الفهرس 
INRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 257 |  |  |
| | | from | 257 | | |
Abstract
Natural pigments can obtained from different sources such as animals, plants, microbes and minerals. The microbial pigments have a great interest due to several advantages such as fast growing of microbes than plants and animals, it can grow at any time and any place under controlled conditions, growing on cheap substances and produce a large amount of different stable pigments. Among microorganisms, actinobacteria are the most economically and biotechnologically useful prokaryotes in natural pigment production. It is widely distributed in soil, water and other natural environments. The genus of Streptomyces is considered the largest group of actinobacteria species and varieties. These species can produce a large number of natural pigments such as melanin and prodigiosin like pigment.
The aims of this study are as follows:
1- To obtain rhizospheric actinobacteria produce natural pigments.
2- Enhancement of pigment production by changing the environmental and cultural conditions.
3- Evaluation of antimicrobial activity of produced pigment(s) against some pathogenic microbes.
4- Determination of dyeing properties of produced pigment(s).
5- Application of nanotechnology to improve the properties of produced pigment (s).
The conclusion from this study is as follows:
A- Isolation of Pigment Producing Actinobacteria from Rhizosphere Soil.
1- Four soil samples were collected from different rhizospheric locations. Two of them from garden of plant department of women’s Faculty for Arts, Science and Education, Ain Shams University and 2 samples from garden of National Research Centre, Egypt.
2- Twelve actinobacteria were isolated from collected samples and screened for pigment(s) production. About 6 pigmented positive actinobacteria isolates were obtained. These isolates were around 50% as pigmented actinobacteria. The morphology characterization of these isolates was noted.
3- The six pigmented isolates were advanced screened on Yeast malt, Glycerol asparagine and Tyrosine media to evaluate the diffusible pigment production.
4- One of isolated Actinobacteria (isolate 10) was the best one in pigments production on the used media and it was produced diffused pigments. This isolate was subjected to identification processes.
5- The morphological characteristics of this isolate were long chains of spiral segmented with hook shaped mycelium and confirmed by scanning electron microscope to indicate the surface of spore which was curly.
6- This isolate was positive in melanin pigment production, nitrate reduction test, starch hydrolysis and not able to hydrolyze of gelatin. Also this isolate was able to produce H2S by fermentation and degrade the xanthine, L-tyrosine and casein. As well as, it was hydrolyzed urea and sensitive to streptomycine antibiotic.
7- The morphological, biochemical and physiological identification of Streptomyces isolate 10 were confirmed using molecular biology techniques. The partial sequence of 16S rRNA of Streptomyces isolate 10 was aligned by Blast program. The nucleotide alignment and distance matrix showed high similarity value (95 %) with species: Streptomyces torulosus. This isolate was recorded in GeneBank under accession number: kx753680
B- Production of natural pigment(s) by Streptomyces torulosus using different media.
1- Three different pigmented media were used to produce natural pigment(s) by Streptomyces torulosus. These media were Yeast malt (ISP2), Tyrosine (ISP7) and Glycerol asparagine (ISP5). Different colours such as black, deep green and brown were obtained in this study.
2- In this study, the source of carbon and nitrogen in the total 3 pigmented media was changed by other sources to enhance the pigment(s) production.
3- In Yeast malt broth medium the obtained results indicated that the dextrose as the main carbon source was the best one in production of reddish black pigment. However the malt (the main nitrogen) and NaNO3 were the best nitrogen sources in production of reddish black and greenish black pigments, respectively.
4- In case of Tyrosine broth medium, glycerol (the main carbon) was the best carbon source in production of brown pigment, while asparagine, yeast and NaNO3 were the most efficient nitrogen sources for production of brown, pal brown and deep brown pigments, respectively.
5- The results of changing the carbon and nitrogen sources in glycerol asparagine broth medium showed that the starch was the best carbon source. While tyrosine, peptone and NaNO3 were the best nitrogen sources for production of brown, deep green and green pigments, respectively.
6- from the enhancing of pigment(s) production by Streptomces torulosus using different carbon and nitrogen sources, eight pigmented media with various colours were obtained. Five media were recorded as the new pigmented media which produce different colours.
7- The antimicrobial activity of the produced pigment(s), was examined in this study. Unfortunately, these pigments didn’t had any antimicrobial activity against the tested pathogenic microorganisms.
8- On the other way, the produced pigments were used in dyeing the different types of textiles such as wool and polyamide. They were gave different colours varied reddish brown, brown, deep beige and grey.
9- By determination of the dyed fabrics properties, it was found that all samples were in red- yellow zone also the washing and light fastness properties of the dyed samples were measured and the results indicated that dyed samples showed good to very good rating of fastness to washing and perspiration and only dyed wool fabrics showed very good rating of fastness to light.
C- Application of Nanotechnology to enhance the properties of produced pigments.
1- To enhance the antimicrobial activity of produced pigments, nanotechnology techniques were applied.
2- Silver nanoparticles were produced by Fusarium oxosporum in potato dextrose broth medium and the filtrate was added to silver nitrate to get silver nanoparticles with concentration of 1.7 mg/ml. The produced silver nanoparticles was characterized using Transimition Electron Microscope (TEM). The results indicated that the size of produced silver nanoparticles was ranged between 7 and 21 nm and the shape was spherical.
3- The antimicrobial activity of silver nanoparticles was evaluated against different groups of microbes (Gram –v, Gram +v bacteria and fungi) and the results indicated the bioactivity of nano silver against tested microbes.
4- The results of antimicrobial activity of dyes enriched by silver nanoparticles indicated that the produced pigments supplemented with silver nanoparticles at concentration of 0.85 mg/ml have antimicrobial activity against both Gram positive (B. cerreus and S. aureus), Gram negative (E. coli and sal typhi ) and also fungi.
5- After improved the dyes with silver nanoparicles, these dyes were used for dyeing wool and polyamide and the results of dyed fabrics showed good to very good (4-5) rating of fastness to washing and perspiration and only dyed polyamide from M6 and all dyed wool fabrics showed very good rating of fastness to light.
6- The antimicrobial activity of the dyed fabrics supplemented with silver nanoparticles indicated that the dyed fabrics have antimicrobial activity against both Gram positive (B. cerreus and Staph. aureus) and Gram-negative (E. coli and sal. typhi) after dyeing process as well as fungi (Saccharomyces cereviciae, Candida albicans and Aspergillus niger).