Chemoselective modification of chitosan with arginine and hydroxyproline: Development of antibacterial composite films for wound healing applications.

This study explored the enhancement of chitosan for wound dressing applications through selective functionalization with arginine and hydroxyproline amino acids, combined with polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) in composite films. The research employed chemoselective amino acid grafting followed by solution casting to fabricate the composite materials. Fourier transform infrared (FTIR) analysis verified successful chitosan modification through the presence of a carbamate bond at 1719 cm and an amide bond shift from 1660 to 1680 cm, with nuclear magnetic resonance (NMR) analysis providing additional confirmation.

Biological activated carbon process for biotransformation of azo dye Carmoisine by spp.

The feasibility of employing the biological activated carbon (BAC) process to debilitate azo dye Carmoisine by spp. was investigated. Plate assay revealed the capability of spp.

Preparation of chitosan-based composites with urethane cross linkage and evaluation of their properties for using as wound healing dressing.

In this research, biocomposite films containing chitosan (CS), polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP), with different ratios, have been provided. The effects of adding hexamethylene 1, 6-di(aminocarboxysulfonate) (HMDACS) as cross-linking agent and the formation of urethane linkage on mechanical properties such as tensile strength, elongation and dynamic-mechanical properties such as storage modulus and tan δ were studied. Also, the antibacterial properties of the composites were investigated by viable bacterial cell counting and compared in reducing the bacterial growth.

Ulcerative dermatitis in barramundi due to coinfection with Streptococcus iniae and Shewanella algae.

Streptococcus iniae is a pathogenic bacterium which causes septicaemia, while Shewanella algae is an opportunistic pathogen found in marine environments. In this study, we investigated an uncommon coinfection of these 2 bacterial species which resulted in systemic disease and cutaneous ulcers in a barramundi Lates calcarifer farm in the Persian Gulf, Iran. Culture, molecular and histopathological specimens were taken from different organs.

Structural characterization and surface activities of biogenic rhamnolipid surfactants from Pseudomonas aeruginosa isolate MN1 and synergistic effects against methicillin-resistant Staphylococcus aureus.

The aim of present work was to study chemical structures and biological activities of rhamnolipid biosurfactants produced by Pseudomonas aeruginosa MN1 isolated from oil-contaminated soil. The results of liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed that total rhamnolipids (RLs) contained 16 rhamnolipid homologues. Di-lipid RLs containing C(10)-C(10) moieties were by far the most predominant congeners among mono-rhamnose (53.

Intra/extracellular biosynthesis of silver nanoparticles by an autochthonous strain of Proteus mirabilis isolated from photographic waste.

There is an enormous interest in developing green synthesis procedures for production of nanoparticles by using biomimetic approaches. In our research focus has been given to the development of an efficient and eco-friendly viable process for the synthesis of nanoscale silver particles using Proteus mirabilis PTCC 1710, a bacterial strain that was isolated during a screening program from photographic waste. A significant result of this study is our observation that silver nanoparticles could be induced to synthesis intra and extracellulary.

Biotransformation of hydrocortisone by a natural isolate of Nostoc muscorum.

Hydrocortisone was converted in the culture of an isolated strain of the cyanobacterium Nostoc muscorum PTCC 1636 into some androstane and pregnane derivatives. The microorganism was, isolated during a screening program from soil samples collected from paddy fields of north of Iran. The bioproducts obtained were purified using chromatographic methods and identified as 11beta-hydroxytestosterone, 11beta-hydroxyandrost-4-en-3,17-dione and 11beta,17alpha,20beta,21-tetrahydroxypregn-4-en-3-one on the basis of their spectroscopic features.