Natural dyes extracted from Cassia fistula and onion peels are used to dye wool that is pretreated with chitosan by using tannic acid as a mordant. The effect of the mordant concentration on the color strength (K/S) is discussed. The results obtained indicated that K/S increases after treatment with chitosan. It is also noticed that K/S increases with an increasing concentration of chitosan. K/S also increases with an increase of mordant concentration until 4% and then decreases. The effect of the dye bath pH, dyeing temperature and dyeing time are also studied. The K/S and dye uptake exhibit high values. Good fastness properties of the dyed fabric are achieved. The antimicrobial activity of chitosan-treated wool fabric is tested in accordance to diffusion agents. Test organisms, such as Escherichia coli, Bacillus subitilus Pseudomons aeruginosa and Staphylococcus aureus are used and the results indicate that the samples treated with a lower concentration of chitosan exhibit a smaller inhibition zone.

Two anthraquinone compounds are extracted from culture filtrates of Fusarium oxysporum isolate no. 4, which were previously isolated from roots of citrus trees affected with root rot disease. These anthraquinone compounds were identified as 2-acetyl-3,8-dihydroxy-and/or 3acetyl-2,8-dihydroxy-6-methoxy-anthraquinone. Dyeing of cationized cotton fabrics with these anthraquinone compounds as natural dyes has been studied. The values of the dyeing rate constant, half-time of dyeing and standard affinity have been calculated and discussed. The results of the dye uptake isotherms of cationized cotton fabrics dyed with these compounds indicate high dye uptake and the standard affinity of cationized cotton fiber is higher. The toxicity assay of culture filtrates as well as anthraquinone pigment extracted from Fusarium oxysporum against root growth (seed germination) of citrus seeds is investigated. Seeds of sour orange are more affected by all tested concentrations of anthraquinone compounds as well as culture filtrates of Fusarium oxysporium than other citrus seeds. Seeds of lime and Cleopatra mandarin are less affected. The effects of dye bath pH, salt concentration, dyeing time and temperature are studied. Color strength and dye uptake exhibit high values. The results of fastness properties of the dyed fabric are good.