Plutella xylostella (L.) population control in sowings of spring rapeseed using pheromones

The diamondback moth Plutella xylostella (Linnaeus, 1758) is a common pest of rapeseed and other crops of Brassicaceae family. Annual yield losses and costs of pest control worldwide are estimated at $ 4-5 billion. The pest has an increased tendency to develop resistance to insecticides. The use of traps with synthetic sex pheromone is a modern instrumental method of monitoring P. xylostella. The use of the mating disruption method will effectively decrease pest numbers and reduce the application of insecticides. In 2017-2020, we researched the pheromone activity and evaluated the mating disruption method in the sowings of spring rapeseed at V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK) (Krasnodar). We established that P. xylostella males were caught in traps with all tested dispenser types. The pheromone showed the greatest activity on the foil-film dispenser (F). The mating disruption method effectively decreased P. xylostella population in rapeseed sowing; the disruption effect by the end of crop vegetation was high and reached 82.5 %.

Candida albicans Secreted Aspartic Protease 7 is Essential for Damage of Human Oral Epithelial Cells

Aims: Candida albicans is an important human fungal pathogen in clinical settings. It possesses a wide spectrum of virulence traits, including but not limited to the production of Secreted Aspartic Proteases (SAPs), to invade host cells under predisposing conditions. The aims of the present study were to investigate the functional role of C. albicans SAP7 in invasion ability. Methods: The present study was carried out to construct C. albicans sap7Δ/Δ mutant strain using a PCR-based gene disruption method. The behaviors of this SAP7 knockout strain was evaluated and compared with the wild type and SAP7 complemented strains between human oral epithelial cells with respect to endocytosis, invasion, and tissue damage. Results: Compared with the wild type C. albicans strain, a 52% reduction in the endocytosis of the sap7Δ/Δ mutant strain by oral epithelial cells was observed, as well as a 25% attenuation of internalization, and a 27% reduction of tissue damage (P<0.05). Conclusion: Our data clearly demonstrates that C. albicans SAP7 contributes to tissue invasion into human oral epithelial cells which warrant further investigations as potential targets for antifungal interventions.

CRISPR-Cas9 cytidine and adenosine base editing of splice-sites mediates highly-efficient disruption of proteins in primary and immortalized cells

CRISPR-Cas9 cytidine and adenosine base editors (CBEs and ABEs) can disrupt genes without introducing double-stranded breaks by inactivating splice sites (BE-splice) or by introducing premature stop (pmSTOP) codons. However, no in-depth comparison of these methods or a modular tool for designing BE-splice sgRNAs exists. To address these needs, we develop SpliceR (http://z.umn.edu/spliceR) to design and rank BE-splice sgRNAs for any Ensembl annotated genome, and compared disruption approaches in T cells using a screen against the TCR-CD3 MHC Class I immune synapse. Among the targeted genes, we find that targeting splice-donors is the most reliable disruption method, followed by targeting splice-acceptors, and introducing pmSTOPs. Further, the CBE BE4 is more effective for disruption than the ABE ABE7.10, however this disparity is eliminated by employing ABE8e. Collectively, we demonstrate a robust method for gene disruption, accompanied by a modular design tool that is of use to basic and translational researchers alike.

Optimization of cell wall disruption and lipid extraction methods by combining different solvents from wet microalgae

Microalgae have emerged as one of the most promising options for biodiesel production over the past few decades. Lipid extraction from microalgae for biodiesel production as a bottleneck of biodiesel production technology was the main purpose of this study. In this study different methods of the cell wall disruption were compared. Then, two methods of ultrasound and bead mill were used as methods of the cell wall disruption. The maximum lipid extracted by ultrasound was 17.10% and by bead mill was 15.16% (based on microalgae biomass dry weight). After the cell wall disruption of microalgae, for lipid extraction, chloroform-methanol solvent combination was used as a high extraction method and hexane-ethanol solvent combination was used as an environmentally friendly method. In this regard, the effect of solvent to biomass ratio, temperature and extraction time was investigated and the optimal results for chloroform-methanol solvent combination were 8 ml/g, 45°C and 60 minutes, respectively, and for hexane-ethanol combination were 6 ml/g, 35◦C and 73 minutes, respectively. Under these optimal conditions, the highest amount of extracted lipid from Chlorella vulgaris with a moisture content of 87.50%, and ultrasound as a cell wall disruption method were obtained 20.39% and 16.41% (based on microalgae dry weight) with a combination of chloroform-methanol solvents and hexane-ethanol respectively. Also the highest extraction rates of 17.63% and 13.85% were obtained for the combination of chloroform-methanol and hexane-ethanol solvents, respectively by bead milling as cell wall disruption method

Current Pretreatment/Cell Disruption and Extraction Methods Used to Improve Intracellular Lipid Recovery from Oleaginous Yeasts

The production of lipids from oleaginous yeasts involves several stages starting from cultivation and lipid accumulation, biomass harvesting and finally lipids extraction. However, the complex and relatively resistant cell wall of yeasts limits the full recovery of intracellular lipids and usually solvent extraction is not sufficient to effectively extract the lipid bodies. A pretreatment or cell disruption method is hence a prerequisite prior to solvent extraction. In general, there are no recovery methods that are equally efficient for different species of oleaginous yeasts. Each method adopts different mechanisms to disrupt cells and extract the lipids, thus a systematic evaluation is essential before choosing a particular method. In this review, mechanical (bead mill, ultrasonication, homogenization and microwave) and nonmechanical (enzyme, acid, base digestions and osmotic shock) methods that are currently used for the disruption or permeabilization of oleaginous yeasts are discussed based on their principle, application and feasibility, including their effects on the lipid yield. The attempts of using conventional and “green” solvents to selectively extract lipids are compared. Other emerging methods such as automated pressurized liquid extraction, supercritical fluid extraction and simultaneous in situ lipid recovery using capturing agents are also reviewed to facilitate the choice of more effective lipid recovery methods.

Disruption-Based Multiobjective Equilibrium Optimization Algorithm

Nature-inspired computing has attracted huge attention since its origin, especially in the field of multiobjective optimization. This paper proposes a disruption-based multiobjective equilibrium optimization algorithm (DMOEOA). A novel mutation operator named layered disruption method is integrated into the proposed algorithm with the aim of enhancing the exploration and exploitation abilities of DMOEOA. To demonstrate the advantages of the proposed algorithm, various benchmarks have been selected with five different multiobjective optimization algorithms. The test results indicate that DMOEOA does exhibit better performances in these problems with a better balance between convergence and distribution. In addition, the new proposed algorithm is applied to the structural optimization of an elastic truss with the other five existing multiobjective optimization algorithms. The obtained results demonstrate that DMOEOA is not only an algorithm with good performance for benchmark problems but is also expected to have a wide application in real-world engineering optimization problems.

Electro-Fenton Based Technique to Enhance Cell Harvest and Lipid Extraction from Microalgae

Currently, lipid extraction remains a major bottleneck in microalgae technology for biofuel production. In this study, an effective and easily controlled cell wall disruption method based on electro-Fenton reaction was used to enhance lipid extraction from the wet biomass of Nannochloropsis oceanica IMET1. The results showed that 1.27 mM of hydroxide radical (HO•) was generated under the optimal conditions with 9.1 mM FeSO4 in a 16.4 mA·cm−2 current density for 37.0 min. After the electro-Fenton treatment, the neutral lipid extraction yield of microalgae (~155 mg) increased from 40% to 87.5%, equal to from 12.2% to 26.7% dry cell weight (DCW). In particular, the fatty acid composition remained stable. The cell wall disruption and lipid extraction processes were displayed by the transmission electron microscope (TEM) and fluorescence microscopy (FM) observations, respectively. Meanwhile, the removal efficiency of algal cells reached 85.2% within 2 h after the reaction was terminated. Furthermore, the biomass of the microalgae cultured in the electrolysis wastewater treated with fresh nutrients reached 3 g/L, which is 12-fold higher than that of the initial after 24 days. These finds provided an economic and efficient method for lipid extraction from wet microalgae, which could be easily controlled by current magnitude regulation.