*4.4.1 Agar diffusion method (SN 195920-1992)*

To study the antibacterial efficacy of the impregnated fabrics, the agarbased diffusion method was performed (SN 195920-1992). Bacterial strains for test in *E. coli* and *S. aureus* (**Figure 10**) were selected to be abundant in the

**Figure 8.** *Antifungal test of fabrics impregnated with the pad-dry-cure method against* Aspergillus *sp.*

*Waste in Textile and Leather Sectors*

(K3BI 1 lav.).

observation). As can be seen in **Figure 6**, which shows the photographs of the test against *Chaetomium globosum*, there is a greater sporulation concentrated in the control fabric, while in the other fabrics containing Ag there is only to a lesser extent on the edges of the fabric. The nomenclature is as follows [44]: control (Tela), SBAg 1 wash cycle (KBI 1 lav.), and S3BAg 1 wash cycle

**Figure 7** shows SEM micrographs of the fabrics tested. Here the difference in growth in the control fabric with respect to the fabrics with KBI and K3BI versus *C. globosum* is noticeable, although the KBI gives less growth than the fabric containing K3BI. It can be seen that KBI has lower growth than K3BI, which has poor and scattered growth. The micrographs, which are shown by way of example, can be seen

*SEM micrographs of the control fabric (above) and the fabrics impregnated with the pad-dry-cure method KBI* 

*and K3BI (medium and down), tested against* C. globosum*.*

**10**

**Figure 7.**

### *Waste in Textile and Leather Sectors*

environment and be related to pathologies affecting human health. The culture medium used is BVAC: 5 g NaCl, 5 g yeast extract, 10 g casein peptone, and 15 g of bacteriological agar 1 l of distilled water. Then, plates were prepared with 15 ml of the culture medium BVAC and inoculated with the inoculum previously prepared, which spread throughout the plate with sterile swabs. Finally, the fabrics were added treated and untreated. The plates were incubated for 24 h at 37°C [14, 46].

#### **Figure 9.**

*SEM micrographs of the control fabric (above) and the fabrics impregnated with the pad-dry-cure method KBI and K3BI (medium and down) and the fabrics impregnated with the pad-dry-cure method, tested against*  Aspergillus *sp.*

**13**

**Figure 11.**

*Antimicrobial Fabrics Impregnated with Ag Particles Included in Silica Matrices*

The inoculum was made from 24-h cultures that were in an oven at 37°C. Suspensions with physiological solution were obtained by adjusting the turbidity to 0.5 of the McFarland scale (1.5 × 108 Ufc/ml). A dilution was then made to obtain a bacterial suspension of 1.5 × 106. After the incubation period of the plates inoculated with the selected strains, the zone of inhibition (ZOI) was recorded. The results were obtained from the average of four measurements taken for each triplicate. In addition, the standard deviation between measurements was determined. **Figures 11** and **12** show the photographic records of the trial and those observed through the magnifying glass of the fabrics against *E. coli*. It can be seen that there is an inhibition halo that is identified as a space adjacent to the fabric (transparent culture medium). There are no noticeable differences in the measures of the ZOI of the fabrics that contained the additives in spite of the washing cycles; therefore it can be concluded that the impregnation method has high durability against washing. Taking into account the values of ZOI, 0.6 ± 0.2 for KBI and 0.7 ± 0.2 for K3BI, it can be said that only at 20 wash cycles there is a decrease in the

*Antibacterial test of fabrics impregnated with the pad-dry-cure method against* Escherichia coli*.*

*DOI: http://dx.doi.org/10.5772/intechopen.91631*

antibacterial effect.

**Figure 10.**

*Photographs of bacterial strains used in the assay.*
