An improved cage system for the bioassay of Metarhizium anisopliae on Thrips tabaci (Thysanoptera: Thripidae)

The ability of thrips and other minute insects to escape from conventional assay cups led to development of a successful assay chamber. In the present study, we evaluated three bioassay systems for thrips; Tashiro cage, microtube assay and leaf sandwich assay and introduced an improved thrips entomopathogenic bioassay system (TEBS). Our objective was to investigate the effect of Metarhizium anisopliae on Thrips tabaci using an easy-to-use and inexpensive holding chamber that would produce bioassay results with acceptable levels of accuracy and precision. In our assays, we found that escape of second-instar larvae from TEBS was significantly less than those of other methods which we tested. Our results indicated that our assay system was more suitable than the other conventional assays for the bioassay of entomopathogenic fungi on T. tabaci.     

Genetic diversity and population structure in four Cirsium (Asteraceae) species

The present study considers genetic diversity of 38 populations in 4 Cirsium species of the genus Cirsium Mill. (Asteraceae), occurring in different ecological regions and tries to compare degree of genetic variability among the species with wide geographical distribution versus endemic C. pyramidale showing confined geographical distribution. The results showed that the endemic species has similar value of genetic diversity parameters as the species with wider distribution. We also studied the possible admixture nature of these populations and tried to understand the relation between genetic changes, geographical distribution and polyploidy level and chromosome pairing in these species. ISSR analysis showed population difference in allele composition and frequency. Clustering and PcoA ordination produced different groupings in each species, while STRUCTURE and reticulation analyses revealed high degree of genetic admixture and gene exchange among populations as well as allelic rearrangement. No significant correlation was observed between geographical distance and genetic distance of the populations and AMOVA test revealed no significant difference among populations in each species studied. However, high amount of within population variation occurred in all 4 species indicating their cross-pollination nature and high genetic admixture. The populations also varied in chiasma frequency and chromosome pairing as well as the occurrence of heterozygote translocations all creating more variability to be used by plants for local adaptation.     

Effect of Fine-Grain Percent on Soil Strength Properties Improved By Biological Method

In many civil engineering projects, the foundation soils do not provide the required mechanical properties and therefore, there is a need to improve the soil. Compaction, soil reinforcement, soil mixing with natural, or chemical additives are common soil stabilization methods used to improve the soil mechanical properties. The incidence of some environmental problems in traditional improvement techniques has encouraged engineers to explore new methods. Recently in this category, a new technique in geotechnical engineering called biogeotechnology is introduced to improve the mechanical properties of the soil. It is an environmentally friendly approach that uses biological methods to solve geotechnical problems. This technique uses minerals producer microorganisms. This study investigates the possibility of improving soil strength properties with microbial calcite precipitation and the effect of fine-grained percentages in this regard. In order to determine the soil strength properties, consolidated drained direct shear tests have been carried on untreated and treated soil samples. The results showed that this method is applicable to improve all soil samples (from 100% coarse-grained (i.e., sand) to 100% fine-grained (i.e., clay)). However, increasing the strength in the sand is much more enhanced than that for finer soils. It was found that a considerable increase in cohesion of treated soil can be achieved for soil samples with maximum 10% fine content.     

Comparison of batch,fed-batch and continuous well-mixed reactors for enzymatic hydrolysis of orange peel wastes

An alternative potential feedstock for bioethanol in the automotive sector is citrus peel waste (CPW), which can be processed through enzymatic hydrolysis and fermentation. The present work considers mathematical modeling of orange peel wastes (OPW) hydrolysis with the use of free enzymes and compares the performance of batch, fed-batch and continuous well-mixed reactors after introducing appropriate rate equations in dynamic mass balances. MATLAB^® was used for model implementation.Following the Michaelis–Menten approach, the authors used their own kinetic parameters for the pectin hydrolysis rate equation. The parameters were generated in an apposite experimental program for OPW hydrolysis to galacturonic acid with consideration of product inhibition; the corresponding values were obtained after Lineweaver–Burk linearization and are: r_max = 0.28 g/(L min), K_m = 19.80 g/L and K_IGA = 6.96 g/L, respectively. Vice-versa, the authors adopted the Kadam's group kinetic schemes and parameters for cellulose hydrolysis to cellobiose and glucose. The mathematical model of a well-mixed batch reactor was perfectly validated against the experimental results of OPW hydrolysis to galacturonic acid. In the case of a continuous well-mixed reactor, high dilution rates determine low conversion of OPW. The increased complication of fed-batch operation does not add advantages when compared to batch processing.     

Phytochemical Variations and Enhanced Efficiency of Antioxidant and Antimicrobial Ingredients in Salvia officinalis as Inoculated with Different Rhizobacteria

Plants produce a variety of secondary metabolites to improve their performance upon exposure to pathogens, pests, herbivores, or environmental stresses. Secondary metabolism in plants is, therefore, highly regulated by presence of biotic or abiotic elicitors in the environment. The present research was undertaken to characterize plant growth‐promoting attributes of four plant growth‐promoting rhizobacteria (PGPR) including two Pseudomonas fluorescens (Pf Ap1, Pf Ap18) and two P. putida (Pp Ap9, Pp Ap14) strains, and to determine their role (individually or in consortium) on growth of Salvia officialis, and biosynthesis of secondary metabolites such as essential oils (EOs), total phenolics, and flavonoids. The antioxidant and antibacterial properties of the extracts and EOs obtained from the inoculated plants were also investigated. The PGPR inoculum was applied to soil, cuttings, and foliage. Results indicated that different PGPR strains varied in their efficiency for production of auxin, siderophore, 1‐aminocyclopropane‐1‐carboxylate deaminase, and phosphate solubilization. All individually inoculated plants had significantly higher shoot and root biomass, leaf P content, EOs yield, total phenolics, and flavonoids content compared to uninoculated control plants. The major constituents of EOs, cis‐thujene, camphor, and 1,8‐cineol, increased following inoculation with reference PGPRs. Although the extract from all inoculated plants had improved antioxidant activity, it was remarkable for the Pf Ap18 strain, which had the lowest IC₅₀ value across treatments. Antibacterial assay of various EOs and their major constituents against pathogenic bacteria showed that the highest activity was observed against Staphylococcus aureus using EOs of Pp Ap14 source. Based on our findings, we suggest that individual inoculation with effective PGPR strains can substantially improve plant growth and secondary metabolism in S. officinalis plants.     

Zinc-leuprolide complex: preparation, physicochemical characterization and release behaviour from in situ forming implant.

Leuprolide acetate (LA) has been accepted as treatment for prostatic cancer and is currently also being evaluated in phase II clinical trials for the treatment of Alzheimer's disease. In this study, the zinc complex of leuprolide was prepared and its structure determined by Fourier-transform infrared (FTIR), differential scanning calorimetry (DSC), UV, X-ray diffraction (XRD), atomic absorption spectroscopy, elemental analysis, and compared with these parameters for leuorolide acetate. Also, the in vitro release profile of leuprolide and its complex form in situ forming implant (ISFI) in comparison to a commercial formulation (Eligard) was investigated. These studies indicate that the zinc complex can be effectively synthesized and influenced on tri-phasic pattern after burst release of LA from the ISFI and shifts this trend to a continuous release profile. Non-linear regression test confirmed this transformation as a zero-order release profile as well.     

Evolutionary implications of fetal and maternal microvillous surfaces in epitheliochorial placentae

According to the “parent-offspring conflict hypothesis” the rapid evolution and diversification of the mammalian placenta is driven by divergent optima of resource allocation between fetus and mother. The fetus has an interest to maximize its resource intake, while the mother has an interest to restrict the transfer of resources, and thus retain resources for subsequent pregnancies. In the epitheliochorial placenta, the contacting fetal and maternal surfaces at the feto-maternal interface are covered with microvilli, which leads to an increase of membrane surfaces available for transport processes. Because membranes are the site of active transport, the conflict hypothesis predicts that the fetal surfaces at the feto-maternal interfaces are larger than the maternal ones. We use transmission electron microscopy and a stereological method to estimate the factors by which the apical fetal and maternal membranes are enlarged by the microvilli. Ten species with an epitheliochorial placenta were studied. Focused ion beam—scanning electron microscopy (FIB-SEM) was used to create three-dimensional models of the interdigitating microvilli of the bovine and porcine placenta. In all species, the fetal surface was larger than the maternal. This was due to a higher number of fetal microvilli and to the presence of membrane folds at the base of the fetal, but not of maternal microvilli. Our results suggest that the ultrastructural morphology of the feto-maternal interface in the epitheliochorial placenta is shaped by conflicting interests between fetus and mother and thus represent a so far neglected arena of the parent-offspring conflict.