Inhibited Bacillus Subtilis Research Articles

Antioxidant, anti-inflammatory, antimicrobial, and anticancer properties of green broad bean pods (Vicia faba L.)

This study featured broad/fava bean pods as by-products of food production. It assessed the chemical composition of green bean pods (Vicia faba L.) and their methanolic extract.
 The extract was tested in vitro for antioxidant, anti-inflammatory, antimicrobial, and anticancer activities against prostate cancer (Pc3) and liver cancer (HepG2) cells. Broad bean pods proved to be rich in carbohydrates, fiber, protein, potassium, calcium, and magnesium. The extract contained 286 mg GAE/g total phenols and 105 mg QE/g total flavonoids. The antioxidant activity of the methanolic extract was measured by 1,1-diphenyl-2-picryl hydrazyl (DPPH) assay. The highest DPPH scavenging activity belonged to the extract concentrations of 1000 μg/mL (80.5%) and 500 μg/mL (73.7%), whereas the IC50 value was 87.35 μg/mL. The methanolic extract possessed the anti-inflammatory effect as it significantly reduced the hemolysis of red blood cells. The maximal inhibition percentage reached 66.7% at 1000 μg/mL. Regarding the antimicrobial activity, the broad bean pod methanolic extract inhibited Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, as well as Candida albicans. The extract reduced the cell viability of human hepatocarcinoma (HepG2) and prostate cancer (PC3) cells in a concentration-dependent manner. It also caused significant changes in cell shape, compared to the control.
 Therefore, broad beans can be recommended for human consumption together with pods, fresh or cooked, as a potential source of bioactive substances in functional food production.

Antibacterial and antibiofilm activity of peptide PvGBP2 against pathogenic bacteria that contaminate Auricularia auricular culture bags

Bacteria contamination in Auricularia auricular culture bags reduces yield and increases the risk of food safety. In this study, 5 species of bacteria, mainly gram-positive bacteria including three species of Bacillus spp., Arthrobacter arilaitensis and Staphylococcus warneri, were isolated and identified from bacteria-contaminated A. auricular culture bags. An in silico predicted antimicrobial peptide from the β-1,3-glucan-binding protein sequence of Penaeus vannamei, designated PvGBP2 (FLKLGRKSRYGMLKL), was screened and its antibacterial effect and mechanism of action on the isolated Bacillus spp. explored. The minimal inhibitory concentrations (MIC) of PvGBP2 on Bacillus spp. were 15.6–31.25 μg/mL. Peptide PvGBP2 could inhibit Bacillus subtilis in A. auricular culture bags to maintain growth and yield of A. auricular. Transmission electron microscopy (TEM) revealed that PvGBP2 kills bacteria by perforating the cell wall, destroying membrane integrity and resulting in the leakage of intracellular solutes. In addition, PvGBP2 inhibits biofilm formation by B. subtilis by 90.6 % at 1 × MIC. Thus, peptide PvGBP2 could be potentially applied as an antibacterial agent to control bacterial infection of A. auricular cultivation and the spread of foodborne pathogens.

Phytochemical Composition and Bioactivities of Aqueous Extract of Rambutan (Nephelium lappaceum L. cv. Rong Rian) Peel.

Thailand is one of the leading exporting countries of rambutan and rambutan peels are considered as a biological waste. In this study, rambutan (Nephelium lappaceum L. cv. Rong Rian) peel extracts (RPE) obtained by water extraction were analyzed for their phytochemical composition, antibacterial and antioxidant activities, and cytotoxicity. The bioactive compounds in RPE identified by GC-MS were mome inositol (35.99 mg/g), catechol (29.37 mg/g), 5-hydroxymethylfurfural (5.69 mg/g), 2-pentenal, (E)-(5.22 mg/g), acetic acid (3.69 mg/g), 1,2,3-propanetriol (3.67 mg/g), 2-furan-carboxaldehyde (2.66 mg/g), and other compounds. FT-IR analysis confirmed the presence of alcohol and phenol in the extract. Antibacterial activities of RPE against food pathogenic and spoilage bacteria showed that RPE could inhibited Bacillus subtilis, B. cereus, Staphylococcus aureus, Vibrio cholerae, V. parahaemolyticus, Pseudomonas aeruginosa, and P. fluorescens, with MIC values ranging between 1024 and 8192 µg/mL. The extract also showed antioxidant properties, as determined by DPPH and ABTS assays. The cytotoxicity analysis after 72 h of treatment showed the IC50 values at 194.97 ± 4.87, 205.92 ± 2.55, and 94.11 ± 1.33 µg/mL for L929, Vero, and MCF-7 cell lines, respectively. Therefore, this study provided a basis of knowledge of rambutan peels as an excellent source of natural bioactive compounds for various applications.

Nano-chitosan Spray as a Preservative and Food Security of Fishery Products in The Middle of the Covid-19 Pandemic

Highlight ResearchThe author mentioned 2 highlights from their results research Nano-chitosan has the best susceptibility to bacterial strains of E. coli, S. enteritidis, L. monocytogenes, B. cereus and S. aureus.Nano-chitosan showed higher degree of inhibition than that done by chitosan. AbstractThe COVID-19 pandemic has impacted the fisheries sector, a decline in exports and fishermen's income caused by the disconnection of the marketing chain due to lockdown implementation in several export destination countries. Fish is a source of protein and as perishable goods, it experiences quality damage due to spoilage, commonly caused by hampered distribution of catches. Natural preservatives are needed to preserve catch so it won’t get spoiled and can be accepted by consumers in suitable conditions for consumption. This study aims to evaluate the particle size of nano-chitosan and determine the effectiveness of nano-chitosan spray with different concentrations as a natural preservative in caught fish. This research method begins with making chitosan through 3 stages: demineralization, deproteination, and deacetylation. Chitosan was made into nano-chitosan with various concentrations of 3:1, 4:1, and 5:1 using ionic gelation. Nano-chitosan underwent several tests, including PSA, antibacterial activity by disc diffusion, organoleptic, and the effectiveness of preservatives. Antibacterial activity of nano-chitosan was able to inhibit Bacillus subtilis at three different concentrations, the potential to inhibit Escherichia coli was optimal at 5:1 treatment. The effectiveness of nano-chitosan preservative bacteria inhibition at three different concentrations proved to be sufficient to be used to extend shelf life and ensure the safety and quality of fishery products. The best concentration of nano-chitosan was 3:1 treatment. Nano-chitosan spray from crab shell waste has good antibacterial activity and preservative effectiveness. It could serve as an antibacterial agent and natural preservative for fishery products during the COVID-19 pandemic.

Potential of Lactic Acid Bacteria From Tape and Jember Tempeh as a Probiotic Candidate

Probiotics are microbes in fermented foods that have beneficial effects on health. Microbes that act as probiotics are lactic acid bacteria (LAB) that can produce metabolites such as lactic acid, hydrogen peroxide, and bacteriocins. This study aimed to obtain lactic acid bacterial isolates from tape and tempeh, and to test the potential of LAB as a probiotic candidate by activity test as an antidiarrhea and its resistance to gastric pH and bile salts. The fermentation products used as a source of LAB isolates are tempeh sumber mas merk, and yellow cassava tape, sari madu merk from Jember. The results of the first stage regarding the isolation of LAB using GYP media showed that there were 2 LAB isolates (TaJ.14 and TaJ.15) from the tape and 4 LAB isolates (TeJ.18, TeJ.22, TeJ.24, and TeJ.25) from tempeh. The results of the antidiarrheal test using the disc diffusion method (oxoid) showed that TaJ.14 and TaJ.15 isolates were able to inhibit Bacillus subtilis, Escherichia coli, and Shigella dysentriae, while TeJ.18, TeJ.22, TeJ.24, TeJ.25, and Lactobacillus casei (control) was only able to inhibit B. subtilis and E. coli. The results of LAB resistance to gastric pH showed that the TeJ.25 isolate had the highest percentage of pH 3 and 2.5 resistance (51.13 and 33.03%) compared to other isolates and controls. LAB resistance test results against bile salts (oxgal) showed that the TeJ.22 isolate had the highest percentage of resistance (75.10%) compared to other isolates although was still higher in control (75.99%).

Nutraceutical Chewing Candy Formulations Based on Acetic, Alcoholic, and Lactofermented Apple Juice Products.

The aim of this study was to develop nutraceutical chewing candy (NCC) formulations based on acetic, alcoholic, and lactofermented apple juice (AJ) products. In addition, different texture-forming (gelatin, pectin) and sweetening (stevia, xylitol) agents were tested. To implement the aim of this study, combinations based on AJ, prepared from fresh and frozen apples, apple cider (C) samples (No.1, No.2, No.3, and No.4), and apple vinegar (V) were used. First, the most appropriate combination was selected by evaluating overall acceptability (OA) and emotions induced for consumers (EIC). In addition, the volatile compound (VC) profile, and physicochemical and antimicrobial characteristics of the developed combinations were analyzed. For AJ fermentation, lactic acid bacteria (LAB) strains possessing antimicrobial properties (LUHS122—L. plantarum and LUHS210—L. casei) were used. AJ prepared from frozen apples had 11.1% higher OA and 45.9%, 50.4%, and 33.3% higher fructose, glucose, and saccharose concentrations, respectively. All the tested C samples inhibited Bacillus subtilis and had an average OA of 6.6 points. Very strong positive correlations were found between AJ and C OA and the emotion ‘happy’; comparing lactofermented AJ, the highest OA was obtained for AJ fermented for 48 h with LUHS122, and a moderate positive correlation was found between AJ OA and the emotion ‘happy’ (r = 0.7617). This sample also showed the highest viable LAB count (7.59 log10 CFU mL−1) and the broadest spectrum of pathogen inhibition (inhibited 6 out of 10 tested pathogens). Further, acetic, alcoholic, and lactofermented AJ product combinations were tested. For the preparation of NCC, the combination consisting of 50 mL of AJ fermented with LUHS122 for 48 h + 50 mL C-No.3 + 2 mL V was selected because it showed the highest OA, induced a high intensity of the emotion ‘happy’ for the judges, and inhibited 8 out of 10 tested pathogens. Finally, the OA of the prepared NCC was, on average, 9.03 points. The combination of acetic, alcoholic, and lactofermented AJ products leads to the formation of a specific VC profile and increases the OA and antimicrobial activity of the products which could be successfully applied in the food and nutraceutical industries.

Characterization of Macro- and Microalgae Extracts Bioactive Compounds and Micro- and Macroelements Transition from Algae to Extract.

The aim of this study was to evaluate the characteristics of macroalgae (Cladophora rupestris, Furcellaria lumbricalis, Ulva intestinalis) and microalgae (Arthrospira platensis (Sp1, Sp2), Chlorella vulgaris) extracts, including micro- and macroelement transition to extract, antioxidant, antimicrobial properties, the concentrations of chlorophyll (-a, -b), and the total carotenoid concentration (TCC). In macroalgae, the highest TCC and chlorophyll content were found in C. rupestris. In microalgae, the TCC was 10.1-times higher in C. vulgaris than in Sp1, Sp2; however, the chlorophyll contents in C. vulgaris samples were lower. A moderate negative correlation was found between the chlorophyll-a and TCC contents (r = −0.4644). In macroalgae extract samples, C. rupestris and F. lumbricalis showed the highest total phenolic compound content (TPCC). DPPH antioxidant activity and TPCC in microalgae was related to the TCC (r = 0.6191, r = 0.6439, respectively). Sp2 extracts inhibited Staphylococcus haemolyticus; C. rupestris, F. lumbricalis, U. intestinalis, and Sp2 extracts inhibited Bacillus subtilis; and U. intestinalis extracts inhibited Streptococcus mutans strains. This study showed that extraction is a suitable technology for toxic metal decontamination in algae; however, some of the desirable microelements are reduced during the extraction, and only the final products, could be applied in food, feed, and others.

Effect of ethanol extract of black soybean coat on physicochemical properties and biological activities of chitosan packaging film.

Chitosan (CS) with an ethanol extract of black soybean coat (EBSC) was prepared, and its physicochemical properties and antioxidant and antibacterial activities were tested. The results showed that EBSC significantly increased the thickness and UV-Vis light barrier ability of the CS-based films, while the swelling degree, water vapor permeability, and tensile strength decreased. The CS-EBSC films had smooth surfaces, compact cross-sections, and no cracks, and they had higher crystallinity than the CS film. Fourier transform-infrared spectroscopy indicated that there were noncovalent bonds (hydrogen bonds) between EBSC and CS. Furthermore, the CS-EBSC III film presented a stronger ABTS radical scavenging ability (66.58%) and could effectively inhibit Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. The lipid oxidation test proved that CS-EBSC films significantly reduced the peroxide value of lard. The results above indicate that CS-EBSC films could be used as an active packaging material to improve the shelf life of food.

Phytochemical Screening and Antibacterial Evaluation of Conventional Antibiotics, Garlic and Ginger on Isolates from Fish Pond Water Samples in Awka, Anambra State, Nigeria

Medicinal plants are used by almost 80% of the world’s population for their basic health care because of their low cost and ease in availability. In the last few decades, many bacteria have continued to show increasing resistance against current antibiotics.
 Aim: In this study, phytochemical screening and antibacterial effects of conventional antibiotics, garlic and ginger on test isolates from fish pond water samples were evaluated between May-November, 2019.
 Methods: Standard methods for phytochemical screening and antibacterial analysis were employed.
 Results: The results showed that amongst the antibiotics used for susceptibility test, Amoxicilin (30 µg) was mostly resisted by all the bacterial isolates except Staphylococcus aureus, Vibrio cholerae, Vibrio parahaemolyticus and Salmonella typhi while erythromycin (10 µg) was unable to inhibit Bacillus subtilis. Ciprofloxacin (10 µg) and pefloxacin (10 µg) inhibited the growth of all the isolates except Pseudomonas aeruginosa. The test isolates showed variable susceptibility to the garlic and ginger extracts (ethanol, methanol and hot water). The extracts inhibited the isolates in descending order; ginger ethanol > ginger methanol > garlic methanol > ginger hot water > garlic ethanol > garlic hot water. Vibrio parahaemolyticus, Vibrio cholerae and Staphylococcus aureus showed little resistant to the extracts while these extracts showed better activity on Klebsiella pneumoniae and Proteus mirabilis. Synergistic effect of garlic and ginger (500mg/ml) inhibited the growth of all the isolates with ethanol extracts having the highest zone diameter (29 mm) on Klebsiella pneumoniae and Proteus mirabilis while hot water extracts had the least zone of inhibition (18 mm) on Acinetobacter calcoaceticus and Vibrio parahaemolyticus. The minimum inhibitory and bactericidal concentration for ethanol, methanol and hot water extracts ranged from 31.25mg/ml to 62.5mg/ml and 62.5mg/ml to 125mg/ml respectively.
 Conclusion: The outcomes of susceptibility experiment depicted that ethanol and methanol extracts of garlic and ginger (each alone and in combination) showed more inhibitory effect than aqueous extracts and also the combination of ethanol, methanol and aqueous extracts resulted in inhibitory effect greater than each of the extracts when used singly. The use of ginger and garlic for control of fish pathogens appears to be justified.

Anti-Biofilm Action of Biological Silver Nanoparticles Produced by Aspergillus tubingensis and Antimicrobial Activity of Fabrics Carrying it

Biological silver nanoparticles (AgNPs) were synthesized using the marine endophytic fungus Aspergillus tubingensis and inhibited Bacillus subtilis biofilm formation at low concentrations. Cotton and polyester fabrics impregnated with AgNPs were analyzed by transmission electron microscopy (TEM), and the concentration of AgNPs in both fabrics was determined using inductively-coupled plasma atomic emission spectrometry (ICP-AES). The fabrics carrying the AgNPs inhibited the Staphylococcus aureus and Escherichia coli growth by 100%. Both fabrics impregnated one time with AgNPs inhibited yeasts' clinical species' growth, Candida albicans, Candida glabrata, and Candida parapsilosis, from 80.1% to approximately 98.0%. Besides the anti-biofilm effect, the AgNPs impregnation process on cotton and polyester fabrics was highly efficient, and both fabrics presented antimicrobial effects against clinically relevant bacteria and yeast species. The results evidence that functionalized textiles containing these biological AgNPs can play an essential role in combating pathogenic microorganisms. Thereby offering an alternative to design effective solutions, mainly for hospital garments and biomedical devices, to avoid microorganisms transmissions and hospital-acquired nosocomial infections.

The exopolysaccharide\u2013eDNA interaction modulates 3D architecture of Bacillus subtilis biofilm

BackgroundBacterial biofilms are surface-adherent microbial communities in which individual cells are surrounded by a self-produced extracellular matrix of polysaccharides, extracellular DNA (eDNA) and proteins. Interactions among matrix components within biofilms are responsible for creating an adaptable structure during biofilm development. However, it is unclear how the interactions among matrix components contribute to the construction of the three-dimensional (3D) biofilm architecture.ResultsDNase I treatment significantly inhibited Bacillus subtilis biofilm formation in the early phases of biofilm development. Confocal laser scanning microscopy (CLSM) and image analysis revealed that eDNA was cooperative with exopolysaccharide (EPS) in the early stages of B. subtilis biofilm development, while EPS played a major structural role in the later stages. In addition, deletion of the EPS production gene epsG in B. subtilis SBE1 resulted in loss of the interaction between EPS and eDNA and reduced the biofilm biomass in pellicles at the air-liquid interface. The physical interaction between these two essential biofilm matrix components was confirmed by isothermal titration calorimetry (ITC).ConclusionsBiofilm 3D structures become interconnected through surrounding eDNA and EPS. eDNA interacts with EPS in the early phases of biofilm development, while EPS mainly participates in the maturation of biofilms. The findings of this study provide a better understanding of the role of the interaction between eDNA and EPS in shaping the biofilm 3D matrix structure and biofilm formation.

Rapid and solitary production of mono-rhamnolipid biosurfactant and biofilm inhibiting pyocyanin by a taxonomic outlier Pseudomonas aeruginosa strain CR1

Biosurfactant - Rhamnolipids (RLs) and antibacterial toxin - pyocyanin (PYO) produced by Pseudomonas aeruginosa strains have great potential for biotechnological applications. Generally, RLs are produced as a mixture of di-rhamnolipids (di-RLs) and mono-rhamnolipids (mono-RLs). Mono-RLs possess superior emulsification and antimicrobial properties and are costlier than di-RLs. In this study, a taxonomic outlier P. aeruginosa strain CR1 isolated from rhizosphere soil was explored for mono-RLs and PYO production. Phylogenetically strain CR1 resembles avirulent outlier P. aeruginosa strain ATCC9027, lacks archetypical virulence genes and harbors unique pathways for the synthesis of solely mono-RLs and PYO. Strain CR1 produced RL biosurfactant which efficiently emulsified hydrocarbons, showed hemolysis and inhibited Bacillus subtilis. At 37 °C, strain CR1 exclusively produced 21.77 g L−1 and 19.22 g L−1 rhamnolipid in glycerol amended Luria Bertani (LB) medium and basal medium amended with rice bran oil, respectively after 54 h growth. Besides RL production was unaffected under varying nitrogen sources. Structural characterization using FTIR, TLC, and LC–MS confirmed that strain CR1 exclusively produced mono-RLs, majorly dominated by Rha-C10-C10, Rha-C10-C8, and CH3-Rha-C12:2-C10:1. The compound was stable over a wide pH range (4–12), salinity (25%) and 100 °C indicating its applicability under harsh environmental conditions. In addition, strain CR1 produced 4.5 μg mL−1 PYO, which could efficiently inhibit biofilm formation by Bacillus species. The environmental outlier strain CR1 can be used for the industrial production of biotechnologically important mono-RLs and PYO.

Synthesis, characterization, and antibacterial potential of silver nanoparticles synthesized from Coriandrum sativum L.

IntroductionNanoparticles (NPs) have become very important owing to their various uses. In this research, an environmentally friendly biological technique was used to synthesize silver nanoparticles with Coriandrum sativum L. The objective of this research to use the source for the fabrication of silver NPs from C. sativum L., and to check the activity of the fabricated silver NPs was determined versus a couple of gram negative and a couple of gram positive bacteria in the presence of antibiotic viz. gentamicin to judge their impact. MethodologyA silver nitrate solution, which served as the reducing and capping agent, was mingled with coriander leaf extract. The solution’s temperature and pH were maintained at 75°C and 8.6, respectively. The observed mean particle size (z-average) and polydispersity index were 390.2nm and 0.452, respectively. The synthesized Ag NPs were characterized using different techniques, including scanning electron microscopy (SEM), X-ray diffraction, and Fourier transmission infrared (FTIR) analysis. The globular shape of the silver nanoparticles was depicted in SEM illustrations. ResultsXRD data revealed the mean size of the particles was 11.9nm. The FTIR analysis showed the existence of various functional groups, including CO and OH. When their antibacterial ability was tested, it was found that the fabricated Ag NPs inhibited Bacillus subtilis, Pasteurella multocida, Enterobacter aerogenes, and Staphylococcus aureus, with a greater effect against B. subtilis and P. multocida compared to E. aerogenes and S. aureus. ConclusionIt has been concluded small silver NPs benefited from a higher surface area ratio, as shown by the results of experiments where smaller particles had a better bactericidal proficiency than large silver-based NPs. Silver-based NPs infiltrate bacterial cells, as well as interfere with their exterior membrane. Silver ions also have the potential to interact with bacterial DNA, inhibiting the reproductive system of the cell.

ISOLASI FUNGI ENDOFIT PENGHASIL ANTIBIOTIKA PADA ALGA MERAH JENIS Gracilaria verrucosa SECARA KLT-BIOAUTOGRAFI

Th is research aim ed to determine the antibacterial fungi endofitic isolate of Gracilaria verrucosa type Rhodophyta that antibiotic as potential by Bioautography-TLC Method. The result of fungi endofitic isolate , obtained that 7 active isolates and purified by quadrant method on potato dextrose agar medium obtained 5 active isolates (isolate 1, 2, 3, 5, 6). The result of the screening of fungi endofitic isolate by cakram method possessed that t he biggest inhibit ory zone is isolate 2 and isolate 6 by 25 mm at Streptococcus mutans . The test results of fungi endofitic isolate activity by Bioautography-TLC obtained Rf 0.07 0.23, 0.56, 0.78, 0.81 and 0.94 value actif inhibited Bacillus subtilis , Shigella disentry , Streptococcus mutans and Eschericia coli . And the identification results of the chemical component shown that the actif compound at isolate 2 and isolate 6 given result positif alkaloid .

ISOLASI FUNGI ENDOFIT PENGHASIL ANTIBIOTIKA PADA ALGA MERAH JENIS Gracilaria verrucosa SECARA KLT-BIOAUTOGRAFI

Th is research aim ed to determine the antibacterial fungi endofitic isolate of Gracilaria verrucosa type Rhodophyta that antibiotic as potential by Bioautography-TLC Method. The result of fungi endofitic isolate , obtained that 7 active isolates and purified by quadrant method on potato dextrose agar medium obtained 5 active isolates (isolate 1, 2, 3, 5, 6). The result of the screening of fungi endofitic isolate by cakram method possessed that t he biggest inhibit ory zone is isolate 2 and isolate 6 by 25 mm at Streptococcus mutans . The test results of fungi endofitic isolate activity by Bioautography-TLC obtained Rf 0.07 0.23, 0.56, 0.78, 0.81 and 0.94 value actif inhibited Bacillus subtilis , Shigella disentry , Streptococcus mutans and Eschericia coli . And the identification results of the chemical component shown that the actif compound at isolate 2 and isolate 6 given result positif alkaloid .

POTENSI ANTIBAKTERI EKSTRAK ETANOL JAMUR KANCING (Agaricus bisporus) SEBAGAI ANTIBAKTERI

A research had been done on antibacterial activity of extract and the aim was to determine the antibacterial activity and inhibitory potency. The research was started by screening test using Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus epidermidis, Shigella dysenteriae, Staphylococcus aureus, Streptococcus mutans and Vibrio cholerae. Results showed that the Agaricus bisporus ekstract inhibited Bacillus subtilis, Shigella dysenteriae, Staphylococcus aureus, and Vibrio cholera at concentrations 0,1% and 1%. The results obtained Minimum Inhibitory Concentration (MIC) Agaricus bisporus extract against at concentrations of 0,1%. In the Minimum Bactericidal Concentration (MBC) test Agaricus bisporus extract against at concentrations of 0,8%. Agaricus bisporus extract has antibacterial activity wich was indicated by the inhibitory zone diameter. The biggest inhibitory zone diameter of Agaricus bisporus contained in bacteria Bacillus subtilis on the concentration of 6.4% (13 mm)

Antimicrobial, hemolytic and thrombolytic activities of some new N-substituted-2-({5-[(1E,3E)F-4-(1,3-benzodioxol- 5-yl)-1,3-butadienyl]-1,3,4-oxadiazol-2-yl}sulfanyl) propanamides

Purpose: To synthesize and evaluate the bioactivity of some N-substituted-2-({5-[(1E,3E)-4-(1,3- benzodioxol-5-yl)-1,3-butadienyl]-1,3,4-oxadiazol-2-yl}sulfanyl)propanamides (9a-o) of the alkaloid piperine (1) extracted from P. nigrum (black pepper). Methods: Extract 1 was subjected to basic hydrolysis to obtain piperic acid (2). The heterocyclic 1,3,4- oxadiazole ring was synthesized from 2 through the formation of an ester and carbohydrazide. A series of electrophiles, 8a-o, were synthesized in the presence of 10 % Na 2 CO 3 . The final compounds, 9a-o, were synthesized by stirring 5-[(1E,3E)-4-(1,3-benzodioxol-5-yl)-1,3-butadienyl]-1,3,4-oxadiazol-2-thiol (5) and 8a-o in LiH/DMF. Spectral analysis was performed using infrared (FTIR), proton nuclear magnetic resonance (1H-NMR) and electron impact mass spectrometry (EI-MS) to determine the structures of 9a-o. Antimicrobial activity was evaluated as zone of inhibition by disc diffusion method. Hemolytic and thrombolytic activities were determined by measuring absorbance before and after incubation of blood cells with test compound. Results: Compound 9d strongly inhibited Bacillus subtilis and Escherichia coli with zone of inhibition values of 16 mm for each. The reference drug, rifampicin, showed zone of inhibition of 21 and 23 mm against B. subtilis and E. coli , respectively. Compound 9a strongly inhibited Aspergillus niger with a zone of inhibition of 18 mm compared to the reference drug, fluconazole, with a zone of inhibition of 19mm. Conclusion: The newly synthesized compounds are more active antimicrobial agents than piperine. Compounds 9a and 9d are the most active. Keywords: Piper nigrum , Piperine, Propanamide, Hemolytic, Thrombolytic, Black pepper

PEGylated ofloxacin nanoparticles render strong antibacterial activity against many clinically important human pathogens

The rise of bacterial resistance against important drugs threatens their clinical utility. Fluoroquinones, one of the most important classes of contemporary antibiotics has also reported to suffer bacterial resistance. Since the general mechanism of bacterial resistance against fluoroquinone antibiotics (e.g. ofloxacin) consists of target mutations resulting in reduced membrane permeability and increased efflux by the bacteria, strategies that could increase bacterial uptake and reduce efflux of the drug would provide effective treatment. In the present study, we have compared the efficiencies of ofloxacin delivered in the form of free drug (OFX) and as nanoparticles on bacterial uptake and antibacterial activity. Although both poly(lactic-co-glycolic acid) (OFX-PLGA) and methoxy poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) (OFX-mPEG-PLGA) nanoformulations presented improved bacterial uptake and antibacterial activity against all the tested human bacterial pathogens, namely, Escherichia coli, Proteus vulgaris, Salmonella typhimurium, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus, OFX-mPEG-PLGA showed significantly higher bacterial uptake and antibacterial activity compared to OFX-PLGA. We have also found that mPEG-PLGA nanoencapsulation could significantly inhibit Bacillus subtilis resistance development against OFX.

Antibacterial Activity of Solanum pubescens - An Ethnomedicinal Plant from South Western Region of Andhra Pradesh

The present movement to find out alternative antibacterial drugs from medicinal plants and the presence bioactive phytochemicals in fruit andstem bark of Solanum pubescens, promoted the authors to take up the antibacterial evaluation of fruit and stem bark extracts of Solanumpubescens. Against clinical and plant pathogenic bacterial strains by employing the methods of National Committee for Clinical LaboratoryStandards (NCCLS). It was observed that all the extracts showed inhibition zone against one or more of the tested bacteria between 80 to 160 μg/ml concentrationswith 3.17 ±0.17 to 10 ± 0.17 mm inhibition. The spectroscopic determination of MIC and MBC exhibited by extracts went between 100-300μg/ml. In fruit extracts, fruit chloroform (FC) has inhibited all the tested organisms, similarly, fruit ethyl acetate (FEA) inhibited Bacillussubtilis and Xanthomonas sp. whereas, fruit ethanol (FET) has been restricted to inhibit Bacillus subtilis at 100 μg/ml. Furthermore, amongall the active extracts of stem bark extracts bark chloroform (BC) showed potential inhibition of Bacillus subtilis and Escherichia coli with81.44% and 82.17% respectively. Similarly, bark bottom crystals (BBC) extracts inhibited Bacillus cereus and Xanthomonas sp. with 77.38%and 77.72% respective inhibition at 100 μg/ml concentration.The present exploration has revealed that the extracts from fruit and stem bark of S. pubescens revealed potential antibacterial activity againstGram (+) and Gram (-) bacteria, which are validating the ethnomedicinal claims and this the first report of investigation of above extracts forits antibacterial activity.DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11280 Int J Appl Sci Biotechnol, Vol. 2(4): 501-509

English

Three lactic acid bacteria (LAB) isolates designated AS1, AS2 and KN4 isolated from kunun-zaki (a sorghum based non-alcoholic beverage widely consumed in Northern Nigeria) and identified as Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus delbruckii, respectively, produced significant inhibitory compounds in broth. The partially purified inhibitory compounds were screened by agar spot assay method for antagonistic activity against target Gram positive and negative bacteria as well as yeasts associated with food spoilage. The partially purified compounds exhibited strong activity against Staphylococcus aureus ATCC 12600, Bacillus cereus and Escherichia coli ATCC 11775. The inhibitory compound produced by AS1 and KN4 inhibited Bacillus subtilis. Only the inhibitory compound produced by AS1 affected Candida albicans and Candida krusei. Analysis of variance indicated that there was a significant difference (P<0.05) in the susceptibility of the different target organisms to partially purified inhibitory compounds. Gram positive bacteria were affected more than yeasts. Proteolytic enzymes, trypsin and pepsin, but not catalase and α-amylase, completely inactivated antagonistic activity of the compounds demonstrating their proteinacious nature. The inhibitory compounds were fairly heat stable and also stable over broad pH ranges. The use of these or related GRAS isolates in the production of this and related beverage may increase the safety, shelf life and marketing appeal of such beverages   Key words: Bacteriocins, lactic acid bacteria (LAB), target organisms, antimicrobial activity.