Penicillium Chrysogenum Strain Research Articles

Developing rational scale-down simulators for mimicking substrate heterogeneities based on cell lifelines in industrial-scale bioreactors

The influence of extracellular variations on the cellular metabolism and thereby the process performance at large-scale can be evaluated using the so-called scale-down simulators. Nevertheless, the major challenge is to design an appropriate scale-down simulator, which can accurately mimic the cell lifelines that record the flow paths and experiences of cells circulating in large-scale bioreactors. To address this, a dedicated SDSA (scale-down simulator application) was purposedly developed on the basis of black box model and process reaction model established for Penicillium chrysogenum strain as well as cell lifelines or trajectories information in an industrial-scale fermentor. Guided by the SDSA, the industrial-relevant metabolic regimes for substrate availability, i.e., excess, limitation and starvation, were successfully reproduced at laboratory-scale three-compartment scale-down (SD) system. In addition, such SDSA can also display individual process dynamics in each compartment, and demonstrate how individual factors influence the entire bioprocess performance, thus serving both educational and research purposes.

Characterization of glucose Oxidase from Penicillium chrysogenum MDC 8358: Prospects for application in food industry

Backgrounds: Food enzymes play a crucial role in enhancing specific food attributes, such as improving texture, eliminating toxins and allergens, producing carbohydrates, and enhancing flavor and appearance characteristics. Glucose oxidase (GOX) catalyzes the oxidation of glucose to produce gluconic acid and hydrogen peroxide, making it applicable in various practical scenarios. This enzyme could be utilized to eliminate glucose, thereby facilitating the creation of functional food suitable for individuals with diabetes and glucose intolerance.Our main goal was to characterize GOX from a Penicillium chrysogenum strain isolated from Armenian ecosystems.Methods:GOX of P. chrysogenum MDC 8358 was obtained by surface fermentation using glucose as a carbon source. The enzyme was purified 230-fold to homogeneity using a three-step purification scheme consisting of ion exchange, adsorption, and gel filtration chromatography. Results:The specific activity of the purified enzyme reached 271.2 U/mg. GOX from P. chrysogenum MDC 8358 has shown to be dimeric with a molecular weight of 135.5 kDa, consisting of two equal subunits with a molecular weight of 70 kDa. Isoelectric focusing has revealed a pH of 4.6. The enzyme has displayed a temperature optimum of 40 °C, and a pH optimum of 6.8, being more thermostable at acidic pH. Characterized GOX was highly specific for β-D-glucose and has shown only minor activities to mannose, xylose, and galactose. Keywords:Penicillium chrysogenum MDC 8358, surface fermentation, glucose oxidase, purification, characterization, functional food preservation

Induction and Characterisation of Lignocellulolytic Activities from Novel Deep-Sea Fungal Secretomes

Fungi are increasingly recognised as being able to inhabit extreme environments. The deep sea is considered an extreme environment because of its low temperatures, high hydrostatic and lithostatic pressures, 3.5% salinity, and low oxygen, nutrient and light availability. Fungi inhabiting the deep sea may have evolved to produce proteins that allow them to survive these conditions. Investigation and characterisation of fungal lignocellulolytic enzymes from extreme environments like the deep sea is needed, as they may have unusual adaptations that would be useful in industry. This work, therefore, aimed to profile in detail the lignocellulolytic capabilities of fungi isolated from deep-sea sediments in the Atlantic Ocean, and a comparative lignocellulolytic terrestrial isolate. The isolates were strains of Emericellopsis maritima, Penicillium chrysogenum, P. antarcticum and Talaromyces stollii. Lignocellulolytic enzyme induction was achieved using liquid-state fermentation (LSF) with wheat bran as the main carbon source, while enzyme characteristics were evaluated using biochemical assays and gel-based proteomics. This study revealed that the isolates were halotolerant, produced xylanase over wide pH and temperature ranges, and produced a variety of glycoside hydrolase and feruloyl esterase activities. The T. stollii secretome demonstrated remarkable levels of exo-glycoside hydrolase activity, with xylanase activity optimum between pH 1.5–6.0 and temperatures between 1–60 °C, making this isolate an ideal candidate for biotechnological applications. This study is the first to quantitatively characterise xylanase activities and exo-glycoside hydrolase activities secreted by E. maritima, P. antarcticum and a marine T. stollii strain. This study is also the first to quantitatively characterise xylanase activities by a marine strain of P. chrysogenum during LSF.

Green synthesis, structural elucidation, antimicrobial, and cytotoxic activities of a Schiff base and its Pd(II) complexes

This paper includes the synthesis of a Schiff base ligand and its palladium(II) complexes by conventional and green microwave-assisted techniques. They were characterized by conductivity measurements, mass spectrometry, FTIR, electronic spectroscopy, 1H NMR, and X-ray powder diffraction techniques. Based on analytical and spectral data, a square planar geometry was proposed for the metal complexes. The ligand(LH) and its metal complex[Pd(L) ] were screened for antimicrobial activity against pathogenic bacterial(Escherichia coli, Staphylococcus aureus) and fungal(Aspergillus niger, Penicillium chrysogenum) strains. Ciprofloxacin and Ketoconazole were used as standard drugs for antibacterial and antifungal activities respectively. The compounds showed moderate activity. The starting material(PdCl ), ligand(LH), and the metal complex [Pd(L) ] were screened for in vitro cytotoxic activity by MTT assay against cancerous cell lines (HeLa, MCF-7). Cisplatin was used as the standard drug. The metal complex, [Pd(L) ] was also screened for cytotoxic activity against normal cell line(HEK 293) to determine the selectivity index. The values of S.I(3.70-4.58) indicated that the complex [Pd(L) ] was more sensitive towards cancerous cell lines than normal cell line and may be studied further to assess its potential as cytotoxic agent.

Penicillium chrysogenum strain 34-P promotes plant growth and improves initial development of maize under saline conditions

Halotolerant plant growth-promoting fungi (PGPF) can help plants tolerate salinity and improve crop productivity in saline areas. This study aimed to investigate the plant-growth promoting properties of the Penicillium chrysogenum strain 34-P. The strain was isolated from grass roots in Pantanal of Nhecolândia. Salt tolerance by the isolate was investigated under the presence of NaCl (0–20% w/v). The isolate was also characterized for growth promoting activities such as the release of indole-3-acetic acid (IAA), ammonia, synthesis of siderophores; phosphate solubilization; and hydrolytic enzyme production under normal and saline conditions (5% NaCl w/v). A pot experiment using maize plants was performed to evaluate how inoculation with P. chrysogenum 34-P affects the maize seedlings growth under two saline conditions: 150 and 300 mM NaCl. P. chrysogenum 34-P showed tolerance to high concentrations of NaCl (3–15% w/v). The isolate produced all plant growth promoting traits in the presence of 5% NaCl. The maize plants inoculated with P. chrysogenum showed significantly higher values of shoot length (18.37% and 32.57%), dry biomass (47.03% and 30.72%), fresh biomass (30.47% and 27.63%), and total chlorophyll (24.79% and 25.94%) than the control (without inoculation with P. chrysogenum) under 150 mM and 300 mM, respectively. Also, proline content was 21.94% higher in plants inoculated with P. chrysogenum in 300 mM NaCl. This research highlights a halotolerant P. chrysogenum obtained in the Pantanal of Nhecolândia as a PGPF. The results provide the potential of the isolate to be used as a stress mitigation strategy in plants growing in saline agricultural soils.

A comprehensive review on the medicinally valuable endosymbiotic fungi Penicillium chrysogenum

Recently, it has been shown that metabolites derived from endosymbiotic fungi attracted high attention, since plenty of them have promising pharmaceutical applications. The variation of metabolic pathways in fungi is considered an optimistic source for lead compounds. Among these classes are terpenoids, alkaloids, polyketides, and steroids, which have proved several pharmacological activities, including antitumor, antimicrobial, anti-inflammatory, and antiviral actions. This review concludes the major isolated compounds from different strains of Penicillium chrysogenum during the period 2013–2023, together with their reported pharmacological activities. From literature surveys, 277 compounds have been identified from P. chrysogenum, which has been isolated as an endosymbiotic fungus from different host organisms, with specific attention paid to those showing marked biological activities that could be useful in the pharmaceutical industry in the future. This review represents documentation for a valuable reference for promising pharmaceutical applications or further needed studies on P. chrysogenum.

Pectinase production by fungal-based solid-state fermentation of selected agricultural wastes

Agricultural waste is the residues from growing and processing raw agricultural products. They can be properly managed using fungi to produce economical materials such as pectinase enzymes that act as biological agents which are applicable in many areas. This research was aimed at producing pectinase by fungal-based solid-state fermentation of agricultural wastes. Fungi were isolated from dump sites soil using the pour plate method. These fungal isolates were inoculated into the pretreated agricultural waste, including watermelon, mango, and pineapple peels. The degradation period was 15 days on mineral salt solid media using separate flasks for each waste and fungus. They were incubated at room temperature (28°C). The pectinase was assayed using pectin and DNSA (dinitrosalicyclic acid). Fungal isolates were identified and screened for pectinase production using standard methods. The pH and temperature were optimized to study the effect on pectinase activities using standard procedures and pectinase was purified using column sephadex G-100. Molecular identifications were carried out on the isolates using 18srRNA gene primers. The fungi were identified as Aspergillus niger strain AGF3 (OM273994), Penicillium Chrysogenum strain AGF2 (OM273982) and Cladosporium tenuissimum strain AGF1 (OM273981). Aspergillus niger strain AGF3 (OM273994) produced the highest specific pectinase activities in mango waste (2400 U/mg. protein/ mL and it can be compared to what was produced by Cladosporium tenuissimum strain AGF1 (OM273981) (1590 U/mg. protein/mL). High specific pecrtinase activity was also obtained from pineapple peels (2200 U/mg. protein/mL) produced by Cladosporium tenussimum strain AGF1 (OM273981). It can be concluded in this study that Aspergillus niger strain AGF3 (OM273994) and Cladosporium tenuissimum strain AGF1 (OM273981) were the best producers of pectinase using mango and pineapple peels, while Penicillium chrysogenum strain AGF2 (OM273982) produced substantial pectinase in all the three agricultural wastes but not at higher levels.

Acetylcholine Esterase Inhibitory Effect, Antimicrobial, Antioxidant, Metabolomic Profiling, and an In Silico Study of Non-Polar Extract of The Halotolerant Marine Fungus Penicillium chrysogenum MZ945518.

Major health issues, such as the rise in oxidative stress, incidences of Alzheimer's disease, and infections caused by antibiotic-resistant microbes, have prompted researchers to look for new therapeutics. Microbial extracts are still a good source of novel compounds for biotechnological use. The objective of the current work was to investigate marine fungal bioactive compounds with potential antibacterial, antioxidant, and acetylcholinesterase inhibitory effects. Penicillium chrysogenum strain MZ945518 was isolated from the Mediterranean Sea in Egypt. The fungus was halotolerant with a salt tolerance index of 1.3. The mycelial extract showed antifungal properties against Fusarium solani with an inhibitory percentage of 77.5 ± 0.3, followed by Rhizoctonia solani and Fusarium oxysporum with percentages of 52 ± 0.0 and 40 ± 0.5, respectively. The extract also showed antibacterial activity against both Gram-negative and Gram-positive bacterial strains using the agar diffusion technique. The fungal extract was significantly more effective with Proteus mirabilis ATCC 29906 and Micrococcus luteus ATCC 9341; inhibition zones recorded 20 and 12 mm, respectively, compared with the antibiotic gentamycin, which recorded 12 and 10 mm, respectively. The antioxidant activity of the fungus extract revealed that it successfully scavenged DPPH free radicals and recorded an IC50 of 542.5 µg/mL. Additionally, it was capable of reducing Fe3+ to Fe2+ and exhibiting chelating ability in the metal ion-chelating test. The fungal extract was identified as a crucial inhibitor of acetylcholinesterase with an inhibition percentage of 63% and an IC50 value of 60.87 µg/mL. Using gas chromatography-mass spectrometry (GC/MS), 20 metabolites were detected. The most prevalent ones were (Z)-18-octadec-9-enolide and 1,2-Benzenedicarboxylic acid, with ratios of 36.28 and 26.73%, respectively. An in silico study using molecular docking demonstrated interactions between the major metabolites and the target proteins, including: DNA Gyrase, glutathione S-transferase, and Acetylcholinesterase, confirming the extract's antimicrobial and antioxidant activity. Penicillium chrysogenum MZ945518, a halotolerant strain, has promising bioactive compounds with antibacterial, antioxidant, and acetylcholinesterase inhibitory activities.

Molecular and Biological Investigation of Isolated Marine Fungal Metabolites as Anticancer Agents: A Multi-Target Approach.

Cancer is the leading cause of death globally, with an increasing number of cases being annually reported. Nature-derived metabolites have been widely studied for their potential programmed necrosis, cytotoxicity, and anti-proliferation leading to enrichment for the modern medicine, particularly within the last couple of decades. At a more rapid pace, the concept of multi-target agents has evolved from being an innovative approach into a regular drug development procedure for hampering the multi-fashioned pathophysiology and high-resistance nature of cancer cells. With the advent of the Red Sea Penicillium chrysogenum strain S003-isolated indole-based alkaloids, we thoroughly investigated the molecular aspects for three major metabolites: meleagrin (MEL), roquefortine C (ROC), and isoroquefortine C (ISO) against three cancer-associated biological targets Cdc-25A, PTP-1B, and c-Met kinase. The study presented, for the first time, the detailed molecular insights and near-physiological affinity for these marine indole alkaloids against the assign targets through molecular docking-coupled all-atom dynamic simulation analysis. Findings highlighted the superiority of MEL's binding affinity/stability being quite in concordance with the in vitro anticancer activity profile conducted via sulforhodamine B bioassay on different cancerous cell lines reaching down to low micromolar or even nanomolar potencies. The advent of lengthy structural topologies via the metabolites' extended tetracyclic cores and aromatic imidazole arm permitted multi-pocket accommodation addressing the selectivity concerns. Additionally, the presence decorating polar functionalities on the core hydrophobic tetracyclic ring contributed compound's pharmacodynamic preferentiality. Introducing ionizable functionality with more lipophilic characters was highlighted to improve binding affinities which was also in concordance with the conducted drug-likeness/pharmacokinetic profiling for obtaining a balanced pharmacokinetic/dynamic profile. Our study adds to the knowledge regarding drug development and optimization of marine-isolated indole-based alkaloids for future iterative synthesis and pre-clinical investigations as multi-target anticancer agents.

Comparative analysis of Penicillium genomes reveals the absence of a specific genetic basis for biocontrol in Penicillium rubens strain 212.

Penicillium rubens strain 212 (PO212) is a filamentous fungus belonging to the division Ascomycete. PO212 acts as an effective biocontrol agent against several pathogens in a variety of horticultural crops including Fusarium oxysporum f.sp. lycopersici, causing vascular wilt disease in tomato plants. We assembled draft genomes of two P. rubens strains, the biocontrol agent PO212 and the soil isolate S27, which lacks biocontrol activity. We also performed comparative analyses of the genomic sequence of PO212 with that of the other P. rubens and P. chrysogenum strains. This is the first Penicillium strain with biocontrol activity whose genome has been sequenced and compared. PO212 genome size is 2,982 Mb, which is currently organized into 65 scaffolds and a total of 10,164 predicted Open Reading Frames (ORFs). Sequencing confirmed that PO212 belongs to P. rubens clade. The comparative analysis of the PO212 genome with the genomes of other P. rubens and Penicillium chrysogenum strains available in databases showed strong conservation among genomes, but a correlation was not found between these genomic data and the biocontrol phenotype displayed by PO212. Finally, the comparative analysis between PO212 and S27 genomes showed high sequence conservation and a low number of variations mainly located in ORF regions. These differences found in coding regions between PO212 and S27 genomes can explain neither the biocontrol activity of PO212 nor the absence of such activity in S27, opening a possible avenue toward transcriptomic and epigenetic studies that may shed light on this mechanism for fighting plant diseases caused by fungal pathogens. The genome sequences described in this study provide a useful novel resource for future research into the biology, ecology, and evolution of biological control agents.

Eco-Friendly Solution Based on Rosmarinus officinalis Hydro-Alcoholic Extract to Prevent Biodeterioration of Cultural Heritage Objects and Buildings.

Biodeterioration of cultural heritage is caused by different organisms capable of inducing complex alteration processes. The present study aimed to evaluate the efficiency of Rosmarinus officinalis hydro-alcoholic extract to inhibit the growth of deteriogenic microbial strains. For this, the physico-chemical characterization of the vegetal extract by UHPLC–MS/MS, its antimicrobial and antibiofilm activity on a representative number of biodeteriogenic microbial strains, as well as the antioxidant activity determined by DPPH, CUPRAC, FRAP, TEAC methods, were performed. The extract had a total phenol content of 15.62 ± 0.97 mg GAE/mL of which approximately 8.53% were flavonoids. The polyphenolic profile included carnosic acid, carnosol, rosmarinic acid and hesperidin as major components. The extract exhibited good and wide spectrum antimicrobial activity, with low MIC (minimal inhibitory concentration) values against fungal strains such as Aspergillus clavatus (MIC = 1.2 mg/mL) and bacterial strains such as Arthrobacter globiformis (MIC = 0.78 mg/mL) or Bacillus cereus (MIC = 1.56 mg/mL). The rosemary extract inhibited the adherence capacity to the inert substrate of Penicillium chrysogenum strains isolated from wooden objects or textiles and B. thuringiensis strains. A potential mechanism of R. officinalis antimicrobial activity could be represented by the release of nitric oxide (NO), a universal signalling molecule for stress management. Moreover, the treatment of microbial cultures with subinhibitory concentrations has modulated the production of microbial enzymes and organic acids involved in biodeterioration, with the effect depending on the studied microbial strain, isolation source and the tested soluble factor. This paper reports for the first time the potential of R. officinalis hydro-alcoholic extract for the development of eco-friendly solutions dedicated to the conservation/safeguarding of tangible cultural heritage.

<em>Ocimum campechianum</em> essential oil: chemical composition and antifungal activity against filamentous fungi

Ocimum campechianum (OC), an aromatic and medicinal plant from the Amazon region, is rich in essential oils with antimicrobial potential. This study aimed to analyze the quality, toxicity, and antifungal action of Ocimum campechianum essential oil(OCEO). The plant species were collected in the city of São Luís-MA (Brazil). The essential oil (EO) was extracted by hydrodistillation in a Clevenger apparatus, and the physical-chemical parameters were analyzed according to the Brazilian Pharmacopoeia norms. The essential oil constituents were identified by gas chromatography-mass spectrometry (GC-MS). Toxicity was evaluated against brine shrimp (Artemia salina Leach). The antifungal activity was evaluated by the method of disk diffusion and microdilution in broth against ATCC strains of filamentous fungi Aspergillus Niger (ATCC 6275), Colletotrichum gloeosporioides (ATCC 96723), and Penicillium chrysogenum (ATCC 10106. The essential oil showed a slightly yellowish color, intense clove aroma, a density of 1.0 ± 0.0 g/mL, a refractive index of 1.52 ± 0.00, solubility in ethanol (1:2), and a yield of 1.40%. The chromatographic profile showed 36 volatile compounds, the majority being eugenol (49.18%), followed by β- caryophyllene (17.26%), elixene (9.46%), methyl eugenol (7.65%), and eucalyptol (2,55%). It presented LC 50 = 955 μg / mL against Artemia salina. The fungi induced growth inhibition zones (14.90 to 17.85 mm). The fungus P. chrysogenum was the most susceptible (MIC 220 μg/ml) compared to the fungi A. niger (MIC 250 μg/mL) and C. gloeosporioides (MIC 270 μg/mL). The minimum fungicide concentration (MFC) was sufficient to inhibit the growth of P. chrysogenum at 380 μg/mL, A. niger at 400.25 μg/mL, and C. gloeosporioides at 416.66 μg/mL. The OCEO showed good quality, low toxicity, and fungicidal action against the filamentous fungi analyzed, suggesting its application as a promising natural antifungal, mainly in combating diseases in post-harvest crops.

Synthesis, molecular structure, electronic, spectroscopic, NLO and antimicrobial study of N-benzyl-2-(5-aryl-1,3,4-oxadiazol-2-yl)aniline derivatives

The cyclization reaction between two benzohydrazides with 2-(benzylamino)benzoic acid afforded the novel 2,5-disubstituted oxadiazole derivatives; N-benzyl-2-(5-phenyl-1,3,4-oxadiazol-2-yl)aniline (NBPOA) and N-benzyl-2-(5-(4-chlorophenyl)-1,3,4-oxadiazol-2-yl)aniline (NBCPOA). Theoretical investigation of these newly synthesized oxadiazole derivatives was carried out by density functional theory (DFT) method at the B3LYP/6-311++G(d,p) level of theory. TD-DFT computations were performed to have insights into the three singlet electronic states of the electronic absorption spectra and to assign and correlate with the experimental UV-Vis spectra. The electronic absorption measurements were done in DCM and DMSO solvents. The increase in solvent polarity exerted a blue shift on the first singlet electronic excited state and a red shift on the second and the third electronic excited states suggesting different polarities of the excited states. Vibrational band assignments were scaled and compared with the experimental frequencies. Structural parameters and chemical reactivity such as HOMO and LUMO energies, MESP surfaces, Mulliken charges, and global reactivity descriptors were analyzed. It was observed that NBCPOA has a smaller HOMO-LUMO energy gap and larger global softness than NBPOA. The charge transfer that takes place in NBPOA and NBCPOA is supported by the oscillator strength. These compounds were also screened for their in vitro antibacterial activity against two Gram-negative bacterial strains namely Escherichia coli and Salmonella typhi and two Gram-positive bacterial strains namely Bacillus subtilis and Bacillus megaterium and antifungal activity against Aspergillus niger, Rhizopus oryzae, Penicillium chrysogenum, and Candida albicans fungal strains. The synthesized compounds exhibited moderate antibacterial and antifungal properties.

Changes in Oxygen Availability during Glucose-Limited Chemostat Cultivations of Penicillium chrysogenum Lead to Rapid Metabolite, Flux and Productivity Responses.

Bioreactor scale-up from the laboratory scale to the industrial scale has always been a pivotal step in bioprocess development. However, the transition of a bioeconomy from innovation to commercialization is often hampered by performance loss in titer, rate and yield. These are often ascribed to temporal variations of substrate and dissolved oxygen (for instance) in the environment, experienced by microorganisms at the industrial scale. Oscillations in dissolved oxygen (DO) concentration are not uncommon. Furthermore, these fluctuations can be exacerbated with poor mixing and mass transfer limitations, especially in fermentations with filamentous fungus as the microbial cell factory. In this work, the response of glucose-limited chemostat cultures of an industrial Penicillium chrysogenum strain to different dissolved oxygen levels was assessed under both DO shift-down (60% → 20%, 10% and 5%) and DO ramp-down (60% → 0% in 24 h) conditions. Collectively, the results revealed that the penicillin productivity decreased as the DO level dropped down below 20%, while the byproducts, e.g., 6-oxopiperidine-2-carboxylic acid (OPC) and 6-aminopenicillanic acid (6APA), accumulated. Following DO ramp-down, penicillin productivity under DO shift-up experiments returned to its maximum value in 60 h when the DO was reset to 60%. The result showed that a higher cytosolic redox status, indicated by NADH/NAD+, was observed in the presence of insufficient oxygen supply. Consistent with this, flux balance analysis indicated that the flux through the glyoxylate shunt was increased by a factor of 50 at a DO value of 5% compared to the reference control, favoring the maintenance of redox status. Interestingly, it was observed that, in comparison with the reference control, the penicillin productivity was reduced by 25% at a DO value of 5% under steady state conditions. Only a 14% reduction in penicillin productivity was observed as the DO level was ramped down to 0. Furthermore, intracellular levels of amino acids were less sensitive to DO levels at DO shift-down relative to DO ramp-down conditions; this difference could be caused by different timescales between turnover rates of amino acid pools (tens of seconds to minutes) and DO switches (hours to days at steady state and minutes to hours at ramp-down). In summary, this study showed that changes in oxygen availability can lead to rapid metabolite, flux and productivity responses, and dynamic DO perturbations could provide insight into understanding of metabolic responses in large-scale bioreactors.

Synthesis, spectral analysis, antibacterial, antifungal, antioxidant and hemolytic activity studies of some new 2,5-disubstituted-1,3,4-oxadiazoles

Series of 1,3,4-oxadiazole derivatives (5a–5g and 5h, 5i) were synthesized and characterized by FT-IR, 1H NMR, 13C NMR and HR-MS spectral analysis. All the target compounds were screened for their in vitro antibacterial activity against two Gram-negative bacterial strains namely Escherichia coli (MTCC 405) and Salmonella typhi (MTCC 3224) and two Gram-positive bacterial strains namely Bacillus subtilis (MTCC 1790) and Bacillus megaterium (MTCC 1684) and antifungal activity against Aspergillus niger (MTCC 282), Rhizopus oryzae (MTCC 262), Penicillium chrysogenum (MTCC 974), and Candida albicans (MTCC 183) fungal strains. The synthesized compounds exhibited significant antibacterial and antifungal potential. Three compounds (5e, 5f and 5g) have shown higher antibacterial activity with very low MIC values comparable to streptomycin. According to the SAR study, the antibacterial efficacy can be intensified by substituting fluoro and methyl substituents at the para position in acid hydrazide. The synthesized compounds were also screened for % radical scavenging activity by OH and DPPH assay and found to be good antioxidant agents. Besides, the hemolytic study revealed that the synthesized 1,3,4-oxadiazoles possessed negligible cytotoxicity compared with the standard.

Chemical Composition and Assessment of Antimicrobial Activity of Lavender Essential Oil and Some By-Products.

The producers of essential oils from the Republic of Moldova care about the quality of their products and at the same time, try to capitalize on the waste from processing. The purpose of the present study was to analyze the chemical composition of lavender (Lavanda angustifolia L.) essential oil and some by-products derived from its production (residual water, residual herbs), as well as to assess their “in vitro” antimicrobial activity. The gas chromatography-mass spectrometry analysis of essential oils produced by seven industrial manufacturers led to the identification of 41 constituents that meant 96.80–99.79% of the total. The main constituents are monoterpenes (84.08–92.55%), followed by sesquiterpenes (3.30–13.45%), and some aliphatic compounds (1.42–3.90%). The high-performance liquid chromatography analysis allowed the quantification of known triterpenes, ursolic, and oleanolic acids, in freshly dried lavender plants and in the residual by-products after hydrodistillation of the essential oil. The lavender essential oil showed good antibacterial activity against Bacillus subtilis, Pseudomonas fluorescens, Xanthomonas campestris, Erwinia carotovora at 300 μg/mL concentration, and Erwinia amylovora, Candida utilis at 150 μg/mL concentration, respectively. Lavender plant material but also the residual water and ethanolic extracts from the solid waste residue showed high antimicrobial activity against Aspergillus niger, Alternaria alternata, Penicillium chrysogenum, Bacillus sp., and Pseudomonas aeroginosa strains, at 0.75–6.0 μg/mL, 0.08–0.125 μg/mL, and 0.05–4.0 μg/mL, respectively.

Use of Wheat Straw for Value-Added Product Xylanase by Penicillium chrysogenum Strain A3 DSM105774.

The present work highlights the valorization of the bulky recalcitrant lignocellulose byproduct wheat straw (WS) for the enhanced production of value-added xylanase by the locally sourced novel Penicillium chrysogenum strain A3 DSM105774 for the first time. The optimized production of xylanase by submerged state of fermentation of WS was achieved using a three-step statistical and sequential approach: one factor at a time (OFAT), Plackett–Burman design (PBD), and Box Behnken design (BBD). Incubation temperature (30 °C), WS, and ammonium sulphate were the key determinants prompting xylanase production; inferred from OFAT. The WS concentration (%(w/v)), yeast extract concentration (%(w/v)), and initial pH of the production medium imposed significant effects (p ≤ 0.05) on the produced xylanase, realized from PBD. The predicted levels of WS concentration, initial pH of the production medium, and yeast extract concentration provoking the ultimate xylanase levels (53.7 U/mL) with an 8.95-fold enhancement, localized by the estimated ridge of the steepest ascent of the ridge analysis path, were 3.8% (w/v), 5.1, and 0.098% (w/v), respectively; 94.7% lab validation. The current data underpin the up-scaling of xylanase production using this eco-friendly, cheap, and robust methodology for the valorization of WS into the value-added product xylanase.

Antimicrobial properties of Pediococcus acidilactici and Pediococcus pentosaceus isolated from silage.

The objective of this study was to isolate multifunctional bacteriocin-producing strains; to characterize the expressed bacteriocin for the control of Listeria monocytogenes and vancomycin-resistant Enterococcus; to evaluate the safety of studied strains; and to explore their antifungal activity. Two Pediococcus strains were isolated from silage samples obtained from an organic farm in Belogradchik, Bulgaria. The strains were identified by 16S rRNA sequencing analysis and characterized as bacteriocins producers. Strong antimicrobial activity was detected against more than 74 different strains of Listeria monocytogenes, 27 different vancomycin-resistant Enterococcus strains. In addition, studied strains were able to inhibit the growth of strains of Alternaria alternate, Aspergillus flavus, Aspergillus niger, Cladosporium sphaerospermum, Penicillium chrysogenum and Penicillium expansum. Some aspects of the antimicrobial mode of action were evaluated, including killing curves and aggregation properties. Both strains generated positive PCR results for the presence of pediocin PA-1, but not for other bacteriocins evaluated in this screening process. Metabolomic analysis of the cell-free supernatants from both strains was performed in order to explain the observed antifungal activity against different moulds. According to PCA and PLS-DA score plot, P. acidilactici ST3522BG and P. pentosaceus ST3633BG were clearly clustered from control (MRS). Increases in the production of benzoic acid, 2-hydroxyisocaproic acid, β-phenyl-lactic acid, α-hydroxybutyric acid and 1,3-butanediol were recorded, these metabolites were previously described as antifungal. Pediococcus acidilactici ST3522BG and P. pentosaceus ST3633BG were evaluated as producing bacteriocin strains with high specificity against Listeria and vancomycin-resistant Enterococcus species. In addition, both investigated Pediococcus strains were evaluated as producer of effective antifungal metabolites with potential for the inhibition of mycotoxin-producing moulds. To the best of our knowledge, this report is a pioneer in the evaluation of Pediococcus strains isolated from silage with highly specific bacteriocinogenic antimicrobial activity against Listeria spp. and vancomycin-resistant Enterococcus spp., and antifungal activity against mycotoxin-producing moulds.

Analysis of gene expression in cucumber roots interacting with Penicillium chrysogenum strain Snef1216 through seed coating, which induced resistance to Meloidogyne incognita

Summary The root-knot nematode, Meloidogyne incognita, is a destructive pathogen with a broad host range, causing serious damage to cucumber globally. Synthetic chemical nematicides are effective for controlling nematodes but they pose harmful effects on the environment and human beings. Thus, the development of natural plant defence mechanisms to contribute resistance to M. incognita is a potentially eco-friendly alternative. In recent decades, the biocontrol activity of P. chrysogenum against various pests and pathogens has been investigated in a variety of plants. The present study aimed to understand the molecular mechanisms of induced resistance by P. chrysogenum strain Snef1216 against M. incognita through its use as seed coating. The expression of 80 genes in roots of cucumber, Cucumis sativus, at four different infection time intervals was examined. Genes belonging to defence, signal transduction, growth, binding and transportation, secondary metabolism, transcription factor, cell death, oxidoreductases and cell wall modification categories were selected and examined with specific primers via RT-qPCR. The greater expression of defence-related or other vital genes demonstrated that P. chrysogenum strain Snef1216 induced priming of defence and plant growth-promoting responses. These data could contribute to breeding new nematode-resistant and biomass-enhancing cultivars of cucumber. Overall, application of P. chrysogenum strain Snef1216 may be a potential alternative to chemical nematicides as part of a future more effective management strategy.

Antifungal and Antioxidant Potential of Methanolic Extracts from Acorus calamus L., Chlorella vulgaris Beijerinck, Lemna minuta Kunth and Scenedesmus dimorphus (Turpin) Kützing

Plant extracts are an important alternative to antibiotics, which are ever more restricted because of their developing microbial resistance and some adverse effects that have been observed following frequent application. The aim of the present study was to determine the antifungal and antioxidant activity of the methanolic extracts of Acorus calamus, Chlorella vulgaris, Lemna minuta and Scenedesmus dimorphus. The antifungal activity of the extracts against strains of Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Aspergillus niger, Aspergillus carbonarius, Fusarium graminearum, Fusarium oxysporum, Penicillium chrysogenum and Alternaria alternata was evaluated via the agar well diffusion method. The antioxidant activity of the extracts was measured through the determination of three parameters—total phenolic content, total flavonoid content and radical scavenging potential (determined through UV/Vis analysis). A. calamus extracts had the highest antimicrobial activity against eight fungal strains, followed by the C. vulgaris, L. minuta and S. dimorphus extracts, which were inhibitory against two to three strains. Among the extracts from the species studied, the extract from S. dimorphus showed the highest antioxidant potential, as determined via the DPPH (1,1’-diphenyl-2-picrylhydrazil-radical) method. This correlated to its high total phenolic and flavonoid content. From A. calamus and L. minuta, methanolic extracts were obtained that exhibited similar values of the aforementioned parameters, followed by C. vulgaris extracts, which showed the lowest antioxidant activity. Based on the Pearson correlation coefficients, the impacts of the total phenolic content and the total flavonoid content on radical scavenging capacity are similar, and flavonoids were a significant part of the total phenolic compounds extracted from the plant materials studied.