojmanskae Bielecki, 1994 found on Salmonidae fish. The fish leech was identified based on a diligent morphological analysis as well as COI gene sequence (DNA barcoding). The phylogenetic relationship with other piscicolid leeches was analyzed as well. Piscicola pojmanskae was found on various fins of both graylings and the resident form of trouts. The prevalence of infection was 1.63%. In this paper, probable causes of the lack of relation between the number of leeches on the fins and the fish body length as well as the host-searching strategy used by P. pojmanskae are discussed.     

Freshwater anostracan, <Emphasis Type="Italic">Branchinella kugenumaensis</Emphasis>, as a potential controlling consumer species on toxic cyanobacteria <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis>

To evaluate the potential of Branchinella kugenumaensis for cyanobacterial bloom control relative to Daphnia, we conducted several feeding experiments on microcystin-free and microcystin-containing unicellular strains of Microcystis aeruginosa and colonial forms of Microcystis using B. kugenumaensis and Daphnia magna in a laboratory. Branchinella kugenumaensis showed higher filtration rates than those of D. magna in all treatments. In particular, the microcystin-containing unicellular strain supported the highest filtration rates of B. kugenumaensis among treatments. Daphnia magna reduced colonies less than 75 μm in length, whereas B. kugenumaensis could graze colonies less than 100 μm. The middle-sized group of B. kugenumaensis had a higher filtration rate than the small and large sized groups in a continuous feeding experiment for 4 days. In survival experiments, survivorships were not different between the two species, whereas ages at the beginning of the experiments affected their survival time. Our results showed that B. kugenumaensis grazed on toxic and colonial cyanobacteria at relatively high rates, indicating that locally abundant grazers like Branchinella may offer a better potential for bloom control than Daphnia.     

Habitat Management to Reduce Human Exposure to <Emphasis Type="Italic">Trypanosoma cruzi</Emphasis> and Western Conenose Bugs (<Emphasis Type="Italic">Triatoma protracta</Emphasis>)

Chagas disease, which manifests as cardiomyopathy and severe gastrointestinal dysfunction, is caused by Trypanosoma cruzi, a vector-borne parasite. In California, the vector Triatoma protracta frequently colonizes woodrat (Neotoma spp.) lodges, but may also invade nearby residences, feeding upon humans and creating the dual risk of bite-induced anaphylaxis and T. cruzi transmission. Our research aimed to assess T. cruzi presence in woodrats in a previously unstudied northern California area, statistically evaluate woodrat microhabitat use with respect to vegetation parameters, and provide guidance for habitat modifications to mitigate public health risks associated with Tr. protracta exposure. Blood samples from big-eared woodrats (N. macrotis) trapped on rural private properties yielded a T. cruzi prevalence of 14.3%. Microhabitat analyses suggest that modifying vegetation to reduce understory density within a 40 meter radius of human residences might minimize woodrat lodge construction within this buffer area, potentially decreasing human exposure to Tr. protracta.     

Post-release evaluation of non-target effects of <Emphasis Type="Italic">Torymus sinensis</Emphasis>, the biological control agent of <Emphasis Type="Italic">Dryocosmus kuriphilus</Emphasis> in Italy

A post-release study was performed to assess the impact of Torymus sinensis (Hymenoptera: Torymidae), the biological control agent of Dryocosmus kuriphilus (Hymenoptera: Cynipidae), on native cynipid gall inducers in Italy. In total, 14,512 non-target galls were collected, corresponding to seven genera: Andricus, Aphelonyx, Biorhiza, Cynips, Diplolepis, Neuroterus, and Synophrus, and 8708 chalcid parasitoids were recorded. The Torymidae family accounted for about 30%, and Bootanomyia (=Megastigmus) dorsalis, Torymus affinis and T. flavipes were the most represented species. A total of 116 T. sinensis emerged from 15 different oak galls, mainly Andricus curvator and A. inflator. In controlled conditions, oviposition was recorded on A. cydoniae, A. grossulariae and A. lucidus, while no mating with native congeneric species occurred. This paper confirms the realised host-range expansion by T. sinensis. Even if it were extremely difficult to evaluate its magnitude, the impact appears minimal, and an occasional feeding with no changes in the distribution or abundance of non-target hosts is expected.     

Metatrancriptomic analysis from the Hepatopancreas of adult white leg shrimp (<Emphasis Type="Italic">Litopenaeus vannamei)</Emphasis>

The amoeba, Mayorella viridis contains several hundred symbiotic green algae in its cytoplasm. Transmission electron microscopy revealed strong resemblance between symbiotic algae from M. viridis the symbiotic Chlorella sp. in the perialgal vacuoles of Paramecium bursaria and other ciliates. Although it is thought that the M. viridis and symbiotic algae could be model organisms for studying endosymbiosis between protists and green algae, few cell biological observations of the endosymbiosis between M. viridis and their symbiotic algae have been published. In this study, we characterized the specificity of endosymbiotic relationships between green algae and their hosts. Initially, we established stable cultures of M. viridis in KCM medium by feeding with Chlorogonium capillatum. Microscopic analyses showed that chloroplasts of symbiotic algae in M. viridis occupy approximately half of the algal cells, whereas those in P. bursaria occupy entire algal cells. The symbiotic algae in P. bursaria contain several small spherical vacuoles. The labeling of actin filaments using Acti-stain? 488 Fluorescent Phalloidin revealed no relationship between host actin filaments and symbiotic algal localization, although the host mitochondria were localized around symbiotic algae. Symbiotic algae from M. viridis could infect algae-free P. bursaria but could not support P. bursaria growth without feeding, whereas the original symbiotic algae of P. bursaria supported its growth without feeding. These data indicated the specificity of endosymbiotic algae relationships in M. viridis and P. bursaria.     

Susceptibility of germinating cruciferous seeds to <Emphasis Type="Italic">Bagrada hilaris</Emphasis> (Hemiptera: Pentatomidae) feeding injury

Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae) is a serious pest that attacks both germinating and seedling stages of a variety of cruciferous crops grown in the Central Coast of California. B. hilaris feeding on germinating seeds can cause severe stunting and plant mortality, and little is known about the feeding preference of B. hilaris for germinating seeds of major cruciferous hosts and varieties of hosts. No-choice and choice experiments were conducted in which germinating seeds in soilless and soil settings were exposed to B. hilaris adults for 7 days. Susceptibility scores were developed using B. hilaris feeding injury sites, distorted leaves, and deformed and dead plants to determine the overall B. hilaris preference for germinating host seeds. Based on the scores, the order of preference was arugula (Eruca sativa L.)?>?turnip (B. rapa L. var. rapa)?>?mizuna (B. rapa L. nipposinica)?>?kale (B. oleracea L. acephala)?>?choi (Brassica rapa L. var. chinensis)?>?broccoli (B. oleracea var. italica Plenck)?>?cauliflower (B. oleracea L. var. botrytis)?>?lettuce (Lactuca sativa L.)?>?sweet alyssum (Lobularia maritima [L.] Desv.). The lowest feeding injury was recorded on germinating lettuce and sweet alyssum seeds. Furthermore, no-choice and choice experiments were conducted with four varieties each of arugula and mizuna, twelve varieties each of kale and choi, and nine varieties/types of leafy Asian greens. The arugula varieties ‘Wild Rocket’ and ‘Spirit’ were more damaged by B. hilaris than other varieties tested. Among mizuna varieties, ‘Beira F1’ was more attractive to B. hilaris than ‘Scarlet’ or ‘Starbor F1.’ The choi varieties ‘Tokyo Bekana,’ ‘Feng Qing Choi F1,’ ‘Joi Choi F1,’ and ‘Win-Win Choi F1’ were more attractive than ‘Rosie F1.’ The leafy Asian greens variety ‘Carlton F1’ was more attractive to B. hilaris than ‘Yukina Savon,’ ‘Tatsoi OG,’ ‘Komatsuna Summerfest F1,’ ‘Red Rain F1,’ and ‘Shungiku.’ Therefore, the results suggest that not all varieties were equally susceptible to B. hilaris feeding and possibly be utilized for further field evaluation as a trap crop or developing more resistant varieties to B. hilaris.     

Lipid metabolism in adipose tissue and liver from diet-induced obese rats: a comparison between <Emphasis Type="Italic">Wistar</Emphasis> and <Emphasis Type="Italic">Sprague-Dawley</Emphasis> strains

Some researchers have proposed important variations in adipose tissue among different strains of rats and mice in response to a high-caloric (hc) diet, but data concerning the mechanisms underlying these differences are scarce. The aim of the present research was to characterize different aspects of triacylglycerol (TG) metabolism and clock genes between Sprague-Dawley and Wistar rats. For this purpose, 16 male Sprague-Dawley and 16 male Wistar rats were divided into four experimental groups (n?=?8) and fed either a normal-caloric (nc) diet or a hc diet for 6 weeks. After sacrifice, liver and epididymal, perirenal, mesenteric, and subcutaneous adipose tissue depots were dissected, weighed and immediately frozen. Liver TG content was quantified, RNA extracted for gene expression analysis and fatty acid synthase enzyme activity measured. Two-way ANOVA and Student’s t test were used to perform the statistical analyses. Under hc feeding conditions, Wistar rats were more prone to fat accumulation in adipose tissue, especially in the epididymal fat depot, due to their increased lipogenesis and fatty acid uptake. By contrast, both strains of rats showed similarly fatty livers after hc feeding. Peripheral clock machinery seems to be a potential explanatory mechanism for Wistar and Sprague-Dawley strain differences. In conclusion, Wistar strain seems to be the best choice as animal model in dietary-induced obesity studies.     

The effect of galling aphids feeding on photosynthesis photochemistry of elm trees (<Emphasis Type="Italic">Ulmus</Emphasis> sp.)

Changes of chlorophyll (Chl) a fluorescence and photosynthetic pigment contents were analysed in galled leaves (visibly damaged and undamaged parts) and intact leaves. The values of minimal fluorescence of the dark-adapted state, maximal quantum yield of PSII photochemistry, effective quantum yield of PSII photochemical conversion, and photochemical quenching coefficient decreased in Ulmus pumila L. leaves galled by Tetraneura ulmi (L.) and in U. glabra Huds. galled by Eriosoma ulmi (L.). Colopha compressa (Koch.) feeding affected these parameters only in damaged parts of U. laevis Pall. galled leaves. The increasing number of T. ulmi galls progressively decreased photosynthetic performance. In gall tissues of all analysed aphid species, the lowest photosynthetic pigment content was found, indicating that the photosynthetic capacity must have been low in galls. Significant reduction of Chl and carotenoid contents were observed in damaged and undamaged portions of galled leaves only in the case of T. ulmi feeding.     

Engineering of <Emphasis Type="Italic">Escherichia coli</Emphasis> for the synthesis of <Emphasis Type="Italic">N</Emphasis>-hydroxycinnamoyl tryptamine and serotonin

Plants synthesize various phenol amides. Among them, hydroxycinnamoyl (HC) tryptamines and serotonins exhibit antioxidant, anti-inflammatory, and anti-atherogenic activities. We synthesized HC–tryptamines and HC–serotonin from several HCs and either tryptamine or serotonin using Escherichia coli harboring the 4CL (4-coumaroyl CoA ligase) and CaHCTT [hydroxycinnamoyl-coenzyme A:serotonin N-(hydroxycinnamoyl)transferase] genes. E. coli was engineered to synthesize N-cinnamoyl tryptamine from glucose. TDC (tryptophan decarboxylase) and PAL (phenylalanine ammonia lyase) along with 4CL and CaHCTT were introduced into E. coli and the phenylalanine biosynthetic pathway of E. coli was engineered. Using this strategy, approximately 110.6 mg/L of N-cinnamoyl tryptamine was synthesized. By feeding 100 μM serotonin into the E. coli culture, which could induce the synthesis of cinnamic acid or p-coumaric acid, more than 99 μM of N-cinnamoyl serotonin and N-(p-coumaroyl) serotonin were synthesized.     

Adequacy of planctomycetes as supplementary food source for <Emphasis Type="Italic">Daphnia magna</Emphasis>

The nutritional quality of daphnids diet can influence their growth, reproduction and survival. In aquatic ecosystems, bacteria can contribute significantly to Daphnia diet by supporting, for instances, their high needs for phosphorus. The laboratory feeding of the model organisms Daphnia spp. is algal based, but should be improved to allow their better performance. The aim of this study was to evaluate the potential of two planctomycetes, Gemmata obscuriglobus and Rhodopirellula rubra, from exponential and stationary growth phases as alternative or supplementary food source for Daphnia magna. The actinobacterium Arthrobacter sp. was used for comparison. The feeding with only bacteria showed the inefficacy of both planctomycetes and actinobacteria as the only food source. However, when used in supplement to Raphidocelis subcapitata, a decrease in the age of first reproduction, a significant increase in reproductive output, in somatic growth and in rate of population increase was found for the highest cell densities of bacteria tested. The typical pink coloration of these bacteria present in daphnids body and eggs confirmed bacterial absorption and metabolization of their pigment. Planctomycetes yielded better results than the actinobacteria Arthrobacter but G. obscuriglobus that possesses sterols did not induce a better performance comparatively to R. rubra. No relation could be established between the feeding treatments that allowed improvement of Daphnia performance and the different kind of Daphnia’ Fatty Acid Methyl Esters. The use of sonication to separate planctomycetal cells before feeding the daphnids proved to be efficient. We confirmed that R. subcapitata supplemented by bacteria allows a better growth performance of D. magna.     

Reproductive tables of predatory phytoseiid mites (<Emphasis Type="Italic">Phytoseiulus persimilis,Galendromus occidentalis</Emphasis>, and <Emphasis Type="Italic">Neoseiulus cucumeris</Emphasis>)

Feeding of predatory mites (Phytoseiulus persimilis, Galendromus occidentalis, and Neoseiulus cucumeris) on different life stages of Tetranychus atlanticus under optimal conditions was studied. Daily and total consumption of prey by predators and selection of prey of different life stages were studied for 5 days and for the entire feeding period. Average daily food consumption [number of individuals] for the entire life period of mature mite females constituted 0.43 females + 5.0 [nymphs and males] + 3.4 eggs of Tetranychus atlanticus in P. persimilis; 0.12 females + 3.70 [nymphs and males] + 3.10 eggs in G. occidentalis; and 0.19 females + 4.10 [nymphs and males] + 3.50 eggs in N. cucumeris. During the entire period of feeding, P. persimilis preferred large individuals and at the postembryonic stages selected prey to a greater extent than G. occidentalis and N. cucumeris (61.8 and 55.1%, respectively). The use of a 5-day express-method is possible for estimation of some biological characteristics of phytoseiids that previously consumed the same food for a long period. In other cases, analysis of characteristics for the entire life period is necessary.