scholarly journals Production and characterization of semi-quinolone antibiotic produced by Streptomyces griseorubens

2020 ◽  
Author(s):  
Waleed Abdulkhair ◽  
Mousa Alghuthaymi
Keyword(s):  
High Performance ◽  
Gel Filtration ◽  
Nuclear Magnetic Resonance Analysis ◽  
Rrna Gene ◽  
Molecular Formula ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Antibacterial Compound ◽  
Flash Column Chromatography ◽  
Active Peak

Abstract This work is an attempt to overcome antimicrobial resistance problem which dispersed worldwide inparticular developing countries due to misuse of antibiotics. Actinobacteria were isolated and screenedagainst selected resistant Gram-negative bacteria to detect the powerful antibacterial activity.Identification of the most potent actinobacterial isolate has been carried out using classical and geneticalmethods. Antibacterial compound has been extracted, purified and characterized using accurate and morespecific techniques and instruments. Among forty actinobacterial isolates, only twenty-two isolates couldinhibit the growth of Gram-negative bacteria. The most potent isolate Eg-7 was identified as S.griseorubens, which has a typical 16S rRNA gene. The antibacterial compound was extracted using ethylacetate, and separated by High Performance Liquid Chromatography using methanol and water as amobile phase. Five active peaks were displayed and retained in the range 40 – 45 min, but the last threepeaks were retained at 41.90, 43.43, and 44.54 min, respectively. The crude extract was analyzed byliquid chromatography mass spectrum, where the active peak was displayed at 721.325 m/z. Theantibacterial compound was purified using flash column chromatography and gel filtration columnchromatography. The active fraction was analyzed by Infra-Red spectrum, where a broad absorption at3338 cm-1 was displayed. Molecular formula of an antibacterial compound was determined by massspectrum as C35H26N6O4. Nuclear magnetic resonance analysis was carried out for an antibacterialcompound. These results suggest that a new antibacterial compound that similar quinolone could beproduced by S. griseorubens and exhibited a higher activity against Gram-negative bacteria.

scholarly journals Keratinolytic protease from Pseudomonas aeruginosa for leather skin processing

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yeasmin Akter Moonnee ◽  
Md Javed Foysal ◽  
Abu Hashem ◽  
Md Faruque Miah
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Enzyme Production ◽  
Biochemical Characterization ◽  
Animal Feed ◽  
Inorganic Nitrogen ◽  
Rrna Gene ◽  
Gram Negative Bacteria ◽  
Leather Industry ◽  
Gram Negative ◽  
Maximum Production

Abstract Background The leather industry generates huge volume of waste each year. Keratin is the principal constituents of this waste that is resistant to degradation. Some bacteria have the ability to degrade keratin through synthesis of a protease called keratinase that can be used as sources of animal feed and industrial production of biodiesel, biofertilizer, and bioplastic. Majority of the studies focused on keratin degradation using gram-positive bacteria. Not much of studies are currently available on production of keratinase from gram-negative bacteria and selection of best parameters for the maximum production of enzyme. The aim of this study was to isolate and characterize both groups of bacteria from soil for keratinase and optimize the production parameters. Results A total of 50 isolates were used for initial screening of enzyme production in skim milk, casein, and feather meal agar. Out of 50, five isolates showed significantly higher enzyme production in preliminary screening assays. Morphological and biochemical characterization revealed 60% of the isolates as gram-negative bacteria including two highest enzyme-producing isolates. The isolates were identified as Pseudomonas aeruginosa through sequencing of 16S rRNA gene. Maximum production of enzyme from P. aeruginosa YK17 was achieved with 2% chicken feather, beef extract, and ammonium nitrate as organic and inorganic nitrogen sources and glucose as a carbon source. Further analysis revealed that 3% inoculum, 40 °C growth temperature and 72-h incubation, resulted in maximum production of keratinase. Conclusion The overall results showed significant higher production of enzyme by the P. aeruginosa YK17 that can be used for the degradation of recalcitrant keratin waste and chemical dehairing in leather industries, thereby preventing environmental pollution.

scholarly journals Alien vs. predator: bacterial challenge alters coral microbiomes unless controlled byHalobacteriovoraxpredators

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3315 ◽  
Author(s):  
Rory M. Welsh ◽  
Stephanie M. Rosales ◽  
Jesse R. Zaneveld ◽  
Jérôme P. Payet ◽  
Ryan McMinds ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Community Dynamics ◽  
Structure Stability ◽  
Rrna Gene ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Coral Microbiome ◽  
Opportunistic Bacteria ◽  
Vibrio Coralliilyticus ◽  
Time Point

Coral microbiomes are known to play important roles in organismal health, response to environmental stress, and resistance to disease. The coral microbiome contains diverse assemblages of resident bacteria, ranging from defensive and metabolic symbionts to opportunistic bacteria that may turn harmful in compromised hosts. However, little is known about how these bacterial interactions influence the mechanism and controls of overall structure, stability, and function of the microbiome. We sought to test how coral microbiome dynamics were affected by interactions between two bacteria:Vibrio coralliilyticus, a known temperature-dependent pathogen of some corals, andHalobacteriovorax, a unique bacterial predator ofVibrioand other gram-negative bacteria. We challenged reef-building coral withV. coralliilyticusin the presence or absence ofHalobacteriovoraxpredators, and monitored microbial community dynamics with 16S rRNA gene profiling time-series.Vibrio coralliilyticusinoculation increased the mean relative abundance ofVibriosby greater than 35% from the 4 to 8 hour time point, but not in the 24 & 32 hour time points. However, strong secondary effects of theVibriochallenge were also observed for the rest of the microbiome such as increased richness (observed species), and reduced stability (increased beta-diversity). Moreover, after the transient increase inVibrios,two lineages of bacteria (RhodobacteralesandCytophagales) increased in coral tissues, suggesting thatV. coralliilyticuschallenge opens niche space for these known opportunists.Rhodobacteralesincreased from 6.99% (±0.05 SEM) to a maximum mean relative abundance of 48.75% (±0.14 SEM) in the final time point andCytophagalesfrom <0.001% to 3.656%.Halobacteriovoraxpredators are commonly present at low-abundance on coral surfaces. Based on the keystone role of predators in many ecosystems, we hypothesized thatHalobacteriovoraxpredators might help protect corals by consuming foreign or “alien” gram negative bacteria.Halobacteriovoraxinoculation also altered the microbiome but to a lesser degree thanV. coralliilyticus, andHalobacteriovoraxwere never detected after inoculation. Simultaneous challenge with bothV. coralliilyticusand predatoryHalobacteriovoraxeliminated the increase inV. coralliilyticus, ameliorated changes to the rest of the coral microbiome, and prevented the secondary blooms of opportunisticRhodobacteralesandCytophagalesseen in theV. coralliilyticuschallenge. These data suggest that, under certain circumstances, host-associated bacterial predators may mitigate the ability of other bacteria to destabilize the microbiome.

The Preparation and Antimicrobial Activity of Peptide Fractions from Blue Mussel (Mytilus edulis) Protein Hydrolysate

2012 ◽  
Vol 485 ◽  
pp. 340-347
Author(s):  
Shi Yuan Dong ◽  
Hong Xia Song ◽  
Yuan Hui Zhao ◽  
Zun Ying Liu ◽  
Bin Bin Wei ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
High Performance ◽  
Blue Mussel ◽  
Protein Hydrolysate ◽  
Gel Filtration ◽  
Gram Negative Bacteria ◽  
Strong Activity ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Peptide Fractions

The blue mussel protein hydrolysates were separated using the consecutive chromatographic methods including ion exchange, gel filtration, high performance liquid chromatography to identify a potent antimicrobial activity. The fraction (MAMP) separated by HPLC, exhibiting strong activity against Gram-positive (E. coli, P. aeruginosa, S. dysenteriae, P. vuigaris, E. aerogenes) with the minimal inhibitory concentrations (MIC) from 15.63 to 31.25 μg/mL, and Gram-negative bacteria (S. aureus, B. subtilis and M. lysodeikticus) with MIC from 31.25 to 62.5 μg /mL. MAMP had good thermal and pH stability, and consisted of three main amino acids (Ser, Pro and Cys). The antimicrobial activity of MAMP was possibly related to its higher cysteine residues and contents of hydrophobic amino acid. Therefore, MAMP could be a natural antimicrobial source suitable for use as a food additive.

scholarly journals SOSUI-GramN: high performance prediction for sub-cellular localization of proteins in Gram-negative bacteria

2008 ◽  
Vol 2 (9) ◽  
pp. 417-421 ◽  
Author(s):  
Kenichiro Imai ◽  
Naoyuki Asakawa ◽  
Toshiyuki Tsuji ◽  
Fumitsugu Akazawa ◽  
Ayano Ino ◽  
...  
Keyword(s):  
Performance Prediction ◽  
High Performance ◽  
Cellular Localization ◽  
Gram Negative Bacteria ◽  
Gram Negative

scholarly journals Molecular Identification of GemellaSpecies from Three Patients with Endocarditis

1998 ◽  
Vol 36 (4) ◽  
pp. 866-871 ◽  
Author(s):  
Bernard La Scola ◽  
Didier Raoult
Keyword(s):  
Specific Problem ◽  
Rrna Gene ◽  
Gram Negative Bacteria ◽  
Opportunistic Pathogens ◽  
Gram Negative ◽  
Identification Schemes ◽  
Gram Positive Bacteria ◽  
Gram Staining ◽  
Testing Susceptibility ◽  
Severe Infections

Gemella morbillorum and Gemella haemolysansare opportunistic pathogens which cause endocarditis and other severe infections. We report on three patients with endocarditis, one with endocarditis caused by G. haemolysans and two with endocarditis caused by G. morbillorum. The paucity of reports concerning these bacteria is probably related to the difficulties associated with their identification. For example, one of the strains reported in this study was originally sent to our laboratory with a preliminary characterization as a short “gram-negative” coccobacillus, highlighting the specific problem associated with Gram staining of these bacteria. The usefulness of 16S rRNA gene amplification, partial sequencing, and comparison of the nucleotide sequence to those in databases when standard phenotypic identification schemes are not helpful is emphasized. We also suggest that the use of simple tests, such as testing susceptibility to vancomycin for gram-negative bacteria and colistin for gram-positive bacteria, could prevent misinterpretation of Gram staining in gram-variable bacteria such as Gemella spp.

Identification of Antibacterial Peptides from Bovine κ-Casein

2006 ◽  
Vol 69 (12) ◽  
pp. 2992-2997 ◽  
Author(s):  
IVÁN LÓPEZ-EXPÓSITO ◽  
FABIO MINERVINI ◽  
LOURDES AMIGO ◽  
ISIDRA RECIO
Keyword(s):  
High Performance ◽  
Antibacterial Effect ◽  
Amino Acid Sequences ◽  
Listeria Innocua ◽  
Tandem Mass ◽  
Gram Negative Bacteria ◽  
Antibacterial Peptides ◽  
Antibacterial Effects ◽  
Gram Negative ◽  
Active Peptides

The objective of the present study was to identify antimicrobial peptides present in several digests of commercial caseins with gastric enzymes. The most active hydrolysate against Escherichia coli ATCC 25922 and Listeria innocua CECT 910T corresponded to a pepsin digest of bovine κ-casein. The protein digest was first separated by semipreparative high-performance liquid chromatography (HPLC), and the most active fractions were again subjected to a second chromatographic step. Finally, identification of the active peptides was carried out by online and offline HPLC–electrospray ionization–tandem mass spectrometry. By means of this technique, 21 peptides were identified in the active HPLC fractions. Although most were derived from bovine κ-casein, some of the identified fragments corresponded to β-casein and αs-casein fragments, a result of the presence of small amounts of these proteins in the preparation of κ-casein. Some of the peptides identified were chemically synthesized and showed antibacterial effects against several gram-positive and gram-negative bacteria. Among the synthesized peptides, κ-casein f(18–24), f(30–32), and f(139–146) were most effective against all bacteria tested. The antibacterial effect of these peptides is discussed in relation to their amino acid sequences.

Sign in / Sign up

Export Citation Format

Share Document