Casein Agar Research Articles

Cellulolytic potentials of aspergillus oryzae and streptomyces griseus isolated from waste dump soil in Nile University Of Nigeria, Abuja

The potential of using microorganisms as biological sources of industrially economic enzymes has stimulated interest in the exploitation of extracellular enzymatic activity in several microorganisms. The aim of this research is to assess the cellulose degrading potentials of two microorganisms, Aspergillus oryzae and Streptomyces griseus using cellulose Congo red agar media. Soil sample collected from waste dump was serially diluted and inoculated in starch casein agar and SDA to isolate S. griseus and A. oryzae respectively. To assess their potentials to utilize cellulose, each of the two microorganisms was inoculated on cellulose Congo-red media and incubated at 30 ºC for 7days. A zone of clearing around the colonies after incubation confirms the secretion of extracellular cellulase, and was used as an indication for cellulose utilization. The zone of clearing was measured with a meter rule. In the results obtained, both microorganisms demonstrated cellulose utilization ability with Aspergillus oryzae showing a zone of clearing of 30.50 ± 0.50 mm while Streptomyces griseus showed a wider zone of clearing of 60.00 ± 1.00 mm. The results indicate that both microorganisms can be potent producers of the enzyme cellulase, with Streptomyces griseus having a higher cellulase-producing ability.

Efficient biodegradation of feathers by a novel and stable metallo-keratinase production strain Stenotrophomonas sp. Yang-5 isolated from swan farming soil

Feather waste produced by livestock and poultry breeding industry is a kind of biomass resource with great application prospect. Current study aims to obtain a feather-degradation bacteria that could efficiently biodegrade feather waste and maintain environmental friendliness. By using the casein agar medium, a novel keratinase production strain Stenotrophomonas sp. Yang-5 was isolated and then identified by subsequent 16S rRNA sequence. Further keratinase production medium was optimized by single factor and orthogonal experiments. Also, crude keratinase was characterized. Consequently, the highest enzyme activity of 161.95 ± 3.65 U/mL was obtained after 48 h of incubation with optimized conditions consisting of reaction temperature 32.5 °C, initial pH 7.5, 0 g/L CaCl2, 50 g/L fructose, and 15 g/L feather. Yang-5 keratinase demonstrated a broad temperature range of 25 °C − 95 °C and optimal catalytic efficiency at pH 9.0. The keratinase had a half-life of more than 120 min at 70° C, indicating satisfactory thermal stability. Furthermore, 0.25 mol/L Mg2+, Mn2+, K+, and Ca2+ could enhance the enzyme activity to some extent and assigned as the metallo-class of keratinase, among of which Mn2+ resulted in the highest improvement by 2-fold activity enhancement. In addition, 5% (v/v) reducing agents including DMSO, DTT and 2-mercaptoethanol all reinforced the enzyme activity by 3–5 folds. To sum up, thermostable alkaline metallo-keratinase from Stenotrophomonas sp. Yang-5 exhibited favorable stability and could serve as a promising candidate for feather waste degradation as well as environmental protection and feed additive industry.

Predominance and bioactive potential studies of endophytic Bacillus Sps. from marine algae of Palkbay costal region, India

The genus Bacillus is a widely distributed and prominent species that has been extensively studied for its numerous benefits in various industries, medical applications, and agriculture. In this study, endophytic Bacillus species were isolated from seven different algal species using various growth media such as Nutrient agar, starch casein agar, ISP 2, and ISP 4. Throughout the study period, a total of 36 bacterial strains with similar morphological characteristics were identified. Among the isolates, five bacterial strains were found to be predominant when grown on ISP 2 media. These five strains were further subjected to 16s RNA Sequencing to determine their taxonomic classification. The results revealed that all of these strains belonged to the genus Bacillus. However, the other endophytic strains could not be identified due to limited sequence homology with existing entries in the NCBI database. To gain further insights into the isolated Bacillus cultures, analytical studies were conducted. Firstly, the functional groups present in the cultures were identified using Fourier-transform infrared spectroscopy (FTIR). Additionally, the compounds present in the crude extracts of the cultures were analyzed using gas chromatography-mass spectrometry (GC-MS). The findings of this current research demonstrate the presence of Bacillus species among green and brown algae in the Palk Bay coastal range. Moreover, these Bacillus strains exhibit potential for various biotechnological applications. The study aims to establish the predominance of Bacillus species in the algae of the Palk Bay region in South India, thereby contributing to our understanding of the microbial ecology in this specific geographical area

The effect of agar on rheological properties and thermal stability of rennet-induced casein micelle gel

Effects of agar on the rheological property and heat stability of casein micelle gels induced by rennet were investigated. The interactions between casein micelle and agar were investigated. Electrostatic interactions between casein micelle and agar were not observed. The movement of agar characteristic bonds indicated the hydrogen bond interaction existed in the casein micelle/agar mixture. The addition of agar promoted the casein micelles aggregation and decreased the rennet coagulation time (RCT) and the storage modulus (G'). The strip-like network microstructure changed into a sheet-like network after the addition of agar. The composite gels were present as a bicontinuous phase structure. The agar and protein were both present as continuous phases. The addition of 0.5% agar increased the water holding capacity (WHC) from 63.30% to 92.44% and decreased the gel hardness from 73.41 g to 60.57 g. The protein digestion rate of gels increased after agar addition during gastric digestion. The WHC increased from 35.20% to 83.56% and the microstructure of gels improved by the addition of 0.5% agar after heating at 80 °C for 30 min. In conclusion, the WHC and thermal stability of the gels improved after the addition of agar.

Green extraction of puromycin-based antibiotics from Streptomyces albofaciens (MS38) for sustainable biopharmaceutical applications.

Background: Microbial secondary metabolites have shown promise as a source of novel antimicrobial agents. In this study, we aimed to isolate, characterize, and evaluate the antimicrobial activity of compound from a novel Streptomyces albofaciens strain MS38. The objective was to identify a potential bioactive compound with broad-spectrum antimicrobial properties. Methods: The isolated strain MS38 on starch casein agar was characterized using morphological, physiological, and molecular identification techniques. The compound was obtained from the fermented broth through extraction with n-butanol and further purification using silica gel column chromatography and high-performance liquid chromatography (HPLC). Structural elucidation was conducted using Ultraviolet (UV), Infrared (IR), nuclear magnetic resonance (NMR), and mass spectrometry (MS) techniques. The antimicrobial activity was evaluated using the agar well diffusion method and the microplate Alamar blue assay (MABA). Results: The isolated strain MS38 was identified as novel S. albofaciens based on morphological characteristics and confirmed by 16S sequences analysis and MALDI-TOF MS. The compound obtained from the fermented broth exhibited substantial antimicrobial activity against a variety of pathogenic bacteria and fungi. Structural analysis revealed a complex chemical structure with characteristic functional groups indicative of potential antimicrobial properties. The compound demonstrated strong activity against both Gram-positive (Staphylococcus Spp.) and Gram-negative (Klebsiella pneumoniae and Escherichia coli) bacteria, as well as fungi, including Candida albicans and Trichophyton rubrum. Conclusion: This study successfully isolated and characterized a bioactive compound from a novel S. albofaciens MS38. The compound exhibited significant antimicrobial activity against a range of pathogenic microorganisms. These findings underscore the importance of exploring microbial biodiversity for the discovery of novel antimicrobial agents. This study contributes to the growing knowledge of microbial secondary metabolites with potential therapeutic value.

Biochemical characterization of actinomycete from Namibia rocky crest mountainous soil and analyzing their bioactive metabolites for antagonistic effect against human respiratory pathogens.

the present study aimed at isolating and characterizing actinomycete from unexplored Windhoek rocky crest mountainous soil and extracting bioactive metabolites as possible therapeutics against common life-threatening Streptococcus pneumonia (S. pneumonia) and Stachybotrys chartarum (S. chartarum). chemotaxonomy and biochemical methods were used to identify the isolates. The solvent extraction method was used to extract bioactive compounds. Agar overlay and disc diffusion methods were used to determine the antimicrobial activity of isolates and extracted bioactive metabolites against S. pneumonia and S. chartarum. The antioxidant activity of the extracted bioactive metabolites was determined using 2.2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method with ascorbic acid as a positive control. Comparison between groups was done using a Two-way ANOVA, followed by Bonferroni post-test. three distinct isolates from 3 soil samples were identified on starch casein agar and distinguished using biochemical tests. All three isolates showed strong inhibitory activity against S. pneumonia with average growth inhibition zones between 18.0±1.00 and 27±0.00 mm p< 0.005. All isolates showed potent inhibitory activity against S. chartarum with the average inhibition zones ranging between 42.0±1.00 and 48±0.00 mm, p< 0.005. The chloroform extracts showed potent DPPH activity of up to 73± 1.41%. growth conditions and extraction solvents can influence the antimicrobial and antioxidant properties of bioactive metabolites.

Screening and Molecular Characterization of Antibacterial Secondary Metabolite Producing Actinomycetes from Soils of Eastern Mountain Regions of Nepal

Antibacterial secondary metabolite is a bioactive compound like antibiotic that can be considered a substance, produced by one microorganism, which in low concentration inhibits the growth of other microorganisms. Actinomycetes, slow-growing gram-positive bacteria, are the major sources of bioactive compounds. This study aimed to screen and identify antibacterial secondary metabolite-producing actinomycetes by sequencing the 16S rRNA method (molecular identification) from the soils of the mountain region of eastern Nepal. Starch casein agar (SCA) medium was used for the isolation of actinomycetes which were confirmed by primary screening and secondary screening. Identification of presumptive genera was done based on macroscopic, microscopic, and biochemical characteristics and confirmed by sequencing their 16S rRNA genes. The antibacterial compound was produced by culturing the potential isolate in starch casein broth. Using organic solvents such as ethyl acetate, n-butanol, chloroform, dichloromethane, and methanol, the chemical was recovered from the fermented broth. TLC performed the antibacterial substance characterization. Only 9 (13.6%) of the 66 actinomycetes isolates showed antibacterial activity against test microorganisms. Only one of the nine isolates, M3, had antibacterial activity in primary screening against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli, Salmonella Typhi, Shigella spp., and Pseudomonas aeruginosa) test bacteria. M3 was chosen for secondary screening due to its strong antibacterial activity. The minimum inhibitory concentration (MIC) of crude antibacterial substances was found to be 2.5 mg/mL against test organisms. According to the TLC chromatogram, the isolate produced only one compound with an Rf value of 0.81, completely distinct from the spot formed by gentamicin (standard), which had an Rf value of 0.89. The isolates were considered Streptomyces spp., a distinct taxonomic group based on characterization by macroscopic, microscopic, biochemical, physiological, and molecular techniques. This study concluded that Mountain regions are the reservoir of antibiotic- producing actinomycetes. Streptomyces is the most common genus.

Development of industrial production technology with determination of the quality of a soft medicine «Vetmikoderm» for veterinary

It is well known, that 1,2,4–triazole derivatives have a wide range of biological properties, showing little toxicity. Original modeling of 1,2,4-triazole derivatives allows obtaining new molecules with unique properties. Such purposeful changes in molecules are popular among many scientists because they make it possible to obtain compounds with «improved» properties. Such a compound was the substance (4-((5-(decylthio)-4-methyl-4H-1,2,4-triazol-3-yl)-methyl)morpholine with the prospect of creating a mild medicinal product – liniment «Vetmikoderm».&#x0D; The main advantage of these medicinal forms is a low traumatic effect on damaged tissue, creating maximum contact with the wound surface, etc. It has been proven, that the antimicrobial agents available on the veterinary drugs’ market, including those ones in the form of ointments, gels and liniments, are characterized by the fact that they do not always stimulate tissue regeneration processes. Medicines with the ability to improve wound healing, as a rule, have minor antiseptic properties. Under these circumstances, the search, development and introduction of the medicines that have antimicrobial and antifungal action is an extremely urgent issue of modern veterinary medicine.&#x0D; The aim of our research was to study the technological aspects and manufacturing features, the substantiation of the composition, the analysis of the soft medicinal form of the drug «Vetmikoderm».&#x0D; During the research, the appearance, transparency, and thickness of the drug were determined. APHI identification was carried out with the determination of its content by the gas chromatography’s method. The external standard method was used. Microbiological purity (bacteria, yeast and mold fungi (in total), the presence of bacteria of the Enterobacteriaceae family, Staphylococcus aureus and Pseudomonas aeruginosa) was determined in accordance with the requirements of the SPHU by the membrane filtration method. Sterile soy–casein agar was used to determine the total number of aerobic bacteria. Determination of harmlessness was carried out according to the «abnormal toxicity» indicator.&#x0D; On the basis of the conducted research, the technological aspects and manufacturing features, substantiation of the composition, quantitative and qualitative analysis of the «Vetmikoderm» liniment were determined, which ensures the possibility of the medicinal form’s obtaining in industrial conditions. The proposed methods of the medicinal form’s analysis are characterized by sensitivity and reproducibility.

Screening of bacteria isolates from earthworm cast for antibacterial activities

The healthy operation of the soil ecosystem is significantly influenced by earthworms. Various medical treatments have included the use of earthworms. This study isolated and screened bacterial species from earthworm cast for antibacterial activities. Two (2) bacteria species were isolated from the earthworm cast by culturing on starch casein agar using pour plate techniques. The isolates were identified as Streptomyces and Actinomadura species while the test isolates include Klebsiella specie, Salmonella shigella and Staphylococcus aureus strains. This study revealed that Streptococcus and Actinomadura metabolite exhibited variable degrees of antimicrobial activities against the test isolates. The highest in-vitro antimicrobial activity is (12.0mm) was exhibited by the Streptococcus metabolite at the highest concentration of 100mg/ml against Staphylococcus aureus, while the least antimicrobial activity (8.0mm) was exhibited at the concentration of 80mg/ml and 40mg/ml against Salmonella species and Staphylococcus aureus. Actinomadura metabolite was effective against Staphylococcus aureus at the highest concentration of 100mg/ml. However there was significant difference observed in antibacterial activity of the metabolites when compared to the standard antibiotic (Gentamicin) (p&lt;0.05). From the minimum inhibitory concentration (MIC) test result, Streptococcus metabolite demonstrated greater activity on Salmonella specie at the range of 3.12mg/ml and a lower activity on Staphylococcus aureus and Klebsiella specie at the range of 12.5mg/ml each. The Actinomadura metabolite demonstrated greater activity on Salmonella species at the range of 1.56mg/ml. Based on the findings of this research, earthworm (Pheretima posthuma) is a good source of antibacterial agents that can be identified and extracted as source of cheap medicines to control serious infections.

Isolation and Screening of Antibacterial Activity of Actinomycetota from the Medicinal Plant, Anthemis pseudocotula Boiss.

Antibiotic resistance is rising dramatically worldwide, and thus the production of new antibiotics is indispensable. Recent scientific initiatives have focused on the bioprospecting of microorganisms' secondary metabolites, with a particular focus on the look for natural products with antimicrobial properties derived from endophytes. All plant species, regardless of their type, are thought to anchor endophytic bacteria (EB). There are many potential uses for the natural therapeutic compounds made by EB in medicine, agriculture, and the pharmaceutical industry. To investigate antibacterial properties in this study, Actinomycetota (formerly, Actinobacteria) were isolated from Anthemis pseudocotula Boiss., identified, and underwent bioprospecting by morphological and molecular methods. Samples were collected from Ilam, Iran, and then divided into roots, leaves, stems, and flowers. After disinfection, they were cut into 2 mm pieces, cultured on casein agar culture medium, and incubated at 28ºC for up to four weeks. Actinomycetota was identified using the polymerase chain reaction method targeting the 16S rRNA gene. To evaluate the antibacterial properties of the isolated Actinomycetota, the agar diffusion method was used. In parallel, the frequencies of biosynthetic gene clusters, including polyketide synthase (PKS-I and PKS-II) and nonribosomal peptide synthetase (NRPS) genes, were determined in the isolated Actinomycetota. Ninety bacteria were isolated from different parts of Anthemis flowers. Thirty-eight (42.2%) of these bacteria belonged to the phylum Actinomycetota, and out of these 38, 15 isolates (39.5%) had antibacterial properties. Of these, 11 isolates (73.3%) exhibited antibacterial effects against Staphylococcus aureus, 2 (13.3%) against Pseudomonas aeruginosa, 3 (20%) against Escherichia coli, and two isolates (13.3%) against Salmonella enterica sub-species of enterica serovar Typhimurium. The results of the molecular analysis of PKS-I, PKS-II, and NRPS genes showed that out of 38 isolated Actinomycetota strains, 23 isolates (60.5%) carried PKS-I gene, 6 (15.8%) harbored PKS-II gene, and 20 isolates (52.6%) had NRPS gene. This study indicates that Anthemis pseudocotula Boiss. has a number of active Actinomycetota that produce secondary metabolites with antibacterial properties.

Isolation and screening of keratinolytic bacteria from feather dumping soil near in Lucknow and Kanpur city, North region of Indian

Background Keratinases are proteolytic enzymes that have the capability of degrading insoluble keratin substrates. LS4, LS5, and KS3 were newly isolated strains showing ability to hydrolyze keratins and keratin based products. Objective In this study, different bacterial strains were isolated from soil, screened for protease and keratinase production, and the best isolates were identified. Methods Serial dilution and plating method were used for isolation of pure bacterial culture. Isolated, 48 strains were screened, and their feather degrading ability on feather meal agar plates and keratin azure-based agar. The proteolytic activity of the isolates was also screened on casein agar. Results Three strains; LS4, LS5, and KS3 shows keratinolytic activity that reveal the keratinase enzyme on medium; feather meal agar, keratin azure agar, and casein agar. Among all the three strains (LS4, LS5, and KS3), KS3 show largest inhibition zone that show maximum enzymatic activity. For its characterization 16S RNA was performed, sequence KS3 was submitted to GenBank and was identified as Bacillus tropicus KS3. Newly isolated strain B. tropicus KS3 showed the keratinase production and highest keratinase activity (35.06 ± 2.5 U/ml). B. tropicus KS3 also show the highest degradation of feather efficiently showed 84% of whole chicken feather biodegradation at 37 °C within 15 days among all the isolated strains. Conclusion Keratinase enzyme possesses a wide range of potential applications in the bioremediation of feather waste and bio-fertilizer in agricultural land. The industry demands a better source of this enzyme due to its multivariate application and huge market demand. In the present study, a novel keratinase-producing bacteria was isolated and characterized as Bacillus tropicus KS3 from poultry waste contamination soil.

GC-MS Based Metabolomic Profiling of Streptomyces clavuligerus Isolated from Ocimum gratissimum Rhizosphere

Streptomyces clavuligerus is a member of the Actinobacteria family primarily known for its production of clavulanic acid antibiotic. The need for identification of new antimicrobials led to the identification of volatile components of S. clavuligerus metabolites using GC-MS. The isolate was obtained from Ocimum gratissimum rhizosphere using starch casein agar, and identified using molecular typing. The preliminary antibacterial screening of the isolate was carried out using some indicator bacteria from wound sites and urinary tract infection. Its bioactive metabolites were obtained using sub-merged fermentation over a four-day period, and the volatile compounds identified using GC-MS. The organism showed significant (p&lt;0.05) inhibition on Pseudomonas aeruginosa and Escherichia coli. Metabolomics study revealed the presence of compounds of alkanone and alkene functional groups. Eicosene was the major antimicrobial compound identified. Likewise, a non-antimicrobial, steroidal metabolite – pregnelonone, was also dominant in the metabolite mixture produced by the organism. Identifying volatile constituents of microbial metabolites may be a route for obtaining new antimicrobials and the GC-MS is a useful tool for achieving such aim.

The antibacterial activity and silk dyeing of the crude pigment extract from J4 actinobacteria strain

Actinobacteria represent a vast variety of prokaryotic microbes that produce a diverse group of secondary metabolites used in medical, agricultural, and industrial applications. The objectives in this study were to investigate the antibacterial activities and potential for silk dyeing of the crude extract from the actinobacterial strain J4. Initially, the antibacterial activities of the crude pigment extracts obtained from the actinobacterial strain J4 isolated from the wasp’s nest were determined. To extract the water-insoluble pigments used for antibacterial activity testing via the agar well diffusion method, ethyl acetate was applied during the pigment extraction. These extracts showed an inhibitory effect against Salmonella Typhimurium TISTR1472, Bacillus subtilis PSRU-01, and Enterococcus faecalis TISTR459. Secondly, evaluation of silk dyeing was carried out. We used the extractant as 70 % (v/v) ethanol in the alternative extraction process when the strain J4 was cultivated by solid-state fermentation with broken-milled rice to prepare actinobacterial dye for silk dyeing. The pigment extract obtained was tested for color stability based on washing methods, and the sensitivity to light was determined according to ISO105-C06:2010(E) and ISO 105-B02:2014(E), respectively. The color stability and sensitivity of the pigment extract to washing showed scores between 3-5, and the sensitivity to light demonstrated scores between 3-4. Taxonomically, the strain J4 was dark-violet colonies, and its water-soluble pigment diffused on sodium caseinate agar (SCA). To identify the strain J4, the phylogenetic identification based on partial sequencing of 16S rDNA was applied. The identification result indicated that the strain J4 was closely related to Streptomyces coacervatus (99.8% sequence similarity). In future, antibacterial activities of the crude extracts obtained from actinobacteria strain J4 should be tested with other food-borne pathogens. The development of Streptomyces dyes should also focus on the stability of the dyes during the silk dyeing process.

Neutrophil-derived reactive agents induce a transient SpeB negative phenotype in Streptococcus pyogenes

BackgroundStreptococcus pyogenes (group A streptococci; GAS) is the main causative pathogen of monomicrobial necrotizing soft tissue infections (NSTIs). To resist immuno-clearance, GAS adapt their genetic information and/or phenotype to the surrounding environment. Hyper-virulent streptococcal pyrogenic exotoxin B (SpeB) negative variants caused by covRS mutations are enriched during infection. A key driving force for this process is the bacterial Sda1 DNase.MethodsBacterial infiltration, immune cell influx, tissue necrosis and inflammation in patient´s biopsies were determined using immunohistochemistry. SpeB secretion and activity by GAS post infections or challenges with reactive agents were determined via Western blot or casein agar and proteolytic activity assays, respectively. Proteome of GAS single colonies and neutrophil secretome were profiled, using mass spectrometry.ResultsHere, we identify another strategy resulting in SpeB-negative variants, namely reversible abrogation of SpeB secretion triggered by neutrophil effector molecules. Analysis of NSTI patient tissue biopsies revealed that tissue inflammation, neutrophil influx, and degranulation positively correlate with increasing frequency of SpeB-negative GAS clones. Using single colony proteomics, we show that GAS isolated directly from tissue express but do not secrete SpeB. Once the tissue pressure is lifted, GAS regain SpeB secreting function. Neutrophils were identified as the main immune cells responsible for the observed phenotype. Subsequent analyses identified hydrogen peroxide and hypochlorous acid as reactive agents driving this phenotypic GAS adaptation to the tissue environment. SpeB-negative GAS show improved survival within neutrophils and induce increased degranulation.ConclusionsOur findings provide new information about GAS fitness and heterogeneity in the soft tissue milieu and provide new potential targets for therapeutic intervention in NSTIs.

Endophytes Producing Proteases from Custard Apple (Annona squamosa L.) Leaves

The cost of the proteolytic enzymes and their inability to remove “fine” hairs from the animal hide has been the main obstacles to the commercialization of an enzymatic dehairing procedure. Endophytic microbes that grow inside various plant tissues without causing tissue damage in the host plant are the important sources of bioactive compounds. They are rich in secondary metabolites and known to produce wide range of enzymes. Several endophytes showing different properties have been reported from Annona leaves and hence this study was performed to isolate endophytes having proteolytic properties. Endophytes from custard apple leaves were isolated and screened for proteolytic activity on casein agar plates. The protease enzyme activity of the promising isolates was determined using casein substrate and tyrosine release assay. Present study conducted on the bacterial endophytes from the Custard apple leaves showed that the plant-associated bacterial endophytes are a good reservoir of proteases. Two promising isolates were obtained on the casein agar plates. These two isolates C and D possessed 113U/ml and 102 U/ml enzyme activity respectively. The isolate C showed more dehairing capacity than isolate D. Purified forms of these enzymes can prove to be potential candidates in biotechnological applications.

Ceropegia rupicola, Acokanthera schimperi, Jatropha variegate Antimicrobial, Cytotoxicity and Phytochemical

In Asian countries, a variety of medicinal plants are utilized in folk medicine for hemostatic and antiseptic. The methanolic extracts of Jatropha variegata, Acokanthera schimperi, and Ceropegia rupicolawere tested for the following purposes: first, isolation of endophytic fungi, second, antimicrobial and cytotoxicity activity, and third, phytoconstituents of the methanolic extract using the GC-Mass technique. The plants came from a variety of Yemeni locations. Endophytic fungus strains were isolated and identified using starch casein and potato dextrose agar medium. Methanol was used to extract the stem and leaves of the plants. The agar well diffusion method was used to test the antibacterial properties of the produced methanolic extracts against four Gram-negative bacteria, three Gram-positive bacteria, and one species of yeast. The IC50 values for the most promising extracts are calculated. The methanolic extracts were also subjected to a phytochemical screening by GC-Mass. A total of forty fungal endophyte isolates were isolated. Fusarium spp. (15), Phomaspp. (6), Alternaria alternata (5), White Sterile mycelia (6), Dark Sterile mycelia (6), Cochlioboluslunatus (1), and Mucor spp. (1). were found throughout the identification process. The highest yield extract was obtained from Jatropha variegate (45.4%), followed by Acokanthera schimperi (32.3%), and finally Ceropegia rupicola (20.5%). Only Gram-negative bacteria were found to have antibacterial activity, and the most effective extract was Acokanthera schimperi against the majority of microorganisms tested (8–18mm). The methanolic extracts of Jatropha variegate had the best antibacterial activity against Klebsiella pneumoniae ATCC 13883015, with a zone of inhibition (45 mm). Furthermore, Ceropegia rupicola extract had the highest inhibitory zone against Candida albicans ATCC 700012 (20mm). In addition, the IC50 results showed that the Jatropha variegate extract on A549 had an IC50 of 84.1ug/ml and a PC3 of 39.4ug/ml. The IC50 for Ceropegia rupicola extract was 49.4ug/ml in A549 cells and 34ug/ml in PC3 cells. Also, the screening for phytochemicals of the three plant extracts revealed the presence of many chemicals such as ethanol, formic acid, and others that may be responsible for the observed actions.

Isolation and Screening of Antibacterial Activity of Actinomycetota from the medicinal plant, Anthemis pseudocotula Boiss

Antibiotic resistance is rising dramatically worldwide, and thus the production of new antibiotics is indispensable. Recent scientific initiatives have focused on the bioprospecting of microorganisms' secondary metabolites, with a particular focus on the look for natural products with antimicrobial properties derived from endophytes. All plant species, regardless of their type, are thought to anchor endophytic bacteria (EB). There are many potential uses for the natural therapeutic compounds made by EB in medicine, agriculture, and the pharmaceutical industry. To investigate antibacterial properties in this study, Actinomycetota (formerly, Actinobacteria) were isolated from Anthemis pseudocotula Boiss., identified, and underwent bioprospecting by morphological and molecular methods. Samples were collected from Ilam, Iran, and then divided into roots, leaves, stems, and flowers. After disinfection, they were cut into 2 mm pieces, cultured on casein agar culture medium, and incubated at 28°C for up to four weeks. Actinomycetota was identified using the polymerase chain reaction method targeting the 16S rRNA gene. To evaluate the antibacterial properties of the isolated Actinomycetota, the agar diffusion method was used. In parallel, the frequencies of biosynthetic gene clusters, including polyketide synthase (PKS-I and PKS-II) and nonribosomal peptide synthetase (NRPS) genes, were determined in the isolated Actinomycetota. Ninety bacteria were isolated from different parts of Anthemis flowers. Thirty-eight (42.2%) of these bacteria belonged to the phylum Actinomycetota, and out of these 38, 15 isolates (39.5%) had antibacterial properties. Of these, 11 isolates (73.3%) exhibited antibacterial effects against Staphylococcus aureus, 2 (13.3%) against Pseudomonas aeruginosa, 3 (20%) against Escherichia coli, and two isolates (13.3%) against Salmonella enterica sub-species of enterica serovar Typhimurium. The results of the molecular analysis of PKS-I, PKS-II, and NRPS genes showed that out of 38 isolated Actinomycetota strains, 23 isolates (60.5%) carried PKS-I gene, 6 (15.8%) harbored PKS-II gene, and 20 isolates (52.6%) had NRPS gene. This study indicates that Anthemis pseudocotula Boiss. has a number of active Actinomycetota that produce secondary metabolites with antibacterial properties.

Production of Fibrinolytic Enzyme by Soil Actinobacteria

Thrombotic diseases are increasingly becoming among the prominent causes of death across the globe. Researchers are now turning attention towards fibrinolytic enzymes as potential alternative treatment for thrombolytic diseases. This present study focused on the production of extracellular fibrinolytic enzyme from soil Actinobacteria and evaluation of its hydrolytic activity on blood clot. The Actinobacteria was isolated from compost soil of semi-arid climate in Nigeria. Bacterial isolation was achieved using starch casein agar. Potent fibrinolytic enzyme producing Actinobacteria were identified and subjected to enzyme production using submerged fermentation method. The interactive effects of incubation time, temperature, pH and media components on enzyme production were analysed. Extracellular fibrinolytic enzyme produced by the selected Actinobacteria was partially purified by ammonium sulphate precipitation and subsequently assayed for blood clot lysis activity. Results of these studies indicated that fibrinolytic enzyme was produced optimally at pH 8 and temperature of 40 oC after 72 hour of fermentation. Partially purified fibrinolytic enzyme was able to degrade blood clot comparable to the positive control. These results shows that soil Actinobacteria of unexplored semi-arid climate of Nigeria present a prospect in search of novel microorganisms with potentials in the production of fibrinolytic enzyme that can serve as an alternative blood clot buster in treating thrombolytic diseases.

Antiproliferative activity of antimicrobial peptides and bioactive compounds from the mangrove Glutamicibacter mysorens.

The Glutamicibacter group of microbes is known for antibiotic and enzyme production. Antibiotics and enzymes produced by them are important in the control, protection, and treatment of chronic human diseases. In this study, the Glutamicibacter mysorens (G. mysorens) strain MW647910.1 was isolated from mangrove soil in the Mangalore region of India. After optimization of growth conditions for G. mysorens on starch casein agar media, the micromorphology of G. mysorens was found to be spirally coiled spore chain, each spore visualized as an elongated cylindrical hairy appearance with curved edges visualized through Field Emission Scanning Electron Microscopy (FESEM) analysis. The culture phenotype with filamentous mycelia, brown pigmentation, and ash-colored spore production was observed. The intracellular extract of G. mysorens characterized through GCMS analysis detected bioactive compounds reported for pharmacological applications. The majority of bioactive compounds identified in intracellular extract when compared to the NIST library revealed molecular weight ranging below 1kgmole-1. The Sephadex G-10 could result in 10.66 fold purification and eluted peak protein fraction showed significant anticancer activity on the prostate cancer cell line. Liquid Chromatography-Mass Spectrometry (LC-MS) analysis revealed Kinetin-9-ribose and Embinin with a molecular weight below 1 kDa. This study showed small molecular weight bioactive compounds produced from microbial origin possess dual roles, acting as antimicrobial peptides (AMPs) and anticancer peptides (ACPs). Hence, the bioactive compounds produced from microbial origin are a promising source of future therapeutics.

Presence of Actinomycetes in agarwood tissues of Aquilaria crassna: A preliminary study

Agarwood is a valuable resin produced inside certain tree species of the family Thymalaeaceae distributed in the Asian region. Agarwood production occurs as a defense mechanism when the trees are under physical or biological stresses. However, the formation of agarwood resins in significant extractable quantities due to natural stress conditions is rare; therefore, the farmers use various methods to induce its formation artificially. Certain fungal species such as Fusarium and Aspergillus become more popular among them to produce high-quality agarwood. However, studies are rare on using other microbial organisms such as Actinomycetes, which exhibit properties of both bacteria and fungi. Among the agarwood-producing species, Aquilaria crassna is one of Asia's most commonly planted species for agarwood production. This species was introduced to Sri Lanka in 2012 for mid and lower elevations of the wet zone. Due to the lack of studies on agarwood resin formation by non-fungal microbial methods, the present study attempted to identify the presence of Actinomycetes species in agarwood resinous tissues of A. crassna. Agarwood resinous tissue samples were collected from four plantations in the wet zone of the country. Surface sterilized, small sized tissues were placed on starch casein agar medium and incubated at room temperature for ten days. Using the morphological and microscopic characteristics, it was possible to identify Nocardia, Psuedonocardia, and three Streptomyces species with varying abundance. The species level should be confirmed using molecular analysis, and their potential for agarwood resin formation inducement should be tested by re-inoculating to the healthy A. crassna trees.