Optimization Of Medium Composition Research Articles

Optimization of Fermentation and Biocontrol Efficacy of Bacillus atrophaeus XHG-1-3m2

Biological control plays an increasingly important role in various aspects of modern agriculture and forestry. Identifying biocontrol strains with commercial potential for effective disease management is currently a focal point in biological control research. In this study, Bacillus atrophaeus XHG-1-3m2, a strain with significant biocontrol potential against Wilsonomyces carpophilus causing shot hole disease in wild apricots, was developed. The study determined the antibacterial activity of the fermentation broth, the optimal fermentation medium composition and conditions, and explored its effectiveness in controlling Wilsonomyces carpophilus. The optimal fermentation medium for strain XHG-1-3m2 comprises 12.5 g/L yeast extract, 12.5 g/L soy peptone, 10.0 g/L sodium chloride, 1 g/L ammonium chloride, 1 g/L potassium dihydrogen phosphate, 1 g/L disodium hydrogen phosphate, and 0.5 g/L magnesium sulfate heptahydrate. With an initial pH of 7.0, a liquid volume of 40%, an inoculum volume of 3%, and shaking incubation at 28 °C for 24 h, the viable cell count reached 14 × 109 CFU/mL. In vitro and in vivo tests on leaves revealed that the fermentation broth and the biocontrol biofertilizer derived from this strain inhibited the leaf lesions caused by Wilsonomyces carpophilus on wild apricots, achieving inhibition rates of 94.62% and 82.46%, respectively.

Optimized medium conditions maximize colony regeneration from a single cell of Botryococcus braunii NIES836

Botryococcus braunii is a colonial alga recognized for its slow growth but high hydrocarbon accumulation. Although using genetic engineering to increase the growth rate and hydrocarbon yield of B. braunii is desirable, the presence of an extracellular matrix (ECM) significantly hinders the emergence of a homogeneous colony from a single DNA-transformed cell. Previously, we developed a method to isolate single cells without ECM from colonies. However, following the isolation of single cells, several months are required to regenerate colonies with a sufficient cell mass for subsequent analysis. To shorten the colony regeneration period, we investigated basal media and medium components, along with growth-promoting additives, in a series of single-factor experiments and optimized the concentrations of the medium constituents via response surface methodology (RSM). The results of the single-factor experiments revealed that the nitrogen source (a mixture of NaNO3 and NH4NO3), 1-naphthylacetic acid (NAA) and Fe(III)-citrate significantly increased the growth of B. braunii single cells into colonies. The optimal medium composition identified by RSM included 151.6 mg/L nitrogen source, 2.419 mg/L NAA and 15.3 mg/L Fe(III)-citrate. Verification experiments showed that the optimized medium resulted in a 1.75-fold increase in colony size compared with that of colonies grown in nonoptimized AF6 medium. This is the first report of the optimal medium composition for the regeneration of B. braunii colonies from single cells.

Increasing the Growth of Bridal Tears Flower Stem Cuttings (Antigonon leptopus) by providing Plant Growth Regulators and Planting Media

It is imperative to implement integrated control measures for Oil Palm Leaf-Eating Caterpillars (UPDKS), as continual chemical management can result in pest resistance and environmental degradation. Utilizing natural enemies for biological control involves the utilization of predators, pest-consuming animals, as well as parasites or bacteria with pathogenic properties against pests. Examples of predators, including Sycanus leucomesus and Eocanthecona furcellata, egg parasitoids, such as Trichogrammatidea thoseae, and larval parasites, such as Chaetexorista javana, are a few of the many types of organisms that can have an impact on the populations of their prey. These indigenous predators sustain themselves by feeding on host plants within their natural habitat. The bridal tears flower (Antigonon leptopus) is considered to be one of the host plants. Thus, it is imperative to promote the growth of Antigonon leptopus in order to provide a habitat for the natural predators of the UPDKS pest. The objective of this research was to identify the components of the planting medium and to establish the most effective concentration of growth regulators for propagating bridal tears stem cuttings (Antigonon leptopus). The research was conducted at the Indonesian Palm Oil Technology Institute (ITSI) Practice Garden in Medan, North Sumatra. The research was conducted over three months, from February to April 2024. The Factorial Randomized Block Design (RAK) method was employed, with the first factor, namely S (Planting Media), comprising three levels: Top Soil without solid, Top Soil with 20% Solid, and Top Soil with 40% Solid. The second factor, namely Plant Growth Regulators, was also treated with three levels: without plant growth regulators, concentration of 100 Mg/l, and concentration of 200 Mg/l. Thus, the study comprises nine treatment combinations, each with four replications. The analysis of variance (ANOVA) table is employed to assess the significance of the observed differences, with the Duncan multiple range test (DMRT) conducted at a 5% level of significance when warranted.The findings from the research indicated that the manipulation of the planting medium composition (S) had a notable impact on the number of leaves, number of roots, and fresh weight of the roots. Additionally, it was found to have a highly significant influence on the height of the shoots. The optimal composition of the planting medium was identified as S2. The manipulation of growth regulators (R) concentration had a notable impact on shoot height and root fresh weight, as well as a highly significant effect on the number of leaves and roots. R2 exhibited the most optimal concentration of growth regulators. The growth of Antigonon leptopus stem cuttings was not affected by the combination of planting medium composition (S) and growth regulator concentration (R) in a non-interacting manner.

Full maturation of in vitro Plasmodium falciparum oocysts using the AlgiMatrix 3D culture system

BackgroundPlasmodium falciparum oocysts undergo growth and maturation in a unique setting within the mosquito midgut, firmly situated between the epithelium and the basal lamina. This location exposes them to specific nutrient exchange and metabolic processes while in direct contact with the mosquito haemolymph. The limited availability of in vitro culture systems for growth of the various P. falciparum mosquito stages hampers study of their biology and impedes progress in combatting malaria.MethodsAn artificial in vitro environment was established to mimic this distinctive setting, transitioning from a 2D culture system to a 3D model capable of generating fully mature oocysts that give rise to in vitro sporozoites.ResultsA two-dimensional (2D) chamber slide was employed along with an extracellular matrix composed of type IV collagen, entactin, and gamma laminin. This matrix facilitated development of the optimal medium composition for cultivating mature P. falciparum oocysts in vitro. However, the limitations of this 2D culture system in replicating the in vivo oocyst environment prompted a refinement of the approach by optimizing a three-dimensional (3D) alginate matrix culture system. This new system offered improved attachment, structural support, and nutrient exchange for the developing oocysts, leading to their maturation and the generation of sporozoites.ConclusionsThis technique enables the in vitro growth of P. falciparum oocysts and sporozoites.

Optimized medium composition in Physalis alkekengi callus culture altered nitric oxide level for inducing antioxidant enzyme activities and secondary metabolites

Physalis alkekengi L. is a valuable medicinal plant from the Solanaceae family and has multiple therapeutic applications. This study aimed to develop an optimized protocol for callogenesis in P. alkekengi to obtain friable calluses with high biomass. The effect of different concentrations of picloram, casein hydrolysate (CH), basal media (Murashige and Skoog (MS) and Gamborg (B5)), and static magnetic field (SMF) were investigated on the callus induction and growth, signaling molecules, and enzymatic and non-enzymatic antioxidants. Results showed that CH (200 mgL−1) and SMF4 mT for 90 min increased callus induction and fresh weight in P. alkekengi, while different concentrations of picloram reduced callogenesis. Hypocotyl explants showed various callogenesis and metabolic responses depending on the basal medium type. The 2B5 medium supplied with CH 200 (mgL−1) induced friable and cream calluses with high biomass (0.62 g) compared to the MS medium (control). The maximum activity of superoxide dismutase and catalase activities was identified in the 2B5 medium and peroxidase in the 2MS medium. The highest total phenolic (129.44 µg g−1DW) content and phenylalanine-ammonia lyase activity were obtained in the 2MS medium, and total withanolides (49.86 µg g-1DW) and DPPH radical scavenging activity were observed in the 2B5 medium. The 2MS medium boosted the hydrogen peroxide and nitric oxide levels, while their contents alleviated in the 2B5 medium, although these parameters were higher than the control. The findings of this study suggest that an effective protocol for successful callogenesis in P. alkekengi and the nutrient composition of culture medium by affecting the level of signaling molecules can control the antioxidant defense system and callus growth.

Comparative genomic analysis and optimization of astaxanthin production of Rhodotorula paludigena TL35-5 and Rhodotorula sampaioana PL61-2.

Astaxanthin is a powerful antioxidant known to enhance skin, cardiovascular, eye, and brain health. In this study, the genome insights and astaxanthin production of two newly isolated astaxanthin-producing yeasts (TL35-5 and PL61-2) were evaluated and compared. Based on their phenotypic and genotypic characteristics, TL35-5 and PL61-2 were identified as basidiomycetous yeasts belonging to Rhodotorula paludigena and Rhodotorula sampaioana, respectively. To optimize astaxanthin production, the effects of cultural medium composition and cultivation conditions were examined. The optimal conditions for astaxanthin production in R. paludigena TL35-5 involved cultivation in AP medium containing 10 g/L glucose as the sole carbon source, supplemented with 1.92 g/L potassium nitrate, pH 6.5, and incubation at 20°C for 3 days with shaking at 200 rpm. For R. sampaioana PL61-2, the optimal medium composition for astaxanthin production consisted of AP medium with 40 g/L glucose, supplemented with 0.67 g/L urea, pH 7.5, and the fermentation was carried out at 20°C for 3 days with agitating at 200 rpm. Under their optimal conditions, R. paludigena TL35-5 and R. sampaioana PL61-2 gave the highest astaxanthin yields of 3.689 ± 0.031 and 4.680 ± 0.019 mg/L, respectively. The genome of TL35-5 was 20,982,417 bp in length, with a GC content of 64.20%. A total of 6,789 protein-encoding genes were predicted. Similarly, the genome of PL61-2 was 21,374,169 bp long, with a GC content of 64.88%. It contained 6,802 predicted protein-encoding genes. Furthermore, all essential genes involved in astaxanthin biosynthesis, including CrtE, CrtYB, CrtI, CrtS, and CrtR, were identified in both R. paludigena TL35-5 and R. sampaioana PL61-2, providing evidence for their ability to produce astaxanthin.

Analytically monitored cultivation of Arthrospira platensis on food waste extracts to compose a sustainable, low-prized, Zarrouk-based medium

ABSTRACT A sustainable, low-cost medium based on food waste for cultivating the cyanobacterium Arthrospira platensis (A. platensis) was investigated. Zarrouk medium components, especially phosphate, were substituted with extracts from beetroot peel, brewer’s grains, and walnut press cake. Ion concentrations of magnesium, calcium, iron, potassium, sodium, phos-phate, nitrate, sulfate, and chloride were analyzed to determine the optimal medium composition. Walnut press cake and brewer’s grains extracts showed high potential due to their magnesium, calcium, and phosphate content. Brewer’s grains extracts also provided glucose as an additional carbon source. Cultivations in shaking flasks and a photobioreactor (PBR) monitored cell growth through optical density and biomass concentration. The excess of magnesium and reduced phos-phate concentrations positively affected biomass production. A. platensis’s ability to metabolize glucose resulted in 68% higher biomass production. Growth in brewer’s grains extract required no additional phosphate. PBR cultivation showed A. platensis consumed significant magnesium and nitrate, achieving higher biomass concentrations with optimized gas exchange and light reflection systems.

Enhancing the yield of Xenocoumacin 1 in Xenorhabdus nematophila YL001 by optimizing the fermentation process

Xenocoumacin 1 (Xcn 1), antibiotic discovered from secondary metabolites of Xenorhabdus nematophila, had the potential to develop into a new pesticide due to its excellent activity against bacteria, oomycetes and fungi. However, the current low yield of Xcn1 limits its development and utilization. To improve the yield of Xcn1, response surface methodology was used to determine the optimal composition of fermentation medium and one factor at a time approach was utilized to optimize the fermentation process. The optimal medium composed of in g/L: proteose peptone 20.8; maltose 12.74; K2HPO4 3.77. The optimal fermentation conditions were that 25 °C, initial pH 7.0, inoculum size 10%, culture medium 75 mL in a 250 mL shake flask with an agitation rate of 150 rpm for 48 h. Xenorhabdus nematophila YL001 was produced the highest Xcn1 yield (173.99 mg/L) when arginine was added to the broth with 3 mmol/L at the 12th h. Compared with Tryptic Soy Broth medium, the optimized fermentation process resulted in a 243.38% increase in Xcn1 production. The obtained results confirmed that optimizing fermentation technology led to an increase in Xcn1 yield. This work would be helpful for efficient Xcn1 production and lay a foundation for its industrial production.

Biological Characteristics of the Mycelium and Optimization of the Culture Medium for Phallus dongsun.

This study aimed to elucidate the influence of various culture medium components, including carbon sources, nitrogen sources, inorganic salts, suspension agents, and temperature, on the mycelial growth characteristics of Phallus dongsun. Employing single-factor experiments and response surface methodology within glass Petri dishes, the research identified that carrot powder, soybean powder, and ZnSO4 notably enhanced the proliferation of aerial mycelium, significantly augmenting the growth rate of P. dongsun mycelium. The resultant mycelium was observed to be dense, robust, and fluffy in texture. In particular, ZnSO4 markedly accelerated the mycelium growth rate. Furthermore, xanthan gum was found to effectively modulate the medium's viscosity, ensuring a stable suspension and facilitating nutrient equilibrium. The optimal cultivation temperature was determined to be 25°C, with mycelial growth ceasing below 5°C and mycelium perishing at temperatures exceeding 35°C. The optimal medium composition was established as follows: wheat starch 5 g/l, carrot powder 5 g/l, soybean powder 7.50 g/l, glucose 10 g/l, ZnSO4 0.71 g/l, NH4Cl 0.68 g/l, xanthan gum 0.5 g/l, and agar 20 g/l. Under these optimized conditions, the mycelium of P. dongsun exhibited a rapid growth rate (1.04 ± 0.14 mm/day), characterized by a thick, dense, and well-developed structure. This investigation provides a theoretical foundation for the conservation, strain selection, and breeding of P. dongsun.

A Comprehensive Study on the Micropropagation of Costus igneus: Media Composition, Growth, and Development

Costus igneus, commonly known as insulin plant, is an ornamental plant valued for its spiral ginger- like foliage and medicinal properties. Micropropagation is an efficient method for rapid multiplication of Costus igneus. This study aims to determine the optimal media composition and culture conditions for in vitro propagation of C. igneus. Axillary bud explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations and combinations of plant growth regulators including auxins (indole-3-acetic acid, indole-3-butyric acid and naphthaleneacetic acid) and cytokinins (6- benzylaminopurine and kinetin). Microshoots cultured on MS + 1.5 mg/L BAP showed the highest shoot proliferation rate (98%) and maximum number of shoots per explant (12.6). Elongated microshoots were rooted on half-strength MS medium supplemented with different auxins. The highest rooting percentage (95%) and maximum number of roots per shoot (9.8) were observed on medium containing 2.5 mg/L IBA. The regenerated plantlets were acclimatized and successfully transferred to pots with 80% survival rate. Morphological and phytochemical analysis showed no significant differences between the in vitro propagated and mother plants. This study demonstrates the potential of micropropagation for large scale production of quality planting material of C. igneus. Further studies on genetic and epigenetic stability are recommended to validate this protocol for commercial applications.

Two-pot optimization of nutrient sources to enhance antioxidants in Citrus reticulata peel powder through solid-state fermentation with Aspergillus niger CGMCC 3.6189

This study aimed to optimize nutrient sources for enhancing the accumulation of antioxidants in Citrus reticulata peel powder (CRPP) through solid-state fermentation (SSF) using Aspergillus niger CGMCC 3.6189. A Plackett-Burman design revealed that four medium compositions, including yeast extract, NH4Cl, CaCl2, and MgCl2, significantly affected antioxidant accumulation in fermented CRPP. The optimal concentrations of these four compositions were predicted as 13.86, 0.40, 0.06, and 0.04 mg/g of CRPP, respectively, using a Box-Behnken design (BBD) when simultaneous optimization of total phenolic content (TPC), total flavonoid content (TFC), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacities using Derringer's desirability function. Under the optimal medium compositions, TPC, TFC, ABTS, and DPPH scavenging capacities of fermented CRPP (FO-CRPP) increased by 25.2%, 26.9%, 45.8%, and 57.3%, respectively, in comparison with the unfermented CRPP (UF-CRPP). The HPLC analysis exhibited notable decreases in the levels of hesperidin, narirutin, nobiletin, and tangeretin, while enhancements in the contents of p-coumaric acid, ferulic acid, narirutin, and hesperetin in FO-CRPP compared to UF-CRPP were observed. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses demonstrated changes in the surface microstructure and functional groups in FO-CRPP. Our findings suggested that yeast extract and NH4Cl significantly improve the accumulation of antioxidants in CRPP during SSF by A. niger CGMCC 3.6189.

Spectral analysis and dynamic properties of polyurethanes dyed with rhodamine 6G and rhodamine B as matrices of a solid-state laser element

A comparison was carried out of the nature of intermolecular interactions, elastic properties and gas permeability of the crosslinked polyurethanes doped with xanthene dyes and original polyurethane using IR spectroscopy, dynamic mechanical analysis (DMA) and electron paramagnetic resonance (EPR). The introduced dye can be considered as useful microimpurity which, however, can affect the efficiency of the laser. In IR spectra of polyurethanes the complex band of stretching vibrations of C=O groups is sensitive to the nature of intermolecular interaction of urethane groups. From the analysis of that band it is shown that in the presence of dyes, self-association of urethane groups within the hard segment predominates and the interaction of urethane groups with the oligoether component decreases, which can contribute to increasing the mobility of the flexible component. A decrease in the dynamic storage modulus (E’) and a decrease in the glass transition temperature (Tc) of polyurethanes in the presence of dyes is shown by the DMA method. The results of both DMA and IR spectroscopy indicate a greater increase in the mobility of the elastic component with the introduction of the rhodamine B dye, covalently bound to the polyurethane chain. According to nitroxyl paramagnetic probe data the introduction of both rhodamine B and rhodamine 6G dyes into polyurethanes increases their permeability to vapors of low-molecular weight compounds, but rhodamine 6G has a more prominent effect on this characteristic. This is consistent with DMA data indicating a greater increase in the Mc value in the presence of rhodamine 6G in polyurethane. The obtained results make it possible to determine the optimal composition of the active laser medium and are important in assessing the radiation resistance of the polymer matrix. Its increase is facilitated by a decrease in the storage modulus and an increase in the gas permeability of the polymer, leading to a decrease in pressure in the area of local heating.

A primary culture method for the easy, efficient, and effective acquisition of oligodendrocyte lineage cells from neonatal rodent brains

Oligodendrocytes (OL) are myelin-forming glial cells in the central nervous system. In vitro primary OL culture models offer the benefit of a more readily controlled environment that facilitates the examination of diverse OL stages and their intricate dynamics. Although conventional methods for primary OL culture exist, their performance in terms of simplicity and efficiency can be improved. Here, we introduce a novel method for primary OL culture, namely the E3 (easy, efficient, and effective) method, which greatly improves the simplicity and efficiency of the primary OL culture procedure using neonatal rodent brains. We also provided the optimal media composition for the augmentation of oligodendrocyte progenitor cell (OPC) proliferation and more robust maturation into myelin-forming OLs. Overall, E3 offers an undemanding method for obtaining primary OLs with high yield and quality. Alongside its value as a practical tool, in vitro characteristics of the OL lineage additionally identified during the development of the E3 method have implications for advancing research on OL physiology and pathophysiology.

A Thermotolerant Yeast Cyberlindnera rhodanensis DK Isolated from Laphet-so Capable of Extracellular Thermostable β-Glucosidase Production.

This study aims to utilize the microbial resources found within Laphet-so, a traditional fermented tea in Myanmar. A total of 18 isolates of thermotolerant yeasts were obtained from eight samples of Laphet-so collected from southern Shan state, Myanmar. All isolates demonstrated the tannin tolerance, and six isolates were resistant to 5% (w/v) tannin concentration. All 18 isolates were capable of carboxy-methyl cellulose (CMC) degrading, but only the isolate DK showed ethanol production at 45 °C noticed by gas formation. This ethanol producing yeast was identified to be Cyberlindnera rhodanensis based on the sequence analysis of the D1/D2 domain on rRNA gene. C. rhodanensis DK produced 1.70 ± 0.01 U of thermostable extracellular β-glucosidase when cultured at 37 °C for 24 h using 0.5% (w/v) CMC as a carbon source. The best two carbon sources for extracellular β-glucosidase production were found to be either xylose or xylan, with β-glucosidase activity of 3.07-3.08 U/mL when the yeast was cultivated in the yeast malt extract (YM) broth containing either 1% (w/v) xylose or xylan as a sole carbon source at 37 °C for 48 h. The optimal medium compositions for enzyme production predicted by Plackett-Burman design and central composite design (CCD) was composed of yeast extract 5.83 g/L, peptone 10.81 g/L and xylose 20.20 g/L, resulting in a production of 7.96 U/mL, while the medium composed (g/L) of yeast extract 5.79, peptone 13.68 and xylan 20.16 gave 9.45 ± 0.03 U/mL for 48 h cultivation at 37 °C. Crude β-glucosidase exhibited a remarkable stability of 100%, 88% and 75% stable for 3 h at 35, 45 and 55 °C, respectively.

Optimization of medium compositions and X-ray irradiation to enhance monacolin K production by Monascus purpureus in submerged fermentation

The secondary metabolite Monacolin K (MK), derived from Monascus, exhibits potential lipid-lowering and anti-tumor effects. In this study, a mutant strain M. purpureus M400–6 was generated through X-ray treatment, resulting in an average MK production of 181.97 mg/L (a 54.20% increase compared to the parent strain M. purpureus M1) over five successive generations. Furthermore, optimization of medium compositions using response surface methodology led to a further enhancement in MK production by the mutant strain to 266.63 mg/L. Moreover, based on the outcomes of single-factor experiments, the addition of L-citrulline demonstrated a significantly higher level of enhancement in MK production. Therefore, a comparative transcriptome analysis was conducted to unveil the impact of L-citrulline on MK biosynthesis in M. purpureus. The data revealed a significant upregulation of glycolysis pathways, while oxidative phosphorylation including the TCA cycle and the electron transport chain, exhibited significant downregulation. Furthermore, the metabolisms of serine, glycine, threonine, alanine, aspartic acid and glutamate were found to be significantly disturbed. Additionally, the expressions of MPs and MK biosynthetic gene cluster showed a significant downregulation and upregulation respectively. Overall, these findings provide insights into enhancing MK production in submerged fermentation and elucidate the impact of L-citrulline on secondary metabolism.

Direct Organogenesis of Citrus Cultivars from Shoot Tip Nodal Segments.

Citrus cultivar improvement via conventional breeding strategies is impeded by factors related to its reproductive biology. The orange is a hybrid between pomelo (Citrus maxima) and mandarin (Citrus reticulata). Among various orange cultivars, Valencia oranges have a bit of bitter tang mixed in with their sweetness, as Navel oranges are, the most widely cultivated citrus species, quite sweeter, and also don't contain any seeds. Tangelo mandarin orange cultivar is a hybrid of C. reticulata × C. maxima or × C. paradisi. The present study was undertaken to optimize the hormonal composition of the media with regard to plant growth regulators for in vitro propagation of sweet orange cultivars from nodal segment explants. The nodal segment explants were collected from three citrus cultivars, Washington Navel, Valencia and Tangelo. Murashige and Skoog (MS) medium supplemented with sucrose and different concentrations of growth regulators was used for shoot proliferation and root induction, and the optimum medium composition was assessed. The patent for Citrus Tissue Culture was obtained from the Office of Research Affairs, Haramaya University. The results indicate that the highest shoot response was recorded for Washington's navel with maximum shoot proliferation rate (99.75%), shoot number per explant (1.76), shoot length (10.70 cm), leaf number per explants (3.54) after three weeks of culture. In all experiments, no growth was observed for the basal MS medium. Phytohormone combinations of IAA (1.2 mg/L) and kinetin (2.0 mg/L) were found to be the best for shoot proliferation. Among the cultivars, there were significant differences for the highest rooting rate (81.255), root number (2.22), and root length (2.95 cm) variables for Washington Navel. The lowest rooting rate (48.45%), root number (1.47) and root length (2.26 cm) were observed for Valencia. The highest rooting rate (84.90%), root number per microshoot (2.22) and root length (3.05 cm) was on MS medium supplemented with 1.5 mg/L NAA. A comparison of different concentrations of IAA and NAA on root induction of microshoots from nodal segments of citrus cultivars demonstrated NAA was a more effective hormone than IAA.

Optimization of Stationary Liquid Fermentation Conditions for N-Methylsansalvamide Production by the Endophytic Strain Fusarium sp. R1

To improve the yield of the therapeutic agent N-methylsansalvamide (SA), optimization of stationary liquid fermentation conditions was conducted on an endophytic strain, Fusarium sp. R1, at flask level. Using a One-Factor-At-a-Time approach, the fermentation conditions for SA production were determined as follows: fermentation time of 13 d, 24 °C, initial pH of 6.5, seed age of 24 h, inoculum size of 5.0% (v/v), loading volume of 50% (v/v), and 20.0 g/L salinity. Sucrose, tryptone, and yeast extract were found to be the best sources of carbon and nitrogen. Using response surface methodology, the optimal medium compositions consisted of 22.5 g/L sucrose, 16.5 g/L tryptone, and 0.024 g/L yeast extract. Verification tests suggested that the SA yield under these optimal conditions reached up to 536.77 ± 2.67 mg/L, which was increased by almost ten times the initial yield (54.05 ± 3.45 mg/L). The findings indicate that a high SA production yield can be achieved by stationary culture of strain R1 under proper fermentation conditions using a low-cost medium. This study paves the way toward industrial-scale SA production by strain R1 for new drug development.

Combinatorial optimization of pathway, process and media for the production of p-coumaric acid by Saccharomyces cerevisiae.

Microbial cell factories are instrumental in transitioning towards a sustainable bio-based economy, offering alternatives to conventional chemical processes. However, fulfilling their potential requires simultaneous screening for optimal media composition, process and genetic factors, acknowledging the complex interplay between the organism's genotype and its environment. This study employs statistical design of experiments to systematically explore these relationships and optimize the production of p-coumaric acid (pCA) in Saccharomyces cerevisiae. Two rounds of fractional factorial designs were used to identify factors with a significant effect on pCA production, which resulted in a 168-fold variation in pCA titre. Moreover, a significant interaction between the culture temperature and expression of ARO4 highlighted the importance of simultaneous process and strain optimization. The presented approach leverages the strengths of experimental design and statistical analysis and could be systematically applied during strain and bioprocess design efforts to unlock the full potential of microbial cell factories.

Optimization of Fermentation Process for New Anti-Inflammatory Glycosylceramide Metabolite from Aspergillus sp.

A novel ceramide compound, named Aspercerebroside A (AcA), was successfully isolated from the ethyl acetate layer of the marine symbiotic fungus Aspergillus sp. AcA exhibited notable anti-inflammatory activity by effectively inhibiting the production of nitric oxide (NO) in RAW 264.7 cells at concentrations of 30 μg/mL and 40 μg/mL, offering a promising avenue for the treatment of inflammatory diseases. To optimize the yield of glycosylceramide (AcA), a series of techniques, including single-factor experiments, orthogonal experiments, and response surface optimization, were systematically employed to fine-tune the composition of the fermentation medium. Initially, the optimal carbon source (sucrose), nitrogen source (yeast extract powder), and the most suitable medium salinity (14 ppt) were identified through single-factor experiments. Subsequently, orthogonal experiments, employing an orthogonal table for planning and analyzing multifactor experiments, were conducted. Finally, a mathematical model, established using a Box-Behnken design, comprehensively analyzed the interactions between the various factors to determine the optimal composition of the fermentation medium. According to the model's prediction, when the sucrose concentration was set at 37.47 g/L, yeast extract powder concentration at 19.66 g/L, and medium salinity at 13.31 ppt, the predicted concentration of glycosylceramide was 171.084 μg/mL. The experimental results confirmed the model's accuracy, with the actual average concentration of glycosylceramide under these conditions measured at 171.670 μg/mL, aligning closely with the predicted value.

Heavy metal tolerance, and metal biosorption by exopolysaccharides produced by bacterial strains isolated from marine hydrothermal vents

The present study highlights heavy metal tolerance, EPS production, and biosorption capacity of four hydrothermal vent bacterial strains, namely Exiguobacterium aquaticum, Mammaliicoccus sciuri, Micrococcus luteus, and Jeotgalicoccus huakuii against As, Cd, Cr, Cu, Co, Pb and Ni. The biosorption assay showed high removal efficiency of As (83%) by E. aquaticum, Cd (95%) by M. sciuri, Cu (94%) by M. luteus, and Ni (89%) by J. huakuii and their produced EPS with these metals in aqueous solution were 84%, 85%, 98%, and 91%, respectively. The maximum EPS yield was attained by optimized medium composition consisting of 1% Xylose, and 1% NaCl at pH 7. In metal-amended conditions, the four bacterial strains showed induced EPS production in the initial concentrations. SEM with EDX and CLSM images showed that the growth and EPS production of bacterial strains were affected by metal ion concentrations. A phenol sulphuric acid method and BCA assay were used to identify both the carbohydrate and total protein content of four extracted EPS. A DPPH assay revealed that EPS influences free radical scavenging and has a highly enhanced synergistic effect with its antioxidant activity. FT-IR analysis of four extracted EPS showed the shifting of peaks in the functional groups of EPS before and after adsorption of metal ions. At pH 5 and after 60 min contact time metal removal efficiency and adsorption capacity increased as calculated for As, Cd, Cu, and Ni by four extracted EPS: (86%, 20 mg/g), (74%, 19 mg/g), (94%, 60 mg/g) and (89%, 32 mg/g) and (89%, 16 mg/g), (85%, 16 mg/g), (96%, 22 mg/g) and (91%, 16 mg/g), respectively. The Langmuir compared to the Freundlich model was found to better represent the adsorption by EPS providing maximum adsorption capacities for As (34.65 mg/g), Cd (52.88 mg/g), Cu (24.91 mg/g), and Ni (58.38 mg/g).