Nutritive Medium Research Articles

Objective: To investigate the use of biological ensiling of organic residues generated by pectiniculture as a nutritive medium in the production of the microalgae Tetraselmis suecica. Theoretical Framework: Biological ensiling is a process that transforms organic residues into a nutritive source through fermentation. In this context, pectiniculture residues, specifically the soft parts of fan shells, can be recycled and used

Objective: To investigate the use of biological ensiling of organic residues generated by pectiniculture as a nutritive medium in the production of the microalgae Tetraselmis suecica. Theoretical Framework: Biological ensiling is a process that transforms organic residues into a nutritive source through fermentation. In this context, pectiniculture residues, specifically the soft parts of fan shells, can be recycled and used as alternative media. Microalgae, such as T. suecica, are photosynthetic organisms that require nutrients for their growth, and their cultivation can benefit from these residues. Method: Twelve vertical bioreactors were used with three experimental treatments (T1, T2, T3) and treatments, one control (CT), with three replicates per treatment. The microalgae were inoculated at a density of 70 x 104 cells mL-1 in a culture volume of 80 L. Cultures were grown in open air with constant aeration. 0-, 60-, 70-, and 80-mL L-1 of the biological silage of fan shell soft parts (EBCA) were dosed. The silage was also chemically characterized and the growth of the microalgae and its relationship with temperature, salinity and pH were determined. Results and Discussion: The results showed that the dosage of 70 mL L-1 of EBCA in T. suecica cultures favors the growth of the microalgae. A significant increase in biomass and cell density was observed compared to the other treatments, indicating that this concentration of silage provides a suitable nutrient medium. The study also analyzed how temperature, salinity and pH conditions affect the growth of T. suecica, finding that certain optimal ranges of these factors can maximize biomass production. Research Implications: Our study demonstrates that pectin culture waste can be effectively recycled as a culture medium for T. suecica production, offering a sustainable and environmentally friendly solution for waste management. This could reduce reliance on traditional culture media and promote more sustainable practices in aquaculture and the microalgal industry. Originality/Value: This study stands out for its innovative approach in the use of organic waste from pectiniculture, such as the soft parts of the fan shell, for the generation of an alternative nutrient medium for microalgae. In addition, large volumes of fan shell wastes are currently being generated, so our work contributes to the management of these wastes.

Metabolic pathways that mediate the effects of food deprivation on reproductive behavior in female Drosophila melanogaster.

In most species studied, energy deficits inhibit female reproductive behavior, but the location and nature of energy sensors and how they affect behavior are unknown. Progress has been facilitated by using Drosophila melanogaster, a species in which reproduction and food availability are closely linked. Adult males and females were either fed or food deprived (FD) and then tested in an arena with a fed, opposite-sex conspecific with no food in the testing arena. Only FD females (not FD males) significantly decreased their copulation rate and increased their copulation latency, and the effects of FD were prevented in females fed either yeast alone or glucose alone, but not sucralose alone, cholesterol alone, or amino acids alone. It is well-known that high-fat diets inhibit copulation rate in this species, and the effects of FD on copulation rate were mimicked by treatment with an inhibitor of glucose but not free fatty acid oxidation. The availability of oxidizable glucose was a necessary condition for copulation rate in females fed either yeast alone or fed a nutritive fly medium, which suggests that the critical component of yeast for female copulation rate is oxidizable glucose. Thus, female copulation rate in D. melanogaster is sensitive to the availability of oxidizable metabolic fuels, particularly the availability of oxidizable glucose or substrates/byproducts of glycolysis.NEW & NOTEWORTHY Copulation rate was decreased in food-deprived female but not in male adults when tested without food in the testing arena. Copulation rate was 1) maintained by feeding glucose alone, yeast alone, nutritive medium lacking yeast, but not sucralose, amino acids, or cholesterol alone; 2) decreased by inhibition of glycolysis in females fed either nutritive medium or yeast alone; and 3) not affected by inhibition of fatty acid oxidation. Thus, female copulation rate was linked to glycolytic status.

Exploring the Interplay of Respiratory Infections and Bacterial Agents

Background: Bacterial infections are often associated with respiratory infections, commonly complicating conditions like pneumonia, bronchitis, and sinusitis. Understanding this link is crucial for effective diagnosis and treatment in managing respiratory health. Materials and Methods: Researcher cultivate bacteria from patients with respiratory diseases in a specialized nutritional medium. This process allows for the identification and characterization of pathogenic microorganisms and their interactions within the respiratory tract. By studying these cultivated samples, scientists can gain valuable insights into the nature of respiratory infections, including the types of bacteria presents, their behaviors, and how they interact with the respiratory system. This method plays a crucial role in understanding the microbiology of respiratory diseases, facilitating the development of targeted treatments and interventions to combat these conditions. Results: The results of our study revealed a significant correlation between the variables under investigation, supporting our hypothesis. Statistical analysis demonstrated a clear pattern of outcomes, with notable trends and variations observed in the collected data. Conclusion: In conclusion, our study underscores the importance of addressing bacterial infections as a critical aspect of managing respiratory illnesses. These findings contribute to a broader understanding of respiratory health and may inform strategies for more effective prevention and management of bacterial complications in respiratory infections.

Androgenesis in Hot Pepper by Chilli Anther Culture

In vitro androgenesis techniques play a key role in the quick generation of fully homozygous lines. This work's goal was to put the procedure for producing androgenic embryos in hot pepper populations into practice. A number of variables can affect androgenetic success, including the types and quantities of carbohydrate sources and the nature of the nutritional medium. Different sugar types were tested at different doses in anther culture of pepper to elucidate their influence on the yield of androgenesis. In this study, sucrose was used as a source of sugar, Murashige & Skoog (1962-MS) medium, silver nitrate (AgNO3), naphthaleneacetic acid (NAA), BAP and one breeding lines of pepper were used to know the genotypic effects on haploid embryo formation. It was found that one of the key elements influencing pepper anther and microspore culture success is genotype. Also, microspore stage and the cold treatment of flower bud responsible for the success of embryo formation. This embryo formation frequency has been calculated according to the results that were generated in one month and the frequency of embryo formation is 0.7%.

Isolation, identification, and tolerance analysis of yeast during the natural fermentation process of Sidamo coffee beans.

Yeast, which plays a pivotal role in the brewing, food, and medical industries, exhibits a close relationship with human beings. In this study, we isolated and purified 60 yeast strains from the natural fermentation broth of Sidamo coffee beans to screen for indigenous beneficial yeasts. Among them, 25 strains were obtained through morphological characterization on nutritional agar medium from Wallerstein Laboratory (WL), with molecular biology identifying Saccharomyces cerevisiae strain YBB-47 and the remaining 24 yeast strains identified as Pichia kudriavzevii. We investigated the fermentation performance, alcohol tolerance, SO2 tolerance, pH tolerance, sugar tolerance, temperature tolerance, ester production capacity, ethanol production capacity, H2S production capacity, and other brewing characteristics of YBB-33 and YBB-47. The results demonstrated that both strains could tolerate up to 3% alcohol by volume at a high sucrose mass concentration (400g/L) under elevated temperature conditions (40 ℃), while also exhibiting a remarkable ability to withstand an SO2 mass concentration of 300g/L at pH 3.2. Moreover, S. cerevisiae YBB-47 displayed a rapid gas production rate and strong ethanol productivity. whereas P. kudriavzevii YBB-33 exhibited excellent alcohol tolerance. Furthermore, this systematic classification and characterization of coffee bean yeast strains from the Sidamo region can potentially uncover additional yeasts that offer high-quality resources for industrial-scale coffee bean production.

Biocompatibility of Synechococcus sp. PCC 7002 with Human Dermal Cells In Vitro.

Being the green gold of the future, cyanobacteria have recently attracted considerable interest worldwide. This study investigates the adaptability and biocompatibility of the cyanobacterial strain Synechococcus sp. PCC 7002 with human dermal cells, focusing on its potential application in biomedical contexts. First, we investigated the adaptability of Synechococcus PCC 7002 bacteria to human cell culture conditions. Next, we evaluated the biocompatibility of cyanobacteria with common dermal cells, like 3T3 fibroblasts and HaCaT keratinocytes. Therefore, cells were directly and indirectly cocultured with the corresponding cells, and we measured metabolic activity (AlamarBlue assay) and proliferation (cell count and PicoGreen assay). The lactate dehydrogenase (LDH) assay was performed to determine the cytotoxic effect of cyanobacteria and their nutrition medium on human dermal cells. The cyanobacteria exhibited exponential growth under conventional human cell culture conditions, with the temperature and medium composition not affecting their viability. In addition, the effect of illumination on the proliferation capacity was investigated, showing a significant impact of light exposure on bacterial growth. The measured oxygen production under hypoxic conditions demonstrated a sufficient oxygen supply for further tissue engineering approaches depending on the number of bacteria. There were no significant adverse effects on human cell viability and growth under coculture conditions, whereas the LDH assay assessed signs of cytotoxicity regarding 3T3 fibroblasts after 2 days of coculturing. These negative effects were dismissed after 4 days. The findings highlight the potential of Synechococcus sp. PCC 7002 for integration into biomedical approaches. We found no cytotoxicity of cyanobacteria on 3T3 fibroblasts and HaCaT keratinocytes, thus paving the way for further in vivo studies to assess long-term effects and systemic reactions.

Uncovering the antifungal activities of wild apple-associated bacteria against two canker-causing fungi, Cytospora mali and C. parasitica

Cytospora canker has become a devastating disease of apple species worldwide, and in severe cases, it may cause dieback of entire trees. The aim of this study was to characterize the diversity of cultivable bacteria from the wild apple microbiota and to determine their antifungal ability against the canker-causing pathogenic fungi Cytospora mali and C. parasitica. Five bacterial strains belonging to the species Bacillus amyloliquefaciens, B. atrophaeus, B. methylotrophicus, B. mojavensis, and Pseudomonas synxantha showed strong antagonistic effects against pathogenic fungi. Therefore, since the abovementioned Bacillus species produce known antifungal compounds, we characterized the antifungal compounds produced by Ps. synxantha. Bacteria grown on nutritional liquid medium were dehydrated, and the active compound from the crude extract was isolated and analysed via a range of chromatographic processes. High-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance analyses revealed a bioactive antifungal compound, phenazine-1-carboxylic acid (PCA). The minimum inhibitory concentration (MIC) demonstrated that PCA inhibited mycelial growth, with a MIC of 10 mg mL−1. The results suggested that PCA could be used as a potential compound to control C. mali and C. malicola, and it is a potential alternative for postharvest control of canker disease.

Influence of nutrition medium composition on biosynthesis of agglutinins of Rhizoctonia solani RS

The influence of the composition of the nutrient medium on the yield of biomass and the biosynthesis of agglutinins of the mold fungus strain Rhizoctonia solani RS was studied. At the first stage of research, the agglutinin-producing micromycete strain was grown on liquid nutrient media (potato-glucose (PG), Chapek, Sabouraud) at a temperature of 28°C for 8 days. At the next stage of research, the composition of the culture medium was modified in order to select sources of nitrogen (NH4NO3, (NH4)2SO4, NaNO3, arginine, tryptophan, asparagine, threonine, peptone) and carbon (sucrose, glucose, starch) nutrition. Cultivation of the Rh. solani RS on a liquid PG medium, containing glucose in an amount of 20.0 g/l led to a maximum yield of fungal biomass of 23.58 ± 1.30 g/l and the production of its agglutinins (titer 16384). The studied micromycete strain was characterized by the ability to actively use the amino acids threonine or asparagine when added to the above nutrient medium in an amount of 0.1 mg/ml. At the same time, the hemagglutination activity of the micromycete agglutinins increased twofold (titer 32768) compared to the activity of agglutinins on the PG medium without the addition of amino acids (titer 16384).

Trehalose Induced regulations in Physio-biochemical attributes of Helianthus annuus under Lead stress

Heavy metal is a substantially severe abiotic environmental stress that is rising in many regions of the world. Current climate change circumstances and rapid industrialization increased heavy metal accumulation in soil and water. Overall, worldwide agricultural production decreased. Trehalose, a well-known plant growth regulator, is crucial in plants' responses to a variety of abiotic conditions. The Morpho-physiological and biochemical parameters were analyzed in hydroponic research to identify the possible role of trehalose in alleviating heavy metal lead acetate stress in sunflower (Helianthus annuus L.) crops. In the sole and mixed form, two Pb(C2H3O2)2 (Control and 30 micron) and one trehalose (50 M L-1) levels were used, and a half-strength Hoagland solution was used as a nutritional medium. The current study found that heavy metal stress had a significant negative impact on plant growth (root and shoot length), fresh and dry biomass, and plant water relations, as well as poor plant water relations, membrane stability, chlorophyll content, and antioxidant enzyme activities such as superoxide dismutase (SOD), peroxide (POD), ascorbate peroxide (APX), and catalase (CAT). MDA and H2O2 are the stress markers reduced by the application of trehalose. Exogenous treatment of trehalose, on the other hand, significantly mitigates the detrimental effects of metal toxicity by altering plant physiology, enhancing water relations, and providing robust antioxidant defense against heavy metal lead acetate stress. The findings of this study provide a new dimension to scientists' understanding of the beneficial usage of trehalose in plant science and offer up new research opportunities.

A meta-analysis of the Prevalence and Risk Factors of Community-acquired MRSA among Students at Abasyn University in Peshawar, Pakistan

Staphylococcus aureus is the most pathogenic species in the genus, having been linked to nosocomial infections as well as community-acquired infections. In healthy people, it frequently colonises the skin and mucous membranes asymptomatically, especially the anterior nares. These days, community-acquired MRSA is a significant issue. The goal of the current investigation was to determine MRSA's detrimental consequences in Khyber Pakhtunkhwa. Fifty samples were gathered from Abasyn University students in Peshawar for this purpose. The samples were taken using sterile nasal swabs, and they were inoculated on nutritional agar medium within eight hours. Catalase and coagulase tests revealed the presence of Staphylococcus aureus. Thirty of the fifty samples tested positive for Staphylococcus aureus. The following antibiotics were used: vincomycin, oxyacillin, augmentin, ampicillin, and foxittin. MRSA prevalence was 76.66%.

Synergism study of Bacopa monnieri and Piriformospora indica and its impact on Biomass and metabolite

BackgroundA symbiotic connection between Piriformospora indica and Bacopa monnieri (L.) Wettest, obtained through co-cultivation synergism, was found to improve growth, biomass production, and bacoside content in the plants. Brahmi (B. monnieri L.), a well-known Indian plant prized for its memory-boosting properties, has a lengthy history and a premium price tag. Because of its remarkable ability to colonize a wide variety of plant species, the axenically cultivable mycorrhiza-like endophytic fungus P. indica has gained a lot of interest recently.MethodsIn the current study, fungal spores from recently revived cultures were added to jam bottles next to rooted Brahmi plants for in vitro co-cultivation. The control plants were left without fungal discs. Pre-rooted micro-propagated Brahmi plants were treated with agar discs containing actively growing hyphae. For a period of 3 months, both trials were conducted with a fully randomized setup. Microscopy of the treated and control plant roots verified co-cultivation.ResultsMicroscopic examination of the roots of co-cultivated plants reveals a high degree of colonization with host plants. These endophytic fungal structures include intracellular chlamydospores, and arbuscules, an intercellular and intracellular hyphae network, and a mycelial network on the root surface. In both in vitro and in vivo co-cultivation studies, the plant extended the host plant’s lifespan in 3 months by displaying continuous regeneration; in contrast, the control plant displayed signs of senescence. With biomass exceeding the control by 1.18 times in vivo and 1.28 times in vitro. In vitro, co-cultivation circumstances also led to an increase in the rate of utilization of nutritional medium. In comparison to the control, the amount of bacoside increases to 100% in vivo after a month of co-cultivation and 33% in vitro after 3 months.ConclusionsIn the present investigation, in vivo co-cultivation showed a favorable interaction effect on biomass production as well as bacoside content, which can satisfy the raw material demands of Brahmi plants in pharmaceutical industries.

Unveiling the efficacy of pre-emergent application of young Eucalyptus globulus leaves as a weed control strategy: Bridging macroscopic effects and cellular responses

Allelopathy, the inhibition of neighbouring plant growth by certain plants, can be particularly useful if applied in a targeted way for weed management. So, this study aimed to assess and characterize the herbicidal activity of fresh and dried leaves from young Eucalyptus globulus Labill. trees applied as a soil amendment. For this, fresh and dried leaves (FL and DL, respectively) were incorporated into the soil at different concentrations (0, 1, 5, and 10% w/w), where Portulaca oleracea L. seeds were sown. After 5 weeks of exposure, results revealed that the soil incorporation of DL at 10% (w/w) presented the strongest herbicidal properties, inhibiting seed germination by 63% and inducing the loss of cell viability. To unravel the possible mode of action and the main targets at both cellular and subcellular levels, an in vitro experiment was performed. Purslane seeds were sown in a nutritive medium containing different dilutions of an aqueous extract prepared with dried eucalyptus leaves. After 5 days of exposure, germinated seedlings were processed for transmission electron microscopy and histological analyses as well as for reactive oxygen species (ROS) in vivo detection by confocal laser scanning microscopy. Results revealed that the allelochemical release from DL induced ROS overproduction, resulting in the loss of cell integrity and organization, which was characterized by damage to several cellular sub-structures, along with enhanced accumulation of lipid droplets. Overall, the incorporation of DL into the soil can represent a sustainable alternative to reduce synthetic herbicide application and subsequent environmental contamination.

Cryopreservation of Lilium Candidum Germplasm: Analysis of Pre- and Post-freeze Treatments

BACKGROUND: Lilium candidum L. is a perennial ornamental plant that has various medicinal properties and is used in the cosmetic industry. The species is facing threats from urbanization and climate change and requires urgent protection. The most secure and efficient technology for the longterm storage of plant genetic resources is cryopreservation, which involves preserving genetic material at extremely low temperatures. OBJECTIVE: Today, plant biodiversity is endangered because of the narrowing of its natural distribution areas and/or destruction for different purposes. This study concentrated on creating a cryopreservation process using shoot tips and calluses as explant sources for the long-term conservation of L. candidum species. MATERIALS AND METHODS: Populations of L. candidum naturally distributed from three different regions of Turkey (Kepsut, Balikesir; the area surrounding Bafa Lake, Aydın ; and Fethiye- Mu la) were grown in vitro to supply shoot tip and callus explants. Prior to freezing by droplet-vitrification and vitrification techniques, shoot tips and calluses were treated with MS nutritional medium supplemented with 0.4 M sucrose 7 g/L agar and plant vitrification solution 2 (PVS2). RESULTS: Cryopreserved shoot tips showed the highest levels of regeneration (71.8%) after a PVS2 treatment of 90 min, while calluses showed the highest levels of regrowth (63.9%) after a PVS2 exposure of 60 min. CONCLUSION: High levels of regrowth are produced when the various cryopreservation procedures described here are used to preserve both shoot tip and callus explants. This potentially makes the method promising for the long-term preservation of endangered L. candidum varieties.

LONG TERM CLASSICAL METHODS FOR THE PRESERVATION OF XANTHAN GUM-PRODUCING - Xanthomonas arboricola pathovar pruni STRAINS

The maintenance of viable and stable Xanthomonas cells is crucial for the xanthan reliable research and industrial production. The method, storage and recovery conditions should preserve both viability and phenotypical and genotypical features. Here, the effectiveness classical methods on the long-term preservation of different Xanthomonas arboricola pathovar pruni strains was to determine. Strains were preserved by monthly sub-culturing in solid medium and lyophilization. After 12 years the viability of the strains, was assessed, as well as their productive capacity and the viscosity of the xanthan gum produced by these strains kept by lyophilization and sub-culturing. Among the lyophilized strains, only those stored at -18 °C were viable after 12 years. The productive capacity of the strains were poorly affected by lyophilization, the passage of the cultures into a solid nutrition medium being sufficient for them to return to their normal metabolism. The viscosity of the synthesized xanthan gum was method-dependent and higher for the lyophilized strains. The work and its findings are new and original because a work on this topic has never been published before. The results obtained allow the breaking of paradigms regarding the preservation of Xanthomonas.

Callus and suspension culture techniques optimized for use in carrot breeding studies (Daucus carota ssp. sativus var. atrorubens Alef and D. carota)

In this study, studies were conducted to optimize callus and suspension culture methods for in vitro mutation breeding in purple and orange carrots. Following this, the developed mutant lines were subjected to in vitro salt stress selection. The study determined the optimal agar dose. The first germination, 50% germination, root-cotyledon formation and genuine leaf formation in carrot seedlings were analyzed daily in the study, which was continued with the determined 7g/L agar dose. The cotyledon and hypocotyl explants from the seedlings were cultivated for callus production in mixtures of MS-1, MS-2 and MS-3 nutritional medium. In the second and fourth weeks following the second subculture, callus production percentages and weights were measured. The MS-3 (1 mg/L 2,4-D + 0.5 mg/L kinetin) nutritional medium and hypocotyl explant were found to be particularly effective at producing callus. The second subculture's data on the number of plants that had successfully regenerated per callus, showed that the MS nutritional medium with 0.2 mg/L Thidiazuron (TDZ) was the best medium for plant regeneration. The dispersed calli were grown in a nutritional medium designed for suspension culture in a nutrient medium mixture comprising MS+0.1 mg/L kinetin. The results obtained with the optimization steps were used in the ongoing study.

Self-healing of recycled aggregate fungi concrete using Fusarium oxysporum and Trichoderma longibrachiatum

This research is aimed to investigate the performance and crack healing phenomenon of recycled aggregate concrete (RAC) by using fungi (Fusarium oxysporum and Trichoderma longibrachiatum) as potential bio-admixtures. The microbial behavior and efficiency of the chosen fungal strains were studied on induction in the RAC by direct intrusion and after being immobilized in recycled coarse aggregate (RCA). The microbial activity in concrete was activated using calcium lactate as nutrition medium. Analysis and comparison of both fungal inoculation approaches with the reference matrix was conducted based on mechanical performance, durability tests, self-healing attributes, and the supporting forensics. Based on the results, F. oxysporum is proven as the potential strain for enhancing RAC performance when immobilized in RCA. The attained increase in compression and tension using F. oxysporum is 11.62 % and 31.18 % respectively at the age of 28 days. Further, the mentioned strain reduced the water absorption by 0.8 % and enhanced the acid resistance of concrete by 4.5 % in terms of measured mass loss. The crack size of 1.34 mm was completely sealed through bio-metabolic activity of F. oxysporum immobilized in RAC and restored 58.75 % of its compressive strength. Fungus hyphae of both the strains were identified in the respective RAC mixes through microscopic examination by Field Emission Scanning Electron Microscopy (FESEM) which proves the compatibility of RCA as the suitable carrier medium for fungi. The crack filler compound was forensically confirmed as bio-calcite through Energy Dispersive X-ray spectroscopy (EDX), Thermogravimetry Analysis (TGA), and X-ray Diffraction (XRD) technique.

Study of the microbiological composition of sludge during the cultivation of Chironomus larvae

Silt (nutrition medium) is the habitat of many microorganisms that adapt well to water and soil. By extended aeration, it partially comes out of the sewage. The nature of organic impurities determines the composition of such a substrate, so its leading indicators may vary. Such a nutrient medium is one of the favorable conditions for the growth and development of Chironomus larvae and various microflora. The article presents the results of studies of bacteriological crops of the substrate for Chironomus larvae to establish the microbiological composition of the nutrient medium under various pasteurization modes. It was found that in native sludge, the growth of a colony of bacteria of the family Pseudomonas spesialis is 80 %, Bacillus subtilis is 15 %, and Micrococcus luteus is 5 % of the total number of colony-forming organisms. It was also found that different modes of pasteurization lead to a decrease in the number of microorganisms in the nutrient medium. When pasteurized at 65 °C (long-term), the number of microorganisms decreased by 16 times. When pasteurized at 75 °C (short-term), the number of colony-forming organisms decreased by 22 times, and at 95 °C (instant), it decreased by 358 times compared with the native form of the nutrient medium.

Microphase separation of living cells

Self-organization of cells is central to a variety of biological systems and physical concepts of condensed matter have proven instrumental in deciphering some of their properties. Here we show that microphase separation, long studied in polymeric materials and other inert systems, has a natural counterpart in living cells. When placed below a millimetric film of liquid nutritive medium, a quasi two-dimensional, high-density population of Dictyostelium discoideum cells spontaneously assembles into compact domains. Their typical size of 100 μm is governed by a balance between competing interactions: an adhesion acting as a short-range attraction and promoting aggregation, and an effective long-range repulsion stemming from aerotaxis in near anoxic condition. Experimental data, a simple model and cell-based simulations all support this scenario. Our findings establish a generic mechanism for self-organization of living cells and highlight oxygen regulation as an emergent organizing principle for biological matter.

Antibacterial and Antioxidant Activity of Ziziphora clinopodioid Lam. (Lamiaceae) Essential Oil.

The genus Ziziphora belongs to medicinal plants. It is often used as a stomach tonic, carminative, antimicrobial, and expectorant; the extracted essential oils can be used as a second line of defence against pathogens. This study aimed to determine the antioxidant activity of essential oils of Z. clinopodioides as well as antibacterial activity against foodborne pathogens (Bacillus sp., Escherichia coli, Staphylococcus aureus and Pseudomonas sp.). The antibacterial activity of Z. clinopodioides essential oil was determined using the microdilution (M.D.) method in the nutritional broth medium and the agar disk diffusion assay. The result demonstrated that essential oil exhibit solid antibacterial properties against both gram-positive and gram-negative bacteria. Sequentially regarding MIC and MBC values, Escherichia coli was a higher level of resistance to the essential oil compared to Bacillus sp. Our findings suggested that the essential oil of Z. clinopodioides could be used as an antibacterial agent. The total antioxidant capacity of Z. clinopodioides leaves was assessed as ascorbic acid equivalents per gram of the leaves essential oil extract. The total antioxidant capacity was determined using ascorbic acid (y=0.1185x + 49.508, R2=0.3877). While the result of Z. clinopodioides was (y=0.1372x + 40.032, R2=0.4503).

Carbonate and Oxalate Crystallization Effected by the Metabolism of Fungi and Bacteria in Various Trophic Conditions: The Case of Penicillium chrysogenum and Penicillium chrysogenum with Bacillus subtilis

The present work contributed to the patterns of crystallization affected by the metabolism of fungi and bacteria in various trophic conditions and specifically covers the case of Penicillium chrysogenum and P. chrysogenum with Bacillus subtilis. The cultivation of microorganisms was carried out on the dolomitic calcite marble in liquid Czapek–Dox nutrient medium with glucose concentrations of 1, 10 and 30 g/L. The study of the crystal component of mycelium formed on the marble surface was supported through powder X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy; the quantitative content of the extracellular polymer substance (EPS) and low-molecular-weight organic acids (LMWOAs) in the medium was determined through chromatography–mass spectrometry (GC-MS). The results obtained clearly demonstrated the unique ability of the fungus P. chrysogenum to not only release organic acids (primarily oxalic), but the EPS also which significantly affected the pH of the culture liquid and, accordingly, the carbonate and oxalate crystallization. Carbonate crystallization manifested in the presence of Bacillus subtilis as well. The transition from oxalate crystallization to carbonate and vice versa could occur with a change in the species composition of the microbial community as well as with a change in the nutritional value medium. Under the conditions closest to natural conditions (glucose content of 1 g/L), through the action of P. chrysogenum, oxalate crystallization occurred, and through the action of P. chrysogenum with B. subtilis, carbonate crystallization was observed. The identified patterns can be used to reveal the role of fungi and bacteria in the oxalate–carbonate pathway.