Synthesis and Antimicrobial Properties of Chitosan: A Case Study

    

    

    Figure 4:  FTIR spectrum of Chitosan.
    
    

Nitrogen content

Nitrogen content of the prepared chitin as well as chitosan was measured. Nitrogen content of chitin was found to be 7.96 and that of chitosan was 8.06.

Antimicrobial activity of chitosan

As per research reports available, the anti-microbial potential of chitin, chitosan and their derivatives were considered to be a bacteriocidal (kills the live bacteria or some fraction therein) or bacteriostatic (hinders the growth of bacteria but does not imply whether or not bacteria are killed). Several studies show that the effect of Degree of Acetylation and molecular weight is significant on the anti-microbial properties [5]. The effect of the required chitosan was evaluated against Staphylococcus aureus, Bacillus subtillis and Escherichia coli and the results are shown in (Table 1) S. aureus can cause skin infections such as pimples, impetigo, boiling, cellulitis folliculitis, carbuncles, scalded skin syndrome, and abscesses, lifethreatening diseases such as Pneumonia, meningitis, osteomyelitis, endocarditis, toxic shock syndrome, bacteremia and sepsis. It is still one of the five most common hospital infections [16]. Escherichia coli is one of the most common causes of numerous common bacterial infections including cholecystitis, bacteria, cholangitis, urinary tract infection and traveler’s diarrhea as well as other clinical infections such as neonatal meningitis and pneumonia [17]. The most common inhibition zone against S. aureus, B. subtillis was observed at 12 mm and 14 mm at 800 and 1000 ppm/well. Many hypotheses have been proposed to determine the mechanism of antibacterial activity of chitosan. Chitosan contains three types of reactive functional groups, an amino / acetamido group, both primary and secondary hydroxyl groups, respectively, in C-2, C-3 and C-6 positions. Amine content is the main reason for differences in their structures and physicochemical properties and their correlation with their chelation, flocculation and biological functions [15]. They are designed with three models that are the most beneficial interactions with the positively charged chitosan molecule and the negatively charged microbe cell membranes. In this model, the interaction is mediated by the protonated NH3+ and negative groups of electrostatic forces [18] probably compete with Ca2+ electroegativní sites on the surface of the membrane [19]. Electrostatic interaction results in two interventions: (i) supporting permeability changes in the properties of the membrane wall, resulting in internal osmotic imbalance and hence reducing microorganism growth and (ii) hydrolysis in the peptidoglycan wall to microorganisms that result in leakage intracellular electrolytes, Such as potassium ions, and other proteins with low molecular weight components [20] Dislodging produces ions and water flow that causes a decrease in internal pressure bacteria [21]. The visual enhancement effective film lysis has also been reported against gram- negative and gram-positive bacteria [22] Given that this mechanism is based on electrostatic interaction suggest that a higher amount of amines katonizovanÝch, the greater is the antibacterial activity [23].

  

    
Concentraion (µg/mL)
  
  

    
 
    
100
    
200
    
500
    
800
    
1000
  
  

    
Zone of inhibition in diameter    (mm)
  
  

    
Test Organisms
    
 
  
  

    
E.coli
    
8
    
9
    
10
    
12
    
13
  
  

    
S. aureus
    
7
    
10
    
10
    
12
    
14
  
  

    
B. subtillis
    
8
    
10
    
11
    
12
    
14
  

Table 1: Antimicrobial activity and zone of inhibition of Chitosan (mm).