A new anaxyelid wood wasp (Hymenoptera: ‘Symphyta’) from the mid-Cretaceous Burmese amber

A new genus and species of anaxyelid wasp is described and figured from the mid-Cretaceous Burmese amber as Curvitexis kopylovi gen. et sp. nov. The placement of this new genus within the Anaxyelidae is corroborated by its wing venation and the configuration of its mesosoma. This new genus differs from all other Syntexinae from the mid-Cretaceous Burmese amber biota, inter alia, owing to its forewing with the vein 1Rs curved and longer than 1M, the crossvein 1r-rs absent, the vein 2Rs + M present; the hind wing with the abscissa 2M + Cu present, the vein m-cu absent, and the cell r closed. The recently described Paraxiphydria resinata Gao et al., 2022 is transferred to Anaxyelidae: Syntexinae, and the subfamily Paraxiphydriinae Gao et al., 2022 is synonymized under Syntexinae.     

A new genus of praeaulacid wasp (Hymenoptera: Evanioidea) from the mid-Cretaceous Kachin amber (Myanmar)

The diversity of praeaulacid wasps in Kachin amber is relatively poorly documented. Here, a new genus and species of praeaulacid wasp are described and illustrated from the mid-Cretaceous Kachin amber as Archeogastrinus kachinensis gen. et sp. nov., and placed in the subfamily Praeaulacinae. This new genus is distinguishable from the other Praeaulacidae because of its particular tibial spurs formula 1-2-2; its forewings with a long and thin pterostigma, a 1-M longer than 1-Rs, a 1-Rs longer than its distance to pterostigma, a crossvein 2r-rs aligned (or nearly) with 2rs-m and originating near the middle of pterostigma, a 2rs-m present, a cell 3rm long, a 1cu-a postfurcal to 1-M, a vein 2-M distinct; its hind wings cu-a reaching Cu distad M + Cu fork; and its metasoma with a first segment petiole-like (i.e., long and thin) and ventrally inflated in its distal half. The position of the genus Mesevania is briefly discussed, as well as the validity of the genus Paleosyncrasis, both described from the mid-Cretaceous Kachin amber.     

New Middle Permian foraminifers (Chitralinidae) from the Karakaya Complex,in northwestern Turkey

One new foraminiferal genus, Rectoformata gen. nov., with two new species, has been described from a Permian limestone block in the Karakaya Complex in the South of the Balya district (Balikesir, northwestern Turkey). The type species of Rectoformata, Rectoformata tekini sp. nov., is characterized by a quadrangular transverse section having a calcareous microgranular wall with fine alveolar structures, whereas Rectoformata acari sp. nov. is recognized by a pentagonal transverse section having a calcareous microgranular wall with fine alveolar structures. The age of the described taxa is assigned as Midian ( = Capitanian) based on the association with small foraminifers and fusulinids. These new taxa are included in the family Chitralinidae, which is emended herein.     

Rahnella victoriana sp. nov., Rahnella bruchi sp. nov., Rahnella woolbedingensis sp. nov., classification of Rahnella genomospecies 2 and 3 as Rahnella variigena sp. nov. and Rahnella inusitata sp. nov., respectively and emended description of the genus Rahnella

Isolations from oak symptomatic of Acute Oak Decline, alder and walnut log tissue, and buprestid beetles in 2009–2012 yielded 32 Gram-negative bacterial strains showing highest gyrB sequence similarity to Rahnella aquatilis and Ewingella americana. Multilocus sequence analysis (using partial gyrB, rpoB, infB and atpD gene sequences) delineated the strains into six MLSA groups. Two MLSA groups contained reference strains of Rahnella genomospecies 2 and 3, three groups clustered within the Rahnella clade with no known type or reference strains and the last group contained the type strain of E. americana. DNA–DNA relatedness assays using both the microplate and fluorometric methods, confirmed that each of the five Rahnella MLSA groups formed separate taxa. Rahnella genomospecies 2 and 3 were previously not formally described due to a lack of distinguishing phenotypic characteristics. In the present study, all five Rahnella MLSA groups were phenotypically differentiated from each other and from R. aquatilis. Therefore we propose to classify the strains from symptomatic oak, alder and walnut and buprestid beetles as: Rahnella victoriana sp. nov. (type strain FRB 225^T = LMG 27717^T = DSM 27397^T), Rahnella variigena sp. nov. (previously Rahnella genomosp. 2, type strain CIP 105588^T = LMG 27711^T), Rahnella inusitata sp. nov. (previously Rahnella genomosp. 3, type strain DSM 30078^T = LMG 2640^T), Rahnella bruchi sp. nov. (type strain FRB 226^T = LMG 27718^T = DSM 27398^T) and Rahnella woolbedingensis sp. nov. (type strain FRB 227^T = LMG 27719^T = DSM 27399^T).     

Description of Massilia rubra sp. nov., Massilia aquatica sp. nov., Massilia mucilaginosa sp. nov., Massilia frigida sp. nov., and one Massilia genomospecies isolated from Antarctic streams,lakes and regoliths

Bacteria of the genus Massilia often colonize extreme ecosystems, however, a detailed study of the massilias from the Antarctic environment has not yet been performed. Here, sixty-four Gram-stain-negative, aerobic, motile rods isolated from different environmental samples on James Ross Island (Antarctica) were subjected to a polyphasic taxonomic study. The psychrophilic isolates exhibited slowly growing, moderately slimy colonies revealing bold pink-red pigmentation on R2A agar. The set of strains exhibited the highest 16S rRNA gene sequence similarities (99.5–99.9%) to Massilia violaceinigra B2^T and Massilia atriviolacea SOD^T and formed several phylogenetic groups based on the analysis of gyrB and lepA genes. Phenotypic characteristics allowed four of them to be distinguished from each other and from their closest relatives. Compared to the nearest phylogenetic neighbours the set of six genome-sequenced representatives exhibited considerable phylogenetic distance at the whole-genome level. Bioinformatic analysis of the genomic sequences revealed a high number of putative genes involved in oxidative stress response, heavy-metal resistance, bacteriocin production, the presence of putative genes involved in nitrogen metabolism and auxin biosynthesis. The identification of putative genes encoding aromatic dioxygenases suggests the biotechnology potential of the strains. Based on these results four novel species and one genomospecies of the genus Massilia are described and named Massilia rubra sp. nov. (P3094^T = CCM 8692^T = LMG 31213^T), Massilia aquatica sp. nov. (P3165^T = CCM 8693^T = LMG 31211^T), Massilia mucilaginosa sp. nov. (P5902^T = CCM 8733^T = LMG 31210^T), and Massilia frigida sp. nov. (P5534^T = CCM 8695^T = LMG 31212^T).     

Découverte d’un micro-organisme commensal impliqué dans une crise biologique chez les gilianelles du Crétacé de Tercis (Landes,France) : Convictorella pusula,nov. gen. nov. sp. (microproblematica)

Discovery of a commensal microfossil involved in a biological crisis among the Cretaceous gilianelles of Tercis (Landes, France): Convictorella pusula nov. gen., nov. sp., (microproblematica). The recently discovered gilianelles commonly show attached microspheres. The morphological relationships indicate that this association is of biological origin with benefit for the microspheres but not for the gilianelles. A local bloom of the commensal microspheres (age estimate: about 73 Ma) coincides with a biological crisis in the evolutionary pattern of the gilianelles. The group convictorelles (microproblematica) and the species Convictorella pusula n. gen. n. sp. are created for this original ethological relationship.     

Lacipirellula parvula gen. nov., sp. nov., representing a lineage of planctomycetes widespread in low-oxygen habitats,description of the family Lacipirellulaceae fam. nov. and proposal of the orders Pirellulales ord. nov., Gemmatales ord. nov. and Isosphaerales ord. nov.

Pirellula-like planctomycetes are ubiquitous aquatic bacteria, which are often detected in anoxic or micro-oxic habitats. By contrast, the taxonomically described representatives of these bacteria, with very few exceptions, are strict aerobes. Here, we report the isolation and characterization of the facultatively anaerobic planctomycete, strain PX69^T, which was isolated from a boreal lake. Its 16S rRNA gene sequence is affiliated with the Pirellula-related Pir4 clade, which is dominated by environmental sequences retrieved from a variety of low-oxygen habitats. Strain PX69^T was represented by ellipsoidal cells that multiplied by budding and grew on sugars, some polysaccharides and glycerol. Anaerobic growth occurred by means of fermentation. Strain PX69^T grew at pH 5.5–7.5 and at temperatures between 10 and 30 °C. The major fatty acids were C18:1ω9c, C16:0 and C16:1ω7c; the major intact polar lipid was dimethylphosphatidylethanolamine. The complete genome of strain PX69^T was 6.92 Mb in size; DNA G + C content was 61.7 mol%. Among characterized planctomycetes, the highest 16S rRNA gene similarity (90.4%) was observed with ‘Bythopirellula goksoyri’ Pr1d, a planctomycete from deep-sea sediments. We propose to classify PX69^T as a novel genus and species, Lacipirellula parvula gen. nov., sp. nov.; the type strain is strain PX69^T (=KCTC 72398^T = CECT 9826^T = VKM B-3335^T). This genus is placed in a novel family, Lacipirellulaceae fam. nov., which belongs to the order Pirellulales ord. nov. Based on the results of comparative genome analysis, we also suggest establishment of the orders Gemmatales ord. nov. and Isosphaerales ord. nov. as well as an emendation of the order Planctomycetales.     

Phylogeny and systematic revision of the karyorelictid genus Remanella (Ciliophora,Karyorelictea) with descriptions of two new species

We present here the systematic relationships and taxonomy of some newly collected karyorelictid ciliates from the genus Remanella isolated from the intertidal zone in China. Three species were investigated using observation in vivo and silver staining methods, of which two new species were identified: R. macrostoma sp. nov. and R. achroma sp. nov. Small subunit (SSU) rRNA genes were sequenced for six species and phylogenetic analyses indicated that the genus Remanella is paraphyletic, with three Loxodes species nesting within it. The monophyly of Remanella, however, could not be rejected through the approximately unbiased (AU) test (p = 0.311 > 0.05) and therefore we considered Remanella to be a valid genus. Based on a critical review of the literature, the validity of all nominal species of Remanella was discussed. Remanella unirugosa and R. multicorpusculata were regarded as junior synonyms of R. rugosa and R. granulosa respectively. We also presented here an illustrated taxonomic key based on morphologic and morphometric characteristics and containing all Remanella species considered identifiable in this revision.     

Paraurosomoida indiensis gen. nov., sp. nov., an oxytrichid (Ciliophora,Hypotricha) from Kyongnosla Alpine Sanctuary,including note on non-oxytrichid Dorsomarginalia

Paraurosomoida indiensis gen. nov., sp. nov. was isolated from a soil sample collected from Kyongnosla Alpine Sanctuary in the Eastern Himalayas. The present study reports the morphology, morphogenesis, and molecular phylogeny inferred from 18S rDNA sequence. The study is based on live and protargol-impregnated specimens. Paraurosomoida indiensis is very flexible, measures about 90 × 25 μm in life and possesses citrine cortical granules randomly distributed singly and in small linear groups. Paraurosomoida indiensis has undulating membranes nearly in Oxytricha pattern; only 11 frontal-ventral cirri due to lack of all pretransverse ventral and transverse cirri; one dorsomarginal row and three bipolar dorsal kineties. Divisional morphogenesis resembles oxytrichids involving six parental cirri in primordia formation. Anlagen V and VI for both proter and opisthe are formed from two primary primordia originating from disaggregated cirri V/4 and V/3 respectively. Three dorsal kineties develop from within row anlagen without a kinety 3 fragmentation. Molecular analyses consistently place P. indiensis with soft bodied oxytrichids.     

Comparative efficiency of algal biofilters in the removal of chromium and copper from wastewater

The performance of a macroalgae (Sargassum sp.), a laboratory-cultivated microalgae (Chlorococcum sp.) and a commercially available granulated activated carbon (GAC) for the removal of copper (Cu) and chromium (Cr) from aqueous solutions was evaluated using batch experiments. Kinetic and isotherm experiments were done at the optimal pH of 4.5 ± 0.1 for Cu (II) and 2.0 ± 0.1 for Cr (total). The equilibrium isotherms were determined and the results were analyzed using the Langmuir and Freundlich models. The best Cu removal performance was observed on Sargassum at a maximum removal of 87.3% obtained for an initial concentration of 20 mg L^?1 Cu. The maximum uptake capacities for Cu (II) were 71.4, 19.3 and 11.4 mg g^?1 of Sargassum, Chlorococcum and GAC, respectively. The biosorbents were also able to remove appreciable amounts of Cr, again with Sargassum showing maximum uptake capacity over the other materials. Kinetic studies also reveal that the removal rate is faster for both metals in Sargassum. Tests with an actual wastewater confirm the maximum uptake capacity of Cu by Sargassum. In all experiments the Sargassum biofilter outperformed GAC, which makes it a promising low-cost alternative to conventional filtration materials for wastewater treatment.     

Natrarchaeobius chitinivorans gen. nov., sp. nov., and Natrarchaeobius halalkaliphilus sp. nov., alkaliphilic,chitin-utilizing haloarchaea from hypersaline alkaline lakes

Two groups of alkaliphilic haloarchaea from hypersaline alkaline lakes in Central Asia, Egypt and North America were enriched and isolated in pure culture using chitin as growth substrate. These cultures, termed AArcht, were divided into two groups: group 1 which includes eleven isolates from highly alkaline soda lakes and group 2 which contains a single isolate obtained from the alkaline hypersaline Searles Lake. The colonies of chitin-utilizing natronoarchaea were red-pigmented and surrounded by large zones of chitin hydrolysis. The free cells of both groups were mostly flat nonmotile rods, while the cells that attached to chitin or formed colonies on chitin plates were mostly coccoid. The isolates are obligate aerobic saccharolytic archaea utilizing chitin and chitosane (less actively) as the only sugar polymers as well as a few hexoses as their carbon and energy source. Both groups are extremely halophilic, growing optimally at 3.5–4 M total Na⁺, but they differ in their pH profiles: the main group 1 isolates are obligately alkaliphilic, while the single group 2 strain (AArcht-Sl^T) is alkalitolerant. The core archaeal lipids in both groups are dominated by C₂₀–C₂₀ and C₂₀–C₂₅ dialkyl glycerol ethers (DGE) in approximately equal proportion. Phylogenetic analysis indicated that the isolates form an independent genus-level lineage within the family Natrialbaceae with 3 species-level subgroups. The available genomes of the closest cultured relatives of the AArcht strains, belonging to the genera Natrialba and Halopiger, do not encode any chitinase-related genes. On the basis of their unique phenotypic properties and distinct phylogeny, we suggest that the obligate alkaliphilic AArcht isolates (group 1) with an identical phenotype are classified into a new genus and species Natrarchaeobius chitinivorans gen. nov., sp. nov., with strain AArcht4^T as the type strain (JCM 32476^T = UNIQEM U966^T), while the facultatively alkaliphilic strain AArcht-Sl^T (group 2) — as a new species Natrarchaeobius halalkaliphilus sp. nov. (JCM 32477^T = UNIQEM U969^T).     

Phenolic compounds composition and physiological attributes of Matricaria chamomilla grown in copper excess

Four-week old plants of chamomile (Matricaria chamomilla) cultivated in nutrient solution were exposed to copper (3, 60 and 120 μM) for 10 days. At 120 μM, Cu decreased dry mass production, water, chlorophyll and nitrogen content in both the leaf rosettes and roots. Five phenolic acids were detected in methanol extracts of the leaf rosettes (protocatechuic, p-hydroxybenzoic, vanillic, chlorogenic and salicylic acid) and six additional compounds (gentisic, syringic, caffeic, sinapic and o-/p-coumaric acid) were released after acid hydrolysis. Most of the 11 phenolic acids detected increased in 60 μM Cu but in the 120 μM treatment their contents were lower or not significantly different from the control. Among coumarin-related compounds, (Z)- and (E)-2-ß-d-glucopyranosyloxy-4-methoxycinnamic acids increased in 60 and 120 μM Cu while herniarin rose in the 3 and 60 μM Cu by the end of the experiment. The amounts of umbelliferone were not affected by any of the doses tested. These facts in relation to antioxidative properties of phenolic metabolites are also discussed. The malondialdehyde content of the leaf rosettes was not affected by exposure of plants to 120 μM Cu in a time-course experiment but in the roots a sharp increase was observed after 24 and 48 h of treatment. At 120 μM, Cu stimulated a 9-fold higher K⁺ loss than the 60 μM treatment while at the lowest concentration it stimulated potassium uptake. Cu accumulation in the roots was 3-, 49- and 71-fold higher than that in the leaf rosettes in the 3, 60, and 120 μM Cu treatments, respectively. Results suggest that 120 μM Cu dose is limiting for chamomile growth under the conditions of present research.     

Two new “flagship” ciliates (Protozoa,Ciliophora) from Venezuela: Sleighophrys pustulata and Luporinophrys micelae

Sleighophrys pustulata nov. gen., nov. spec. and Luporinophrys micelae nov. gen., nov. spec. were discovered in a slightly saline mud and soil sample from some flat, dry puddles in the Maracay National Park on the north coast of Venezuela. Their morphology was studied in vivo, in protargol preparations, and in the scanning electron microscope. The new genera are monotypic and belong to the trachelophyllid haptorids. They are characterized by the unique shape of the epicortical scales (lepidosomes). Sleighophrys pustulata, which has a size of about 180×23 μm, possesses type I and unique type V lepidosomes which are hat-shaped and about 7×7 μm in size. Luporinophrys micelae, which has a size of about 200×35 μm, possesses types I, II, and unique type VI lepidosomes which are narrow, about 10 μm high cones composed of fibrous stripes connected by polygonal meshes. The conspicuous body size and the richly structured, comparatively large lepidosomes make S. pustulata and L. micelae biogeographic flagships which may help to cast some light on the pending question whether or not microorganisms have biogeographies. The available data suggest that both species have a restricted geographic distribution, not only because they were not described previously, but mainly because they were absent in about 2000 freshwater samples from central Europe and in about 1000 soil samples collected globally.     

Crucial factors affecting the nitrile hydratase production of Mesorhizobium sp. F28

Mesorhizobium sp. F28 contains cobalt-NHase, which effectively converts acrylonitrile into acrylamide. When urea was added to the culture medium, the NHase activity was 62.3 U ml^?1 (R2A–R2A/urea) after 22.5 h of cultivation, which was similar to that in the medium without addition (R2A–R2A, 70.0 U ml^?1). The relative activity of the purified NHase was 100%, 92%, 94%, and 92% in the medium containing, respectively, 0 mM, 2 mM, 5 mM, and 10 mM of urea. Urea had no significant effect on the purified NHase activity of Mesorhizobium sp. F28. This research did not observe the NHase production by Mesorhizobium sp. F28 when acrylonitrile was supplemented in the culture medium except that cobalt ions existed. The highest enzyme activity was 328.5 U ml^?1 as cobalt ions were added in the pre-culture and culture medium after 22.5 h of cultivation (R2A/Co-R2A/Co); compared to media without cobalt ions (R2A–R2A, 22.5 h, 70.5 U ml^?1) this is an almost five-fold enhancement. It can be concluded that culture media containing cobalt ions was beneficial for the formation of active NHase of Mesorhizobium sp. F28.     

Phylogeny,ultrastructure and histopathology of Myxobolus lomi sp. nov., a parasite of Prochilodus lineatus (Valenciennes, 1836) (Characiformes: Prochilodontidae) from the Peixes River,São Paulo State,Brazil

This paper presents the morphological, histological, molecular and ultrastructural data on Myxobolus lomi sp. nov., a parasite of the gill filaments of Prochilodus lineatus from the Peixes River (48º06′38″W; 22º 49′53.1″S), São Paulo State, Brazil. From 20 P. lineatus specimens examined, 90.0% (n = 18) were infected. The plasmodia were white and round, measuring 250 to 300 μm in diameter and the development occurred in the base of the gill filament. The spores showed symmetrical and smooth valves, with the polar filament having 8 to 11 coils. A thorough comparison with all the Myxobolus species described so far is provided. A partial sequencing of the 18S rDNA gene revealed approximately 1600-bp. The Myxobolus species parasite of P. lineatus did not match any of the Myxozoa available in GenBank. In the phylogenetic analysis, M. lomi sp. nov. is clustered with ten other species and only four of these parasites were from gills. Histological analysis of P. lineatus gills infected by M. lomi sp. nov. revealed numerous well-delimited cysts at the base of the primary lamella, between connective tissue and bone, next to the gill arteries. However no pronounced inflammatory response was found at the infection site.     

A megalichthyid sarcopterygian fish from the Lower Permian (Autunian) of the Saar-Nahe Basin,Germany

A nearly complete specimen of a sarcopterygian fish from the Lower Permian (Autunian) of the Saar-Nahe Basin, southwest Germany, is described as a new genus and species of megalichthyids, Palatinichthys laticeps. It is characterized by the following unique list of characters: (1) lacrimal forms lateral margin of external naris, (2) postparietal short with respect to parietal, (3) tabular broad and shorter than supratemporal, (4) anterior margin of median extrascapular very narrow, (5) supraorbitals short, thus parietal and intertemporal participating in formation of orbital margin, (6) distance between external naris and orbit very short, and (7) squamosal abbreviated and deep. A phylogenetic analysis finds a monophyletic Megalichthyidae consisting of two clades, (Palatinichthys nov. gen. + Ectosteorhachis) and [(Megalichthys + Sengoerichthys) + Cladarosymblema)]. The sister taxa Palatinichthys nov. gen. and Ectosteorhachis share a short posterior skull table as a derived character, whereas Megalichthys, Sengoerichthys and Cladarosymblema retain an elongate postorbital region of the skull, regarded as plesiomorphic for “osteolepiforms”. After their nearly worldwide distribution in the Late Devonian and Carboniferous, megalichthyids had become rare in the Permian and have so far been reported only from North America (Ectosteorhachis) and Norway (?Megalichthys). Palatinichthys nov. gen. is a further representative within the European-North American equatorial distribution of megalichthyids during the Permian. It was probably not a common inhabitant of the large Saar-Nahe lakes. Rather, it might have lived in a different habitat within the same general area, such as deltaic streams or rivers.     

Lindane uptake and degradation by aquatic Streptomyces sp. strain M7

Five actinomycete strains isolated from pesticide-contaminated sediments were able to grow in the presence of 10 μg l⁻¹ lindane, an organochlorine pesticide. The strain growing best in the presence of lindane as the only carbon source was identified as Streptomyces sp. M7. After 96 h of incubation in synthetic medium containing lindane and glucose, both substrates were simultaneously consumed; glucose 6.0 g l⁻¹ improved lindane degradation and obtained biomass. When Streptomyces sp. M7 was cultured in presence of lindane plus glucose, the disappearance of the pesticide from the medium and the lindane degradation was observed after 72 h of incubation. This is the first report of lindane degradation without intracellular accumulation or biotransformation products of lindane using Streptomyces sp. under aerobic conditions.Relevance to industryThis is the first report of lindane removal without intracellular accumulation or biotransformation products of lindane using Streptomyces sp. strain M7, an actinomycete isolated from pesticide-contaminated sediments from Tucuman, Argentina.     

Metal uptake by medicinal plant species grown in soils contaminated by a smelter

The hypothesis tested in this study was if medicinal plants could be grown as alternative crops in heavy metal polluted soils without contamination of the final marketable produce. Furthermore, medicinal crops may offer a phytoremediation option for mildly heavy metal polluted agricultural soils. The effect of metal-enriched soils was evaluated in five medicinal species (Bidens tripartita L., Leonurus cardiaca L., Marrubium vulgare L., Melissa officinalis L. and Origanum heracleoticum L.). Soils were sampled in the vicinities of the Non-Ferrous Metals Combine (Pb–Zn smelter) near Plovdiv, Bulgaria, from plots at 0.5 km (soil 1), 3 km (soil 2), 6 km (soil 3) and 9 km (control soil) from the smelter. Cadmium, Pb and Zn concentration in soil 1 were above the critical total (HNO₃-extractable) concentrations for these elements in soils. Generally, heavy metals in soil 1 decreased dry mater yields of the five species relative to the control. However, the essential oil content of M. vulgare, M. officinalis and O. heracleoticum was within the usual range for respective species and was not affected by the treatments. The overall metal uptake was in the order: B. tripartita > M. vulgare > O. heracleoticum > L. cardiaca > M. officinalis for Cd, L. cardiaca = M. vulgare > B. tripartita = M. officinalis = O. heracleoticum for Pb, L. cardiaca = M. vulgare > O. heracleoticum > B. tripartita = M. officinalis for Cu and B. tripartita > L. cardiaca = M. vulgare > M. officinalis = O. heracleoticum for Mn and Zn. Overall, metal concentration in plant parts was in the order: roots > leaves > flowers > stems for Cd, Pb and Cu, leaves > roots > flowers > stems for Mn and Zn. The concentration of Cd, Pb, Cu and Zn in plant tissue correlated to the exchangeable (EXCH) and the carbonate (CARB) bound fractions of metals in soil. Heavy metals caused disruptions of the plasma membrane of some root cortical cells and alterations in chloroplasts thylakoids in plants grown in soil 1. Metal content in teas prepared from the species was negligible, the essential oils were free of metals. Generally, the transfer factor (TF) was less than 1, indicating the tested species did not have a significant phytoextraction potential. This study demonstrated the three essential oil species M. vulgare, M. officinalis and O. heracleoticum can be grown as alternative high-value crops in metal polluted agricultural soils around the smelter and provide metal-free marketable produce.     

Insulin-releasing and cytotoxic properties of the frog skin peptide,tigerinin-1R: a structure–activity study

The frog skin host-defense peptide tigerinin-1R (RVCSAIPLPICH.NH₂) is insulinotropic both in vitro and in vivo. This study investigates the effects on insulin release and cytotoxicity of changes in cationicity and hydrophobicity produced by selected substitutions of amino acids by l-arginine, l-lysine and l-tryptophan. The [A5W], [L8W] and [I10W] analogs produced a significant (P < 0.01) increase in the rate of insulin release from BRIN-BD11 rat clonal β cells at concentration of 0.01 nM compared with 0.1 nM for tigerinin-1R. The increase in the rate of insulin release produced by a 3 μM concentration of the [S4R], [H12K], and [I10W] analogs from both BRIN-BD11 cells and mouse islets was significantly greater (P < 0.05) than that produced by tigerinin-1R. No peptide stimulated the release of lactate dehydrogenase at concentrations up to 3 μM indicating that plasma membrane integrity had been preserved. [A5W] tigerinin-1R was the only analog tested that showed cytotoxic activity against human erythrocytes (LC₅₀ = 265 ± 16 μM) and inhibited growth of Escherichia coli (MIC = 500 μM) and Staphylococcus aureus (MIC = 250 μM). The circular dichroism spectra of tigerinin-1R and [A5W] tigerinin-1R indicate that the peptides adopt a mixture of β-sheet, random coil and reverse β-turn conformations in 50% trifluoroethanol/water and methanol/water. Administration of [S4R] tigerinin-1R (75 nmol/kg body weight) to high-fat fed mice with insulin resistance significantly (P < 0.05) enhanced insulin release and improved glucose tolerance over a 60 min period following an intraperitoneal glucose load. The study supports the claim that tigerinin-1R shows potential for development into novel therapeutic agents for treatment of type 2 diabetes mellitus.