Solid Medium Research Articles

Identification and characterisation of antimicrobial compound produced by probiotic Alkalihalobacillus clausii 088AE.

In the present study, Alkalihalobacillus clausii 088AE was evaluated for the production of antimicrobial compounds, their characterisation, and identification. The results showed that, 48-h-old A. clausii supernatant is able to inhibit the growth of indicator bacteria Micrococcus luteus MTCC 106T (7.0 ± 0.51 mm). The cultivation of 088AE on solid media along with XAD16N beads for 5 days, and isopropanol extraction of antimicrobial compound thereof showed enhanced antimicrobial activity (19.67 ± 0.58 mm) against indicator strain. Further purification with a reversed-phase C18 cartridge yielded a powder with 389.12 ± 10.08 μg of protein per mg. The UV spectra of the sample revealed the characteristic aromatic amino acid peaks at 262 and 276 nm. The results of triple-quadrupole mass spectrometry showed a peak of 1055 m/z, confirming the existence of 10542+, i.e., 2108 Da, suggestive of class I lantibiotic clausin. Furthermore, in silico analysis confirmed the presence of genes responsible for the production of lanthipeptide clausin. The clausin is stable in the presence of proteases (trypsin and pepsin), high temperature (100 °C), pH up to 11 and showed antimicrobial activity against Listeria monocytogenes ATCC 19115, M. luteus, and Staphylococcus aureus ATCC 6538P. Therefore, it could be useful to control gut infections caused by Gram-positive pathogens.

Computational and spectral analysis of derivatives of 9,9-dimethyl-9,10-dihydroacridine and 10-Phenyl-10H-phenothiazine-5,5-dioxide with hybridized local and charge-transfer excited states for optoelectronic applications

Aiming to combine the advantages of both prompt fluorescence and thermally activated delayed fluorescence in single emitter, molecular design of emitters with hybridized locally excited and charge transfer states were investigated by computational approaches and optical spectroscopy. Taking into account the results of the theoretical screening, the most promising derivatives of 9,9-dimethyl-9,10-dihydroacridine and 10-phenyl-10H-phenothiazine-5,5-dioxide based with the different linking topology (meta- and para-isomers) were selected for the synthesis and experimental investigations. Both the compounds exhibit ultraviolet LE emission peaking at ca. 360 nm, green ICT peaking at ca. 510 nm, and deep-blue HLCT emission peaking at ca. 430 nm when they are molecularly dispersed in the solid media of the different polarity. The developed emitters allow to obtain deep-blue electroluminescence for the host-containing OLEDs and green electroluminescence of host-free devices with the efficiency of exciton production of 42 and 73%, respectively. Efficient exciton production is due to the spin-flip switching via thermally activated processes which is much more efficient than prompt fluorescence. Showing the impact of the linking topology, the para-isomer demonstrated more efficient triplet harvesting in OLEDs than meta-isomer. A detailed discussion on the structure–property relationships and on some discrepancies between the results of the results of theoretical calculations and spectral analysis allows to obtain important insights on the photophysical properties of these compounds.

Streptomyces marispadix sp. nov., isolated from marine beach sediment.

A novel actinomycetal strain, designated M600PL45_2T, was isolated from marine sediments obtained from Ingleses beach, Porto, on the Northern Coast of Portugal and was subjected to a polyphasic taxonomic characterisation study. The here described Gram-reaction-positive strain is characterised by the production of a brown pigment in both solid and liquid medium and forms typical helical hyphae that differentiate into smooth spores. The results of a phylogenetic analysis based on the 16S rRNA gene sequence indicated that M600PL45_2T has a high similarity to two members of the genus Streptomyces, Streptomyces bathyalis ASO4wetT (98.51 %) and Streptomyces daqingensis NEAU ZJC8T (98.44 %). The genome of M600PL45_2T has a size of 6 695 159 bp, a DNA G+C content of 70.71 mol% and 5538 coding sequences. M600PL45_2T grows at 15-37 °C and with a maximal growth rate between 25 °C and 30 °C. Growth at pH 6.0 to 9.0 with the optimal range between 6.0 and 7.5 was observed. M600PL45_2T showed a high salinity tolerance, growing with 0-10 % (w/v) NaCl, with best growth with 1-3% (w/v) NaCl. Major cellular fatty acids are iso-C15:0 (25.03 %), anteiso-C15:0 (17.70) and iso-C16:0 (26.90 %). The novel isolate was able to grow in media containing a variety of nitrogen and carbon sources. An antimicrobial activity screening indicated that an extract of M600PL45_2T has inhibitory activity against Staphylococcus aureus. On the basis of the polyphasic data, M600PL45_2T (= CECT 30365T = DSM 114036T) is introduced as the type strain of a novel species, that we named Streptomyces marispadix sp. nov.

Paracholeplasma manati sp. nov. isolated from Florida manatees (Trichechus manatus latirostris).

Four novel strains of a member of the genus Paracholeplasma (OakleyT, Holly, Lorelei and Ariel) were isolated from skin of Florida manatees (Trichechus manatus latirostris). These strains were phenotypically and genetically characterized and compared with the known species of the genera Acholeplasma (A.), Alteracholeplasma (Al.), Haploplasma (H.), Paracholeplasma (P.) and Mariniplasma (M.). All the strains produced acid from glucose but did not hydrolyze arginine or urea. All were propagated in ambient air supplemented with 5±1 % CO2 at 35-37 °C using SP4-Z, Columbia and brain-heart infusion medium. Colonies on solid medium showed a typical fried-egg appearance and transmission electron microscopy revealed a typical mycoplasma-like cellular morphology. The results of phylogenetic analyses based on partial 16S rRNA, rpoB, gyrB and parE gene sequences and the whole proteome data indicated that the novel species is a unique species but phylogenetically closely related to Paracholeplasma vituli, Paracholeplasma morum and 'Paracholeplasma brassicae'. The average nucleotide identity and digital DNA-DNA hybridization values between strain OakleyT and the closely related species were significantly lower than the accepted thresholds for describing novel prokaryotic species at the genomic level. On the basis of the genomic, phenotypic and phylogenetic properties, the novel strains represent a novel species of the genus Paracholeplasma, for which the name Paracholeplasma manati sp. nov. with the type strain OakleyT (=NCTC 14352T =DSM 110686T) is proposed. The genomic DNA G+C content and complete draft genome size for the type strain are 38.35 % and 1 873 856 bp, respectively.

Neutrinos above the Earth's Surface

In article “Doppler Effect and neutrino acoustic signatures”, published in the journal “LA MULTIAPP” on February 25, 2022, I was forced to touch on an astrophysical topic when, in the data stream obtained by monitoring the acoustic noise of the earth’s crust with high amplitude resolution (more 240 dB) and in a wide frequency band (from 0.1 Hz to 50 kHz) events began to appear, the forms and frequencies of which are not typical for geophysics and seismology. Similar forms can be seen in works on the detection of acoustic traces of neutrino decay in water and ice. The possibilities of increasing the sensitivity in measurements in a solid medium are discussed. In addition, underwater and underground facilities are being built that use the effect of Cherenkov radiation. All of these methods require complex and very expensive installations on a huge scale. Even acoustic measurements in water and in wells are very laborious and expensive, and most importantly: such measurements are forever tied to a specific place. Therefore, the creation of a light, compact and mobile device for recording acoustic traces of neutrino decay is an urgent task, the solution of which will allow recording traces of neutrino decay not only in water and the earth's crust, but also in air, into space, on planets and satellites.

Combined System for the Simultaneous Delivery of Levofloxacin and Rifampicin: Structural and Functional Properties and Antibacterial Activity.

The therapy of resistant forms of tuberculosis requires the simultaneous use of several drugs, in particular, a combination of rifampicin and levofloxacin. In this paper, we aimed to design a combined system for the simultaneous delivery of these drugs for potential inhalation administration. A feature of this system is the incorporation of rifampicin into optimized liposomal vesicles capable of forming a multipoint non-covalent complex with chitosan-β-cyclodextrin conjugates. Levofloxacin is incorporated into cyclodextrin tori by forming a host-guest complex. Here, a comprehensive study of the physicochemical properties of the obtained systems was carried out and special attention was paid to the kinetics of cargo release for individual drugs and in the combined system. The release of levofloxacin in combined system is slow and is described by the Higuchi model in all cases. The release of rifampicin from liposomes during the formation of complexes with polymeric conjugates is characterized by the change of the Higuchi model to the Korsmeyer-Peppas model with the main type of diffusion against Fick's law. Microbiological studies in solid and liquid growth media a consistently high antibacterial activity of the obtained systems was shown against B. subtilis and E. coli.

Enhanced production of bioactive plumbagin in hairy root cultures and adventitious root cultures of Plumbago zeylanica L. by a novel apocarotenoid elicitor, α-ionone

Plumbagin, a medicinally important secondary metabolite is produced in the roots of Plumbago zeylanica Linn. Natural harvest of plumbagin from roots is a destructive process that destroys the entire plant. The aim of this study was the in vitro production of plumbagin at high concentrations. For this purpose, hairy root cultures (HRCs) and adventitious root cultures (ARCs) were induced from P. zeylanica leaf explants. Additionally, first-time α-ionone was used as an elicitor to trigger plumbagin biosynthesis. HRCs were developed using the two different strains of Agrobacterium rhizogenes (LBA1334, and R1000). R1000 strain showed the highest HR induction efficiency. ARCs were induced from the leaf explants growing in Murashige and Skoog (MS) solid media supplemented with 1 mg/L indole-3-butyric acid. Newly emerged adventitious roots were used to develop root suspension cultures in a liquid MS medium. Plumbagin content was determined by HPLC/DAD. Both HRCs and ARCs showed fast growth kinetics. The greatest increase in the production of plumbagin was achieved with 10 µM α-ionone. As compared to untreated controls, the optimum α-ionone dose resulted in a 3.6-fold and 3.1-fold increase in plumbagin in HRCs, and ARCs, respectively. These results support that α-ionone elicitor-treated HRCs and ARCs are promising technology for improved production of plumbagin to meet commercial demand.

Exploring the Antibacterial Effects of Ozonated Oils in Medicine: A Study on Escherichia coli Inhibition

ABSTRACT Ozonated oil has a long tradition in medical therapy. Here, the results from previous studies regarding the antibacterial effects of ozonated oils were compared. In addition, the aim of this study was to further examine the antibacterial activity against Escherichia coli for two different ozonated oils, in regard to the ozone exposure time and amount. Using agar dilution, the minimum inhibitory concentration of the oils was studied. For all of the tested concentrations with the agar dilution method, bacterial growth was observed. Furthermore, agar dilution was combined with spread-plating to determine the inhibition zone with and without the emulsifier. The emulsifier-free and emulsifier-containing experiments with agar dilution and spread-plating did not result in an inhibition of bacterial growth by ozonated oils. Moreover, the bacteria were exposed to the oils for various intervals before being grown on either solid or liquid medium to determine the time-dependent antibacterial effects of the ozonated oil. For both media, the results were compared to non-ozonated oil and NaCl solution as a negative control. The bacteria in the solid medium were already completely inactivated after 5 min of exposure with the ozonated oil. For the liquid medium, also shorter exposition times were investigated. After 1 min, there was no inhibition in the ozonated oils with the liquid medium. After 5 min, the bacterial growth in the ozonated oils was significantly reduced in the liquid medium.

Reduced Survival and Resistance of Rhodotorula mucilaginosa Following Inhibition of Pigment Production by Naftifine.

Pigments produced by micro-organisms could contribute to their pathogenesis and resistance. The investigation into the red pigment of R. mucilaginosa and its ability to survive and resist has not yet been explored. This study aimed to investigate the survival and resistance of the R. mucilaginosa CQMU1 strain following inhibition of pigment production by naftifine and its underlying mechanism. The red-pigmented Rhodotorula mucilaginosa CQMU1 yeast was isolated from an infected toenail of a patient with onychomycosis. Cultivation of R. mucilaginosa in liquid and solid medium showed the effect of naftifine after treatment. Then, analysis of phagocytosis and tolerance to heat or chemicals of R. mucilaginosa was used to evaluate the survival and resistance of yeast to different treatments. Naftifine reversibly inhibited the pigmentation of R. mucilaginosa CQMU1 in solid and liquid media. Depigmented R. mucilaginosa CQMU1 showed increased susceptibility toward murine macrophage cells RAW264.7 and reduced resistance toward different types of chemicals, such as 1.5-M NaCl and 0.5% Congo red. Inhibition of pigment production by naftifine affected the survival and growth of R. mucilaginosa and its resistance to heat and certain chemicals. The results obtained could further elucidate the target of new mycosis treatment.

Cellulase and Xylanase Production by a Newly Isolated Penicillium crustosum Strain under Solid-State Fermentation, Using Water Hyacinth Biomass as Support, Substrate, and Inducer

Cellulase and xylanase have been widely studied for bioconversion processes and applied in various industries. The high cost of these enzymes remains to be the major bottleneck for large-scale commercial application of lignocellulosic biorefinery. The use of agroindustrial residues and weeds as fermentation substrates is an important strategy to increase cellulolytic enzymes production and reduce costs. Penicillium crustosum was newly isolated and selected to study its enzyme production during solid-state fermentation (SSF). Natural and pretreated water hyacinth (WH) biomass was used as support, substrate and inducer of cellulases and xylanases. Thermochemical pretreatments of WH biomass at 121 °C and sulfuric acid at three concentrations (0.2, 0.6 and 1 M) were assayed. The pretreatments of WH biomass released mono- and oligo-saccharides that favored fungal growth and enzymes production on SSF. WH is a cost-effective substrate-support and inducer, which to be used as a solid medium, was impregnated with a saline solution, containing only (NH4)2SO4, KH2PO4 y MgCl2. Maximum cellulases (carboxymethylcellulase (CMCase)) and xylanases productions of P. crustosum cultured on SSF were reached using the WH pretreated biomass with H2SO4 0.6 M and 121 °C. The simultaneous CMCase and xylanases production reached (647.51 and 4257.35 U/g dry WH, respectively) are among the highest values ever reported.

Metabolic Characteristics of Hairy Root Clones of Scutellaria pycnoclada and Scutellaria baicalensis

Scutellaria baicalensis is the most studied species of the genus, while Scutellaria pycnoclada is a poorly studied endemic species. Ten lines of the hairy roots of S. pycnoclada were obtained using Agrobacterium rhizogenes A4. The hairy root cultures of S. pycnoclada and the previously obtained roots of S. baicalensis were cultured on liquid and agar Gamborg media. A total of 14 flavonoids were detected via HPLC MS/MS in S. pycnoclada, and 17 were detected in S. baicalensis. Among them were flavones characteristic of both the roots and the aboveground parts of the plants. S. pycnoclada had a lower diversity of methylated flavones than S. baicalensis. Moreover, tenaxin I was absent in all S. pycnoclada lines on agar medium. HPLC analysis revealed that the flavone content in the different hairy root lines was 1.4–12.7 times higher on liquid medium than on agar medium. S. baicalensis and S. pycnoclada differed significantly in the ratio of the main flavones. In S. baicalensis, baicalin (7.83 mg/g DW) and wogonoside (6.29 mg/g DW) dominated when cultured on liquid medium, and wogonin (2.08 mg/g DW) dominated when cultured on solid medium. In S. pycnoclada, baicalin predominated (52–88% of the total content). S. pycnoclada is assumed to have a different set of O-methyltransferases and less biosynthetic enzyme activity than S. baicalensis.

Genetic resistance to Ceratocystis fimbriata in elite genotypes of Gmelina arborea

Introduction. In Costa Rica, an incidence of nearly 40 % has been reported for a disease caused by Ceratocystis fimbriata in commercial plantations of Gmelina arborea (melina), which is the second most widely planted forest tree species in the country. Consequently, there is a pressing need to explore genetic material that exhibit resistance to this pathogen. Objective. To evaluate two methods of C. fimbriata inoculation and their effect on elite genotypes of melina, for their use within the melina genetic improvement program at the international forest genetic improvement cooperative GENFORES. Materials and methods. A pathogenicity test was established using the CIF 001 isolate of C. fimbriata under greenhouse conditions, in Santa Clara, San Carlos, Costa Rica. Two inoculation methods were evaluated in five elite genotypes from October 2019 to January 2020. The effect of the pathogen was evaluated by measuring total height development, basal diameter, number of leaves, incidence, and internal injury within the plant. The assessment was conducted at 30, 60, 90, and 120 days. Results. Mortality was observed from day 38 and reached an incidence of 26.7 % at 120 days. The treatment using solid medium displayed the highest incidence percentage. Genotypes 15N and 58 exhibited high susceptibility to the CIF 001 isolate, whereas genotypes 1 and 57 exhibited high tolerance. Based on the results, it was determined that the pathogenicity test of C. fimbriata on melina can be evaluated at 90 days. Conclusion. Solid medium was the most effective method for inoculating melina with C. fimbriata (isolate CIF 001). Evaluations showed the need to assess results at least 90 days after inoculation. Based on the analysis of the internal lesion, genotype 1 was identified as highly resistant to the effect of the pathogen. The inclusion of this genotype as an evaluation technique will substantially enhance the protocol for assessing tolerance to the pathogen.

Characterization of Bacterial Exopolysaccharides Produced from Different Fruit-Based Solid Media

Bacterial exopolysaccharides (EPSs) share their compositional and structural features with plant dietary fibers. Therefore, analysis of bacterial EPSs produced during fermentation of fruit or vegetables interferes with that of plant fibers. To get rid of this effect, bacteria were grown on a solid medium containing fruit juice or purée and EPSs were recovered in a quantitative dependent manner and were quantified with the phenol-sulfuric acid colorimetric method. The protocol was assayed both on MRS medium and fruit-based media, with three bacterial strains from two species, Leuconostoc pseudomesenteroides 56 and Weissella cibaria 21 and 64. With that method, differences in EPS production levels were shown according to the strain and cultivation conditions, such as sucrose content and pH. Complementary analysis with NMR indicated that glucose and sucrose were partly recovered with EPSs, pointing out the requirement for a further purification step. It also showed that EPSs’ ramified structure differed according to the strain and the fruit used in the medium. This method for EPS recovery is helpful to select strains and to pilot EPS production during lactic fermentation of fruit or vegetable foods.

Effect of <i>Yersinia pestis</i> on the Soil Nematodes <i>Panagrolaimus</i> sp. from the Gorno-Altai High-Mountain Focus of Plague

The aimof the work was to study interaction ofYersinia pestiswith soil nematodes isolated on the territory of the Gorno-Altai high-mountain plague focus.Materials and methods. We used the fluorescentY. pestisstrain KM2083, a derivative of the natural strain of the 4.ANT phylogenetic line, the antique biovar of the main subspecies, and a nematode culture isolated in the same area of the Gorno-Altai plague focus. The taxonomy of nematodes was determined by the region of the18SrRNA gene; phylogenetic analysis was performed using the Maximum Likelihood method based on the Tamura-Nei model in the Mega 7.0 software. The interaction of theY. pestisKM2083 strain and the nematodes was studied during cultivation on a solid NGM agar medium. Nematodes were observed using microscopes Stemi-2000C (Carl Zeiss, Germany) and Axio Imager Z2 (Carl Zeiss, Germany).Results and discussion. It has been established that the nematodes from the Gorno-Altai high-mountain plague focus used in the work belong to the genusPanagrolaimus. Cultivation of nematodes on the lawn of theY. pestisstrain of the main subspecies of antique biovar, the 4.ANT phylogenetic line for 24 hours did not lead to a reduction in the lifespan of nematodes compared to the control sample, which indicates the absence of toxicity of the used strain towardsPanagrolaimusnematodes. On the cuticle of nematodes, the formation of a biofilm in the genital area and tail has been noted, and accumulations of fluorescent cells of the plague pathogen observed in the digestive tract. The data obtained can indicate the ability of nematodes to carry the plague pathogen in the soil biocoenosis.

Antimicrobial Agent against Methicillin-Resistant Staphylococcus aureus Biofilm Monitored Using Raman Spectroscopy.

The prevalence of antimicrobial-resistant bacteria has become a major challenge worldwide. Methicillin-resistant Staphylococcus aureus (MRSA)-a leading cause of infections-forms biofilms on polymeric medical devices and implants, increasing their resistance to antibiotics. Antibiotic administration before biofilm formation is crucial. Raman spectroscopy was used to assess MRSA biofilm development on solid culture media from 0 to 48 h. Biofilm formation was monitored by measuring DNA/RNA-associated Raman peaks and protein/lipid-associated peaks. The search for an antimicrobial agent against MRSA biofilm revealed that Eugenol was a promising candidate as it showed significant potential for breaking down biofilm. Eugenol was applied at different times to test the optimal time for inhibiting MRSA biofilms, and the Raman spectrum showed that the first 5 h of biofilm formation was the most antibiotic-sensitive time. This study investigated the performance of Raman spectroscopy coupled with principal component analysis (PCA) to identify planktonic bacteria from biofilm conglomerates. Raman analysis, microscopic observation, and quantification of the biofilm growth curve indicated early adhesion from 5 to 10 h of the incubation time. Therefore, Raman spectroscopy can help in monitoring biofilm formation on a solid culture medium and performing rapid antibiofilm assessments with new antibiotics during the early stages of the procedure.

Comparison of the effectiveness of solid nutrient medium in the in vitro cultivation of Neisseria gonorrhoeae isolates

Background. Neisseria gonorrhoeae is a facultatively anaerobic microorganism which is extremely demanding to the composition of a nutrient media and cultivation conditions. In a situation of the increasing shortage and cost of foreign components for the preparation of solid nutrient media, it is important to study the possibility of growing hard-to-cultivate microorganisms on domestically produced nutrient media.The aim of the study. To evaluate the growth of gonococcus colonies on two types of solid nutrient media – chocolate agar with growth and selective additives prepared using imported reagents and chocolate agar with growth additives manufactured by “Gem LTD” (Moscow, Russian Federation).Materials and methods. А reference strain of N. gonorrhoeae NCTC 12700/ ATCC 49226 and two types of chocolate agar (the first one – prepared in the State Scientific Center of Dermatovenerology and Cosmetology using imported components and the other one – from the domestic manufacturer “Gem LTD”) were used in the research.Results. The equivalence of the growth properties of both studied types of nutrient media when cultivating pure gonococcus was revealed.Conclusions. Ready-to-use chocolate agar with growth additives produced by “Gem LTD” can be successfully used in the laboratory for the cultivation of N. gonorrhoeae pure culture. Primary isolation of N. gonorrhoeae strains from clinical material is more appropriate to carry out on a medium that suppresses the growth of foreign microflora due to the inclusion of antibiotic additive. The organization of production of domestic bacteriological media for microorganisms with high nutrient requirements reduces the dependence of domestic microbiology on import and ensures their rapid delivery to laboratories.

The evaluation of electrical circuits for adjusting sound transmission properties of piezoelectric metamaterials

In rods and beams, piezoelectric patches with external circuits have been extensively studied to dampen structural vibrations at the sound source. This work uses a large flat-layer type of piezoelectric acoustic metamaterial (AM) model for noise attenuation in the sound transmission stage rather than at the sound source. This could be directly implemented as a large space sound transmission barrier at the interface of diverse media including gas, liquid, and solid materials. The general analytical model to derive acoustic properties of the piezoelectric acoustic metamaterial is established by the equivalent transfer matrix approach for normal incidence waves. This has been validated numerically using the finite element method and experimentally in the solid medium propagation for the first time. Moreover, a parametric study of sound transmission properties in air, water, and steel is conducted by adjusting external circuit parameters, flat-layer structures, and piezoelectric materials. The findings demonstrate the ability to control sound resonance frequency and bandwidth through the propagation process over a wide range using external circuit parameters alone. This endows the piezoelectric acoustic metamaterial with great versatility relative to conventional, fixed structure, metamaterials used as sound barriers at the interface of diverse media. In addition, the size of the piezoelectric AM can reach a deeply sub-wavelength level, less than 10−3 of the resonance wavelength in both water and solid media, which goes far beyond the wavelength-to-thickness ratio of classical acoustic metamaterials. The layer-type piezoelectric AM thus shows excellent performance in tunability and compactness for space-sensitive applications as well as great potential in combining metamaterials with electronic control.

Mechanochemical Duff Reaction in Solid Phase for Easy Access to Mono- and Di-formyl Electron-Rich Arenes.

A sustainable alternative to the century-old Duff reaction was developed by adopting a solid-phase mechanochemical route. A series of mono-formyl electron-rich arenes were prepared in high yields in silica as the solid reaction media using a combination of hexamethylenetetramine (HMTA) as the formyl source and a small amount of H2SO4 in a mixer mill. The use of toxic, costly, and low-boiling trifluoroacetic acid was avoided in the new mold of the mechanochemical Duff reaction. The mono-formyl phenols were obtained with exclusive ortho-selectivity, whereas unprecedented para-formylation was observed for other electron-rich aromatics. By controlling the stoichiometry of HMTA, the method offers easy access to di-formylated phenols as well. The scalability of the reaction was validated with selected substrates at the gram-scale level. In a case study, a mechanochemical tandem reaction was explored in the synthesis of a rhodol derivative. The solvent-free, metal-free mild method of formylation, with the absence of tedious work-up steps and shorter reaction times using an inexpensive mineral acid, is a sustainable alternative to the available methods for aromatic formylation.

Evaluation of an Automated System for the Counting of Microbial Colonies.

Counting of microbial colonies is a common technique employed in research and diagnostics. To simplify this tedious and time-consuming process, automated systems have been proposed. This study aimed to elucidate the reliability of automated colony counting. We evaluated a commercially available instrument (UVP ColonyDoc-It Imaging Station) in regard to its accuracy and potential time savings. Suspensions of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterococcus faecium, and Candida albicans (n = 20 each) were adjusted to achieve growth of approximately 1,000, 100, 10, and 1 colony per plate, respectively, after overnight incubation on different solid media. Compared with manual counting, each plate was automatically counted by the UVP ColonyDoc-It with and without visual adjustment on a computer display. For all bacterial species and concentrations automatically counted without visual correction, an overall mean difference from manual counts of 59.7%, a proportion of isolates with overestimation/underestimation of colony numbers of 29%/45%, respectively, and only a moderate relationship (R2 = 0.77) with the manual counting were shown. Applying visual correction, the overall mean difference from manual counts was 1.8%, the proportion of isolates with overestimation/underestimation of colony numbers amounted to 2%/42%, respectively, and a strong relationship (R2 = 0.99) with the manual counting was observed. The mean time needed for manual counting compared with automated counting without and with visual correction was 70 s, 30 s, and 104 s, respectively, for bacterial colonies through all concentrations tested. Generally, similar performance regarding accuracy and counting time was observed with C. albicans. In conclusion, fully automatic counting showed low accuracy, especially for plates with very high or very low colony numbers. After visual correction of the automatically generated results, the concordance with manual counts was high; however, there was no advantage in reading time. IMPORTANCE Colony counting is a widely utilized technique in the field of microbiology. The accuracy and convenience of automated colony counters are essential for research and diagnostics. However, there is only sparse evidence on performance and usefulness of such instruments. This study examined the current state of reliability and practicality of the automated colony counting with an advanced modern system. For this, we thoroughly evaluated a commercially available instrument in terms of its accuracy and counting time required. Our findings indicate that fully automatic counting resulted in low accuracy, particularly for plates with very high or very low colony numbers. Visual correction of the automated results on a computer screen improved concordance with manual counts, but there was no benefit in counting time.

Micropropagation of Three Citrus Rootstocks by Tissue Culture

The experiments were conducted in the Laboratory of Tissue culture/Department of Forestry/College of Agriculture and Forestry/the University of Mosul. To propagate three citrus rootstocks (Citrus aurantium L., Citrumelo swingle, and Cariso 35 (C35))In vitro. During the Initiation stage, the single nodes were planted on a solid MS medium supplemented with five concentrations of BA (0, 1, 2, 3, and 4 mg L-1). After four weeks, the best significant percentage of response for Cariso35 and Citrumelo swingle, while the highest value of BA effect was at 2 mg BA L-1(96.67%). The No. of shoots there are nonsignificant differences, While the best No. of the shoot (1.41) obtained at 2 mg BA L-1, The highest significant shoot length (2.14cm) was obtained at Cariso35 compared with other rootstocks, so that, 1mg BA L-1 was achieved (2.01 cm). At the multiplication stage, Citrumelo swingle achieved the highest significant value (2.68shoots), whereas adding 4 mg BA L-1 gave the best significant No. shoots (3.10). as soon as, the shoot length (1.03cm) was obtained for Cariso35, while control treatment achieved a significant increase in shoot length (1.30cm) which differ significantly from other treatments. The highest significant number of leaves was (11.50 leaves) for Citrumelo swingle, while BA at 2 mgL-1 was dominated value achieved at 11.00 leaves. In the rooting stages, the best rooting percentage was 60% for Cariso 35 cultured on MT solid medium, but a non-significant difference between all IBA concentrations. While the significant No. of roots was 3.28 obtained from Citrumelo swingle, and the concentration 1.5 and 2 mg IBA L-1 achieved the highest significant values (2.90 and 2.24 root) respectively. Citrumelo swingle and the 1.5 mg IBA L-1 gave the shortest significant duration to formed roots which were 21.56 and 18.60 days respectively.