Hybrid Strains Research Articles

Cannabis sativa: Botany, Cross Pollination and Plant Breeding Problems

This review paper highlights about the Cannabis botany, problems of cross pollination, lack of Germplasm collection and absence of Genebank facilities have been discussed. Cannabis is a dioecious species, meaning that male and female flowers are borne on separate plants. The risk of cross-pollination in Cannabis is one of the unique major challenge in Cannabis industry. More research can be conducted to assess the risk of cross-pollination in Cannabis and policy should be created to mitigate that risk. Cannabis research work remains years behind than other crops because of the long legacy of prohibition and stigmatization. However, lack of public germplasm repositories remains an unresolved problem in the Cannabis industry. Therefore, accessible germplasm resources are crucial for long-term economic viability, preserving genetic diversity, breeding, innovation, and long-term sustainability of the Cannabis crop. Germplasm accessions are the building blocks for breeding of new cultivars. However, there are no public seed or Clonal gene banks for Medical Cannabis sativa (marijuana or drug type). On the other hand there are some public hemp collections. Despite its economic, medicinal, and societal importance, Medical Cannabis sativa (marijuana or drug type) is missing from the list of available species in public Genebanks and only exist as private collections. Most of the Cannabis varieties in the market today are hybrids (700 hybrid strains) with both Cannabis sativa and Cannabis indica genetics. Hence there should be a public Cannabis Genebanks to play a fuller and more effective role in conservation, sustainable use, and exchange of Cannabis genetic resources.

Effect of Metal Film Thickness on Strain-Sensing Performance of Crack-Based Stretchable Hybrid Piezoresistive Electrode

In recent decades, many research efforts have been devoted to developing high-performance stretchable strain sensors due to their potential for application in various emerging wearable sensor systems. This work presents a facile yet highly efficient way of modulating the sensing performance of a thin metal film/conductive composite hybrid piezoresistor-based stretchable strain sensor by simply controlling the metal film thickness. The hybrid strain sensor can be simply fabricated by sputtering a thin platinum (Pt) film onto a silver nanowire (AgNW)/dragon skin (DS) composite substrate prepared via a facile embed-and-transfer process in a reproducible manner. The density of the network-shaped mechanical crack induced in the Pt film tended to decrease with increasing the Pt thickness, thereby leading to a higher gauge factor of the sensor. The fabricated hybrid strain sensor also exhibited a large stretchability of 150% owing to its electrical robustness under strain, based on the unique morphology, formed of the network-shaped Pt crack and AgNW percolation network embedded in the DS matrix. Thanks to the balanced strain-sensing performance of the hybrid strain sensor in conjunction with large stretchability, the device was successfully demonstrated as a wearable human-activity monitoring solution that can monitor a wide range of human motions in real time.

B-SDM: A bounding surface stiffness degradation method for modelling the long-term ratcheting response of offshore wind turbine foundations

Long-term cyclic loading from environmental conditions can lead to excessive permanent rotation of offshore wind turbines (OWTs) due to the ratcheting response of sand.A practical hybrid strain accumulation approach, termed the bounding surface stiffness degradation method (B-SDM), for finite element analysis (FEA)-based design of OWTs under cyclic loading is presented. This method includes a base elastoplastic constitutive model that captures the stress–strain relationship in the first load-unload cycle and a cyclic strain accumulation scheme for modelling the subsequent cycles. The presented approach allows for a versatile overlay scheme that calculates cyclic strain accumulationto be applied to a range of base elastoplastic models. The base constitutive model utilisedis established based on the bounding surface concept and considers strain-hardening and plastic volume change before failure. The method has been validated by single element test data on sand and used in finitesingle-element element modelling of monopile response in cyclic loading. When the monopile response is modelled in 3D FEA, the conventional step-by-step modelling approach is used until the end of the first regular cycle. Strain accumulation in subsequent cycles is modelled using the B-SDM, in which the plastic modulus and dilatancy relationship are scaled based on a strain accumulation law.

A Perforated High-Order Element for Fracture Mechanics Problems Using the Hybrid Strain Method

In this paper, a novel hybrid approach with complex and conformal mapping functions is proposed for the first time. This strain-based approach is based on the special trial functions and the assumed natural strain (ANS) theory, which provides a unified framework for solving fracture problems. In the utilized method, the proposed super-element is divided into perforated and solid domains. For the perforated domain, Muskhelishvili–Kolosov potential function is employed to simulate the perforated discontinuity. For the solid domain, the higher-order strain field is assumed as the enriched interpolation functions. Moreover, the rigid body terms are imposed into the kinematic variables to enhance the convergence ability and the element performance. Numerical examples demonstrate that the proposed element (PHSM20) produces high precision results for both displacement and stresses.

Highly Selective Pd Nanosheet Aerogel Catalyst with Hybrid Strain Induced by Laser Irradiation and P Doping Postprocess.

Strain engineering of electrocatalysts provides an effective strategy to improve the intrinsic catalytic activity. Here, the defect-rich crystalline/amorphous Pd nanosheet aerogel with hybrid microstrain and lattice strain is synthesized by combining laser irradiation and phosphorus doping methods. The surface strain exhibited by the microstrain and lattice strain shifts the d-band center of the electrocatalyst, enhancing the adsorption of intermediates in the ethanol oxidation reaction and thus improving the catalytic performances. The measured mass activity, specific activity and C1-path selectivity of the Pd nanosheet aerogel are 4.48, 3.06, and 5.06 times higher than those of commercial Pd/C, respectively. These findings afford a new strategy for the preparation of highl activity and C1 pathway selective catalysts and provide insight into the catalytic mechanism of strain-rich heterojunction materials based on tunable surface strain values.

Cross-Breeding Improvement and Performance Analysis of Dominant Production Traits in Grazing-Type Alfalfa (Medicago sativa L.).

Rhizome-rooted Medicago sativa L. "Qingshui" is an excellent germplasm for establishing grazing and ecological grasslands but inferior in yield, in which both high production and ecological values can be achieved by cross-breeding. We have obtained valuable rhizome-rooted hybrid strains (RSA-01, RSA-02, and RSA-03) by crossing of Qingshui and the high-yielding Medicago sativa L. "WL168." In this study, the Qingshui plants with low production performance were crossed for improvement, and progenies with better production and higher quality than those of Qingshui were selected. The results reveal that the branch number, crude protein (CP) content, and relative feed value (RFV) of RSA-01; the stem thickness, CP content, and ether extract (EE) content of RSA-02; and the plant height, stem thickness, branch number, and dry hay yield of RSA-03 were higher than those of Qingshui. Except for the leaf/stem ratio and plant height of RSA-01, leaf/stem ratio of RSA-02, and plant height of RSA-03, the coefficient of variation (CV) of yield traits of the hybrid strains was lower than those of Qingshui, ranging from 0.1% to 4.28%. In addition to the lignin and acid detergent fiber content of RSA-01 as well as EE content of RSA-02 and RSA-03, the CV of the nutritional traits of the hybrid strains was low, ranging from 0.60% to 3.43%. The tested samples were ranked as follows based on yield performance and nutritional values: WL168 > RSA - 03 > RSA - 01 > RSA - 02 > Qingshui and RSA - 01 > WL168 > RSA - 03 > Qingshui > RSA - 02, respectively. Compared with parental Qingshui, RSA-01, RSA-02, and RSA-03 show better yield performance; meanwhile, RSA-01 and RSA-03 had higher nutritional traits. RSA-01 shows heterosis in branch number, CP content, and RFV; RSA-02 shows heterosis in stem thickness and RSA-03 in plant height, stem thickness, branch number, fresh yield, dry hay yield, and CP content. Notably, the low production performance of Qingshui was improved after crossing it with WL168, substantially resulting in an abundant rhizome-rooted germplasm resource for the establishment of grazing grasslands.

Observational and theoretical evidence for frictional-viscous flow at shallow crustal levels

Along the Hikurangi Subduction Margin, accretionary prism uplift has exposed the Hungaroa fault zone, an inactive thrust developed within the Middle to Late Eocene Wanstead Formation. Within the ~33 m-wide fault core, deformation of the smectitic, calcareous mudstone matrix produced a penetrative foliation that locally wraps around clasts. Deformation occurred at temperatures constrained by syntectonic calcite vein clumped isotope thermometry, which yielded a narrow range of Δ 47 values between 0.445 ± 0.024‰ and 0.482 ± 0.013‰, corresponding to a mean calcite precipitation temperature of 82 −12 +13 °C. Optical and scanning electron microscopy analyses reveal that calcite underwent: dissolution along stylolites and clast, vein, and microlithon margins; precipitation in foliation-parallel and foliation-perpendicular extension veins; and precipitation in hybrid veins and strain fringes. Maximum differential stress estimates obtained from calcite twin densities (44.1 ± 13.9 to 96.6 ± 20.8 MPa) are consistent with those sustainable by a cohesionless fault at ~3 km depth with a friction coefficient in the range measured for two calcareous mudstones (μ = 0.38 to 0.50) and a micrite clast (μ = 0.61 and 0.64). Marlstone clasts within the foliated calcareous mudstone matrix contain mutually cross-cutting shear fractures and extension veins with crack-seal textures, providing evidence for temporal fluctuations in shear strength resulting from pore fluid overpressure transients. At strain rates imposed during laboratory experiments, frictional sliding involves granular flow processes. Yet, calcite microstructures indicate that diffusive mass transfer played an important role in accommodating deformation. We model the fault zone rheology assuming diffusion-controlled frictional-viscous flow, with deformation at strain rates γ ˙ ≤ 10 −9 s −1 able to have taken place at very low shear stresses ( τ < 10 MPa) given sufficiently short diffusion distances ( d < 0.1 mm), even in the absence of pore fluid overpressures. However, if grain-scale and fracture-scale processes change the diffusion distance, fault zones deforming via frictional-viscous flow can exhibit temporally variable strain rates. Thus, our results suggest that the shallow (up-dip) limit of the seismogenic zone is not a simple function of temperature in fault zones governed by a frictional-viscous flow rheology. • Displacement occurred via distributed deformation across a 33 m-wide fault core. • Fault core rocks experienced spatiotemporal variations in stress and strength. • Frictional-viscous flow can explain the weakness of shallow crustal thrust faults. • Frictional-viscous flow can occur at temporally variable strain rates.

Comparative analysis of amino acid content and protein synthesis-related genes expression levels in breast muscle among different duck breeds/strains

Evidences have found important effects of breeds/strains on the content of amino acids (AAs) which is an important substrate for protein synthesis and contributes greatly to meat quality. Therefore, the objective of the present study was to compare the AAs content and protein synthesis-related genes expression levels in breast muscle of native breed (Jianchang duck (J)), hybrid strains (BH1, BH2, and MC♂×(BGF2♂×GF2♀)♀ (MC)), and commercial breed (Cherry Verry duck). Results showed that a total of 17 AAs (TAAs) was detected from breast muscle among 5 duck breeds/strains including 11 essential AAs (EAAs). Among these AAs, the contents of Proline, Threonine, Glutamine, Serine, Methionine, Phenylalanine, Histidine, and Cysteine were significant difference among 5 duck breeds/strains. The contents of EAAs, TAAs, and flavor AAs were higher in breast muscle of J and BH2 than those in other duck breeds/strains, and the ratio of EAAs/TAAs was higher in breast muscle of BH2. Furthermore, the expression levels of eukaryotic translation initiation factor 4E-binding protein 1, mammalian target of rapamycin, and proton-coupled amino acid transporter 1 were the highest in breast muscle of BH2, and that of solute carrier family 38 member 2 was the highest in breast muscle of J. Meanwhile, principal component analysis results showed that principal component 1 of BH1, principal component 3 of BH2, and principal component 2 of MC were positively corelated with EAAs/TAAs, and principal component 1 was positively correlated with flavor AAs and EAAs. In conclusion, compared to BH1, MC, and Cherry Verry duck, AA content was higher in breast muscle of BH2 and J, which might be associated with the higher expression levels of mammalian target of rapamycin, eukaryotic translation initiation factor 4E-binding protein 1, and proton-coupled amino acid transporter 1 in breast muscle of BH2 and solute carrier family 38 member 2 in breast muscle of J. The comparative analysis of AA content in breast muscle among different duck breeds/strains could provide an important basis for improving the nutritional value of duck meat in the breeding process.

Luminescence mechanism of InGaAs self-fit well-cluster composite structure with super-wide spectra

This paper reports an InGaAs/GaAs well-cluster composite(WCC) quantum structure, which has shown great advantages in the development of new types of lasers with super-wide spectra. The spectral bandwidth is broadened to 6-fold broader than that of a classic InGaAs quantum well under the same carrier density. However, the luminescence mechanism of InGaAs/GaAs WCC structure is still unclear because of the self-fit distribution of indium contents and hybrid strain types in InxGa1-xAs material. In this paper, the gain spectra and energy band structure containing both compressive and tensile strain states are obtained to reveal the super-wide spectra with dual peaks in transverse electric (TE) and transverse magnetic (TM) polarization modes. The super-wide spectrum with a bimodal feature is attributed to all emissions from normal In0.17Ga0.83As region and indium-deficient InxGa1-xAs regions caused by the self-fit migration of indium atoms. The band offsets of heavy holes and light holes in normal and indium-deficient InxGa1-xAs regions are determined by calculating the peak space of TE and TM spectra. In addition, the thickness fluctuation and hybrid strain distribution in the asymmetrical WCC structure are also obtained by comparing the intensity of dual peaks. The significance of this result is that it not only reveals the energy band characteristics and luminescence mechanism but also determines the critical thickness of indium atom self-fit migration. The result is significant to greatly enhance the performance of InGaAs-based WCC tunable lasers in extending spectral tuning range.

Accessing the Variability of Multicopy Genes in Complex Genomes using Unassembled Next-Generation Sequencing Reads: The Case of Trypanosoma cruzi Multigene Families.

Repetitive elements cause assembly fragmentation in complex eukaryotic genomes, limiting the study of their variability. The genome of Trypanosoma cruzi, the parasite that causes Chagas disease, has a high repetitive content, including multigene families. Although many T. cruzi multigene families encode surface proteins that play pivotal roles in host-parasite interactions, their variability is currently underestimated, as their high repetitive content results in collapsed gene variants. To estimate sequence variability and copy number variation of multigene families, we developed a read-based approach that is independent of gene-specific read mapping and de novo assembly. This methodology was used to estimate the copy number and variability of MASP, TcMUC, and Trans-Sialidase (TS), the three largest T. cruzi multigene families, in 36 strains, including members of all six parasite discrete typing units (DTUs). We found that these three families present a specific pattern of variability and copy number among the distinct parasite DTUs. Inter-DTU hybrid strains presented a higher variability of these families, suggesting that maintaining a larger content of their members could be advantageous. In addition, in a chronic murine model and chronic Chagasic human patients, the immune response was focused on TS antigens, suggesting that targeting TS conserved sequences could be a potential avenue to improve diagnosis and vaccine design against Chagas disease. Finally, the proposed approach can be applied to study multicopy genes in any organism, opening new avenues to access sequence variability in complex genomes. IMPORTANCE Sequences that have several copies in a genome, such as multicopy-gene families, mobile elements, and microsatellites, are among the most challenging genomic segments to study. They are frequently underestimated in genome assemblies, hampering the correct assessment of these important players in genome evolution and adaptation. Here, we developed a new methodology to estimate variability and copy numbers of repetitive genomic regions and employed it to characterize the T. cruzi multigene families MASP, TcMUC, and transsialidase (TS), which are important virulence factors in this parasite. We showed that multigene families vary in sequence and content among the parasite's lineages, whereas hybrid strains have a higher sequence variability that could be advantageous to the parasite's survivability. By identifying conserved sequences within multigene families, we showed that the mammalian host immune response toward these multigene families is usually focused on the TS multigene family. These TS conserved and immunogenic peptides can be explored in future works as diagnostic targets or vaccine candidates for Chagas disease. Finally, this methodology can be easily applied to any organism of interest, which will aid in our understanding of complex genomic regions.

Characterization and magnification of hybrid strain production by intraspecific protoplast fusion of Monascus ruber and Pleurotus ostreatus

Characterization and magnification of hybrid strain production by intraspecific protoplast fusion of Monascus ruber and Pleurotus ostreatus

Genomic Analysis of a Hybrid Enteroaggregative Hemorrhagic Escherichia coli O181:H4 Strain Causing Colitis with Hemolytic-Uremic Syndrome.

Hybrid diarrheagenic E. coli strains combining genetic markers belonging to different pathotypes have emerged worldwide and have been reported as a public health concern. The most well-known hybrid strain of enteroaggregative hemorrhagic E. coli is E. coli O104:H4 strain, which was an agent of a serious outbreak of acute gastroenteritis and hemolytic uremic syndrome (HUS) in Germany in 2011. A case of intestinal infection with HUS in St. Petersburg (Russian Federation) occurred in July 2018. E. coli strain SCPM-O-B-9427 was obtained from the rectal swab of the patient with HUS. It was determined as O181:H4-, stx2-, and aggR-positive and belonged to the phylogenetic group B2. The complete genome assembly of the strain SCPM-O-B-9427 contained one chromosome and five plasmids, including the plasmid coding an aggregative adherence fimbriae I. MLST analysis showed that the strain SCPM-O-B-9427 belonged to ST678, and like E. coli O104:H4 strains, 2011C-3493 caused the German outbreak in 2011, and 2009EL-2050 was isolated in the Republic of Georgia in 2009. Comparison of three strains showed almost the same structure of their chromosomes: the plasmids pAA and the stx2a phages are very similar, but they have distinct sets of the plasmids and some unique regions in the chromosomes.

Distribution of fitness effects of cross-species transformation reveals potential for fast adaptive evolution

Bacterial transformation, a common mechanism of horizontal gene transfer, can speed up adaptive evolution. How its costs and benefits depend on the growth environment is poorly understood. Here, we characterize the distributions of fitness effects (DFE) of transformation in different conditions and test whether they predict in which condition transformation is beneficial. To determine the DFEs, we generate hybrid libraries between the recipient Bacillus subtilis and different donor species and measure the selection coefficient of each hybrid strain. In complex medium, the donor Bacillus vallismortis confers larger fitness effects than the more closely related donor Bacillus spizizenii. For both donors, the DFEs show strong effect beneficial transfers, indicating potential for fast adaptive evolution. While some transfers of B. vallismortis DNA show pleiotropic effects, various transfers are beneficial only under a single growth condition, indicating that the recipient can benefit from a variety of donor genes to adapt to varying growth conditions. We scrutinize the predictive value of the DFEs by laboratory evolution under different growth conditions and show that the DFEs correctly predict the condition at which transformation confers a benefit. We conclude that transformation has a strong potential for speeding up adaptation to varying environments by profiting from a gene pool shared between closely related species.

Telomerase activity, relative telomere length, and longevity in alfalfa (Medicago sativa L.)

Background Medicago sativa L. ‘Qingshui’ is a valuable rhizomatous forage germplasm resource. We previously crossed Qingshui with the high-yielding Medicago sativa L. ‘WL168’ and obtained novel rhizomatous hybrid strains (RSA-01, RSA-02, and RSA-03). Telomere dynamics are more accurate predictors of survival and mortality than chronological age. Based on telomere analyses, we aimed to identify alfalfa varieties with increased stamina and longevity for the establishment of artificial grazing grasslands. Methods In this study, we performed longitudinal analysis of telomerase activity and relative telomere length in five alfalfa varieties (Qingshui, WL168, RSA-01, RSA-02, and RSA-03) at the age of 1 year and 5 years to examine the relationship among telomerase activity, rate of change in relative telomere length, and longevity. We further aimed to evaluate the longevity of the examined varieties. Telomerase activity and relative telomere length were measured using enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively. Results We observed significant differences in telomerase activity between plants aged 1 year and those aged 5 years in all varieties except WL168, and the rate of change in telomerase activity does not differ reliably with age. As telomerase activity and relative telomere length are complex phenomena, further studies examining the molecular mechanisms of telomere-related proteins are needed. Relative telomere lengths of Qingshui, WL168, RSA-01, RSA-02, and RSA-03 in plants aged 5 years were higher than those aged 1 year by 11.41, 11.24, 9.21, 10.23, and 11.41, respectively. Relative telomere length of alfalfa tended to increase with age. Accordingly, alfalfa varieties can be classified according to rate of change in relative telomere length as long-lived (Qingshui, WL168, and RSA-03), medium-lived (RSA-02) and short-lived (RSA-01). The differences in relative telomere length distances of Qingshui, WL168, RSA-01, RSA-02, and RSA-03 between plants aged 1 and 5 years were 10.40, 13.02, 12.22, 11.22, and 13.25, respectively. The largest difference in relative telomere length was found between Qingshui and RSA-02 at 2.20. Our findings demonstrated that relative telomere length in alfalfa is influenced by genetic variation and age, with age exerting a greater effect.

Cropping duration and non-rhizomorphic mycelial phenotype of Pleurotus djamor woody1 co-segregate in the hybrid progenies

Crop duration of the cultivated Pleurotus spp. is 45 to 50 days. P. djamor isolate woody-1 was collected as natural selection and was found to be short cropping duration variety with total cropping duration of 30 days but it is less palatable. It produced very thin, loose and non-rhizomorphic mycelia appearing light white color. Whereas, other commercial Pleurotus varieties such as P. florida and P. djamor MDU1 are long crop duration varieties and palatable producing thick, compact and rhizomorphic mycelia with bright white color. Co-segregation of non-rhizomorphic mycelial phenotype and short cropping duration trait of P. djamor woody- 1 in hybrid progenies was evaluated. Hybrid strains viz., H2W12 and H2W14 have thin, loose and non-rhizomorphic mycelium and they produced primordia in 9-10 days after spawning with total cropping duration of 29-32 days. Whereas, hybrid strain namely Pf1W2 has thick, compact and rhizomorphic mycelial phenotype and it produced primordia in 20 days after spawning with the total cropping duration of 47 days. This study indicated that genes governing short cropping duration and non-rhizomorphic mycelial pattern were tightly linked and co-segregated in the progenies. Thus, non-rhizomorphic mycelial phenotype of P. djamor woody1 can be used as a phenotypic marker for selection of hybrid cultivar having short cropping duration with other desired agronomic traits in future breeding strategy.

Novel production of β-cryptoxanthin in haskap (Lonicera caerulea subsp. edulis) hybrids: Improvement of carotenoid biosynthesis by interspecific hybridization

Carotenoids are important color pigments that contribute to human health. Haskap (Lonicera caerulea subsp. edulis), a shrub mainly distributed in Hokkaido, produces violet-blue berries low in carotenoid amount. We have conducted interspecific hybridization between Miyama-uguisukagura (Lonicera gracilipes var. glandulosa) and haskap to obtain interspecific hybrids for improving fruit quality. In this study, we compared four carotenoid concentrations in fruits using liquid chromatography/tandem mass spectrometry (LC/MS/MS) to reveal carotenoid accumulation changes by interspecific hybridization. β-Carotene was the main carotenoid, and the concentration in interspecific hybrids (0.49–0.77 mg/100 g FW) was higher than Miyama-uguisukagura (0.37 mg/100 g FW) and haskap (0.25–0.35 mg/100 g FW). β-Cryptoxanthin concentration was below the quantification limit in haskap strains; however, we could quantify β-cryptoxanthin in interspecific hybrids. β-Cryptoxanthin concentration in Miyama-uguisukagura fruits and the interspecific hybrid strain that contained higher β-cryptoxanthin tended to increase during maturation, although others did not increase. Our study revealed that interspecific hybridization changed carotenoid biosynthesis, increased β-carotene, and induced the conversion of β-cryptoxanthin to haskap. This study proposes a strategy to expand color variation by interspecific hybridization in fruit breeding programs and provides novel materials to analyze the “vigor” phenomenon in hybrid plants.

Antioxidant activities and chemical composition of hot water-soluble extracts and fractions of selected Schizophyllum commune Fr. strains

Oxidative stress is a conjoint pathological mechanism that can be triggered by free radicals leading to cellular senescence or apoptosis. Antioxidants have the potential to inhibit free radicals’ generation and balance the irregulated oxidative stress to restore cellular homeostasis. Schizophyllum commune, also known as the split-gill mushroom, is well-known for its nutritional values and bioactive compounds. This study aimed to investigate the antioxidant activity and chemical composition of the hot water extracts of selected strains of S. commune including natural, gamma-irradiated and hybrid strains. The fruiting bodies of different strains of S. commune were subjected to hot water extraction and the extracts were evaluated by radical scavenging, and reducing capacity assays. Results showed that, overall, the antioxidant activity of the various strains was comparable. The natural strain W and the strain obtained when strain W was subjected to gamma-irradiation at a dose of 4000 Gy (W4000) consistently exhibited high antioxidant activities in all assays and they were either comparable or higher than common edible mushrooms, Pleurotus pulmonarius and Agaricus bisporus. Moreover, the gamma-irradiated strains R2000 and R4000 exhibited higher reducing activities (0.40 and 0.41 mmol Fe2+/g extract) than the parental strain R (0.27 mmol Fe2+/g extract).

Separation of microalgae cells in a microfluidic chip based on AC Dielectrophoresis

AbstractBACKGROUNDMicroalgae is an important natural resource with extensive applications in various fields, such as health products, animal feed, biopharmaceuticals, and clean energy. However, before the research and utilization of microalgae resources, the microalgae cells of interest must be separated from hybrid strains and bacteria. The traditional method of microalgae separation requires manual labor under the microscope that is time‐consuming and labor‐intensive.RESULTSHerein, a novel microalgae cell separation method based on the dielectrophoresis (DEP) technique was proposed. A unique DEP separation chip with a 3D electrode was designed. Chlorella and Closterium were used as the experimental samples to verify the effectiveness of the proposed method because they have similar volumes and very different electrical properties. Within a certain frequency range, Chlorella suffers from negative dielectrophoresis (nDEP) force and Closterium suffers from positive dielectrophoresis (pDEP) force, so their separation can be achieved. The separation efficiency exceeded 90%. In addition, the DEP response of the Chlorella and Closterium were studied, and the DEP spectra of the two microalgae cells were obtained. Moreover, the effects of DEP force on cell viability under different voltages and frequencies were experimentally analyzed.CONCLUSIONThese findings will contribute to DEP technology, to the portable and harmless separation of microalgae, and to research on the dielectric properties of microalgae cells. © 2022 Society of Chemical Industry (SCI).

Hybridization and spore dissection of native wine yeasts for improvement of ethanol resistance and osmotolerance.

Global warming has a significant impact on different viticultural parameters, including grape maturation. An increment of photosynthetic activity generates a rapid accumulation of sugars in the berry, followed by a dehydration process which leads to a higher concentration of soluble solids. This effect is exacerbated by current viticultural practices which favor the harvest of very mature grapes to obtain wines with sweet tannins. Considering the initial hyperosmotic stress conditions and the high ethanol concentration of the produced wine, fermentation of grape musts with high sugar content could be problematic for yeast starters. In the present study, we were able to obtain by classical hybridization and spore dissection methods one hybrid and one monosporic wine yeast strain with a combined ethanol and osmotolerant phenotype. The improved yeasts were tested in vinification trials with high sugar concentration and displayed excellent fermentation performance. Importantly, the obtained wines also showed good organoleptic properties during sensory analysis. Based on our results, we believed our improved hybrid and monosporic strains can be considered good alternatives to be used as yeast starters for fermentations with high sugar content.

Enhanced Bridge Weigh-in-Motion System Using Hybrid Strain–Acceleration Sensor Data

Enhanced Bridge Weigh-in-Motion System Using Hybrid Strain–Acceleration Sensor Data