Exploring Mediterranean and Arctic Environments as a Novel Source of Bacteria Producing Antibacterial Compounds to be Applied in Aquaculture

The need to discover new natural compounds has become urgent as a possible alternative solution to contrast the spread of antibiotic resistance, also in the aquaculture field. Bacterium–bacterium inhibitory activity against bacterial pathogens relevant in aquaculture was evaluated on agar plates for bacteria isolated from cold Arctic (Kongsfjorden, Svalbard Islands; i.e., seawater and sediment samples) and temperate Mediterranean (Lake Faro in Messina and the Straits of Messina, Italy; i.e., brackish water and benthic filter-feeding organisms) environments. Cell-free supernatants (both pure and concentrated 10-fold) were further assayed and, in the case of a positive response, crude extracts were obtained and tested. After the pre-screening procedures, about 30% of the bacterial isolates inhibited the growth of at least one pathogen used as a target. The 10-fold concentrated supernatants of two Arctic Salinibacterium spp. strains and the Mediterranean Bacillus sp. PS62 (associated with the pennatulacean Pteroeides spinosum Ellis, 1764) resulted in being active against P. damselae subsp. piscicida. The crude extracts obtained from Bacillus sp. PS62 also showed inhibitory activity against the same pathogen. Our findings suggest that tested bacteria could represent a novel source of compounds to be applied to overcome pathogenesis in the aquaculture field.

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Isolation, Characterization and Application of Protease Enzyme from Marine Bacteria

Research Journal of Pharmacy and Technology ◽

10.52711/0974-360x.2021.00735 ◽

2021 ◽

pp. 4236-4240

Author(s):

Sneha S ◽

Mrunal Palsokar ◽

Vemula Sai Jahnavi ◽

Anwesha Sarkar ◽

K. V. Bhaskara Rao

Keyword(s):

Marine Bacteria ◽

Peptide Bond ◽

Mangrove Sediment ◽

Bacillus Sp ◽

Bacterial Isolates ◽

Sediment Samples ◽

Protease Enzyme ◽

Stain Removal ◽

Marine Sediment Sample ◽

Protease Assay

Protease constitutes the major group of catalytic enzymes which is involved in hydrolyzing peptide bond of proteins. Marine sediment sample were collected and protease producing bacterial isolates were identified by using casein as a substrate. The organisms were characterized by biochemical test and identified as Bacillus sp. In order to check for the production of protease enzyme, quantitative protease assay and Lowry’s method of protein estimation was carried out. The crude extract of protease was subjected for blood stain removal activity and the enzyme proved to be efficient which removed the stain in 15 min. The purpose of the current study is to isolate, identify, characterize and to carry out applications of protease enzyme from marine bacteria isolated from mangrove sediment samples.

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Characterization of bacteriocin and chitinase producing bacterial isolates with broad-spectrum antimicrobial activities

SN Applied Sciences ◽

10.1007/s42452-021-04740-z ◽

2021 ◽

Vol 3 (8) ◽

Author(s):

Muhammad Yasir ◽

Basit Zeshan ◽

Nur Hardy A. Daud ◽

Izzah Shahid ◽

Hafza Khalid

Keyword(s):

Antimicrobial Activity ◽

Inhibitory Activity ◽

Antifungal Drugs ◽

Proteinase K ◽

Diffusion Method ◽

List Type ◽

Bacterial Isolates ◽

E Coli ◽

Inhibitory Potential

Abstract There is a need for more efficient and eco-friendly approaches to overcome increasing microbial infections. Bacteriocins and chitinases from Bacillus spp. can be powerful alternatives to conventional antibiotics and antifungal drugs, respectively. The purpose of this study was to assess the inhibitory potential of bacteriocins and chitinase enzymes against multiple resistant bacterial and fungal pathogens. Bacterial isolates were selected by growth on minimal salts medium and after that were morphologically and biochemically characterized. The physiochemical characterization of bacteriocins was carried out. The inhibitory potential of bacteriocins towards six pathogenic bacteria was determined by the well diffusion assay while chitinase activity towards three fungal strains was determined by the dual plate culture assay. Two bacterial strains (WW2P1 and WRE4P2), out of nine showed inhibition of K. pneumonia, P. aeruginosa, E. coli and MRSA while WW4P2 was positive against S. typhimurium and E. coli and WRE10P2 against P. aeruginosa, S. pneumoniae. Two bacterial isolates (WW3P1 and WRE10P2) were chosen for further study on the basis of their antifungal activities. Of these, WW3P1 isolate was more effective against A. fumigatus as well as A. niger. The proteinaceous nature of the bacteriocins was confirmed by treatment of the crude extract with proteinase K. It was found that the inhibitory activity of strain WW3P1 against E. coli was highest at 20 °C, and against S. pneumoniae it was at 20 °C and pH 10 after treatment with EDTA. Inhibition by strain the WRE10P2 against P. aeruginosa was highest at 20 °C and pH 14. It was found that EDTA increased the inhibitory activity of strain WW2P1 against P. aeruginosa, K. pneumoniae and E. coli by 2 ± 0.235, 3.5 ± 0.288, 2.5 ± 1.040 times, respectively, of strain WRE4P2 against P. aeruginosa and E. coli by 2.5 ± 0.763, 2.7 ± 0.5 times, respectively, and of strain WRE10P2 against S. pneumoniae by 3 ± 0.6236 times. The isolates have promising inhibitory activity, which should be further analyzed for the commercial production of antimicrobials. Article highlights The current study aimed to isolate the microbiome from wheat plant (Triticum aestivum L.), to screen for bacteriocin production and to assess its antimicrobial activity against human pathogens. Forty-one phenotypically different bacterial colonies were subjected to bacteriocin purification from which 25 colonies showed positive reactions. These 25 bacterial isolates were screened against six different human bacterial pathogens using the well diffusion method to check the antimicrobial activity. Out of nine bacterial isolates, WW3P1 and WRE10P2 were able to degrade the chitin and utilize it as their sole energy source. Strain WRE4P2 exhibited partial inactivation in its activity against MRSA after treatment with proteinase K.

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Tyrosinase Inhibitory Activity of Flavonoids from Artocarpus Lowii King

Jurnal Teknologi ◽

10.11113/jt.v71.2711 ◽

2014 ◽

Vol 71 (1) ◽

Author(s):

Shajarahtunnur Jamil ◽

Siti Awanis Abdullah ◽

Siti Mariam Abdul Lathiff ◽

Hasnah Mohd Sirat

Keyword(s):

Inhibitory Activity ◽

Kojic Acid ◽

Mushroom Tyrosinase ◽

Tyrosinase Inhibitory Activity ◽

Crude Extracts ◽

Ic50 Value ◽

Microplate Reader

Tyrosinase inhibitory activity was studied on the crude extracts and flavonoids successfully isolated from the leaves and heartwoods of Artocarpus lowii King. The flavonoids were fully characterized spectroscopically as isobavachalcone (1), 4-hydroxyonchocarpin (2), 2',4'-dihydroxy-4-methoxy-3'-prenyldihydrochalcone (3), 2',4'-dihydroxy-3,4-(2",2"-dimethylchromeno)-3'-prenyldihydrochalcone (4), artocarpin (5), cycloheterophyllin (6) and 4',5-dihydroxy-6,7-(2,2-dimethylpyrano)-2'-methoxy-8-γ,γ-dimethyl allylflavone (7). Tyrosinase inhibitory activity of the samples was determined against mushroom tyrosinase using ELISA microplate reader. Cycloheterophyllin (6) exhibited an excellent inhibitory activity against mushroom tyrosinase comparable to the standard kojic acid with the IC50 value of 52.5 µg/mL (88.3%).

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Phytochemistry and Inhibitory Activity of Chrozophora senegalensis Extracts against Some Clinical Bacterial Isolates

Bayero Journal of Pure and Applied Sciences ◽

10.4314/bajopas.v4i1.32 ◽

2011 ◽

Vol 4 (1) ◽

Author(s):

M Yusha’u

Keyword(s):

Inhibitory Activity ◽

Bacterial Isolates

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BIOAKUMULASI LOGAM Pb DAN Cr DALAM SISTEM BIOFILTRASI VERTIKAL DENGAN INOKULUM BAKTERI YANG DIISOLASI DARI BEBERAPA PERAIRAN KAWASAN DENPASAR SELATAN

ECOTROPHIC Jurnal Ilmu Lingkungan (Journal of Environmental Science) ◽

10.24843/ejes.2016.v10.i02.p07 ◽

2016 ◽

Vol 10 (2) ◽

pp. 123

Author(s):

Dini Imanniar ◽

I.W. Budiarsa Suyasa ◽

I. W. Sudiarta

Keyword(s):

Liquid Medium ◽

Processing Time ◽

Active Suspension ◽

Bacillus Sp ◽

Sediment Sources ◽

Aquatic Sediments ◽

Initial Concentration ◽

Sediment Samples ◽

Bacterial Inoculum

Research of bioaccumulation of Pb and Cr in vertical biofiltration systems with bacterial inoculum derived from aquatic sediments South Denpasar aims to get the best sediment sources that can be used as an active suspension to process metals Pb and Cr dissolved. Sediment samples taken from some waters are ecosystems Mangrove Statue Ngurah Rai Tuban, Benoa Harbour and Estuary Dam Suwung. Each sediment samples were grown in a liquid medium to get the best active suspension, which was determined by an increase in biomass ( VSS ) and the speed of growth. Best active suspension is used as inoculum in the vertical biofilters to decreaseconcentration of Pb and Cr dissolved. Ability of vertical biofilter is determined by their effectiveness in lowering levels of Pb and Cr and capacity of the system used. The results showed that the vertical biofiltration system capable of lowering the concentration of Pb and Cr to each concentration became 0.1680 ppm and 0.1460 ppm within 6 hours of treatment with initial concentration of 2 ppm respectively. The results showed that the vertical biofiltration system capable of decreasing the concentration of Pb and Cr became 0.1680 ppm and 0.1460 ppm within 6 hours of treatment with initial concentration of 2 ppm respectively. This concentration has been below the qualitystandard (PerGub Bali No.8 Tahun 2007). The highest effectiveness of vertical biofilters system against Pb and Cr occurred while processing time of 24 hours with the respective value amounted to 99.49 % and 99.41 %. While the value of biofiltration capacity in lowering the concentration of Pb and Cr amounting 4,3188x10-3 mg/g and 4,5369x10-3 mg/g. In microbiological tests, one type of bacteria that play a role in the process of bioaccumulation of Pb and Cr is Bacillus sp in the amount of 20 CFU/g.

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INHIBITION ACTIVITY OF CLEOME SPECIES EXTRACT ON ONION GUEST ROOT

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2019.v11s3.m0007 ◽

2019 ◽

pp. 1-2

Author(s):

SUTTHIDUEAN CHUNHAKARN ◽

PRAKAIDAO YINGSANGA ◽

LADA MATHURASA

Keyword(s):

Root Growth ◽

Ethyl Acetate ◽

Crude Extract ◽

Inhibitory Activity ◽

Crop Productivity ◽

Distilled Water ◽

Crude Extracts ◽

Cleome Spinosa ◽

Whole Plants ◽

Potent Inhibitory Activity

Objective: Biological control is useful in agricultural. Allelopathy plays an important factor in crop productivity. The effect of allelopathy is able to produce and release allelochemicals or phytochemicals to inhibit or stimulate seed germination, seeding growth, shoot and root growth of other crops. The aim of this study was to evaluate the inhibitory activity of Cleome viscose and Cleome spinosa extracts on onion guest roots length.Methods: The whole plants of C. viscose and C. spinosa were extracted with dichloromethane, ethyl acetate, methanol and distilled water, respectively. Each group of onion guests was sprayed at various concentrations as 100, 200, 400, 800 and 1600 parts per million for the treatment. The root growth was measured every day for 1 month.Results: At concentration of 1600 ppm, methanol crude extract of C. spinose showed the highest percent inhibitory activity value of 91.68. Ethyl acetate and methanol crude extracts of C. viscose showed strong inhibitory activity with percentage values of 90.17 and 90.90, respectively, at concentration of 1600 ppm. Moreover, the methanol extract of C. viscose and C. spinosa evaluated higher inhibitory activity than other solvent. However, distilled water crude extract of C. spinose showed weak inhibitory activity with the percentage value of 40.05 at concentration of 1600 ppm.Conclusions: In this study, the methanol crude extract of C. spinose showed potent inhibitory activity on root growth. Moreover, ethyl acetate and methanol crude extracts of C. viscose evaluated strong inhibitory activity. C. viscose and C. spinosa extracts possessed allelochemicals for postharvest biology and technology in plants.

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Phosphonopeptides Revisited, in an Era of Increasing Antimicrobial Resistance

Molecules ◽

10.3390/molecules25061445 ◽

2020 ◽

Vol 25 (6) ◽

pp. 1445 ◽

Cited By ~ 1

Author(s):

Emma C.L. Marrs ◽

Linda Varadi ◽

Alexandre F. Bedernjak ◽

Kathryn M. Day ◽

Mark Gray ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Enterococcus Faecalis ◽

Antibacterial Agents ◽

Methicillin Resistant Staphylococcus Aureus ◽

Peptide Mimetics ◽

Antibacterial Resistance ◽

Bacterial Isolates ◽

New Agents ◽

Antibacterial Compounds

Given the increase in resistance to antibacterial agents, there is an urgent need for the development of new agents with novel modes of action. As an interim solution, it is also prudent to reinvestigate old or abandoned antibacterial compounds to assess their efficacy in the context of widespread resistance to conventional agents. In the 1970s, much work was performed on the development of peptide mimetics, exemplified by the phosphonopeptide, alafosfalin. We investigated the activity of alafosfalin, di-alanyl fosfalin and β-chloro-L-alanyl-β-chloro-L-alanine against 297 bacterial isolates, including carbapenemase-producing Enterobacterales (CPE) (n = 128), methicillin-resistant Staphylococcus aureus (MRSA) (n = 37) and glycopeptide-resistant enterococci (GRE) (n = 43). The interaction of alafosfalin with meropenem was also examined against 20 isolates of CPE. The MIC50 and MIC90 of alafosfalin for CPE were 1 mg/L and 4 mg/L, respectively and alafosfalin acted synergistically when combined with meropenem against 16 of 20 isolates of CPE. Di-alanyl fosfalin showed potent activity against glycopeptide-resistant isolates of Enterococcus faecalis (MIC90; 0.5 mg/L) and Enterococcus faecium (MIC90; 2 mg/L). Alafosfalin was only moderately active against MRSA (MIC90; 8 mg/L), whereas β-chloro-L-alanyl-β-chloro-L-alanine was slightly more active (MIC90; 4 mg/L). This study shows that phosphonopeptides, including alafosfalin, may have a therapeutic role to play in an era of increasing antibacterial resistance.

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