Product Yield Research Articles

Enhanced mycelium biomass and polysaccharide production in genetically modified Pleurotus ostreatus using agricultural wastes

Edible fungi, healthier for humans and sustainable for the planet, attract unprecedented attention. In the study, the genetically modified Pleurotus ostreatus overexpression phosphoglucomutase (PGM) was constructed. P. ostreatus overexpression PGM (Po::PGM) had 4.96-folds higher expression level of PGM. Po::PGM grew thicker mycelium and more mycelium branches. Additional Ca2+ can inhibit mycelium growth, and cyclic adenosine monophosphate completely inhibited their growth of Po::PGM. Secondly, Overexpression of PGM made P. ostreatus become more sensitive to cell wall disruptors, and caused 12.75 % reduction of β-1, 3-glucan and 40.53 % increase of chitin in cell wall. In submerged fermentation, the mycelia biomass yield and endopolysaccharide (IPS) production of Po::PGM in basic PDB can reach 11.18 g/l and 2.55 g/l, increasing by 20.86 % and 28.79 %, respectively. Whereas exopolysaccharide (EPS) reduced by 3.28 %. After replacing potato and glucose in PDB by wheat bran, mycelia biomass and EPS production of Po::PGM were all improved. The additional lactose in wheat bran did not only furtherly enhance mycelia biomass yield of Po::PGM to 27.78 g/l by 199.03 %, but IPS production also increased by 277.99 % to 6.07 g/l. The results provided us key ideas and important research directions that at least manipulating the PGM gene could obtain high-efficient use of agricultural wastes producing more fungus-based foods.

Advances on multiclass pesticide residue determination in citrus fruits and citrus-derived products - A critical review.

The application of agrochemicals in citrus fruits is widely used to improve the quality of crops, increase production yields, and prolong post-harvest life. However, these substances are potentially toxic for humans and the ecosystem due to their widespread use, high stability, and bioaccumulation. Conventional techniques for determining pesticide residues in citrus fruits are chromatographic methods coupled with different detectors. However, in recent years, the need for analytical strategies that are less polluting for the environment has encouraged the appearance of new alternatives, such as sensors and biosensors, which allow selective and sensitive detection of pesticide residues in real time. A comprehensive overview of the analytical platforms used to determine pesticide residues in citrus fruits and citrus-derived products is presented herein. The review focuses on the evolution of these methods since 2015, their limitations, and possible future perspectives for improving pesticide residue determination and reducing environmental contamination.

Enhanced photocatalytic CO2 conversion into reusable fuels with efficient solid-state proton donors

Lead halide perovskites driven photocatalytic CO2 reduction reaction (CO2RR) is restricted by H2O proton source due to the poor water-resistance of perovskites and difficult dissociation of H2O molecules. In this paper, a novel solid-state proton donor of amino acid modified melamine foam (Ami-MF) is developed, which could improve CO2RR of CsPbBr3/Bi2WO6 S-scheme heterojunction. On the one hand, amino acid molecules possess abundant –COOH and –NH2 groups, which are broken easily by catalyst oxidation compared with H2O, supplying sufficient protons for CO2RR. Product yield of Glu-MF/CsPbBr3/Bi2WO6 reaches 112.81 μmol/g/h, which is 3.8 times higher than that (29.83 μmol/g/h) of H2O-MF/CsPbBr3/Bi2WO6. Moreover, glutamic acid (Glu), cysteine (Cys), arginine (Arg) as typical acidic, neutral and basic amino acids are selected to explore proton supply from different amino acids. Glu-MF/CsPbBr3/Bi2WO6 exhibits the best CO2RR than other two Ami-MF, ascribing to the dicarboxylic structure of Glu. On the other hand, MF is an integral part in solid-state proton donor. Product yield of Glu-MF/CsPbBr3/Bi2WO6 is about 46.2 times higher than that (2.44 μmol/g/h) of powdery Glu/CsPbBr3/Bi2WO6, which ascribes to the efficient gas–solid CO2RR system induced by the three-dimensionality and porosity of MF. This study develops an efficient solid proton donor to enhance perovskites driven CO2RR.

Identification of bioactive compounds in cavalcade leaves for nematicidal activity against Hirschmanniella mucronata and Meloidogyne graminicola using LC-QTOF-MS

Hirschmanniella mucronata and Meloidogyne graminicola are the main plant-parasitic nematodes found in paddy fields in Thailand causing significant rice production yield losses. Although these nematodes are found widely in fields, an effective management method has not been documented. Here, we examined the nematicidal effects of different cavalcade leaf ages (1-, 2- and 3-month-old), used as aqueous extracts and soil amendments, on H. mucronata and M. graminicola. In vitro tests evidenced maximum mortality of H. mucronata (55.6 to 60.0%) in 50 mg ml-1 extract from all leaf ages, while mortality (65.9%) and hatchability (67.0%) of M. graminicola second-stage juveniles were observed in 50 mg ml-1 extract from 1-month-old leaves only. Moreover, aqueous extracts of cavalcade showed a repellent effect on both nematodes. Similarly, greenhouse experiments showed a significant reduction of H. mucronata population densities and reproduction of M. graminicola in soil amended with 0.5 and 1.0% (w/w) from each leaf age. LC-QTOF-MS analysis determined that three bioactive compounds, including quercetin, rutin, and kaempferol, are associated with the nematicidal activity of cavalcade against H. mucronata and M. graminicola. The information derived from this study indicates that the leaves of cavalcade are a source of promising phytonematicidals. This is the first study to assess and document its potential for nematicidal activity against H. mucronata and M. graminicola in Thailand. However, further research is needed to evaluate their efficacy under paddy field conditions.

Membrane-based fermentation enables highly selective caproic acid production from wine lees

Chain elongation is a green chemistry approach to convert organic waste or agro-industrial side-products into caproic acid. Nonetheless, such feedstocks may contain microorganisms and chemical pollutants that could deteriorate the product yield and purity. This study introduces a membrane-based fermentation process designed to isolate the caproic acid producing bacteria from these contaminants. A tubular polysiloxane (silicone) membrane submerged into a fermentor allowed the selective diffusion of ethanol and acetic acid while preventing the cross-over of bacteria and contaminants such as ions and metals. Abiotic tests confirmed that membrane thickness, feedstock pH and flow velocity can be adjusted to independently control the diffusion of ethanol and acetic acid. Thereof, optimal ethanol:acetic acid ratios for chain elongation (6:1) were obtained from a feedstock solution with equimolar (1 M) concentrations of both. In the biotic tests, this resulted in a highly selective (>90 %) caproic acid production at a highest rate of 3.1 g/(L·d). Maintaining the pH above 6.8, thereby keeping most caproic acid in its dissociated form, prevented its back-diffusion through the membrane. Similar caproic acid productivity was achieved from diluted wine lees (1 M ethanol), amended with 1 M acetic acid. In contrast, unamended wine lees resulted in three times lower caproic acid production rate, although the product selectivity remained high (94 %). Downstream processing by acidification and phase separation yielded 6–13 mL/Lfeedstock of an oily product containing up to 784 g/L caproic acid (84.3 % purity). In conclusion, membrane-based fermentation enables highly selective caproic acid production from highly concentrated and unbalanced substrates.

Tingkat Kepuasan Petani Terhadap Penggunaan Pupuk Hayati Boc-Srf dan Pupuk Hayati X dalam Meningkatkan Produksi Cabai Merah

Red chilli is a plant that has always been the subject of discussion because it can cause inflation in Indonesia. Even though demand is high, the lack of goods causes prices to soar. One effort to increase red chilli productivity is the use of fertilizer. The Center for the Study and Application of Technology (BPPT) has produced superior biological fertilizers, namely BOC-SRF Biological Fertilizers, which farmers use on red chilli plants. Farmers as consumers certainly feel satisfied or not after using this fertilizer or other biological fertilizers; therefore, it is necessary to research the level of satisfaction of farmers regarding the use of BOC-SRF Biofertilizer and Biological Fertilizer Hayati BOC-SRF with Hayati X in Sukatani Village, Pacet District, Cianjur Regency with 40 farmers as respondents. The analysis method uses the Customers Satisfaction Index (CSI), Important Performance Analysis (IPA) and Diagonal Analysis (Suharjo Split). As a result, farmers were very satisfied with the performance of BOC-SRF biofertilizer (CSI: 81%), while farmers using X biofertilizer were satisfied with an index value of 74.4%. The attribute that is the main priority but performs poorly when using BOC-SRF biological fertilizer is the "productive period". In contrast, for X biological fertilizer, it is the "productive period and production yield". The analysis of service efficiency levels showed that over-service occurred in the HPT resistance attribute of BOC-SRF biofertilizer, while other attributes experienced under-service. At the level of biofertilizer service efficiency X, all attributes are experienced under service.

Temperature effects on chemical reactions and product yields in the Co-pyrolysis of wood sawdust and waste tires: An experimental investigation

This study investigates the effects of varying temperatures on the co-pyrolysis of wood sawdust (WS) and waste tires (WT) within a stainless steel fixed-bed reactor under a nitrogen atmosphere. The experiments were conducted at three different temperatures: 400 °C, 500 °C, and 600 °C, focusing on the thermal behavior and resultant product yields. At 600 °C, WS produced the highest oil yield (63.6 wt%), suggesting a tendency to generate more aqueous and volatile components. Conversely, WT alone showed an optimal oil yield of 46.4 wt% at 500 °C, while the WS-WT blend achieved 55.6 wt%. Gas chromatography-mass spectrometry (GC-MS) analyses of the pyrolytic oils indicated that WS-heavy mixtures were rich in aliphatic compounds, whereas WT-dominant samples had increased aromatic and phenolic contents, demonstrating the potential for creating valuable chemicals from waste. Additionally, gas analysis highlighted significant variations in syngas composition, with increased methane and decreased CO2 levels at higher temperatures, emphasizing the role of the water-gas shift reaction. These findings underscore the critical importance of temperature control in optimizing the efficiency and quality of products from co-pyrolysis, presenting a viable method for enhancing the value derived from waste materials.

Generation of lysolipin derivatives by genetic engineering

Lysolipin I is a halogenated, polycyclic xanthone natural product belonging to the polyketide class of antibiotics, naturally produced by Streptomyces violaceoniger TÜ96 and Streptomyces tendae TÜ4042. The biosynthesis is encoded on a 43 kb-spanning biosynthetic gene cluster. Heterologous expression of the gene cluster has been established in previous work by using the cosmid 4H04, which was transferred to Streptomyces albus. In the current study, we demonstrate the optimization of production yields of therapeutically interesting lysolipin derivatives with extended activity against Gram-negatives and less cytotoxic bioactivities, respectively, by using mutated heterologous S. albus producer strains. Production yields were significantly increased by adapting cultivation conditions as well as by inactivating the transcriptional repressor gene llpRI, which lead to increased and consistent lysolipin (derivatives) production. Furthermore, cultivation of a S. albus 4H04∆llpOI mutant strain in bromide-containing fermentation medium resulted in the production of a new brominated lysolipin derivative (C28H20BrNO9).

Sponge-shaped Au nanoparticles: A stand-alone metallic photocatalyst for driving the light-induced CO2 reduction reaction.

Coinage metal nanoparticles (NPs) enable plasmonic catalysis by generating hot carriers that drive chemical reactions. Making NPs porous enhances the adsorption of reactant molecules. We present a dewetting and dealloying strategy to fabricate porous gold nanoparticles (Au-Sponge) and compare their CO2 photoreduction activity with respect to the conventional gold nanoisland (Au-Island) morphology. Porous gold nanoparticles exhibit an unusually broad and red-shifted plasmon resonance which is in agreement with the results of finite difference time domain (FDTD) simulations. The key insight of this work is that the multi-step reduction of CO2 driven by short-lived hot carriers generated by the d → s interband transition proceeds extremely quickly as evidenced by the generation of methane. A 3.8-fold enhancement in the photocatalytic performance is observed for the Au-Sponge in comparison to the Au-Island. Electrochemical cyclic voltammetry measurements confirm the 2.5-fold increase in the surface area and roughness factor of the Au-Sponge sample due to its porous nature. Our results indicate that the product yield is limited by the amount of surface adsorbates i.e. reactant-limited. Isotope-labeled mass spectrometry using 13CO2 was used to confirm that the reaction product (13CH4) originated from CO2 photoreduction. We present the plasmon-mediated photocatalytic transformation of 4-aminothiophenol (PATP) into p,p'-dimercaptoazobenzene (DMAB) using Au-Sponge and Au-Island samples.

The Impact of Salinity on the Productivity and Quality of Durum and bread Wheat

Salinity poses a significant challenge to the quality and productivity of crops. In the primary wheat cultivation areas worldwide, salinity negatively affects wheat growth, yield, and quality. To address this issue, the development of tolerant wheat varieties through selective breeding techniques is essential. The aim of this study was to assess the effects of salinity on grain yield, protein content, and thousand-kernel weight (TKW) among 55 different varieties and accessions of bread and durum wheat. The findings revealed that the application of salt treatment (100 mM NaCl solution) resulted in reduced growth and yield production in 45 bread and durum wheat varieties. However, 6 durum wheat varieties, 3 durum wheat accessions, and 1 common wheat accession showed insignificant susceptibility to salinity. These included Chryssodur from Greece, Saragolla, Silur, and Dakter from Italy, Sculptur from France, Karim from Tunisia, Algeria 70-2 from Algeria, Ethiopia 201 and Ethiopia 229 from Ethiopia, and the Morocco 85 accession of bread wheat from Morocco. The decline in grain yield could be attributed to salinity, which led to a decrease in photosynthetic capacity, resulting in reduced starch synthesis and accumulation in the grain. Furthermore, the study demonstrated that winter wheat exhibited greater tolerance to salt stress compared to spring wheat, and durum wheat displayed higher tolerance than common wheat. Additionally, salt accumulation was found to increase protein content in five varieties and one accession of durum wheat. This variation may be linked to the relatively stable nitrogen metabolism under salt stress, contributing to higher protein concentrations. TKW also decreased in all 10 varieties and accessions, irrespective of the species.

1,3-Hydro-di/monofluoromethylation of N,N'-Cyclic Azomethine Imines with HCF2SO2Na/H2CFSO2Na via Photocatalytic Radical Addition.

The radical 1,3-hydro-di/monofluoromethylation of N,N'-cyclic azomethine imines with HCF2SO2Na/H2CFSO2Na via photoredox catalysis is described. This reaction exhibits broad functional group compatibility, providing the desired products in good yields. However, CF3SO2Na failed to produce the trifluoromethyl product. DFT calculations revealed that the transition state activation energy for radical trifluoromethylation was significantly higher and the isotropic charge repulsion makes it difficult for the CF3 radical to transfer electrons.

Rice Response to Spermine Foliar Application and Its Association with Aerial Imagery Monitoring Under Water Stress Conditions

Rice is the most consumed food in the world, mainly in Asia and Africa. Malaysia is the second-largest rice importer in Southeast Asia after Indonesia. However, rice yield is limited by water stress. One alternative for a quicker strategy to mitigate water stress is through a combination of foliar spermine application and efficient rice management practices via image monitoring techniques using drone technology. The present study was aimed at evaluating the effects of spermine on rice physiological response and its association with aerial imagery and yield under reproductive during reproductive stage under water stress. The experiment was carried out under greenhouse conditions using a two-factorial randomized complete block design (RCBD), with foliar spermine treatment as the first factor and water stress as the second factor. Physiological parameters showed significantly higher tiller number per pot and photosynthesis rate by 29% and 31%, respectively. Correspondingly, the Normalised Difference Vegetation Index (NDVI) using aerial imagery monitoring showed an increased value in spermine treatments by 2% compared to control. Furthermore, NDVI readings and photosynthetic rate were positively correlated linearly with R2= 0.51. Interestingly, spermine treatments alleviated water stress effects by 40%, 17% and 12% in grain weight per pot, grain number per panicle and percentage filled grain. Biomass partitioning in roots improved by 44% in spermine treatments, even under water stress, due to an efficient translocation of assimilates. In conclusion, spermine foliar application significantly improved growth, grain filling and rice yield production, which was also supported by NDVI values using aerial imagery monitoring.

Cooling the high temperature nutrition solution to improve growth, yield and water productivity of hydroponic red lettuce (Lactuca sativa L Var Red rapids) in a tropical location

Red lettuce is preferred because of its high nutritional, vitamin, and antioxidant contents. Hydroponic cultivation has been known to successfully improve the quality and productivity of red lettuce. But the efforts to increase the productivity of hydroponic red lettuce face constraints of high temperatures in the tropics. The aim of this study was to compare the growth, yield, and water productivity of red lettuce in three hydroponic systems namely wick, floating raft, and dry systems by controlling the temperature of the nutrient solutions using protected nutrient containers. The experimental design of randomized complete block split plots with the main plots of the nutrient containers which consisted of three levels: Refrigerated container, styrofoam-insulated container, and bare bucket container in which the nutrient solution was delivered to plants in three separated gutters as the cultivation beds, then recirculated back to the corresponding nutrient container. The secondary plot is hydroponic systems including three systems namely wick, floating raft, and dry systems. The blocks were the arrangement of plants according to the flow direction of the nutrient solution, namely upstream, middle and downstream in each gutter. Each experimental unit was represented by 3 plants. Data sets were analyzed by using analysis of variance and followed by LSD multiple comparisons at the 5% level. The results showed that the temperature of the nutrient solution controlled by the three containers had a significant effect on all observed plant parameters. Meanwhile, the hydroponic systems and the blocks had no significant effect. The use of Refrigerated container showed the best performance in improving the growth, yield, and water productivity of the red lettuce.

Hypoxia-preconditioned WJ-MSC spheroid-derived exosomes delivering miR-210 for renal cell restoration in hypoxia-reoxygenation injury

BackgroundRecent advancements in mesenchymal stem cell (MSC) technology have paved the way for innovative treatment options for various diseases. These stem cells play a crucial role in tissue regeneration and repair, releasing local anti-inflammatory and healing signals. However, challenges such as homing issues and tumorigenicity have led to exploring MSC-exosomes as a promising alternative. MSC-exosomes have shown therapeutic potential in conditions like renal ischemia-reperfusion injury, but low production yields hinder their clinical use.MethodsTo address this limitation, we examined hypoxic preconditioning of Wharton jelly-derived MSCs (WJ-MSCs) 3D-cultured in spheroids on isolated exosome yields and miR-21 expression. We then evaluated their capacity to load miR-210 into HEK-293 cells and mitigate ROS production, consequently enhancing their survival and migration under hypoxia-reoxygenation conditions.ResultsMiR-210 overexpression was significantly induced by optimized culture and preconditioning conditions, which also improved the production yield of exosomes from grown MSCs. The exosomes enriched with miR-210 demonstrated a protective effect by improving survival, reducing apoptosis and ROS accumulation in damaged renal cells, and ultimately promoting cell migration.ConclusionThe present study underscores the possibility of employing advanced techniques to maximize the therapeutic attributes of exosomes produced from WJ-MSC spheroid for improved recovery outcomes in ischemia-reperfusion injuries.

A comprehensive thermodynamic analysis of hydrogen and synthesis gas production from steam reforming of propionic acid: Effect of O2 addition and CaO as CO2 sorbent

A thermodynamic analysis was performed for the production of synthesis gas and hydrogen gas from steam reforming of propionic acid, one of the constituents of the bio-oil, using ASPEN Plus v8.8. The aim of the study was to perform a global analysis on steam reforming of propionic acid focusing on several parameters such as steam-to-propionic acid ratio, reaction temperature, addition of O2 in the feed stream and presence of CaO as a CO2 sorbent in the reaction environment. The results showed that higher amounts of steam/propionic acid ratio resulted in higher H2 and CO2 yields. It was also observed that high H2O/PA molar ratios led to reduced coke production as WGS reaction was favored with excess steam, causing CO in the reaction mixture to be consumed through the WGS reaction rather than the Boudouard reaction. Addition of O2 in the reaction environment was observed to negatively affect yield of H2. Yet, coke formation was deprived and increasing the O2 amount in the feed stream decreased the energy required for the process. Furthermore, the presence of CaO enhanced H2 yield and energy requirements of the process compared to conventional steam reforming process. 100 % yield of H2 production with a heat generation of −83.4 MJ/kmol of PA and almost zero formation of CO2, CO, CH4 and coke is achieved at 600 °C for sorption enhanced steam reforming of propionic acid.

B(C6F5)3/Chiral Phosphoric Acid Promoted Asymmetric C-3 gem-Difluoroalkylation of Quinoxalin-2-ones with Difluoroenoxysilanes.

The asymmetric Mannich-type reaction of quinoxalin-2-ones with difluoroenoxysilanes has been developed for the synthesis of chiral gem-difluoroalkylated quinoxalin-2-ones. The reaction worked in the presence of chiral phosphoric acid CPA 1 and B(C6F5)3 in THF at room temperature. The reaction exhibited a good substrate scope furnishing the products in good yields (up to 97%) with up to 96% ee.

PRODUCTION OF BIODIESEL FROM MICROALGAE CULTIVATED WITH VINASSE

Purpose: The objective of this work was to carry out the cultivation of the microalgae Chlorella sorokiniana with diluted vinasse, verifying its potential for remediation of nutrients and increase of its lipid fraction, to produce biodiesel according to the current regulation. Theoretical Framework: The quest to reduce fossil fuels, which are responsible for negative environmental impacts, has boosted the demand for biofuels in recent years. Biodiesel has been gaining prominence as a promising alternative to replace petroleum derivatives since it can be produced from various raw materials, such as microalgae. Design/Methodology/Approach: Different vinasse dilutions were studied for the cultivation of Chlorella sorokiniana CTT 7727, being 5, 10 and 15% (v v-1) and N:P:K (20:5:20) 1% (v v-1) medium as a comparative standard. Biodiesel was produced by direct transesterification and analyzed by gas chromatography coupled to a flame ionization detector, enabling the identification and quantification of the fatty acid profile. Findings: The results obtained indicated that vinasse 10% (v v-1) proved to be promising for application as a culture medium for this microalgae species, as it guaranteed a good cell growth rate, high biomass productivity and lipid yield. Considering the biodiesel produced, it fits the regulatory standards analyzed by the National Agency of Petroleum, Natural Gas and Biofuels (ANP). Research, Practical & Social Implications: The research demonstrates the feasibility of cultivating the microalga Chlorella sorokiniana with diluted vinasse, highlighting the 10% concentration as promising for optimizing cell growth and lipid yield. The results ensure compliance with ANP regulations for biodiesel production, indicating immediate and sustainable applicability on an industrial scale. Socially, it contributes to the pursuit of biofuels, reducing dependence on fossil sources and promoting more sustainable practices in the bioenergy industry. Originality/Value: The study's originality lies in the unique combination of Chlorella sorokiniana CTT 7727, diluted vinasse, and biodiesel production in accordance with ANP regulations. It stands out for identifying the optimal vinasse concentration (10%) for cultivation, presenting an economical and effective approach. The strategic value is in the use of an alternative raw material cultivated with an industrial residue, promoting the diversification of the energy matrix and mitigating environmental impacts associated with conventional fuels.

Saturated Heterocyclic Sulfamoyl Fluorides: Building Blocks for the SuFEx Chemistry

A scalable protocol for direct SO2F2‐based fluorosulfonylation of saturated (hetero)cyclic and functionalized amines is reported. The method is cost‐effective and applicable for multigram preparation of structurally diverse compounds, as illustrated by the synthesis of 58 building blocks decorated with common functional groups. A comparison of overall yields of products demonstrates the advantages of the present method over alternative approaches. The obtained functionalized sp3‐enriched sulfamoyl fluorides can be considered a new generation of building blocks for SuFEx (sulfur fluoride exchange) chemistry. The synthetic utility of the synthesized building blocks was demonstrated by late‐stage reactions tolerating the SO2F functionality as well as transformations to provide the corresponding sulfamide, sulfamate, and sulfonamide derivatives.

Strain and model development for auto- and heterotrophic 2,3-butanediol production using Cupriavidus necator H16

The production of platform chemicals from renewable energy sources is a crucial step towards a post-fossil economy. This study reports on the production of acetoin and 2,3-butanediol heterotrophically with fructose as substrate and autotrophically from CO2 as carbon source, H2 as electron donor and O2 as electron acceptor with Cupriavidus necator. In a previous study, the strain was developed for the production of acetoin with high carbon efficiency. Acetoin can serve as a precursor for the synthesis of 2,3-butanediol by the integration of a butanediol dehydrogenase. In this study, different plasmid backbones and butanediol dehydrogenases were evaluated regarding efficiency for CO2-based 2,3-butanediol production. The developed strain utilizes the pBBR1 plasmid bearing a 2,3-butanediol dehydrogenase from Enterobacter cloacae and is characterized by 2,3-butanediol as the main product and a heterotrophic total product yield of 88.11%, an autotrophic volumetric productivity of 39.45 mg L−1 h−1, a total product carbon yield of 81.6%, an H2 efficiency of 33.46%, and a specific productivity of 0.016 g product per gram of biomass per hour. In addition, a mathematical model was developed to simulate the processes under these conditions. With this model, it was possible to calculate productivities and substrate usage at distinct time points of the production processes and calculate productivities and substrate usage with high resolution which will be useful in future applications.

Impact of irrigation systems on water saving and yield of greenhouse and open field cucumber production in Saudi Arabia

Water resources worldwide are limited, especially in desert areas like Saudi Arabia. Therefore, the rational and sustainable management of irrigation water supply is an imperative requirement. This research aimed to assess how different irrigation systems, such as partial root-zone drying (PRD) and regulated deficit irrigation (RDI), would affect the growth of cucumber crops. The study specifically focused on comparing the impact of these irrigation techniques when implemented with surface (S) and subsurface (SB) drip irrigation methods. The research was conducted in both controlled environments and open-field settings in central Saudi Arabia. Additionally, the study aimed to promote the adoption of RDI and PRD irrigation systems among Saudi farmers as a means to conserve essential irrigation water resources. The treatments consisted of two groups: the drip irrigation group with a single line (RDI), which includes full irrigation and deficit irrigation, and the group with the (PRD) for the root zone with two lines with the same irrigation ratios as the first group. The productivity of the RDI-S regular drip irrigation treatment was considered 100 % as the control on which the results of all treatments are measured. The results showed that in terms of irrigation technique, the PRD-SB technique had the highest productivity during the winter season in a greenhouse, with an average of 13.8 kg m−2 for all irrigation levels, while the RDI-SB technique had the highest productivity during the summer season, with an average of 16.1 kg m−2. Regarding irrigation level results, the study showed that an irrigation level of 100 % is the highest yield in all irrigation techniques, with a general average of 14.9 kg m−2 for all irrigation techniques during the winter season and 16.4 kg m−2 during the summer. The study showed that irrigation with the PRD-SB system was the most productive in the open field at all irrigation levels, with an average of 7.3 kg m−2. It could be concluded that using PRD and RDI systems for indoor and outdoor cucumber production can save irrigation water in arid regions.