Automated identification of toxigenic cyanobacterial genera for water quality control purposes.

Cyanobacteria are the dominating microorganisms in aquatic environments, posing significant risks to public health due to toxin production in drinking water reservoirs. Traditional water quality assessments for abundance of the toxigenic genera in water samples are both time-consuming and error-prone, highlighting the urgent need for a fast and accurate automated approach. This study addresses this gap by introducing a novel public dataset, TCB-DS (Toxigenic Cyanobacteria Dataset), comprising 2593 microscopic images of 10 toxigenic cyanobacterial genera and subsequently, an automated system to identify these genera which can be divided into two parts. Initially, a feature extractor Convolutional Neural Network (CNN) model was employed, with MobileNet emerging as the optimal choice after comparing it with various other popular architectures such as MobileNetV2, VGG, etc. Secondly, to perform classification algorithms on the extracted features of the first section, multiple approaches were tested and the experimental results indicate that a Fully Connected Neural Network (FCNN) had the optimal performance with weighted accuracy and f1-score of 94.79% and 94.91%, respectively. The highest macro accuracy and f1-score were 90.17% and 87.64% which were acquired using MobileNetV2 as the feature extractor and FCNN as the classifier. These results demonstrate that the proposed approach can be employed as an automated screening tool for identifying toxigenic Cyanobacteria with practical implications for water quality control replacing the traditional estimation given by the lab operator following microscopic observations. The dataset and code of this paper are publicly available at https://github.com/iman2693/CTCB.

Manipulation and epigenetic control of silent biosynthetic pathways in actinobacteria.

Most biosynthetic gene clusters (BGCs) of Actinobacteria are either silent or expressed less than the detectable level. The non-genetic approaches including biological interactions, chemical agents, and physical stresses that can be used to awaken silenced pathways are compared in this paper. These non-genetic induction strategies often need screening approaches, including one strain many compounds (OSMAC), reporter-guided mutant selection, and high throughput elicitor screening (HiTES) have been developed. Different types of genetic manipulations applied in the induction of cryptic BGCs of Actinobacteria can be categorized as genome-wide pleiotropic and targeted approaches like manipulation of global regulatory systems, modulation of regulatory genes, ribosome and engineering of RNA polymerase or phosphopantheteine transferases. Targeted approaches including genome editing by CRISPR, mutation in transcription factors and modification of BGCs promoters, inactivation of the highly expressed biosynthetic pathways, deleting the suppressors or awakening the activators, heterologous expression, or refactoring of gene clusters can be applied for activation of pathways which are predicted to synthesize new bioactive structures in genome mining studies of Acinobacteria. In this review, the challenges and advantages of employing these approaches in induction of Actinobacteria BGCs are discussed. Further, novel natural products needed as drug for pharmaceutical industry or as biofertilizers in agricultural industry can be discovered even from known species of Actinobactera by the innovative approaches of metabolite biosynthesis elicitation.

Augmented antiviral activity of chlorhexidine gluconate on herpes simplex virus type 1, H1N1 influenza A virus, and adenovirus in combination with salicylic acid.

BACKGROUND: The excessive usage of chlorhexidine gluconate (CHG) as a broad-spectrum antimicrobial reagent can have a negative impact on the environment and on human health. The aim of this study was to investigate the effectiveness of some plant-derived compounds in reducing the CHG concentration required to exert its antiviral activity. METHODS: Antiviral assays were conducted according to EN 14476 (2019) against herpes simplex virus type 1 (HSV-1), H1N1 influenza A virus, and adenovirus type 5 (Ad-5) as enveloped and non-enveloped viral models to assess the synergistic interaction of CHG and natural additive compounds. RESULTS: The effective concentration of 0.247 mM CHG against HSV-1 was decreased tenfold in combination with 0.0125 mM salicylic acid, with a titer reduction of 1.47 ⋅ 104 CCID50/ml. The time required for complete inactivation of HSV-1 particles was reduced to 15 min when the virus was exposed to 0.061 mM CHG and 0.0125 mM salicylic acid. Additionally, the presence of salicylic acid protected the CHG activity against interfering substances. CONCLUSION: Our supplemented CHG formulation showed immediate antiviral effectiveness, which is important for management of the infections. CHG can be combined with salicylic acid to exhibit synergistic antiviral activity at lower concentrations and reduce the time required for inactivation. Furthermore, in the presence of interfering substances, the combination has higher antiviral activity than CHG alone.

In vitro and in silico pharmaceutical activities of the methylated cyclic pentapeptide, persipeptides.

AIMS: The persipeptides were recognized as a promising source of multiple pharmaceutical activities which were revealed following structure-activity prediction and examination in experimental analysis. METHODS AND RESULTS: The profile of toxicity, antioxidant, anti-inflammatory, anti-diabetic and anti-ageing activity of persipeptides and the crude extract were evaluated experimentally. The pure Persipeptide A and B revealed a moderate xanthine oxidase inhibition activity at the concentration of 10 µg/ml. Persipeptide exhibited α-glucosidase inhibition activity (~10% inhibition) and less than 2% tyrosinase inhibition activity at the concentration of 10 µg/ml. The extract exhibited the inhibition of less than 2% acetylcholine esterase inhibition activity, but the pure persipeptide showed 6%-14% inhibition activity at the concentration of 10 µg/ml. The molecular docking analysis revealed that the activities of Persipeptide A and B are due to interaction with xanthin oxidase, α-amylase, α-glucosidase, tyrosinase and acetylcholine esterase enzymes. CONCLUSIONS: The persipeptides showed a similar inhibition rate with positive control that might imply its potential as an anti-diabetic and anti-gout compound among. Only acetylcholine esterase inhibition of persipeptide was higher than the extract. The interacting amino acids of the molecules with different targets show that persipeptides might have antioxidant, anti-inflammatory, anti-diabetic, anti-ageing activity and even other potential pharmaceutical activities that were not investigated in this study. SIGNIFICANCE AND IMPACT OF THE STUDY: This report was presented to find some new pharmaceutical activities of Persipeptide A and B including the α-glucosidase inhibition activity as a molecular target of diabetes mellitus. Persipeptides also exhibited an effective inhibition of xanthine oxidase (XO) which can be a drug-like candidate in the treatment of diseases associated with XO like gout. The binding values indicated the interaction of persipeptides with these enzymes.

Potential of blockchain approach on development and security of microbial databases.

Approaches developed based on the blockchain concept can provides a framework for the realization of open science. The traditional centralized way of data collection and curation is a labor-intensive work that is often not updated. The fundamental contribution of developing blockchain format of microbial databases includes: 1. Scavenging the sparse data from different strain database; 2. Tracing a specific thread of access for the purpose of evaluation or even the forensic; 3. Mapping the microbial species diversity; 4. Enrichment of the taxonomic database with the biotechnological applications of the strains and 5. Data sharing with the transparent way of precedent recognition. The plausible applications of constructing microbial databases using blockchain technology is proposed in this paper. Nevertheless, the current challenges and constraints in the development of microbial databases using the blockchain module are discussed in this paper.

Glycomyces sediminimaris sp. nov., a new species of actinobacteria isolated from marine sediment.

A novel Glycomyces strain, designated as MH2460T, was isolated from marine sediment collected from 12 m depth in Rostami seaport, Bushehr Province in Iran. On International Streptomyces Project 2 medium it produced branching substrate hyphae that developed into a large number of irregularly shaped spores in 8 days. It showed optimal growth at 25-35 °C, pH 6.0-8.0 and in salinity between 2.5-5 % (w/v) NaCl. Chemotaxonomic and molecular characteristics of the isolate matched descriptions for members of the genus Glycomyces. Whole-cell hydrolysates of strain MH2460T contained meso-diaminopimelic acids along with glucose, ribose and small traces of xylose and galactose. The phospholipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides as well as two unidentified phosphoglycolipids, one unidentified phospholipid and an unidentified aminolipid. The predominant menaquinones were MK-11(H4) and MK-10(H4). The fatty-acid pattern was mainly composed of anteiso-C15 : 0, anteiso-C17 : 0, iso-C15 : 0 and iso-C16 : 0. The strain belongs to the genus Glycomyces based on 16S rRNA gene sequence with the highest pairwise sequence identity (98.3 %) with Glycomyces phytohabitans KLBMP 1483T. The DNA-DNA hybridization value showed 53.9±2.7 % identity when MH2460T was compared to this reference strain. The G+C content of the DNA was 70.2 mol%. Based on phenotypic, biochemical, chemotaxonomic and genotypic features, strain MH2460T (DSM 103727T=UTMC 2460T=NCCB 100631T) is considered to represent a novel species of the genus Glycomyces, for which the name Glycomyces sediminimaris is proposed.

Isolation and identification of two alkaloid structures with radical scavenging activity from Actinokineospora sp. UTMC 968, a new promising source of alkaloid compounds.

For decades, natural products from Actinomycetes have been recognized as one of the inestimable sources of therapeutic compounds. Presently, due to some challenges in the identification of novel compounds including the validation of novel natural products and their compatibility with the high throughput screening bioassays, evaluating new activity from known commercial ones would be an important designation. On the other hand, finding new sources of bioactive compounds from Actinomycetes can be promising in attaining pharmaceutical compounds with fewer purification steps and cost-effective production of the bioproducts. Here we describe the isolation and identification of two alkaloid compounds from a soil actinobacterium Actinokineospora sp. UTMC 968 including N-acetyltyramine (1) and N-acetyltryptamine (2) with revealing a new bioactivity for these molecules. The producer is a rare actinobacterium belonging to family Pseudonocardiaceae as the first alkaloid compounds producer genus in its family. The structures of alkaloid 1 and 2 were assigned on the basis of 1D and 2D NMR spectroscopy and MS analyses. Compound 1 and 2 are used commercially for their pharmaceutical activity but their radical scavenging activity has not previously been reported. The results of 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay represented a remarkable DPPH radical scavenging capability with an IC50 value of 64.7 ± 0.5 and 131.3 ± 1.8 µg/mL for compound 1 and 2, respectively.

Potential of rare actinomycetes in the production of metabolites against multiple oxidant agents.

CONTEXT: Actinobacteria are a precious source of novel bioactive metabolites with potential pharmaceutical applications. OBJECTIVES: Representatives of 11 genera of rare Actinobacteria were selected for the evaluation of antioxidant activity. MATERIAL AND METHODS: Fermentation broths of the Actinobacteria were extracted and dosage of 10 to 2000 µg/mL were applied for in vitro antioxidant-related bioassays. Cytotoxicity was assessed at the concentration of 2.5-20 µg/mL. RESULTS: In the DPPH scavenging activity, 15 out of 52 extracts showed 17.0-26.8% activity in quantitative evaluation. Metabolites of five prominent antioxidant producing strains protected the DNA (pUC19) against UV-induced photolyzed H2O2-oxidative degradation. The potent antioxidant extracts inhibited two oxidative enzymes of xanthine oxidase in the range of 17.5-45.2% (three extracts had IC50 less than allopurinol) and lipoxygenase in the range of 36-55% (all five extracts had IC50 values less than daidzein). All these extracts could also protect eythrocytes from iron-induced hemolysis with ED50 values in a range of 0.014-1.25 mg/mL. Growth restoration of the yeast cells lacking the sod1 gene was observed by the antioxidant metabolite of Saccharothrix ecbatanensis UTMC 537 at the concentration of 1 mg/mL. CONCLUSIONS: The presence of nonidentical metabolites might be responsible for antioxidant and enzyme inhibitory activities of S. ecbatanensis, newly described actinobacterium in family Pseudonocardiaceae. The scavenging of the free electrons, protection of DNA and model yeast cells against oxidative stress, in addition to the inhibition of the oxidating enzymes are the main mechanisms of the antioxidant effect of the introduced resource in this study.

Promicromonospora kermanensis sp. nov., an actinobacterium isolated from soil.

A novel strain belonging to the genus Promicromonospora, designated HM 533T, was isolated from soil in Kerman Province, Iran. It produced long and branched hyphae on ISP 2 medium that developed into a large number of irregular-shaped spores. It showed optimal growth at 25-30 °C and pH 5.0-8.0 with 0-4 % (w/v) NaCl. The peptidoglycan type of strain HM 533T was A4α l-Lys-l-Ala-d-Glu. Whole-cell hydrolysates of strain HM 533T contained the sugars ribose, glucose and galactose. The main phospholipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, two unknown glycolipids and an unknown phospholipid. MK-9(H4) and MK-9(H2) were the predominant menaquinones. The fatty acids pattern was mainly composed of the saturated branched-chain acids anteiso-C15 : 0 and iso-C15 : 0. The 16S rRNA gene sequence analysis showed the highest pairwise sequence identity (99.5-97.1 %) with the members of the genus Promicromonospora. Based on phenotypic and genotypic features, strain HM 533T is considered to represent a novel species of the genus Promicromonospora, for which the name Promicromonospora kermanensis is proposed with strain HM 533T (=DSM 45485T=UTMC 00533T=CECT 8709T) as the type strain.

Saccharothrix ecbatanensis sp. nov., an actinobacterium isolated from soil.

A novel actinomycete, designated HM 537T, was isolated from soil in Hamedan Province, Iran. Cell-wall hydrolysates of strain HM 537T contained meso-diaminopimelic acid, and whole-cell hydrolysates contained ribose, glucose, galactose, rhamnose and traces of mannose. The main phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol and an unknown phospholipid. MK-9(H4), an unknown MK and MK-10(H4) were the predominant menaquinones. The major fatty acids included iso-C16 : 0, iso-C15 : 0, iso-C16 : 1 G and 9(?)-methyl C16 : 0. Strain HM 537T had the highest 16S rRNA gene sequence similarity to Saccharothrix hoggarensis DSM 45457T (99.5 %) and Saccharothrix saharensis DSM 45456T (99.0 %). DNA-DNA hybridization studies showed relatedness values of 13.8 ± 3.3 % with S. hoggarensis DSM 45457T and 16.3 ± 3.5 % with S. saharensis DSM 45456T. Based on the results of phenotypic and genotypic studies, strain HM 537T represents a novel species of the genus Saccharothrix, for which the name Saccharothrix ecbatanensis sp. nov. is proposed. The type strain is HM 537T ( = DSM 45486T = UTMC 00537T = CCUG 63021T).

Biotechnological application and taxonomical distribution of plant growth promoting actinobacteria.

Plant growth promoting (PGP) bacteria are involved in various interactions known to affect plant fitness and soil quality, thereby increasing the productivity of agriculture and stability of soil. Although the potential of actinobacteria in antibiotic production is well-investigated, their capacity to enhance plant growth is not fully surveyed. Due to the following justifications, PGP actinobacteria (PGPA) can be considered as a more promising taxonomical group of PGP bacteria: (1) high numbers of actinobacteria per gram of soil and their filamentous nature, (2) genome dedicated to the secondary metabolite production (~5 to 10 %) is distinctively more than that of other bacteria and (3) number of plant growth promoter genera reported from actinobacteria is 1.3 times higher than that of other bacteria. Mechanisms by which PGPA contribute to the plant growth by association are: (a) enhancing nutrients availability, (b) regulation of plant metabolism, (c) decreasing environmental stress, (d) control of phytopathogens and (e) improvement of soil texture. Taxonomical and chemical diversity of PGPA and their biotechnological application along with their associated challenges are summarized in this paper.

Streptomyces zagrosensis sp. nov., isolated from soil.

The taxonomic position of a novel actinomycete isolated from soil in Fars Province (Iran) was determined using a polyphasic approach. Phenotypic characterization and 16S rRNA gene sequence analysis of the isolate matched those described for members of the genus Streptomyces. On ISP2 medium, strain HM 1154(T) produced a dark cream, branched substrate mycelium and Retinaculiaperti aerial hyphae that in some images also appeared spiral and that developed into greyish-white spore chains with a smooth surface. The isolate showed optimal growth at 28 °C and pH 6-9 with 0-4% (w/v) NaCl. Whole-cell hydrolysates contained ll-diaminopimelic acid as diagnostic diamino acid, ribose and glucose. The main phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, three unknown phospholipids and an unknown aminophospholipid; MK-9(H4) and MK-9(H2) were the predominant menaquinones. The major cellular fatty acids were the branched saturated iso-C16:0 and anteiso-C15:0. Strain HM 1154(T) exhibited the highest 16S rRNA gene sequence similarities to Streptomyces coerulescens DSM 40146(T) (99.4%), Streptomyces varsoviensis DSM 40346(T) (99.3%), Streptomyces youssoufiensis DSM 41920(T) (99.2%), Streptomyces abikoensis DSM 40831(T) (99.2%), Streptomyces rimosus subsp. rimosus DSM 40260(T) (99.1%), Streptomyces luteireticuli DSM 40509(T) (99.1%), Streptomyces thioluteus DSM 40027(T) (99.1%), Streptomyces blastmyceticus DSM 40029(T) (99.0%) and Streptomyces hiroshimensis DSM 40037(T) (99.0%). DNA-DNA hybridization studies showed relatedness values of 11.0-35.8% with the closest related species. Based on these results, strain HM 1154(T) is considered to represent a novel species within the genus Streptomyces, for which the name Streptomyces zagrosensis sp. nov. is proposed. The type strain is HM 1154(T) ( = DSM 42018(T) = UTMC 1154(T) = CECT 8305(T)).

Promicromonospora iranensis sp. nov., an actinobacterium isolated from rhizospheric soil.

A novel strain of the genus Promicromonospora, designated HM 792(T), was isolated from soil in Fars Province, Iran. On ISP 2 medium, the yellow-pigmented isolate produced long and branched hyphae that developed into a large number of irregularly shaped spores. It showed growth at 25-30 °C and pH 6.0-9.0 with 0-8 % (w/v) NaCl. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Promicromonospora. Whole-cell hydrolysates of strain HM 792(T) contained the amino acids d-glutamic acid, l-alanine and l-lysine along with the sugars glucose and ribose. The main polar lipids were diphosphatidylglycerol, two unknown phospholipids, two unknown glycolipids and two unknown phosphoglycolipids, complemented by minor concentrations of phosphatidylinositol and phosphatidylglycerol. MK-9(H4) was the predominant menaquinone. The fatty-acid pattern was composed mainly of the saturated branched-chain acids anteiso-C15 : 0 and iso-C15 : 0. 16S rRNA gene sequence analysis showed the highest pairwise sequence identity (96.6-99.0 %) with the members of the genus Promicromonospora. Based on phenotypic and genotypic features, strain HM 792(T) is considered to represent a novel species of the genus Promicromonospora, for which the name Promicromonospora iranensis sp. nov. is proposed. Strain HM 792(T) ( = DSM 45554(T) = UTMC00792(T) = CCUG 63022(T)) is the type strain.

Modulation of proteins by rare earth elements as a biotechnological tool.

Although rare earth element (REE) complexes are often utilized in bioimaging due to their photo- and redox stability, magnetic and optical characteristics, they are also applied for pharmaceutical applications due to their interaction with macromolecules namely proteins. The possible implications induced by REEs through modification in the function or regulatory activity of the proteins trigger a variety of applications for these elements in biomedicine and biotechnology. Lanthanide complexes have particularly been applied as anti-biofilm agents, cancer inhibitors, potential inflammation inhibitors, metabolic elicitors, and helper agents in the cultivation of unculturable strains, drug delivery, tissue engineering, photodynamic, and radiation therapy. This paper overviews emerging applications of REEs in biotechnology, especially in biomedical imaging, tumor diagnosis, and treatment along with their potential toxic effects. Although significant advances in applying REEs have been made, there is a lack of comprehensive studies to identify the potential of all REEs in biotechnology since only four elements, Eu, Ce, Gd, and La, among 17 REEs have been mostly investigated. However, in depth research on ecotoxicology, environmental behavior, and biological functions of REEs in the health and disease status of living organisms is required to fill the vital gaps in our understanding of REEs applications.

Mining the soil myxobacteria and finding sources of anti-diabetic metabolites.

Secondary metabolites produced by myxobacterial genera are often characterized as diverse molecules with unique structural properties which drove us to search for myxobacterial source of anti-diabetic drug discovery. In the present study, from 80 soil samples, out of sixty-five observed isolates, 30 and 16 were purified as Myxococcus and non-Myxococcus, respectively. Isolated strains taxonomically belonged to the genera Myxococcus, Corallococcus and Cystobacter, Archangium, Nanocystis, and Sorangium, and some could not be attributed. Secondary metabolites of selected non-Myxococcus isolates extracted by the liquid-liquid method showed that the myxobacterium UTMC 4530 demonstrated the highest inhibition on the formation of carbonyl group and fructosamine, respectively. In addition, it showed 23% and 15.8% inhibitory activity on α-glucosides and α-amylase compared to acarbose (23%, 18%), respectively. The extract of strain UTMC 4530 showed 35% induction effect on glucose adsorption while showing no radical scavenging activity and no toxic effect on HRBC lysis and HepG2 in cytotoxicity assays. The strain UTMC 4530 (ON808962), with the multiple antidiabetic activity, showed 87.3% similarity to Corallococcus llansteffanensis which indicates its affiliation to a new genus. The results of this study revealed that secondary metabolites produced by strain UTMC 4530 can be considered a promising source to find new therapeutic and pharmaceutical applications perhaps a multi-mechanism anti-diabetic compound.

Kribbella shirazensis sp. nov., isolated from Iranian soil.

The taxonomic position of a strain isolated from soil in Shiraz, Fars province, Iran, was investigated. Strain UTMC 693(T) produced an extensively branched substrate mycelium and aerial hyphae consisting of hyphae that fragment into short to elongated rod-like elements. The chemotaxonomic characteristics of the isolate matched those described for the genus Kribbella. Strain UTMC 693(T) showed the highest 16S rRNA gene sequence similarity to Kribbella karoonensis DSM 17344(T) (98.3%), K. swartbergensis DSM 17345(T) (98.2%), K. hippodromi S1.4(T) (98.0%), K. aluminosa HKI 0478(T) (98.0%) and K. jejuensis HD9(T) (98.0%). DNA-DNA hybridization studies with closely related type strains showed 56.3% relatedness to K. karoonensis, 21.3% to K. swartbergensis, 39.0% to K. jejuensis and 42.0% to K. aluminosa. Thus, strain UTMC 693(T) can be considered to represent a novel Kribbella species. Strain UTMC 693(T) showed the typical morphology found among members of Kribbella, but can be differentiated easily from closely related species by genotypic characteristics, chemotaxonomic results and other phenotypic markers. Based on these results, strain UTMC 693(T) ( =DSM 45490(T) =CCUG 61792(T)) is considered the type strain of a novel species of the genus Kribbella, for which the name Kribbella shirazensis sp. nov. is proposed.

Systematic and biotechnological aspects of halophilic and halotolerant actinomycetes.

More than 70 species of halotolerant and halophilic actinomycetes belonging to at least 24 genera have been validly described. Halophilic actinomycetes are a less explored source of actinomycetes for discovery of novel bioactive secondary metabolites. Degradation of aliphatic and aromatic organic compounds, detoxification of pollutants, production of new enzymes and other metabolites such as antibiotics, compatible solutes and polymers are other potential industrial applications of halophilic and halotolerant actinomycetes. Especially new bioactive secondary metabolites that are derived from only a small fraction of the investigated halophilic actinomycetes, mainly from marine habitats, have revealed the huge capacity of this physiological group in production of new bioactive chemical entities. Combined high metabolic capacities of actinomycetes and unique features related to extremophilic nature of the halophilic actinomycetes have conferred on them an influential role for future biotechnological applications.

Neurological manifestations of SARS-CoV-2 infections: towards quantum dots based management approaches.

Developing numerous nanotechnological designed tools to monitor the existence of SARS-CoV-2, and modifying its interactions address the global needs for efficient remedies required for the management of COVID-19. Herein, through a multidisciplinary outlook encompassing different fields such as the pathophysiology of SARS-CoV-2, analysis of symptoms, and statistics of neurological complications caused by SARS-CoV-2 infection in the central and peripheral nervous systems have been testified. The anosmia (51.1%) and ageusia (45.5%) are reported the most frequent neurological manifestation. Cerebrovascular disease and encephalopathy were mainly related to severe clinical cases. In addition, we focus especially on the various concerned physiological routes, including BBB dysfunction, which transpired due to SARS-CoV-2 infection, direct and indirect effects of the virus on the brain, and also, the plausible mechanisms of viral entry to the nerve system. We also outline the characterisation, and the ongoing pharmaceutical applications of quantum dots as smart nanocarriers crossing the blood-brain barrier and their importance in neurological diseases, mainly SARS-CoV-2 related manifestations Moreover, the market status, six clinical trials recruiting quantum dots, and the challenges limiting the clinical application of QDs are highlighted.

Persipeptides A and B, two cyclic peptides from Streptomyces sp. UTMC 1154.

Two new N-methylated cyclopeptides, persipeptide A (1) and B (2), have been isolated from Streptomyces sp. UTMC1154. Their structures were established using 1D and 2D NMR experiments. 2D TOCSY experiments were applied to identify the amino acid residues, while HMBC correlations were used to determine their sequence. According to Marfey's method, all amino acids had the l-configuration. The two cyclic peptides had the same ring size and amino acid composition, but differed in their sequence; they did not show activity against the tested bacteria, fungi and algae. Molecular identification experiments placed the strain in the genus Streptomyces closely related to Streptomyces coerulescens DSM40146(T) (99.45%) and Streptomyces varsoviensis DSM40346(T) (99.25%).

Nanomaterial-Augmented Formulation of Disinfectants and Antiseptics in Controlling SARS CoV-2.

The worldwide COVID-19 pandemic has brought significant consideration toward innovative strategies for overcoming the viral spread. Nanotechnology will change our lives in several forms as its uses span from electronics to pharmaceutical procedures. The use of nanoparticles provides a possibility to promote new antiviral treatments with a low possibility of increasing drug resistance compared to typical chemical-based antiviral treatments. Since the long-term usage of disinfectants and antiseptics at high concentrations has deleterious impacts on well-being and the environment, this review was intended to discuss the antiviral activity of disinfectants and antiseptics required for their activity against respiratory viruses especially SARS-CoV-2. It could improve the inhibition of viral penetration into cells, solvation of the lipid bilayer envelope, and ROS production, therefore enhancing the effect of disinfectants. However, significant concerns about nanomaterial's hazardous effects on individuals and the environment are increasing as nanotechnology flourishes. In this review, we first discuss the significant and essential types of nanomaterials, especially silver and copper, that could be used as antiviral agents and their viral entry mechanisms into host cells. Further, we consider the toxicity on health, and environmental concerns of nanoparticles. Eventually, we present our outlook on the fate of nanomaterials toward viral diseases.