Medium Composition Research Articles

Application of Biotechnology for Sunflower Inbred Line Development: Immature Embryo Rescue

Immature embryos rescued in sunflower breeding programs represent one of the important procedures for creating a competitive research program. The development of inbred lines in a short period offers a significant advantage, enabling faster adaptation of sunflower hybrids to farmers’ needs, including new herbicide technologies, such as existing sulfonylurea- and imidazoline-based treatments or the introgression of new disease-resistant genes. In our research, we initiated immature embryo rescue by harvesting at 168 h, 216 h, 264 h, and 312 h after fecundations. The media used were based on MS (Murashige and Skoog) and supplemented with different concentrations of BAP, NAA, and GA3. For the experiments, three types of genotypes were used: inbred lines, populations, and sunflower hybrids. Our results demonstrated a significant connection between harvest timing, the medium used, and the genotype. The highest survival rates were recorded as up to 81% for hybrids and 71% for inbred lines. For immature embryo rescue, they were obtained at 312 h on MS5—2.0:0.4:0.4 (BAP:NAA:GA3). The genotype, culture medium composition, and harvesting time are essential factors for optimizing the in vitro rescue technique of immature sunflower embryos. The survival rates of immature embryos were significantly influenced by the interaction of these factors.

Cost-reduction strategy to culture patient derived bladder tumor organoids.

Organoids as self-organized structure derived from stem cells can recapitulate the function of an organ in miniature form which have developed great potential for clinical translation, drug screening and personalized medicine. Nevertheless, the majority of patient-derived organoids (PDOs) are currently being cultured in the basement membrane matrices (BMMs), which are constrained by xenogeneic origin, batch-to-batch variability, cost, and complexity. Besides, organoid culture relies on biochemical signals provided by various growth factors in the composition of medium. We propose sodium alginate hydrogel scaffold in addition to the fibroblast conditioned medium (FCM)-enriched culture medium that is inexpensive and easily amenable to clinical applications for the culture of bladder cancer PDOs. PDOs grown in sodium alginate and FCM based medium have proliferation potential, growth rate, and gene expression that are similar to PDOs cultured in BME. According to the results, sodium alginate has substantial mechanical properties and reduces variance in early passage bladder tumor organoid cultures collected from patients. Furthermore, using FCM based medium as an alternative solution to eliminate some essential growth factors can be considered, especially for low-resource situation and develop cost effective tumor organoids.

Flecking of fat-filled milk powders.

Flecking is an insolubility issue in fat-containing milk powders. The undissolved particles (flecks) are of different shapes and structures, primarily composed of fat and/or protein. The occurrence of flecking in reconstituted milk powders negatively impacts the visual appearance and overall quality of the final product, thereby influencing consumer acceptance and brand trust. Standard quality control measures, like wettability or insolubility, and analysis including rehydration testing are important but not sufficient in predicting, identifying and/or quantifying flecking, often necessitating additional measures to be implemented. Suitable additional analyses for flecking include confocal laser scanning microscopy, electron microscopy, particle size, and density analysis. However, it is crucial to highlight that merely tightening quality control parameters is insufficient to combat flecking. This approach does not allow for the implementation of rapid solutions when the issue is detected at the final stages of quality assessment. To effectively address fleck formation, it is necessary to scrutinize unit operations and identify precisely where, and how, in the process flecks are formed. The issue often requires reformulation and/or engineering interventions, making the final product more robust and resilient to fleck formation. To date, protein denaturation/aggregation and emulsion instability are proposed as major mechanisms governing fleck formation. Additionally, the effect of seasonality of milk chemical composition and reconstitution medium (water/coffee/tea) are other important factors. This work aims to review flecking in reconstituted fat-filled milk powder solutions by interrogating the production process, including the skim milk base wet and dry processing, alongside the powder storage conditions and reconstitution methods, and thereby identify strategies for the control of flecking.

Polysulfone-reinforced quorum quenching media with silica cage encapsulation: Advancing biofouling control in anaerobic membrane bioreactors

Microbial quorum quenching (QQ) using live QQ cells entrapped in a hydrophilic polymer network (e.g., hydrogel) reduces membrane biofouling but encounters challenges regarding mechanical robustness and long-term stability. This study addresses this limitation by developing a novel composite biomedia that encapsulates QQ cells (Rhodococcus sp. BH4) within porous silica cages, which act as a protective barrier against solvent exposure, and further reinforces the structure with polysulfone, a thermally and chemically stable polymer. Surface observations confirmed the successful encapsulation of the cells within the silica matrices. Further analyses revealed the distinct nature of the composite media composed of QQ bacteria, silica, and polymer networks with an amorphous structure essential for flexibility and cell viability. The mechanical properties of the polysulfone-reinforced biomedia were significantly improved, with tensile strength nearly four times higher than that of the conventional hydrogel-based biomedia, making it far more durable for long-term applications. When exposed directly to the solvent dimethylacetamide, unprotected BH4 cells experienced severe death and inactivation; however, encapsulation in the porous silica cages maintained 70% cell viability and 77% QQ activity, demonstrating the protective efficacy of the silica matrix. In anaerobic membrane bioreactor applications, the reinforced QQ media showed remarkable biofouling mitigation, extending operational times by approximately threefold and twofold compared to reactors with no media and vacant media, respectively. Using composite QQ media led to significant reductions in the concentrations of biopolymers and quorum-sensing signal molecules, contributing to prolonged membrane service times without negatively impacting overall treatment performance. These findings represent a significant advancement in developing QQ media for antifouling, sustaining the functionality of live QQ cells within durable polymer matrices.

Transport through a chiral tiling: The effect of Aperiodicity on flow and particle capture

There have been many models built to describe composite or porous media. Most are built from collections of regular objects, like spheres, or space filling tilings, that are arranged or modified after the fact in a random or pseudo-random configuration. In this article, the use of an aperiodic, chiral tiling as an alternative is explored. Using these tilings, the underlying structure is not uniform, and the behaviors exhibited by this kind of system when pairs of walls are removed uniformly from each tile are considered. A number of different flow patterns arise, some with a braided structure, some with distinct channeling, and others that explored nearly the entirety of the space available. Particle capture in these systems could approach 90% and was nearly independent of the permeability of the system. The tortuous path particles were forced to travel through the structure contributed to its performance. Extruding the structure indicates that it has potential to be used to disperse a concentrated inlet. Applications are in the area of catalytic converters, heat exchangers, separations equipment, thermal interface materials, and even structural components.

Biofiltration for odor mitigation in water resource recovery facilities.

Odor emissions, primarily from anthropogenic activities like waste treatment and industrial processes, pose significant challenges in urban areas, particularly near water resource recovery facilities. While these emissions are generally not toxic, they can adversely affect community wellbeing and investment, prompting stricter regulations in some regions. For example, New York State's hydrogen sulfide guidelines are more stringent than federal standards. Hydrogen sulfide, along with other reduced sulfur compounds, volatile organic compounds, and nitrogen compounds, are among the key odorants produced by water resource recovery facilities. Various methods have been explored to mitigate these odors, including chemical treatments, operational modifications, and air treatment strategies like biofiltration, activated carbon adsorption, and regenerative incineration. Among these, biofiltration stands out as an environmentally friendly option due to its high efficiency in removing hydrogen sulfide and other odorants without the need for chemicals. Biofiltration systems, including biofilters and biotrickling filters, use microorganisms immobilized in a bed of porous media to degrade odorous compounds. Biofilters, which operate with intermittent water supply, are highly effective at total odor removal. In contrast, biotrickling filters, which use continuous nutrient and water flow, are better suited for higher pollutant loads but struggle with compounds of low solubility. Key factors influencing biofilter performance include the empty bed residence time, media type, moisture content, and microbial diversity. This review explores recent advancements in biofilter technology, with a focus on the removal of hydrogen sulfide and organic sulfur compounds. It also highlights real-world applications in water resource recovery facilities and discusses critical design and operational parameters for improving odor control, such as media selection, residence time, pH regulation, and microbial management. Key studies underscore the importance of media composition and nutrient supply in optimizing biofilter performance, especially at higher pollutant concentrations. Understanding these factors will help inform future improvements in odor management for water resource recovery facilities.

Varied Growth Media Necessitate Different Light Regimes for Indoor Duckweed Cultivation

Controlled indoor cultivation of duckweed plants can support remediation of wastewaters through generation of plant biomass. Despite numerous advantages, indoor cultivation of duckweeds on agri-food wastewaters remains underexplored. Lighting regimes need to be optimised for duckweed growth and affordability of energy consumption, as it has been shown that the composition of wastewater growth medium can alter light utilisation. In the present study, four duckweed (Lemna minor) clones were grown under four different light regimes on either optimised half-strength Hutner’s medium or wastewater derived from the liquid fractions of anaerobically digested pig slurry. Cultivation of L. minor was assessed for the four light regimes using a commercial hydroponics plant growth medium in a 3.96 m2 multitiered cultivation system. When cultivated on optimised half-strength Hutner’s medium or diluted pig slurry under laboratory conditions, it appeared that photoperiod rather than light intensity was more important for duckweed growth. Yet, under moderate flow conditions within a larger scale multitiered cultivation system, greater light intensity appeared to support duckweed cultivation irrespective of photoperiod. These findings emphasise the need to move beyond small-scale and static assessments of duckweed before embarking on larger, industry-relevant scales.

Effect of Growing Media Composition and Watering Intervals on the growth of Gmelina arborea Roxb seedlings

Gmelina arborea Roxb is one type of forestry plant that has the potential to be cultivated. This is because in addition to having a high economic value, Gmelina arborea Roxb is a plant that is able to grow in critical areas and has a short life cycle. In addition, Gmelina arborea Roxb is one type of wood that has high productivity, high economic value, has a wide natural distribution, has a large genetic variation, can be bred easily, easy to master cultivation techniques, and is resistant to pests and diseases. The purpose of this study was the effect of planting media composition and watering interval on the growth of Gmelina arborea Roxb seedlings. The study used a complete randomised design (RCD) factorial pattern consisting of two factors: The first factor: the composition of planting media, the second factor: watering interval. The results showed that the treatment of media composition and watering intensity treatment and the combination of treatments had a significant effect on the growth of gmelina seedlings. The treatment with the composition of 750 g soil and 250 g cocopeat with watering intensity once a day gave the best results for the growth of gmelina seedlings.

Corn or Soybean Oil as the Sole Carbon Source for Polyhydroxybutyrate Production in a Biofuel Biorefinery Concept

The use of polyhydroxybutyrate (PHB) can help diminish fossil chemical dependency because it can partially replace petrochemical plastics due to its biodegradability and similar mechanical properties. However, its production costs are high compared with fossil-based plastics. Alternative carbon sources can be used in the fermentation media because they are renewable and low-cost. Vegetable oils are especially attractive due to their high carbon content, contributing to high production rates per gram of substrate. This work aimed to produce PHB from Cupriavidus necator LPB1421 using either corn or soybean oil as the sole carbon source. Urea was the best nitrogen source, enabling a DCW production of 4.35 g/L (corn oil) and 10.4 g/L (soybean oil). After media optimization, the DCW of corn oil reached 22.13 g/L, with 57.46% PHB accumulation (12.71 g PHB/L), whereas soybean oil led to a DCW of 19.83 g/L, with 54.91% PHB accumulation (10.89 g PHB/L). This media composition was employed in a kinetics assay, revealing similar fermentation parameters among both oils and a yield of 0.2118 g PHB/g for corn oil and 0.1815 g PHB/g for soybean oil. These results open the possibility of integrating PHB production with biofuel manufacturing in a bioethanol/biodiesel biorefinery concept.

MATRIX: a platform for cultivation profiling and bioactive discovery in natural product research

The MATRIX protocol presents a novel miniaturized 24-well plate approach for microbial cultivation profiling, enabling the efficient and parallel assessment of microbial metabolite production. This method integrates a media MATRIX within a microbioreactor to facilitate the creation of diverse growth conditions for microbial cultivation. The 24-well format supports the simultaneous study of multiple microbial strains and conditions, allowing the discovery of novel bioactive compounds. By employing a variety of media compositions and cultivations, MATRIX enhances the understanding of microbial metabolic pathways and interactions. This protocol provides a robust platform for natural product discovery, microbial ecology studies, and drug development, showcasing its potential to uncover new natural products and other valuable bioactives. The MATRIX approach offers a resource-efficient platform for microbial biodiscovery, contributing significantly to natural product research and drug development.

DMEM and EMEM are suitable surrogate media to mimic host environment and expand leptospiral pathogenesis studies using in vitro tools.

Pathogenic Leptospira species can survive and thrive in a wide range of environments. Distinct environments expose the bacteria to different temperatures, osmolarities, and amounts and sources of nutrition. However, leptospires are mostly cultured, in a laboratory setting under in vitro conditions that do not reflect natural environments. This constraint on laboratory cultures limits the applicability of in vitro studies to the understanding of even simple pathogenic processes. Here we report, investigate, and identify a medium and conditions that mimic the host environment during leptospirosis infection, expanding the available in vitro tools to evaluate leptospiral pathogenesis. We quantified genome-wide gene expression of pathogenic Leptospira interrogans cultured in different in vitro media compositions (EMJH, DMEM, EMEM, and HAN). Using EMJH as standard, we compared gene expression in these compositions to genome-wide gene expression gathered in a host environment: whole blood (WB) of hamsters after infection with pathogenic leptospires. Leptospires cultured in DMEM and EMEM media shared 40% and 47% of all differentially expressed genes (DEGs) of leptospires present within WB (FDR<0.01), while leptospires cultured in HAN media only shared 20% of DEGs with those from WB. Furthermore, gene and pathway expression of leptospires cultured on DMEM and EMEM media exhibited a better correlation with leptospires grown in WB, including promoting expression of a similar leptospiral lipid A profile to the one identified directly in host tissues. Taken together, these results indicate that commercial cell-culture media EMEM or DMEM are better surrogates for in vivo pathogenic studies than EMJH or HAN media in Leptospira . These alternative culture conditions, using media that are a standard supply worldwide, provide a reproducible and cost-effective approach that can accelerate research investigation and reduce the number of animal infections necessary for basic research of leptospirosis.

Biocementation beyond the Petri dish, scaling up to 900 L batches and a meter-scale column

Microbial-induced calcite precipitation (MICP), which leverages ureolytic microorganisms, has received significant attention during the past decade as a promising method for sustainable building and geoenvironmental applications. However, transitioning from lab-scale experimentation to volumes suitable for practical use poses challenges. This study addresses these obstacles by screening and analyzing over 50 strains sourced from (i) a natural environment in the canton of Ticino in Switzerland; (ii) microorganism banks; and (iii) an industry-scale bioreactor. Several ureolytic Sporosarcina species have been identified in the natural environment, and their ureolytic potential has been compared with that of other strains. A reference, banked microorganism yielded the highest ureolysis rate. When this latter strain was inoculated in 900 L batches and continuously cultivated at 5400 L, no contamination issues were observed, and the reference strain remained the dominant species. The produced culture, obtained under an optimized medium composition involving the circular valorization of NH4+, was subsequently used to induce the biocementation of a 650 kg column of 0–1 mm sand. The results reveal the successful stabilization of the whole mass, with undrained Tresca strength values ranging from 90 to 140 kPa. This research lays the groundwork for scalable MICP production, which is capable of meeting the demands of real-world building and geoenvironmental projects.

Thermal and Mechanical Bifurcation Stability Analyses of Clamped Hybrid Dual-FG Composite Annular and Circular Plates

This research evaluates the thermal buckling of novel hybrid dual-functionally graded (dual-FG) composite annular and circular plates. This composite plate is made of FG polymeric matrix which is reinforced with graphene platelets (GPLs) fillers for better performance. The distribution of GPLs is assumed based on the various linear FG models. Modeling of this medium is conducted by means of a consecutive homogenization approach. In the first step, the Voigt micromechanical rule is employed to obtain the effective elasticity properties of the polymeric FG materials. In the next step, the homogenization of the medium comprised of polymeric FG materials as the matrix and GPLs as the reinforcements is performed using the Halpin–Tsai micromechanical rule. It should be mentioned that the distribution and orientation of fillers are assumed uniform and random within the composite medium. Moreover, the uniform temperature rise state within the immovable clamped plate is selected when the thermal stability is target. Besides, when the mechanical stability is considered, a movable clamped plate under uniform compressive loads is selected. The nonlinear equilibrium equations are derived by considering the exponential higher-order shear deformation theory and geometrically nonlinear von Kármán strain relations. Utilizing the adjacent-equilibrium criterion and appropriate linearization, the equations of pre-buckling path and bifurcation point are characterized. A semi-analytical method based on the generalized differential quadrature and trigonometric expansion approaches is implemented to solve them. After verifying the provided model and solution technique by comparing the present model with simpler studies, novel results are calculated. In obtaining the novel results, the effect of hybrid dual-FG composite characteristics in tuning the critical temperature or compressive loads of the system is completely examined.

Development of supported nickel-containing catalysts for methane tri-reforming: influence of pretreatment conditions

To improve the efficiency of catalysts for methane tri-reforming, the effect of pretreatment conditions of the Ce0.2Ni0.8O1.2/Al2O3 catalyst on its physicochemical and functional properties was studied. A set of methods (thermal analysis, low-temperature nitrogen adsorption, X-ray phase analysis, electron microscopy, temperature-programmed reduction with hydrogen) has established that varying the composition of the gaseous medium (oxidizing, inert, reducing) used during pretreatment at 800 °C allows one to adjust the textural, structural and redox characteristics of the catalyst and, as a consequence, its functional properties. It has been shown that in the series of compositions of the gas environment used in the pretreatment of the catalyst, oxidative → inert → reducing, an increase in the specific surface area and dispersion of the active component is observed, but a decrease in the resistance of the sample to reoxidation and coking. It has been established that the highest and most stable performance of the methane tri-reforming process (H2 yield – 86 % at CH4 conversion – 95 %) is provided by the catalyst after pretreatment in an inert environment due to the implementation of the optimal degree of metal-support interaction and an increase in the concentration of centers involved in CO2 activation.

Development, Shelf Stability, and In-Vitro Evaluation of Liquid Bacterial Inoculant Acinetobacter lwoffii Strain PAU_31LN.

Acinetobacter has been recognized as a versatile plant growth promoting (PGP) rhizobacteria (PGPR) that produce multiple PGP traits. The present study was conducted to formulate an efficient and stable liquid bacterial inoculant (LBI) of Acinetobacter lwoffii strain PAU_31LN. In the current investigation, total 16 endophytic bacteria were isolated from cotton leaves and evaluated for plant growth-promoting features such as production of phytohormones, mineral solubilization, siderophore production, hydrogen cyanide (HCN) production, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. The leaf endophytic bacteria designated as 31LN was found promising for all the PGP traits and it was identified as A. lwoffii strain PAU_31LN by 16S rRNA gene sequencing. For the development of LBI of A. lwoffii strain PAU_31LN, 4.5 g/L yeast extract, 5 g/L NaCl, 5 g/L peptone, and 12.5 mM food-grade trehalose was optimized as appropriate medium composition using response surface methodology (RSM) and Box-Behnken design. Further, the viability of A. lwoffii strain PAU_31LN in the optimized formulation was observed as 1.1 folds higher over the control after 180 days of storage at room temperature. Moreover, nonsignificant variation was recorded in the functional traits of 180 days old LBI of A. lwoffii strain PAU_31LN and freshly prepared LBI. The in-vitro plant growth parameters such as length and seed vigor index of 7-day-old cotton seedlings were enhanced by the seed bio-priming with LBI of A. lwoffii strain PAU_31LN over the control. The results of the present study signify the importance of endophytes and statistical methods to formulate prominent LBI.

Formation of a Novel Antagonistic Bacterial Combination to Enhance Biocontrol for Cucumber Fusarium Wilt.

Paenibacillus polymyxa strain PJH16, isolated and tested by our team, suppresses cucumber Fusarium wilt as an efficient biocontrol agent. For further investigation, the strain has been combined with two other Bacillus strains (Bacillus velezensis VJH504 and Bacillus subtilis JNF2) to enhance biocontrol ability, which formed high-efficiency microbial agents in the current study. The methodological target taken is based on achieving the optimal growth conditions of the combined microbial agents; hence, the medium composition and culture conditions were optimized through a single-factor test, orthogonal test and response surface methodology. Following this, the effectiveness of the microbial combination was assessed through pot experiments, which provided a theoretical foundation for the synthesis of microbial flora to significantly control cucumber Fusarium wilt. The results showed excellent compatibility, proving suitable for the proliferation and growth of Paenibacillus polymyxa PJH16, Bacillus velezensis VJH504, and Bacillus subtilis JNF2 strains together, specifically, when the inoculation amounts were adjusted to 4% of each. Using the single-factor test and orthogonal test analysis, the optimum composition of culture medium for the composite strain was identified as 3% glucose as the optimal carbon source, 2% yeast extract powder as the preferred nitrogen source, and 1% dipotassium hydrogen phosphate as the most suitable inorganic salt. Furthermore, the optical density (OD600) of the composite strain solution reached its highest level at 3.16 under the following culture conditions: inoculation volume of 200 µL, 171 rpm culture speed, 21.6 h culture time, 30 °C cultural temperature, and an initial pH of 7.0. The pot experiment demonstrated that the mixed bacterial solution achieved a relative control efficacy of 93.4% against cucumber Fusarium wilt, which was significantly superior to that of single- strain or pesticide treatment, and also promoted cucumber growth. In summary, the microbial flora synthesized by the three Bacillus strains displayed a high bacterial concentration, following the optimization of culture conditions, and exerted remarkable control and growth-promoting effects on cucumber Fusarium wilt. This finding holds great significance for future developments of composite microbial agents.

Evaluating the impact of media and feed combinations on CHO cell culture performance and monoclonal antibody (trastuzumab) production

The choice of media and feeds significantly influences the performance of Chinese Hamster Ovary (CHO) mammalian cell cultures in producing desired biologics like monoclonal antibodies (mAb). Sub-optimal nutrient feed/media composition can severely impact cell proliferation and the quality of the final mAb product. For instance, proper protein glycosylation, crucial for mAb stability, safety, and efficacy, heavily relies on cell culture conditions. Currently, starter CHO culture media and daily supplemental feeds used in industrial manufacturing consist of proprietary composition of nutrients critical for mAb production. Standardized optimal media/feed combinations necessary for different cell lines are often lacking, necessitating individualized optimization for each cell line and mAb product. Here, we focused on a CHO-K1 cell line engineered to produce a Trastuzumab biosimilar and evaluated the effects of fourteen commercially relevant basal media and seven feeds on cell culture parameters such as viable cell density, viability, nutrient consumption, metabolite production, mAb titer, and mAb N-glycosylation. Our findings demonstrate clearly that the compositions of the basal medium and feed play a pivotal role in enhancing cell growth and mAb production. This work offers valuable insights into strategies for optimizing feed/media composition for glycosylated monoclonal antibody production using CHO cells.

Batch and semi-continuous fermentation with Parageobacillus thermoglucosidasius DSM 6285 for H2 production

BackgroundParageobacillus thermoglucosidasius is a facultatively anaerobic thermophile that is able to produce hydrogen (H2) gas from the oxidation of carbon monoxide through the water–gas shift reaction when grown under anaerobic conditions. The water–gas shift (WGS) reaction is driven by a carbon monoxide dehydrogenase–hydrogenase enzyme complex. Previous experiments exploring hydrogenogenesis with P. thermoglucosidasius have relied on batch fermentations comprising defined media compositions and gas atmospheres. This study evaluated the effects of a semi-continuous feeding strategy on hydrogenogenesis.ResultsA batch and two semi-continuous fermentations, with feeding of the latter fresh media (with glucose) in either 24 h or 48 h intervals were undertaken and H2 production, carbon monoxide dehydrogenase (CODH) activity, and metabolite consumption/production were monitored throughout. Maximum H2 production rates (HPR) of 0.14 and 0.3 mmol min−1, were observed for the batch and the semi-continuous fermentations, respectively. Daily feeding attained stable H2 production for 7 days, while feeding every 48 h resulted in high variations in H2 production. CODH enzyme activity correlated with H2 production, with a maximum of 1651 U mL−1 on day 14 with the 48 h feeding strategy, while CODH activity remained relatively constant throughout the fermentation process with the 24 h feeding strategy.ConclusionsThe results emphasize the significance of a semi-continuous glucose-containing feed for attaining stable hydrogen production with P. thermoglucosidasius. The semi-continuous fermentations achieved a 46% higher HPR than the batch fermentation. The higher HPRs achieved with both semi-continuous fermentations imply that this approach could enhance the biohydrogen platform. However, optimizing the feeding interval is pivotal to ensuring stable hydrogen production.

Enzyme loading in the support and medium composition during immobilization alter activity, specificity and stability of octyl agarose-immobilized Eversa Transform.

Eversa Transform (ETL) was immobilized on octyl agarose beads at two different enzymes loadings (1 mg/g and 15 mg/g) under 18 different conditions, including different pH values, buffers, additives (different solvents, Ca2+, NaCl). Their activity was analyzed at pH 5 and 7 with p-nitrophenyl butyrate and at pH 5 with triacetin, determining also its stability at pH 5 and 7 (in different media). Ca2+ stabilized ETL biocatalysts while phosphate destabilized them. The overloaded biocatalysts were generally less stable and with a lower specific activity than the lowly loaded biocatalyst. Results show that enzyme activity (even by a 3 fold factor) and stability of the immobilized enzyme may be tailored by controlling the immobilization conditions, but the effects of the immobilization conditions on activity depend on the substrate and conditions of activity determination, the effects on stability depend on the inactivation conditions. Moreover, the enzyme loading of the biocatalysts defines the effects of the immobilization conditions, and there are clear interactions between immobilization conditions (e.g., immobilization pH determines the effect of the presence of NaCl). These suggest that the extrapolation of the results obtained with one substrate under one condition to other conditions can lead to wrong decisions.

Various Planting Media And Concentrations Of Shallot Extract On The Growth Of Javanese Chili Cuttings(Piper retrofractum Vahl)

Effect of Various Planting Media and Concentration of Shallot Extract on the Growth of Java Chili Plant Cuttings (Piper retrofractum Vahl). Various Planting Media and Concentration of Shallot Extract on the Growth of Java Chili Plant Cuttings (Piper Retrofractum Vahl). The purpose of this study was to determine the composition of planting media and the concentration of shallot extract on the growth of cuttings of Javanese chili plants. This research was conducted in the experimental garden of the Faculty of Agriculture, Baturaja University, from January to April 2024. This study used a factorial completely randomized design (CRD), with 2 factors, namely: 1) comparison of planting media as many as 4 treatments, namely Soil (Control), Soil + Sand + Manure (1:1:1), Soil + Cocopeat + Manure (1:1:1), Soil + Husk Charcoal + Manure (1:1:1); 2) concentration of shallot extract as many as 4 treatments, namely; No Shallot Extract, 30% Concentration, 60% Concentration, 90% Concentration, and repeated 3 times. Observed variables: Shoot growth time, shoot length, number of leaves, root length, number of roots. The results showed that the interaction between planting media and growth hormone (shallot extract) had no significant effect on the growth parameters of Javanese chili plants. The combination of planting media soil + cocopeat + manure with 90% concentration of shallot extract gives results that tend to be better on all variables observed. The single factor treatment is a treatment that tends to be better on all observed variables. The single factor treatment of also gives results that tend to be better on all variables observed.