S1 Strain Research Articles

Hla protein expression and artesunate prevented mice from further damage caused by Staphylococcus aureus pneumonia

The laboratory standard MRSA strain WHO-2 and clinical isolate S1 were used to establish a pneumonia infection model. The results showed that methicillin increased the expression of Hla and PVL protein at subminimum inhibitory concentration, while artesunate decreased the secretion of Hla and PVL protein. Artesunate alone reduced hemolysin expression and reversed methicillin-induced increases in Hla and PVL proteins. In addition, the study found that the combination of artesunate and methicillin had the best therapeutic effect, with survival rates of 70 % and 40 % at seven days, respectively (corresponding to the WHO-2 and S1 strains). The combination treatment was able to reduce cell mortality, showing a 65 % and 46 % reduction in cell mortality, respectively. The study also found that the combination therapy decreased the expression of alpha-hemolysin and pantone valentin leukin in the culture medium and significantly reduced the activation of NF-kB. This is caused by a significant decrease in the expression of inflammatory factors.

N-3-Methylbutyl-benzisoselenazol-3(2H)-one Exerts Antifungal Activity In Vitro and in a Mouse Model of Vulvovaginal Candidiasis.

In the present work, we evaluated the antifungal activities of two novel ebselen analogs, N-allyl-benzisoselenazol-3(2H)-one (N-allyl-bs) and N-3-methylbutylbenzisoselenazol-3(2H)-one (N-3mb-bs). Colorimetric and turbidity assays were performed to determine the minimum inhibitory concentration (MIC) of these compounds in S1 (fluconazole-sensitive) and S2 (fluconazole-resistant) strains of C. albicans. N-3mb-bs was more active than the N-allyl-bs compound. It is noteworthy that the concentration of N-3mb-bs observed to inhibit fungal growth by 50% (18.2 µM) was similar to the concentration observed to inhibit the activity of the yeast plasma membrane H+-ATPase (Pma1p) by 50% (19.6 µM). We next implemented a mouse model of vulvovaginal candidiasis (VVC) using the S1 strain and examined the mouse and yeast proteins present in the vaginal lavage fluid using proteomics. The yeast proteins detected were predominately glycolytic enzymes or virulence factors associated with C. albicans while the mouse proteins present in the lavage fluid included eosinophil peroxidase, desmocollin-1, and gasdermin-A. We then utilized the N-3mb-bs compound (12.5 mg/kg) in the mouse VVC model and observed that it significantly reduced the vaginal fungal burden, histopathological changes in vagina tissue, and expression of myeloperoxidase (MPO). All in all, the present work has identified a potentially promising drug candidate for VVC treatment.

In-vitro Inhibitory Activities of Potential Probiotic Isolated from Pangasius nasutus against Aeromonas hydrophila and Streptococcus agalactiae

In aquaculture, using probiotics is crucial for strengthening the immune system and encouraging the growth and survival of many aquatic organisms, including the Pangasius species. This approach is particularly significant given the impact of bacterial diseases on Pangasius survival. This study aimed to assess the effectiveness of probiotics isolated from Pangasius nasutus as alternatives to antibiotics for combating infections caused by Aeromonas hydrophila and Streptococcus agalactiae. Potential bacteria were isolated from the intestine and stomach of healthy P. nasutus. Seventy probiotic strains were successfully isolated and further screened using A. hydrophilaand S. agalactiae as pathogens in an in vitro disc diffusion assay. Preliminary screenings indicated that five probiotic strains inhibited the growth of A. hydrophila. Stomach-derived strain S1 and intestine-derived strain L1 suppressed A. hydrophila growth with inhibition zones of 10.5±1 mm and 8.5±1 mm, respectively. Likewise, strains L2, L8, and L12 from the intestine showed inhibitory zones of 6.0±1 mm, 6.5±1 mm, and 6.0±1 mm, respectively. Of these, only L12 inhibited the growth of S. agalactiae with a clear zone of 5.0±1 mm. In the elimination of pathogenic strains, potential strains S1 and L1 did not grow on the Aeromonas isolation medium. Co-culture assays demonstrated that both potential strains significantly inhibited Aeromonas hydrophila growth at concentrations of 106 and 108 CFU mL-1 over 48- and 96-hour periods, respectively. The potential bacterial strains were identified using 16s rRNA gene sequencing and were classified as follows: S1 - Lactococcus lactis, L1 - Weissella confusa, L2 - Cosenzaea myxofaciens, L8 - Lactococcus garvieae, and L12 - Plesiomonas shigelloides. Strain S1 L. lactis and strain L1 W. confusa are suggested for further evaluation and acquired additional research to fully elucidate their mechanisms and potential as probiotics.

Panoptic elucidation of algicidal mechanism of Raoultella sp. S1 against the Microcystis aeruginosa by TMT quantitative proteomics

Harmful algal blooms (HABs) due to eutrophication are becoming a serious ecological disaster worldwide, threatening human health and the optimal balance of aquatic ecosystems. The traditional approaches to eradicate HABs yield several drawbacks in practical application, while microbial algicidal technology is garnering mounting recognition due to its high efficiency, eco-friendliness, and low cost. In our previous study, we isolated a bacterium strain Raoultella sp. S1 from eutrophic water with high efficiency of algicidal properties. This study further investigated the flocculation and inactivation efficiency of S1 on Microcystis aeruginosa at different eutrophic stages by customizing the algal cell densities. The supernatant extract of S1 strain exhibited remarkable flocculation and inactivation effects against low (1 × 106 cell/mL)and medium (2.7 × 106 cell/mL)concentrations of algal cells, but unexceptional for higher densities. The results further revealed that algal cells at low and medium counts manifested a more apparent antioxidant defense response, while the photosynthetic efficiency and relative electron transport rate were considerably reduced within 24 h. TEM observations confirmed the disruption of thylakoid membranes and cell structure of algal cells by algicidal substances. Moreover, TMT proteomics revealed alterations in protein metabolic pathways of algal cells during the flocculation and lysis stages at the molecular biological level. This signified that the disruption of the photosynthetic system is the core algicidal mechanism of S1 supernatant. In contrast, the photosynthetic metabolic pathways in the HABs were significantly upregulated, increasing the energy supply for the NADPH dehydrogenation process and the upregulation of ATPases in oxidative phosphorylation. Insufficient energy provided by NADPH resulted in a dwindled electron transport rate, stagnation of carbon fixation in dark reactions, and blockage of light energy conversion into chemical energy. Nonetheless, carbohydrate metabolism (gluconeogenesis and glycolysis) proteins were down-regulated and hampered DNA replication and repair. This study aided in unveiling the bacterial management of eutrophication by Raoultella sp. S1 and further arrayed the proteomic mechanism of algal apoptosis.

Fear conditioning and extinction distinctively alter bidirectional synaptic plasticity within the amygdala of an animal model of post-traumatic stress disorder

Synaptic plasticity in the amygdala plays an essential role in the formation and inhibition of fear memory; however, this plasticity has mainly been studied in the lateral amygdala, making it largely uninvestigated in other subnuclei. Here, we investigated long-term potentiation (LTP) and long-term depression (LTD) in the basolateral amygdala (BLA) to the medial division of the central amygdala (CEm) synapses of juvenile C57BL/6N (B6) and 129S1/SvImJ (S1) mice. We found that in naïve B6 and S1 mice, LTP was not induced at the BLA to CEm synapses, whereas fear conditioning lowered the threshold for LTP induction in these synapses of both B6 and S1 mice. Interestingly, fear extinction disrupted the induction of LTP at the BLA to CEm synapses of B6 mice, whereas LTP was left intact in S1 mice. Both low-frequency stimulation (LFS) and modest LFS (mLFS) induced LTD in naïve B6 and S1 mice, suggesting that the BLA to CEm synapses express bidirectional plasticity. Fear conditioning disrupted both types of LTD induction selectively in S1 mice and LFS-LTD, presumably NMDAR-dependent LTD was partially recovered by fear extinction. However, mLFS-LTD which has been known to be endocannabinoid receptor 1 (CB1R)-dependent was not induced after fear extinction in both mouse strains. Our observations suggest that fear conditioning enhances LTP while fear extinction diminishes LTP at the BLA to the CEm synapses of B6 mice with successful extinction. Considering that S1 mice showed strong fear conditioning and impaired extinction, strong fear conditioning in the S1 strain may be related to disrupted LTD, and impaired extinction may be due to constant LTP and weak LFS-LTD at the BLA to CEm synapses. Our study contributes to the further understanding of the dynamics of synaptic potentiation and depression between the subnuclei of the amygdala in juvenile mice after fear conditioning and extinction.

Significant Impact of AcrB Amino Acid Polymorphism at Residue 716 on Susceptibility to Tigecycline and Other Antibiotics in Klebsiella pneumoniae.

AcrAB-TolC is a multidrug RND-type efflux pump that is widespread in Gram-negative bacteria. As the substrate-binding subunit, AcrB was shown to modulate antimicrobial resistance in Escherichia coli, but the influence of AcrB mutation on Klebsiella pneumoniae, a major clinical pathogen, has not been well-studied. The finding of an R716L mutation in AcrB in a clinical tigecycline-nonsusceptible K. pneumoniae S1 strain inspired us to probe the role of AcrB residue 716 in antimicrobial resistance. This residue was subsequently subjected to saturation mutagenesis, followed by antibiotic susceptibility tests, survival assays, and antibiotic accumulation assays, showing strong influences of AcrB mutation on antimicrobial resistance. In particular, resistance levels to azithromycin, tetracycline, tigecycline, and cefoxitin were significantly changed by AcrB mutation at residue 716. Mutations to charged residues, polar residues, and residues that disrupt secondary structures have particularly reduced the antimicrobial susceptibility of bacteria, except for azithromycin, and the impact is not due to the abolishment of the efflux function of the pump. Therefore, it is concluded that residue 716 is an important residue that significantly influences antimicrobial resistance in K. pneumoniae, adding to our understanding of antimicrobial resistance mechanisms in this key clinical pathogen.

Protease production and molecular characterization of a protease dipeptidyl-aminopeptidase gene from different strains of Sordaria fimicola.

The current research was designed to reach extracellular protease production potential in different strains of Sordaria fimicola which were previously obtained from Dr. Lamb (Imperial College, London) from North Facing Slope and South Facing Slope of Evolution Canyon. After initial and secondary screening, two hyper-producers strains S2 and N6 were selected for submerged fermentation and cultural conditions including temperature, pH, incubation period, inoculum size, substrate concentration, and different carbon and nitrogen sources were optimized for enzyme production. S2 strain showed maximum protease production of 3.291 U/mL after 14 days of incubation at 30 °C with 7 pH, 1% substrate concentration and 1 mL inoculum, While N6 strain showed maximum protease production of 1.929 U/mL under fermentation optimized conditions. Another aim of the present research was to underpin the biodiversity of genetics and post-translational modifications (PTMs) of protease DPAP (peptidyl-aminopeptidase) in Sordaria fimicola. Five polymorphic sites were observed in amino acid sequence of S. fimicola strains with reference to Neurospora crassa. PTMs prediction from bioinformatics tools predicted 38 phosphorylation sites on serine residues for protease peptidyl-aminopeptidase in S1 strain of S. fimicola while 45 phosphorylation sites on serine in N7 strain and 47 serine phosphorylation modifications were predicted in N. crassa. Current research gave an insight that change in genetic makeup effected PTMs which ultimately affected the production of protease enzyme in different strains of same organism (S. fimicola). The production and molecular data of the research revealed that environmental stress has strong effects on the specific genes through mutations which may cause genetic diversity. S. fimicola is non- pathogenic fungus and has a short life cycle. This fungus can be chosen to produce protease enzyme on a commercial scale.

Cause Analysis and Countermeasures of Human Infection in Sheep Brucellosis Immunization

Brucellosis of sheep is an important way to cause human infection. Immunization of sheep is an effective measure for the prevention and control of brucellosis of sheep. Now, M5 and S2 strains of vaccines are commonly used to immunize sheep, while M5 and S2 strains of vaccines are live vaccines, which are easy to cause infection of epidemic prevention personnel during the epidemic prevention process. Because the epidemic prevention personnel are worried that they will be infected with brucellosis due to immunization of sheep, it is difficult to promote the immunization of sheep against brucellosis, In order to reduce the risk of infection of epidemic prevention personnel in the immunization of sheep brucellosis and ensure the normal development of the immunization of sheep brucellosis, combined with three years of experience in the immunization of oral S2 strain of brucellosis, the epidemic prevention personnel infected with brucellosis due to immunization of sheep against brucellosis were carefully investigated, and it was found that the main reason for personnel infection was the weak protection awareness of the epidemic prevention personnel, the risk of scattered bacteria in oral immunization, the lax implementation of epidemic prevention operation procedures and the problems of personal protective equipment, etc. Find corresponding solutions to these problems. The quality of epidemic prevention personnel should be strengthened; Select safe immunization mode; Strictly implement the operation procedures and optimize personal protective equipment. The improvement of these measures can effectively prevent human infection caused by immunization against sheep brucellosis. Eliminating the fear of epidemic prevention personnel about being infected with brucella in the immunization of sheep brucellosis, thus ensuring the solid progress of the immunization of sheep brucellosis, and playing a positive role in reducing human infection with brucellosis.

Draft Genome Assembly of Stutzerimonas sp. Strain S1 and Achromobacter spanius Strain S4, Two Syringol-Metabolizing Bacteria Isolated from Compost Soil.

Two bacterial strains able to use syringol as a sole carbon source were isolated from compost. The isolates, named S1 and S4, were sequenced using the Illumina platform. The final assemblies contained 4.2 Mbp, 63% GC, and 3,912 genes for S1 and 6.2 Mbp, 64% GC, and 5,503 genes for S4.

Ghrelin receptor agonist MK0677 and overnight fasting do not rescue deficient fear extinction in 129S1/SvImJ mice.

The hunger hormone ghrelin has been implicated in the modulation of anxiety- and fear-related behaviors in rodents and humans, while its dysregulation may be associated with psychiatric illness. Along these lines, the ghrelin system has been suggested as a potential target to facilitate fear extinction, which is the main mechanism underlying cognitive behavioral therapy. So far, this hypothesis has not been tested in individuals that have difficulties to extinguish fear. Thus, we investigated pharmacological (ghrelin receptor agonist MK0677) and non-pharmacological (overnight fasting) strategies to target the ghrelin system in the 129S1/SvImJ (S1) mouse strain, which models the endophenotype of impaired fear extinction that has been associated with treatment resistance in anxiety and PTSD patients. MK0677 induced food intake and overnight fasting increased plasma ghrelin levels in S1 mice, suggesting that the ghrelin system is responsive in the S1 strain. However, neither systemic administration of MK0677 nor overnight fasting had an effect on fear extinction in S1 mice. Similarly, our groups previously reported that both interventions did not attenuate fear in extinction-competent C57BL/6J mice. In summary, our findings are in contrast to several studies reporting beneficial effects of GHSR agonism and overnight fasting on fear- and anxiety-related behaviors in rodents. Rather, our data agree with accumulating evidence of divergent behavioral effects of ghrelin system activation and underscore the hypothesis that potential benefits of targeting the ghrelin system in fear extinction may be dependent on factors (e.g., previous stress exposure) that are not yet fully understood.

The probiotic effects, dose, and duration of lactic acid bacteria on disease resistance in Litopenaeus vannamei

Four lactic acid bacteria with a high capacity for acid production were screened from 113 lactic acid bacteria (LAB) isolated from aquaculture systems, and were identified as Lactococcus lactis (S1 and S2), Enterococcus faecali (F3 and F7) by 16S rDNA sequencing. These four candidates exhibited favorable probiotic properties, including no haemolytic activity, good auto-aggregation performance, tolerance to simulated gastric fluid, and antagonistic activity against pathogens. To determine the ideal probiotic feeding dose and duration that would maximize protection against pathogens, L. vannamei were fed a probiotic supplemented diet at a series of concentrations for up to 60 days, and then challenged with Vibrio harveyi every 15 days. In vivo studies demonstrated that supplementation with L. lactis (S1 and S2) and E. faecalis (F3 and F7) significantly improved growth performance and feed utilization in the probiotic-treated groups compared to the control group. The findings suggested that administration of F7 and S2 strains at 106 CFU g−1 for 30–45 d was more effective at suppressing V. harveyi infection than any of the other feeding regimens. This study establishes a theoretical foundation for the practical use of probiotics.

Genetic polymorphisms of <i>helicobacter pylori</i> clinical isolates in St. Petersburg, Russia

Introduction. Helicobacter pylori was proved to be the principal causative agent of gastroduodenal disorders in human. Although Russian Federation is among the countries with a high prevalence of H. pylori infection (6090%), currently there is a very limited number of studies evaluating H. pylori genotypes in Russia. Objective. Based on the assessment of virulence-associated cagA, oipA, and vacA genes, our study was aimed to determine H. pylori genotypes associated with the clinical outcomes in patients with H. pylori infection in St. Petersburg, Northwest Russia. Materials and methods. Using PCR for the detection of cagA, oipA, and vacA s, m, i allelic variants, we analyzed 61 H. pylori isolates isolated and cultured from biopsies collected during endoscopy of patients with chronic gastritis (G), duodenal ulcer (DU), and gastric cancer (GC). Results. The genetic diversity of H. pylori clinical isolates has been revealed (HGDI 0.88): 41 (67%) of 61 H. pylori isolates were cagA-positive, 38 (62%) oipA-positive. The proportions of cagA+ isolates differed in patients with G (56.7%) and DU (80.9%) (p = 0.06). The s, m, and i allelic variants of the vacA gene were detected in all strains, although the vacA s1 allele was significantly dominant in patients with DU (95.2%) rather than with G (64.9%) (p = 0.01). The vacA alleles m1 and i1 in the isolates from patients with G and DU were found in almost equal proportions: 45.9% and 42.8% for m1 allele, 45.9% and 47.6% for i1 allele, respectively. Seven isolates (11.5%) were positive for different mixed combinations of vacA alleles s, m, and i. Noteworthy, all vacA s2 strains were cagA-negative and had the m2 allele. OipA+ strains were found in almost equal proportions in patients with G (62.2%) and DU (57.1%) (p = 0.71). All three cagA- and oipA-positive isolates from patients with GC carried vacA s1/m1/i1 alleles. Different combinations of virulence-associated determinants constituted 17 genetic profiles. The most common combined genotype cagA+/oipA+/vacA s1/m1/i1 comprised 18 (29.5%) H. pylori isolates. Conclusion. We have determined predominant genotypes in the H. pylori population in the Northwest of Russia. The significant association between vacA s1 genotype of the pathogen and clinical manifestations of H. pylori infection has been established in our study.

Inoculation of Lactobacillus sakei on Quality Traits of Dry Fermented Sausages.

In this study, fermented sausage prepared by inoculating different strains of Lactobacillus sakei was assessed for their physiochemical, microbiological, and textural characteristics during fermentation and ripening. Five treatments were prepared: Control (commercial starter culture, C), L. sakei Korean Collection for Type Cultures (KCTC)-3802 (S1), L. sakei KCTC-3598 (S2), L. sakei KCTC-5053 (S3), and L. sakei KCTC-3603 (S4). The different strains of L. sakei did not show substantial differences (P>0.05) in pH values for dry fermented sausages at the end of the ripening period. Water activity (aw) values for all treatments were below 0.85 (P<0.05). Total viable count at the end of the study decreased in all L. sakei starter culture inoculated fermented sausages as S3> S2> S1> S4. High values of lactic acid bacteria (LAB) count and hardness were observed in the S2 batch as compared to other L. sakei inoculated treatments at the end of ripening (21st day). S3 inoculated with L. sakei strain exhibited significantly (P<0.05) higher value of a* (redness). A significant difference (P<0.05) in thiobarbituric acid reactive substances was exhibited in the following order: S4> S2> S1> S3> C. This study suggests that inoculation of S3 (L. sakei KCTC-5053) strain can improve the red color and reduce lipid oxidation while S2 enhances better microbiological quality as LAB. Incorporation of S3 and S2 strains accordingly can be helpful to enhance the quality of dry fermented sausages.

Potentiating effects of leaderless enterocin DD14 in combination with methicillin on clinical methicillin-resistant Staphylococcus aureus S1 strain

Biofilm formation by pathogenic bacteria as well as their resilience to antibiotic treatments are a major health problem. Here, we sequenced and analyzed the genome of the clinical methicillin-resistant Staphylococcus aureus S1 (MRSA-S1) strain and established its sensitivity to the combination of methicillin and the leaderless two peptides enterocin DD14 (EntDD14). Such sensitivity was assessed in vitro based on the MIC/FIC values as well as on killing curves experiments. Moreover, combination of EntDD14 and methicillin was able to reduce the biofilm formation of Staphylococcus aureus S1 of about ∼30 %. Interestingly, genes thought to be involved in the virulence of MRSA-S1, like nuc and pvl which code, respectively, for nuclease and Panton-Valentine leucocidin, were shown to be downregulated following treatment with EntDD14 and methicillin. Similar effects were registered for other genes such as cflA, cflB and icaB, coding for bacterial ligands clumping factors A, B and intercellular adhesion factor respectively. All these data, suggest that combinations of bacteriocins and antibiotics are useful as a backup for treatment of bacterial infections.

Methyl red biodegradation based on Taguchi method by two novel bacteria

In this paper, the microbial degradation of methyl red (MR) was investigated by novel isolated bacteria S1 and K1 from wastewater effluent. Based on morphological, biochemical and molecular methods, strain S1 belonged to the Staphylococcus schleiferi subsp. coagulans GA 211 with 92.67% similarity (accession number MT573965) and strain K1 belonged to the Klebsiella michiganensis W14 with 99.85% similarity (accession number MT572941). To the best of our knowledge, this is the first report of dye degradation activity of these bacteria. The Taguchi Statistical Method (TSM) was used to optimize the experimental conditions. Taguchi’s L18 orthogonal array (OA) was performed, and the results were used to calculate signal-to-noise (S/N) ratios. According to S/N ratios, it was discovered that optimum experimental conditions are at pH 8, temperature 40°C, initial dye concentration 50 mg/l, carbon source glucose, rpm 75, inoculum 3% v/v and strain S1. Analyzing the results of the biodegradation assay by Minitab 19 statistical software, it was found that rpm and temperature are most and less effective in the MR biodegradation assay, respectively. Significant changes in the HPLC and UV-Vis spectrum of samples of strain S1 before and after biodegradation assay confirmed the complete biodegradation of MR by S1 strain.

Fermented Parkia biglobosa seeds as a nitrogen source supplementation for bioethanol production from cashew apple juice

Nutritional requirements in the fermentation process are key parameters for optimal yeast development and ethanol production. Natural nutritional supplements rich in nitrogen, phosphorus, sulfur, and micro-elements can improve the performance of yeasts and offer a sustainable, cost-effective, and environmentally friendly alternative to synthetic chemicals. This study aimed at investigating the effect of a natural yeast nutrient (fermented Parkia biglobosa seeds) on bioethanol production from cashew apple juice by Saccharomyces cerevisiae. The proximate and mineral compositions of fermented seeds were evaluated. Their powder was added to yeast medium at a concentration of 4–12 g/L. The behavior of two yeast strains (Angel brand super alcohol (S1) and Angel brand thermal-tolerant alcohol (S2)) was inspected. Titratable acidity, pH, °Brix, and density were evaluated during 144 h of fermentation. Sugar consumption was maximal after 72 and 48 h of fermentation for S1 and S2 yeast strains, respectively. The best ethanol yields of 0.19 and 0.22 g/g were obtained with S1 and S2 yeast strains, respectively, using 12 g/L of nutrients for the first and without nutrient supplementation for the second (control sample). The non-conventional nutrients from fermented P. biglobosa seeds seem to be favorablefor ethanol production using only S1 yeast strain.

A Metabolomics and Molecular Networking Approach to Elucidate the Structures of Secondary Metabolites Produced by Serratia marcescens Strains.

An integrated approach that combines reverse-phase high-performance liquid chromatography (RP-HPLC), electrospray ionization mass spectrometry, untargeted ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MSE) and molecular networking (using the Global Natural Products Social molecular network platform) was used to elucidate the metabolic profiles and chemical structures of the secondary metabolites produced by pigmented (P1) and non-pigmented (NP1) Serratia marcescens (S. marcescens) strains. Tandem mass spectrometry-based molecular networking guided the structural elucidation of 18 compounds for the P1 strain (including 6 serratamolides, 10 glucosamine derivatives, prodigiosin and serratiochelin A) and 15 compounds for the NP1 strain (including 8 serratamolides, 6 glucosamine derivatives and serratiochelin A) using the MSE fragmentation profiles. The serratamolide homologues were comprised of a peptide moiety of two L-serine residues (cyclic or open-ring) linked to two fatty acid chains (lengths of C10, C12, or C12:1). Moreover, the putative structure of a novel open-ring serratamolide homologue was described. The glucosamine derivative homologues (i.e., N-butylglucosamine ester derivatives) consisted of four residues, including glucose/hexose, valine, a fatty acid chain (lengths of C13 – C17 and varying from saturated to unsaturated) and butyric acid. The putative structures of seven novel glucosamine derivative homologues and one glucosamine derivative congener (containing an oxo-hexanoic acid residue instead of a butyric acid residue) were described. Moreover, seven fractions collected during RP-HPLC, with major molecular ions corresponding to prodigiosin, serratamolides (A, B, and C), and glucosamine derivatives (A, C, and E), displayed antimicrobial activity against a clinical Enterococcus faecalis S1 strain using the disc diffusion assay. The minimum inhibitory and bactericidal concentration assays however, revealed that prodigiosin exhibited the greatest antimicrobial potency, followed by glucosamine derivative A and then the serratamolides (A, B, and C). These results provide crucial insight into the secondary metabolic profiles of pigmented and non-pigmented S. marcescens strains and confirms that S. marcescens strains are a promising natural source of novel antimicrobial metabolites.

English

Post-translational modifications (PTMs) regulate different complex mechanisms of cell and affect cell growth, stress, evolution of living organisms and adaptations due to environment. The purpose of the present research is to investigate the genetic diversity and PTMs of protease (Carboxypeptidase A1) n Sordaria fimicola. They perform a variety of functions ranging from housekeeping: e.g., protein maturation, signal peptide cleavage, signal transduction, intracellular protein turnover, immune response, apoptosis, and reproduction. S. fimicola is a microscopic filamentous fungus, has been preferably used in this study because of its easy growing pattern on Potato Dextrose Agar (PDA) and a short life cycle of 7 to 12 days. The genomic DNA of six of the strains S. fimicola was used to amplify the carboxypeptidases A1 gene (CpA1), the product size was 940 bp. The multiple sequence alignment of the nucleotide sequences of six strains of S. fimicola with Neurospora crassa (as a reference strain) was studied. The numbers of polymorphic sites in six strains of S. fimicola with respect to N. crassa were six. Posttranslational modifications were depicted by using bioinformatics tools i.e., YinOYang1.2, NetPhos 3.1 and NetNES 1.1 Server to calculate O-glycosylation, phosphorylation sites, and nuclear export signals respectively. The study has predicted 19 phosphorylation sites on serine residues for protease Carboxypeptidase A1 in S1 strains of S. fimicola while 15 phosphorylation sites on serine in N7 strain and 17 serine phosphorylation modifications were predicted in N. Crassa. The results of this research will be helpful for further in vitro investigations of this industrially important enzyme under study. © 2021 Friends Science Publishers

Antifungal Activity of Topical Formulation Containing Artemisia Herba Alba Asso Essential Oil

Given the increase in antibiotic resistance phenomena and the undesirable effects of synthetic drugs. Medicinal plants are used as a direct or indirect source of the active ingredients. Our research constitutes a development of essential oils from Artemisia herba alba Asso cultivated in the Mascara region. A hydrophobic ointment has been formulated based on this essential oil and tested against five strains of Candida albicans. Several physicochemical and microbiological tests were used to verify the quality and the toxicity of the product. Then, the determination of the antifungal activity of this preparation was assessed against five strains of Candida albicans (S1, S2, S3, S4 and S5) by the disk-diffusion agar method. The results revealed that this preparation was devoid of total aerobic germs, yeasts and molds. However, the pH value was found equal to 5.98. In addition, the irritation primary index was marked less than 0.5. The ointment was powerful against S1, S3, S4 and S5 strains with inhibition diameters ranging from 16± 4 mm to 23 ± 2 mm. The Nystatin ointment was observed active against strains S2, S4 and S5 with diameters of the zones of inhibition; 21 ± 2 mm, 21± 1 mm and 20 ± 3 mm respectively. The ointment formulated with essential oil from Artemisia herba alba asso has proven useful against candidiasis caused by Candida albicans species.

Partially inbred maize lines in topcrosses and hybrid performance

ABSTRACT In plant breeding programs, the selection of potential progenies in early generations of inbreeding is an essential step. Considering that, the adoption of topcrosses helps the breeder in the selection, this study aimed to verify the potential of S2 strains for synthesis of synthetic varieties and to obtain experimental information on yield and agronomic potential of topcross hybrids. As such, 75 topcross hybrids were generated from crossing 75 S2 lines with F2 generation of the commercial hybrid. The 75 hybrids were grown in a field, along with two commercial hybrids in a randomized complete block design with 4 replicates and in 4-meter plots. Flowering, plant height, height, diameter, length and weight in the ear, and grain yield traits were examined. Analysis of variance was performed, the combining ability was estimated, and, from the means, the Scott & Knott test was conducted. So, the topcross hybrids that distinguished themselves for grain yield were those composed by lines 67, 14, 44, and 69, presenting high CGA, therefore indicating good potential for producing synthetic or base population. For the other traits of agronomic interest that were assessed in maize, a potential for selection with different focuses was found: reduction of cycle and height and increase in length and diameter of the ear.