Culture Cycle Research Articles

Changes in phycospheric and environmental microbes in Neoporphyra haitanensis during the cultivation cycle

Neoporphyra haitanensis is an economic seaweed widely cultivated along the coast of China, allowing 4–5 times harvests during a cultivation season. The composition and functions of algal-microbial communities are intricate, dynamic, and closely linked to the health of algae. This study utilized metagenomic and 16S ribosomal RNA (rRNA) sequencing to investigate the dynamic changes in the phycospheric microbial communities of Neoporphyra haitanensis (PMC-Nh) and bacterial communities of surrounding seawater (BC-SW) during the cultivation cycle, providing valuable reference data for monitoring and preventing diseases of cultivated seaweed. The results indicated that N. haitanensis might possess the ability to “recruit” and “select” surrounding microbial communities. Beneficial bacteria contributing to carbon, nitrogen, sulfur or phosphorus cycles, such as Proteobacteria, Firmicutes, Cyanobacteria at the class level, and Rhodobacteraceae, Saprospiraceae, Flavobacteriaceae at the family level, exhibited increased abundance. A symbiotic relationship based on resource supply formed between algae and PMC-Nh. However, potential pathogenic bacteria capable of degrading algae, such as Aquimana, Nonlabens, Alteromonas, Loktanella, also successfully colonized. The yield and quality of N. haitanensis in the 2nd and 3rd harvests are crucial for annual production and income. However, potential pathogenic bacteria and factors peaked in abundance during the 2nd harvest. At this point, the symbiotic body formed by Neoporphyra and the PMC-Nh was in a state of equilibrium on the “tip of the needle”. Biomarkers in the 2nd harvest, such as Nonlabens and Alteromonas, have been reported as algal pathogens. Moreover, pathways or factors associated with bacterial pathogenesis were significantly enriched in the algal-associated microbial community in the 2nd harvest, such as biofilm formation, flagellar assembly, bacterial secretion system pathways, and virulence factors of the Virulence Factors of Pathogenic Bacteria (VFDB) database. This may be attributed to the variable and frequently intense temperature increases in the coastal areas of the East China Sea during the 2nd harvest period in mid to late October, leading to significant shifts in microbial balance. The PMC-Nh remained relatively stable during the 3rd harvest. Until the end of cultivation, pathways related to glycometabolism and the content of glycoside hydrolases in the PMC-Nh increased, possibly due to heightened polysaccharide content and the maturation or senescence of the final stage of N. haitanensis, favoring polysaccharide exudation. Our results suggest that the 2nd harvest stage is a high-risk period for N. haitanensis cultivation, and effective cultivation management should be conducted to prevent widespread algal decay and reduce production losses.

Tuber production of Tropaeolum pentaphyllum Lam. from different sizes of seed-tubers in two cultivation cycles

The liana Tropaeolum pentaphyllum Lam. is an unconventional food plant with potential economic exploitation. This study aimed to evaluate the vegetative propagation of T. pentaphyllum using seed-tubers. A total of 140 tubers were classified into four mass classes: I) < 10 g, II) 10 to 30 g, III) 30 to 70 g, and IV) > 70 g. Each mass class contained 35 tubers. The experiment was carried out in a greenhouse at Federal Institute of Rio Grande do Sul, Sertão, southern Brazil, with temperature and relative humidity of 25°C and 50%, respectively. When the senescence of the aerial stem system occurred, the mass of the tubers was measured using a precision scale (0.01 grams). Analysis of variance and Tukey’s test (p < 0.05) were used to analyze the data obtained in the experiment. In addition, descriptive statistics (mean ± standard deviation) were also used. The ratio between the initial and final masses per tuber class was calculated and the production averages between tuber classes were compared. The annual and biennial productions show that the classes of tuber seeds with mass above 10 g (II, III, and IV) produce more tubers. Class II and III are indicated for annual cultivation considering both the production in number and mass. Regarding the production of tubers for sale, class I with biennial planting is indicated since it presents a more significant mass increment.

Transcriptional control of the Cryptosporidium life cycle.

The parasite Cryptosporidium is aleading agent of diarrhoeal disease in young children, and a cause and consequence of chronic malnutrition1,2. There are no vaccines and only limited treatment options3. The parasite infects enterocytes, in which it engages in asexual and sexual replication4, both of which are essential to continued infection and transmission. However, their molecular mechanisms remain largely unclear5. Here we use single-cell RNA sequencing to reveal the gene expression programme of the entire Cryptosporidium parvum life cycle in culture and in infected animals. Diverging from the prevailing model6, we find support for only three intracellular stages: asexual type-I meronts, male gamonts and female gametes. We reveal a highly organized program for the assembly of components at each stage. Dissecting the underlying regulatory network, we identify the transcription factor Myb-M as the earliest determinant of male fate, in an organism that lacks genetic sex determination. Conditional expression of this factor overrides the developmental program and induces widespread maleness, while conditional deletion ablates male development. Both have a profound impact on the infection. A large set of stage-specific genes now provides the opportunity to understand, engineer and disrupt parasite sex and life cycle progression to advance the development of vaccines and treatments.

Transcriptome analysis reveals molecular targets of erythrocyte invasion phenotype diversity in natural Plasmodium falciparum isolates from Cameroon

Further understanding of the molecular mediators of alternative RBC invasion phenotypes in endemic malaria parasites will support malaria blood-stage vaccine or drug development. This study investigated the prevalence of sialic acid (SA)-dependent and SA-independent RBC invasion pathways in endemic Plasmodium falciparum parasites from Cameroon and compared the schizont stage transcriptomes in these two groups to uncover the wider repertoire of transcriptional variation associated with the use of alternative RBC invasion pathway phenotypes. A two-color flow cytometry-based invasion-inhibition assay against RBCs treated with neuraminidase, trypsin, and chymotrypsin and deep RNA sequencing of schizont stages harvested in the first ex vivo replication cycle in culture were employed in this investigation. RBC invasion phenotypes were determined for 63 isolates from asymptomatic children with uncomplicated malaria. Approximately 80% of the isolates invaded neuraminidase-treated but not chymotrypsin-treated RBCs, representing SA-independent pathways of RBC invasion. The schizont transcriptome profiles of 16 isolates with invasion phenotypes revealed a total of 5,136 gene transcripts, with 85% of isolates predicted at schizont stages. Two distinct transcriptome profile clusters belonging to SA-dependent and SA-independent parasites were obtained by data reduction with principal component analysis. Differential analysis of gene expression between the two clusters implicated, in addition to the well-characterized adhesins, the upregulation of genes encoding proteins mediating merozoite organelle discharges as well as several conserved, virulent, merozoite-associated, and exported proteins. The latter majority have been shown to have structural and physiological relevance to RBC surface remodeling and immune evasion in malaria and thus have potential as anti-invasion targets.

Comparative analysis for nutrients, flavor compounds, and lipidome revealed the edible value of pond-cultured male Pelodiscus sinensis with different ages

Pelodiscus sinensis is an aquatic product with a long growth cycle in pond culture and high nutritional value meat. The flavor compounds, nutrients, and lipidome were investigated to explore the edible value changes of turtle meat aged 3 to 6 years (Y3 to Y6). Typically, P. sinensis meat is rich in high-quality protein (EAAI ≥81.22, AAS ≥86.47). Y6 has the highest level of Se, protein, amino acids, and high unsaturated fatty acids, including EPA + DHA. Y5 has the most delicious amino acids, polyunsaturated fatty acids, and key odorant content. The stronger flavor of Y5 may be mainly related to C18:2n6t and C18:2n6c. Further, triacylglycerols (TAG) and phosphatidylcholine (PC) were significant changes in Y5. Additionally, PI (16:0/18:1) was identified as the potential biomarker. These results provided available information on P. sinensis marketing age and revealed the potential impact of nutrients on the formation of VOCs.

Precision Phenotyping of Wild Rocket (Diplotaxis tenuifolia) to Determine Morpho-Physiological Responses under Increasing Drought Stress Levels Using the PlantEye Multispectral 3D System

The PlantEye multispectral scanner is an optoelectrical sensor automatically applied to a mechatronic platform that allows the non-destructive, accurate, and high-throughput detection of morphological and physiological plant parameters. In this study, we describe how the advanced phenotyping platform precisely assesses changes in plant architecture and growth parameters of wild rocket salad (Diplotaxis tenuifolia L. [DC.]) under drought stress conditions. Four different irrigation supply levels from moderate to severe, required to keep 100, 70, 50, and 30% of the water-holding capacity, were adopted. Growth rate and plant architecture were recorded through the digital measure of biomass, leaf area, Canopy Light Penetration Depth, five convex hull traits, plant height, Surface Angle Average, and Voxel Volume Total. Vegetation color assessments included hue, lightness, and saturation. Vegetation and senescence indices were calculated from canopy reflectance in the red (620–645 nm), green (530–540 nm), blue (peak wavelength 460–485 nm), near-infrared (820–850 nm), and 3D laser (940 nm) ranges. The temperature, relative humidity, and solar radiation of the environment were also recorded. Overall, morphological parameters, color, multispectral data, and vegetation indices provided over 7200 data points through daily scans over three weeks of cultivation. Although a general decrease in growth parameters with increasing stress severity was observed, plants were able to maintain the same morpho-physiological performances as the control during the early growth stages, keeping both 70% and 50% of the total water-holding capacity. Among indices, the Normalized Differential Vegetation Index (NDVI) contributed the most to the differentiation between different stress levels during the cultivation cycle. Across the 3 weeks of growth, statistically significant differences were observed for all traits except for the Saturation Average. Comparisons with respect to the control highlighted the strong impact of drought stress on morphological plant traits. This study provided meaningful insights into the health status of wild rocket salad under increasing drought stress.

Environmental Influence on Feeding and Biodeposition Rates of Pacific Oysters (Crassostrea gigas) Throughout Its Culture Cycle in a Coastal Lagoon with Upwelling Influence

Environmental Influence on Feeding and Biodeposition Rates of Pacific Oysters (Crassostrea gigas) Throughout Its Culture Cycle in a Coastal Lagoon with Upwelling Influence

Resources and potential for utilization of low-exergy heat from mung bean sprouts cultivation – case study

Poland is a significant producer of vegetable sprouts, which, due to the high content of nutrients, are produced for food purposes. The cultivation cycle of these plants, especially the mung beans (Vigna radiata), is associated with significant exploitation of natural resources (as much as 275 dm3 of water per 1 kg of dry seeds) and requires appropriate temperature conditions. However, since producing of vegetable sprouts is an exothermic process, there are reasons to organize the growth conditions of these plants in a quasi-autonomous manner. Estimated preliminary studies show that during the entire period of sprout growth, as much as 2.86 MJ of heat from 1 kg of dry seeds can be used, which, taking into account the scale of production of these plants, places them among the significant sources of low-temperature waste heat. The paper presents the results of temperature measurements carried out in a growth chamber used for the industrial production of the mung bean vegetable sprouts. Based on the prepared energy balance, the total amount of heat generated (4.9 GJ) and recovered (3.3 GJ) in the seed germination process was determined. The amount of energy lost in the process of imbibition and the amount of heat needed to ensure optimal plant growth conditions were determined. The study shows that the use of low-temperature heat generated by plants allows for a significant reduction in the energy consumption of the production process.

The study of novelty nutrients supplementary scheme and methodology on advanced carbon sequestration of microalgae

Microalgae has great potential in carbon sequestration and production of biofuel even with a low concentrations of CO2. In this paper, an Andrews based microalgae growth kinetic model and a novel and multiple nutrient supplementary scheme that significantly extends the carbon sequestration period and enhances growth rates of microalgae are proposed. First, the correlation between nutrient concentration and microalgal growth is constructed experimentally. The advanced growth kinetic model incorporating nitrogen and phosphorus consumption is developed. Then, the optimum cultivation conditions including initial nutrients concentration, nutrients supplementary interval and daily nutrients supplementary quantities are obtained in the conical flask reactor. The findings led to a novel nutrient supplementation strategy that initiates with a 0.2BC concentration, followed by a 0.3BC addition at 100 h, with subsequent supplements every 72 h. After adopting this supplementary strategy, the microalgae growth rate is increased by 42.9 % and the carbon sequestration rate is increased by 56.2 % compared with that of the original microalgae cultivation method in one cultivation cycle. Finally, the universal microalgae nutrients supplementary model is proposed in a piecewise model. It can be concluded from the model that in the first cultivation period, microalgae needs a higher affinity for nutrients and after nutrients supplementary, the sensitivity to nutrient inhibition is reduced. The paper is significantly helpful to improve the sustainability of the microalgae growth rate and the carbon sequestration rate.

Biological and economic feasibility of cultivating the mangrove cockle Anadara tuberculosa (Sowerby, 1833) in a shrimp farm reservoir with estuarine influence in Santa Elena, Ecuador

The extraction of Anadara tuberculosa, a commercially valuable species in the tropical Eastern Pacific mangroves, presents significant ecological risks. To mitigate these risks, captive production of A. tuberculosa is crucial. This study examines the somatic conditions of laboratory-produced A. tuberculosa spat and their cultivation on a pilot scale in a canal-reservoir of a shrimp farm. Spat measuring 6.2 ± 0.9 mm were placed in baskets and cultured in suspension at a density of 776.6 ± 26.0 cockles (0.54 cockle per square centimeter). Environmental variables at the culture site were monitored. After 24 months of culture, the cockles reached a size of 44.7 ± 0.6 mm with a survival rate of 65.0 ± 0.6%. These production results were extrapolated to evaluate the economic viability of production in a shrimp farm canal-reservoir with estuarine influence. The proposed economic model yielded 325,000 market-ready Anadara tuberculosa mangrove cockles (in five culture cycles) with an estimated net present value (NPV) of $22,914.00. The modified internal rate of return (MIRR) reached 15.20 percent, and the cost-benefit ratio was $1.96. Economic projections indicate that the initial capital investment could be recovered within five years and one month (payback). This research provides evidence of the biological feasibility, including somatic growth, survival rates, and the relationship with environmental variables at the site, as well as the economic feasibility of cultivating A. tuberculosa in a canal of a shrimp farm with estuarine influence. The findings offer valuable insights for scaling up aquaculture production and initiating restoration processes for this species.

Biochemical, functional and antioxidant potential of higher fungi cultivated on agro-industrial residues. Part II: Cultures on mixtures of spent mushroom substrates and mushroom cropping by-products

Novel substrates consisted of different fresh agro-industrial residues, their corresponding and commercial spent mushroom substrates (i.e. SMS deriving from laboratory-scale experiments and SMS deriving from industrial-scale experiments by Green Zin S.A. - SMS GZ) and Pleurotus waste (PW; stipes/mishappen mushrooms) were used in blends for a new cultivation cycle of Pleurotus ostreatus and P. eryngii mushrooms in bags. Their impact on the biochemical properties (intra-cellular polysaccharides - IPSs, protein, lipid, total phenolic compounds - TPCs, individual carbohydrates composition of the IPSs) in the first- and second-flush whole mushrooms, pilei and stipes, as well as the fatty acids composition, the antioxidant activity (in the first-flush mushroom parts) and glucan content of stipes were examined. Both species produced satisfactory IPSs quantities in all substrates (28.69–46.38 %, w/w) and significant protein amounts (18.37–26.80 %, w/w). The further SMS addition (80 %, w/w instead of 40 %, w/w) in the cultivation substrates affected positively the mushroom IPSs values, whereas the highest protein content was detected in mushroom's parts cultivated on substrates consisted of fresh agro-industrial residues. Mushroom's lipid content was affected differently by the various substrate combinations, with SMS presence resulting in mushrooms with a lower fat content than those produced in substrates with PW addition. Fresh substrates with PW and those with coffee residue were the most favorable for TPCs production. Regarding production flushes, the nutritional value of mushrooms was comparable between them, only a slight increase in TPCs of second-flush carposomes was detected. Glucose was the predominant monosaccharide of the produced IPSs, combined with a significant production of total and β- glucans. SMSs and PW addition had a positive impact on antioxidant activity, too. A higher quantity of lipids, TPCs and significant antioxidant activity were detected in all Pleurotus pilei than stipes, whereas the latter were richer in IPSs. Both pilei and stipes had a significant protein amount. Hence, the data obtained by this study support the positive effect of different types of SMS and mushroom waste on P. ostreatus and P. eryngii nutritional value.

Sugarcane Water Productivity for Bioethanol, Sugar and Biomass under Deficit Irrigation

Knowledge of how certain crops respond to water stress is one of the prerequisites for choosing the best variety and best management practices to maximize crop water productivity (WPc). The selection of a more efficient protocol for managing irrigation depths throughout the cultivation cycle and in the maturation process at the end of the growth period for each sugarcane variety can maximize bioethanol productivity and WPc for bioethanol, sugar and biomass, in addition to the total energy captured by the sugarcane canopy in the form of dry biomass. This study aimed to evaluate the effect of four irrigation depths and four water deficit intensities on the maturation phase for eight sugarcane varieties under drip irrigation, analyzing the responses related to WPc for bioethanol, sugar and biomass. These experiments were conducted at the University of São Paulo. The plots were positioned in three randomized blocks, and the treatments were distributed in a factorial scheme (4 × 8 × 4). The treatments involved eight commercial varieties of sugarcane and included four water replacement levels and four water deficits of increasing intensity in the final phase of the crop season. It was found that for each variety of sugarcane, there was an optimal combination of irrigation management strategies throughout the cycle and during the maturation process. The RB966928 variety resulted in the best industrial bioethanol yield (68.7 L·Mg−1), WPc for bioethanol (0.97 L·m−3) and WPc for sugar (1.71 kg·m−3). The energy of the aerial parts partitioned as sugar had a direct positive correlation with the availability of water in the soil for all varieties. The RB931011 variety showed the greatest potential for converting water into shoots with an energy of 1.58 GJ·ha−1·mm−1, while the NCo376 variety had the lowest potential at 1.32 GJ·ha−1·mm−1. The productivity of first-generation bioethanol had the highest values per unit of planted area for the greatest water volumes applied and transpired by each variety; this justifies keeping soil moisture at field capacity until harvesting time only for WR100 water replacement level with a maximum ethanol potential of 13.27 m3·ha−1.

Experimental evolution of extremotolerant and extremophilic fungi under osmotic stress.

Experimental evolution was carried out to investigate the adaptive responses of extremotolerant fungi to a stressful environment. For 12 cultivation cycles, the halotolerant black yeasts Aureobasidium pullulans and Aureobasidium subglaciale were grown at high NaCl or glycerol concentrations, and the halophilic basidiomycete Wallemia ichthyophaga was grown close to its lower NaCl growth limit. All evolved Aureobasidium spp. accelerated their growth at low water activity. Whole genomes of the evolved strains were sequenced. No aneuploidies were detected in any of the genomes, contrary to previous studies on experimental evolution at high salinity with other species. However, several hundred single-nucleotide polymorphisms were identified compared with the genomes of the progenitor strains. Two functional groups of genes were overrepresented among the genes presumably affected by single-nucleotide polymorphisms: voltage-gated potassium channels in A. pullulans at high NaCl concentration, and hydrophobins in W. ichthyophaga at low NaCl concentration. Both groups of genes were previously associated with adaptation to high salinity. Finally, most evolved Aureobasidium spp. strains were found to have increased intracellular and decreased extracellular glycerol concentrations at high salinity, suggesting that the strains have optimised their management of glycerol, their most important compatible solute. Experimental evolution therefore not only confirmed the role of potassium transport, glycerol management, and cell wall in survival at low water activity, but also demonstrated that fungi from extreme environments can further improve their growth rates under constant extreme conditions in a relatively short time and without large scale genomic rearrangements.

Colour change in potato (Solanum tuberosum L.) tubers by disruption of the anthocyanin pathway via ribonucleoprotein complex delivery of the CRISPR/Cas9 system

Potato is an important part of the traditional Norwegian diet, and the crop faces several challenges with respect to pests and diseases, as well as the increasingly challenging changes in climate. Genome editing may provide tools to improve the resilience of Norwegian potato cultivars to new climate challenges. We have altered the skin colour of two potato cultivars, ‘Desirée’ and ‘Nansen’ from red to yellow, as a proof-of-concept for the use of CRISPR/Cas9 in a Norwegian cultivar. Our method has involved the use of protoplasts and we have grown the regenerants for three successive clonal tuber generations to evaluate the stability of the edited plants over time and under varying temperature conditions in contained rooms in a greenhouse. We found that the protoplast method is well suited to achieving CRISPR/Cas9 applications. The results show that the yellow skin is consistent over the three generations of tuber propagation. We found some suspected somaclonal variation in the protoplast regenerants. Some of the variation which we observed under high temperatures (up to nearly 40ºC) during the second growth cycle, disappeared when cultivated under lower temperatures in the third cultivation cycle.

The transition from shifting cultivation to indigenous agroforestry as nature-based solution for land restoration in the Indian Eastern Himalayas

In the Indian Eastern Himalayas, shifting cultivation has long been a major cause of land degradation. However, indigenous communities, like the Hmar, have successfully transitioned from shifting cultivation to agroforestry systems such as pineapple agroforestry, leading to land restoration and increased household incomes. Despite these positive outcomes, little is known about how soil health indicators change during this transition. Thus, the present study aimed to investigate changes in selected soil health indicators and erodibility across different age classes of pineapple agroforestry systems (<5, 5–10, 11–15, and > 15 years old) compared to shifting cultivation and nearby natural forests. Soil samples were collected from six sites, including different stages of pineapple agroforestry systems, shifting cultivation phases, and a natural forest. At each site, three (10 × 10 m) quadrats were selected, and two (1 × 1 × 1 m) vertical soil pits were dug in each quadrat, sampling soil depths from 0 to 100 cm. The transition from shifting cultivation to pineapple agroforestry improved soil organic carbon (SOC) and stratification ratios while reducing soil erodibility. SOC stocks were estimated at 182.7 Mg C/ha for natural forest land and 188.2 Mg C/ha for the cropping phase in shifting cultivation. On the other hand, estimated SOC stocks for < 5, 5–10, 11–15 and > 15 years old stands of pineapple agroforestry system were 169.7 Mg C/ha, 157.2 Mg C/ha, 168.9 Mg C/ha and 177 Mg C/ha respectively. Thus, the estimated SOC stocks under > 15 years of pineapple agroforestry were comparable with adjacent natural forest land. The stratification ratios (SR > 2) for SOC and macronutrients indicated better soil quality in the pineapple agroforestry system than in the cropped land. The clay and modified clay ratios decreased with increasing age of pineapple agroforestry stands. The highest clay ratio was recorded in the topsoil of < 5-year-old pineapple agroforestry system, indicating a greater risk of exposure to rainfall events than in natural forest land and the cropping phase in the shifting cultivation cycle. It is concluded that transitioning from shifting cultivation to a pineapple agroforestry is a nature-based solution to restore degraded lands and presents an excellent opportunity for sustainable soil health and carbon sink management.

Use of geotechnologies to promote the sustainable expansion of fish farming: an analysis for the municipality of Chopinzinho, Brazil

The expansion of fish production in a sustainable way in small municipalities has become an objective for both fish farmers and consumers, whether for nutritional and/or environmental appeal. The objective of this work was to map natural resources in the municipality of Chopinzinho/Pr using geotechnology to subsidies the planning of fish production in the municipality. The methodology used was based on geoprocessing and remote sensing tools. Results indicate annual growth in fish production, an amount of 53.1 hectares of water depth and 242 excavated ponds, the majority (81.8%) measuring less than 3,000 meters. The estimated nutrient input, due to fish farming, in excavated ponds, during the cultivation cycle was 104.14 tons of Total Nitrogen and 12.78 tons of Total Phosphorus and during harvesting 3.95 tons of Total Nitrogen and 0,85 tons of Total Phosphorus. Therefore, the use of geotechnology tools to map natural resources and excavated ponds, for subsequent estimation of nutrient input, has the potential to become a methodology to promote the expansion of fish production in a sustainable manner.

Influence of tree species on the productivity of banana trees in the second cultural cycle in Kinshasa, DRC

Les systèmes sylvo-bananiers est une réponse efficace, d’une part, aux problèmes de l’amélioration de la productivité de bananiers, d’autre part, à la préservation de nos forêts, surtout dans les régions où la déforestation est accrue. Afin d’améliorer la production des bananes à Kinshasa, une étude évaluative des systèmes sylvo-bananiers a été menée dans les conditions de plateau de Batéké. Il était question de comparer les différentes associations bananiers-arbres, afin de connaitre leurs impacts sur la productivité de bananiers. Cinq cultivars de bananiers ont été associés avec douze essences forestières arborescentes, réparties en trois groupes: les légumineuses, les non légumineux et les arbres fruitiers. L’évaluation de l’influence des arbres forestiers sur le comportement de bananiers au deuxième cycle de production avait fait l’objet de cette étude. Ces pieds de bananiers étaient issus de rejets successeurs sélectionnés à la fin du premier cycle de production. Au regard des résultats obtenus avec l’ACP, il sied de noter que sur les 60 associations sylvo-bananierès étudiées, les plus performantes (poids de régimes et rendements élevés) étaient celles formées avec le cultivar Nsikumuna respectivement en association avec: Pterocarpus indicus Willd.; Millettia laurentii; Maesopsis eminii Engl.; Gmelina arborea Roxb. ; Eugenia malaccensis L.; Lannea welwitschii (Hiern) Engl.; Persea americana; Terminalia superba Anglais. &amp; Diels ; Mangifera indica L. ainsi que Dacryodes edulis. Toutes ces essences peuvent être retenues et recommandées en systèmes sylvobananiers en mettant un accent particulier sur les quatre premières.

Bioconversion of lavender oil extraction wastes through cultivation of Pleurotus eryngii var. ferulae: Its effects on yield, nutritional content and antioxidant capacity of the mushroom

The study was carried out to investigate the effect of growing media prepared by mixing different ratios of poplar sawdust (PS) and lavender extraction wastes such as lavender straw (LS) and lavender flower wastes (LFW), on the cultivation cycle, yield and biological efficiency (BE%), nutritional profil and antioxidant capacity of Pleurotus eryngii var. Ferulae mushroom. Moreover, functional and organic compounds of the fruiting body were examined by FTIR analysis. The mushroom production was experimented with seven different growing media. A raised yield of 216.3 g/kg ±6.4 g/kg and BE% of 61.8 ± 1.8% were recorded in the growing medium where the PS, LS and LWF were used in the ratio of 5:3:2, whereas the maximum protein content (17.94 ± 0.04 g100 g-1), total phenolic content (5.09 ± 0.08 mg GAE g−1), ABTS (54.36 ± 2.39 μmol TE g−1) and CUPRAC (58.89 ± 0.91 μmol TE g−1) were observed in the growing medium prepared with mixture of PS and LS (the ratio of 7:3). Moreover, all the growing media added LS and LFW resulted in improved mushroom yield, the nutritional profile and antioxidant capacity of P. eryngii var. Ferulae when compared to the control medium. According to the results, LS and LFW can be used as efficient, cost-effective and promising substrates for the production of P eryngii var. Ferulae, a valuable medicinal and edible mushroom species.

Risk level assessment of typhoon-induced wave fields around a large-scale suspended mussel farm

Suspended shellfish aquaculture, utilizing longlines and buoys fixed on the sea surface, is a crucial source of global seafood. However, typhoons, as the most common disasters in coastal regions, can generate massive waves and pose a threat to the safety of suspended aquaculture facilities. Therefore, it is essential to investigate the risk levels associated with suspended aquaculture farms during typhoon waves. The example of a large-scale suspended mussel farm in the East China sea was examined in this study. The wave conditions under extreme wind conditions (25m/s) and different typhoon paths were predicted using the SWAN model and modeled results compared well with the observed wave and wind data. The results indicated that when the center of the east-side typhoon was located at the same latitude as the farm, it will face the highest risk level. However, for the west-side and intermediate sweeping typhoons, the risk level reached highest in the farm, when the typhoon center is lower than the latitude of it. Under the combined effects of wind fetch and topography, the risk level in the southeast farming area of the island is the highest under different wind conditions. The farms to the northwest of the island face a higher risk level during the passage of east-side sweeping typhoons, while the southern farms of the island experience an elevated risk level during the west-side and intermediate sweeping typhoons. It is suggested that farming regions with lower risk levels are more conducive to the cultivation of species with longer culture cycles. Conversely, regions considered at higher risk are more suitable for species with shorter culture cycles. The study affords a reference for the optimization and insurance of suspended aquaculture farms.

Purification technology design, biochemical and immunological characteristics of the recombinant chimeric antigen for evaluation of T cell immunity against coronavirus infection

Diagnosis of specific T cell immunity to the antigenic determinants of SARS-CoV-2 in patients seems to be an increasingly important task due to accumulation of data about the role of T cell immune response in course of coronavirus infection and clearance of SARS-CoV-2 in case of secondary infection. Previously, we designed the recombinant CorD_PS antigen for evaluation of T cell antiviral immunity, containing conservative and immunogenic sequences of structural proteins of the SARS-CoV-2 coronavirus. E. coli CorD_PS producing strain with stable expression of the recombinant CorD_PS antigen was obtained. Aim of the present work is to design a laboratory technology for the production of recombinant antigen CorD_PS, to control the quality of the obtained chimeric protein and to study its immunological activity. Development of the cultivation conditions for E. coli CorD_PS cells was carried out in conical flasks in LB-M_Km medium at 37 °C, then scaled in a fermenter with a volume of 30 liters. Expression was induced by the addition of IPTG. Expression was controlled in culture lysates in 12% SDS-PAGE. The resulting biomass was lysed using an ultrasonic disintegrator with followed by centrifugation. The compositions of lysing and solubilizing buffers were selected, as well as conditions for refolding of the recombinant protein. Cation exchange (SP-sepharose), hydrophobic (Butylsepharose) and exclusive (Sephacryl S-200 HR) chromatography were used sequentially to purify the dissolved protein. Protein impurities in the preparation were determined by reverse-phase HPLC and electrophoresis in 12% SDS-PAGE, residual lipopolysaccharides were determined using a gel-thrombin variant of the LAL test, residual proteins of the producer strain were determined by enzyme immunoassay, residual DNA of the producer strain was determined by binding with PicoGreen dye. Specificity was controlled by indirect enzyme immunoassay. The evaluation of cytokine production by CD4+T lymphocytes in response to their stimulation by recombinant antigen ex vivo was performed on a flow cytofluorimeter. The biomass yield during cultivation of E. coli CorD_PS in a 30L fermenter was up to 20 g/L for 4 hours of 0.1 mM IPTG induction. Sequential washing of inclusion bodies from bacterial cellular components and their subsequent solubilization in a buffer containing 8 M urea allowed to obtain a solution of denatured antigen with a concentration of 10 mg/mL. The efficiency of refolding by dilution was 75%. After three stages of chromatographic purification, protein samples with a concentration of 1.2-1.4 mg/mL, HPLC purity of 98.43%, corresponding to key quality parameters according to the OFS.1.7.1.0007.15, were obtained. The recombinant antigen showed specific binding to a sample of the First WHO International Standard and sample Company Reference Standard No. 3 of anti- SARS-CoV-2 human immunoglobulins in a specified concentration range. CD4+T lymphocytes effectively responded to recombinant antigen treatment by increasing IFNγ production. The optimal concentration of recombinant coronavirus antigen was 5 μg/mL. The developed technological process makes it possible to obtain 5-7 grams of coronavirus recombinant CorD_PS antigen in one cultivation cycle in 30 liters of fermentation medium with key quality parameters according to the OFS.1.7.1.0007.15. As a result of specific immunological activity studies of the recombinant coronavirus antigen CorD_PS, the concept of its possible use as a diagnostic tool for determining the formation of a T cell immune response was confirmed.