Diversity and antibacterial activity of actinomycetes from wetland soil

2010 ◽  
Vol 28 (1) ◽  
pp. 52 ◽  
Author(s):  
Maya George ◽  
Gisha George ◽  
A. A. Mohamed Hatha

Diversity of soil actinomycetes isolated from various regions of a wetland was analysed. The strains were assigned under 11 genera according to their morphological and biochemical characteristics. They are: Nocardia, Pseudonocardia, Streptomyces, Micromonospora, Rhodococcus, Actinosynnema, Nocardiodes, Kitasatospora, Gordona, Intrasporangium and Streptoalloteichus. Around 55% of the identified strains are Nocardioform actinomycetes. Screening for their antibacterial activities revealed that 96% of the isolated strains showed different degrees of inhibition potential against 12 test pathogenic bacteria (including various serotypes of Salmonella, Vibrio cholerae, Bacillus subtilis and Escherichia coli). Of these about 41% of strains showed antagonism towards Bacillus subtilis. The Nocardioform actinomycetes exhibited antibacterial activity against 9 out of 12 test organisms. The least antibacterial potential was exhibited by Gordona, Rhodococcus, Micromonospora and Kitasatospora. The isolated strains differed among themselves in their ability to decompose proteins and amino acids and also in enzyme production potential.

Author(s):  
Kaur M. ◽  
Sharma S. ◽  
Garg S. ◽  
Arora M.

This study describes the antibacterial activities of three different solvent extracts of leaves of Chenopodium album. Methanol, acetone and chloroform extracts of C. album were prepared. The antibacterial activity was assessed using well plate method and were examined for the size of zone of inhibition. Different extracts were investigated against the test organisms namely Lactobacillus, Bacillus subtilis and Escherichia coli. The maximum activity was observed at 100% concentration of different extracts of leaves. The maximum zone of inhibition for 100% concentration were observed as E. coli (19 mm) and Lactobacillus (19 mm) in diameter respectively. C. album did not show any antibacterial activity against B. subtilis. Antibacterial activity was compared with standard Amoxicillin and it was found to be 23 mm diameter for Lactobacillus and 25 mm for both E. coli and B. subtilis in terms of zone of inhibition.


Author(s):  
Sara Adel Amer ◽  
Hala Mohamed Abushady ◽  
Rasha Mohamed Refay ◽  
Mahmoud Ahmed Mailam

Abstract Background Bacteriocins are proteinaceous compounds produced from lactic acid bacteria. Bacteriocins are well-known for their antibacterial potential and safety for application in food. However, the commercial availability of bacteriocin is facing several limitations; among them is the low yield and short stability period. That calls for a new strategy for overcoming these hurdles. Among these approaches is incorporating bacteriocin in nanoparticles. So, the aim of this study was to enhance the plantaricin produced from isolated Lactobacillus plantarum strain using nanotechnology. Results In this study, the plnEF genes encoding plantaricin EF have been identified and sequenced (accession number of MN172264.1). The extracted bacteriocin (EX-PL) was obtained by the ammonium sulfate method. Then, it was used for biosynthesizing plantaricin-incorporated silver nanoparticles (PL-SNPs). The synthesized nanoparticles were confirmed by SEM-EDAX analysis. The antibacterial activity of both combined (PL-SNPs) and extracted plantaricin (EX-PL) were tested against some strains of foodborne pathogenic bacteria. The results revealed that the antibacterial activities were increased by 99.2% on the combination of bacteriocin with the silver nanoparticle. The MIC of EX-PL (7.6 mg/mL) has been lowered after incorporating into silver nanoparticles and reached 0.004 mg/mL for PL-SNPs. Despite that extracted plantaricin showed no inhibitory activity towards Listeria monocytogenes, plantaricin-incorporated silver nanoparticles displayed inhibitory activity against this strain. Furthermore, the stability period at 4 °C was increased from 5 days to 60 days for EX-PL and PL-SNPs, respectively. Conclusions Plantaricin-incorporated silver nanoparticles possess higher antibacterial activity and more stability than the free one, which makes it more fitting for combating foodborne pathogens and open more fields for applications in both food and pharmaceutical industries. Graphical abstract


Author(s):  
Mahmoud Osanloo ◽  
Abbas Abdollahi ◽  
Alireza Valizadeh ◽  
Niloufar Abedinpour

Background and Objectives: Plant-derived essential oils (EOs) shave many usages in health and medicine, such as anti- bacterial agents. The aim of this study was the improvement of antibacterial activities of two EOs using nanotechnology. Materials and Methods: Antibacterial activity was investigated on four important human pathogenic bacteria using the 96-well plate microdilution method, a quantitative approach. Eleven formulations were prepared using each of the EOs. Eventually, the best nanoformulation with the smallest particle size and polydispersive indices (PDI and SPAN) was selected using each EO for further investigations. Moreover, two microemulsions with similar ingredients and the same portion in comparison with two selected nanoemulsions were also prepared. Antibacterial activity of each EO was compared with its micro- and nano-emulsions. Results: The antibacterial efficacy of Zataria multiflora EO (ZMEO) was significantly better than Mentha piperita EO (MPEO). Besides, the antibacterial activity of nanoemulsion of ZMEO with a particle size of 129 ± 12 nm was significantly better than no- and micro-formulated forms of ZMEO. Interestingly, the efficiency of MPEO nanoemulsion (160 ± 25 nm) was also significantly better than MPEO and its micro-formulated form. Conclusion: Regardless of the intrinsic antibacterial property of two examined EOs, by formulating to nanoemulsion, their efficiencies were improved. Nanoemulsion of ZMEO introduced as an inexpensive, potent and green antibacterial agent.


2010 ◽  
Vol 65 (1-2) ◽  
pp. 34-38 ◽  
Author(s):  
Babita Paudel ◽  
Hari Datta Bhattarai ◽  
Hong Kum Lee ◽  
Hyuncheol Oh ◽  
Hyun Woung Shin ◽  
...  

The development of new antibacterial compounds is an urgent issue to meet the evolution of resistivity of pathogenic bacteria against the available drugs. The objective of this study was to investigate the antibacterial compounds from the Antarctic lichen species Ramalina terebrata. A total of fi ve compounds, usnic acid, usimine A, usimine B, usimine C, and ramalin, were isolated by bioactivity guided-fractionation of the methanol extract of R. terebrata after several chromatographic procedures. The qualitative antibacterial activities of the crude extract and isolated compounds were determined by the disk diffusion method while the minimum inhibitory concentration (MIC) determination assay gave the quantitative strength of the test samples. All the test samples showed antibacterial activity against Bacillus subtilis. The crude extract and usnic acid showed antibacterial activity against Staphylococcus aureus. The MIC values of the isolated compounds against B. subtilis were in the range of 1 to 26 μg/mL. These observed experimental data showed the strong antibacterial potential of these compounds against B. subtilis.


Author(s):  
Gouse Basha Sheik ◽  
Muazzam Sheriff Maqbul ◽  
Gokul Shankar S. ◽  
Ranjith M S

Objective: To isolate and characterize novel actinomycetes and to evaluate their antibacterial activity against drug-resistant pathogenic bacteriaMethods: In the present study, 19 soil samples were collected from different localities of Ad-Dawadmi, Saudi Arabia. Actinomycetes were isolated from these samples using serial dilution and plating method on Actinomycetes isolation agar supplemented with nalidixic acid and actidione to inhibit bacteria and fungi. Crude extracts of potential actinomycetes were produced by submerged fermentation. The antimicrobial activity of crude extracts of actinomycetes was tested against different bacteria using the agar well diffusion method. Characterization of the isolates was done by morphological, physiological and biochemical methods.Results: A total of 9 (47%) isolates of actinomycetes were isolated from 19 different soil samples tested. Among them, 4 (44%) isolates confirmed as Streptomyces sp. showed potential antimicrobial activity against one or more test organisms. Crude extracts were made from these 4 actinomycetes isolates(DOM1, DOM3, DP3, DP4)and tested for their antibacterial activities against 4 different clinical bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus). Crude extract from DP3 isolate showed highest antibacterial activity against all the four test organisms (28 mm, 21 mm, 20 mm and 18 mm) respectively and DP4 showed lowest antibacterial activity against all the four test organisms (14 mm, 12 mm, 0 mm, 6 mm) respectively. The highest zone of inhibition was shown by DP3 against Staphylococcus aureus (28 mm) and Escherichia coli was resistant for DP4. Most of the Inhibition zones produced by crude extracts showed significant differences when compared with control, tested against test organisms (P<0.05). Inhibition zones produced by DP3 and DOM1 against Staphylococcus aureus were 28 mm and 23 mm, respectively which were strong active when compared with control Ciprofloxacin (18 mm).Conclusion: Further studies for purification of bioactive metabolites and molecular characterization analysis of isolated Streptomyces sp. are in progress which would be helpful in discovering novel compounds of commercial value.


BIBECHANA ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 143-153
Author(s):  
Richa K. Gupta ◽  
Ganesh M. S. Thakuri ◽  
Gan B Bajracharya ◽  
Ram Narayan Jha

Antioxidant and antibacterial activities of natural anthraquinones namely chrysophanol (1) and emodin (2), and synthesized anthraquinones viz. 2-methylanthraquinone (3), anthraquinone (4), 2-bromoanthraquinone (5), rubiadin (6), chrysophanol diacetate (7), rubiadin diacetate (8) and 1,8-dimethoxy-3-methylanthraquinone (9) were investigated. Anthraquinones 9, 3, 6, 5 and 2 exhibited a high DPPH• radical scavenging capacity (IC50 = <500 μg/mL) showing their therapeutic potentiality for the treatment of cancers. These anthraquinones 1-9 have also displayed a weak to moderate antibacterial activity against Bacillus subtilis. Chrysophanol diacetate (7) including emodin (2) have been appeared as the valuable antibacterials. BIBECHANA 18 (2) (2021) 143-153


Author(s):  
Naritsara Toobpeng ◽  
Pannapa Powthong ◽  
Pattra Suntornthiticharoen

  Objective: The objective of this investigation was to assess the biological activity of fresh fruit juices and freeze dried fruit juices including antioxidant and antibacterial activity.Methods: The fruits used in this study were Schleichera oleosa (Lour.) Oken, Carissa carandas L., and Sandoricum koetjape (Burm.f.) Merr. The fresh juice sample (FJS) was extracted and also prepared for freeze drying sample (FDS) by freeze dryer. The antioxidant capacity of FJS and FDS was assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assays and determination for total phenolic contents (TPCs) by Folin–Ciocalteu’s reagent. Antimicrobial tests were carried out by agar diffusion methods and evaluated by measuring the zone of inhibition against 10 isolates of pathogenic bacteria.Results: The highest antioxidant activity of FJS and FDS was found in S. oleosa and related to the scavenging effect on DPPH radical of FJS (100% concentration) and FDS (200 mg/ml) was found in the value of 93.05±0.31% and 82.18±0.33%, respectively. TPC of FJS and FDS from S. oleosa at the same concentration as in the DPPH assay was 1,003.53±1.96 ug GAE/300 g of matter and 827.77±23.15 ug GAE/100 ml of matter, respectively. Both FJS and FDS revealed antibacterial activity. The zone of inhibition of FJS was ranging from 8.3±0.6 to 24.0±1.0 mm and FDS values of 7.3±0.5-21.0±0.9 mm. The most potent sample against bacteria was FJS and FDS from S. oleosa which FJSs against Escherichia coli ESBL and FDS against Pseudomonas aeruginosa MDR2.Conclusion: Fruit juices of S. oleosa, C. carandas, and S. koetjape associated with antioxidant activity in the form of both fresh fruit juices and FDS. The result of this study showed that the value of DPPH and TPCs were slightly decreased in FDS compare with fresh juice. Screening of FJS and FDS of C. carandas revealed broad spectrum antibacterial activity. However, FJS of S. oleosa and S. koetjape showed inhibition of growth of bacteria, but few of FDS from these fruits could inhibit limited bacterial isolates. For antibacterial activity against pathogenic bacteria, the samples of fresh and freeze dried exhibited a different degree of activity.


2018 ◽  
Vol 10 (1) ◽  
pp. 24 ◽  
Author(s):  
Neneng Siti Silfi Ambarwati ◽  
Berna Elya ◽  
Amarila Malik ◽  
Muhammad Hanafi ◽  
Hanita Omar

Objective: The objective of this study was to identify fractions with the highest antibacterial activity against Bacillus subtilis and to determineantioxidant activities and establish the chromatographic fractions as candidate antibacterial and antioxidant agents.Methods: Extracts were fractionated using column chromatography, and antibacterial activities were assayed by the analyses of inhibition zones andbioautography, as well as by broth microdilution techniques. Antioxidant activities were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH)assay.Results: The strongest antibacterial activity against B. subtilis (ATCC 6633) was observed with fractions B and C obtained in this research, witha minimum inhibitory concentration value of 312.5 μg/mL. The effective percentage (EP) value of crude extract at 10 μg/mL was 29.47±2.01%.Fractions C and D had greater EP values than the crude extract, whereas fraction D had the highest scavenging activity against DPPH free radicals(37.73±1.44%) when used at 10 μg/mL. The half effective concentration of the extract was 23.40 μg/mL, whereas that of the most active fraction Dwas 19.38 μg/mL and quercetin as positive control was 3.72 μg/mL.Conclusion: The present data confirm that fractions of methanol extract from Garcinia latissima Miq. leaves possess antibacterial and antioxidantactivities. These observations may facilitate the development of antimicrobial phytomedicines with a wide spectrum of activities and standardizedantioxidant properties.


Author(s):  
Shruti Tyagi

Objective: This study demonstates  a simple, cost effective protocol  for biosynthesis of stable silver (Ag) and gold (Au) nanoparticles from Hibiscus Rosa sinesis and their comparison by applying antibacterial activities against nine pathogenic bacterial species.Methods: Silver (Ag) and gold (Au) nanoparticles were biosynthesized from Hibiscus Rosa sinesis were characterized by UV–VIS spectroscopy, FTIR and TEM. The antibacterial activities  of AgNPs  and AuNPs were evaluated against  9 pathogenic bacterial species  Pseudomonas aeroginosa, Bacillus subtilis Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter aerogens, Escherichia coli, Streptococcus pneumoniae, Aeromonas hydrophila by the agar disc diffusion method.Results: Synthesized AgNPs  were obtained in 13.01 to 28.14 nm size range, while AuNPs were in  6.32 to 18.19 nm size range. The results of Fourier transform infrared spectroscopy (FTIR) spectra indicates  that the AuNPs are bound to amine groups and the AgNPs to carboxylate ion groups. The antibacterial activities  of AgNPs,  the zone of inhibition significantly increased with the  increases of concentrations of AgNPs in all pathogenic bacterial species  except  in the case of S. epidermidis at 50%, S. aerogenes and A. hydrophila at 70%, while in case of AuNPs antibacterial activity  was displayed  only against B. subtilis at 20% and 100% concentration.Conclusion: This study suggests that AgNPs exhibits outstanding antibacterial activity against pathogenic bacteria as compared to AuNPs synthesized from Hibiscus Rosa sinensis leaf extract and insights to their potential applicability as an alternative antibacterial  agent in microbial and human health system to reduce the resistance ability of pathogenic bacteria. Keywords: silver nanoparticles; gold  nanoparticles; UV–VIS spectroscopy; FTIR; TEM; antibacterial activities.  


2017 ◽  
Vol 901 ◽  
pp. 124-132
Author(s):  
Artania Adnin Tri Suma ◽  
Tutik Dwi Wahyuningsih ◽  
Deni Pranowo

Some novel N-phenylpyrazolines were synthesized and investigated for their antibacterial activitiy. Chalcones 2-4 which were prepared from acetophenone and veratraldehyde derivatives were reacted with phenylhydrazine to give N-phenylpyrazolines 5-7. All of the synthesized compounds were characterized using FTIR, GC-MS, and NMR spectrometers. Further, antibacterial activity of N-phenylpyrazolines were evaluated by agar well-diffusion method against Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Escherichia coli, and Shigella flexneri. The highest activity (highest inhibition zone) of compound 5 was 2.6 mm (at 1000 ppm) against B. subtillis, compound 6 was 7.25 mm (at 1000 ppm) against S. aureus, and compound 7 was 6.75 mm (at 500 ppm) against S. aureus. The results indicated that compound 6 and 7 exhibited promising antibacterial activity.


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