Eco-friendly bio-processing of flax fibers and bioremediation of industry wastes / Gebreil Mostafa Mohamed Gebreil ; Supervised Mohammed Zakeria Sedik , Ali Talat Sabor

Thesis (M.Sc.) - Cairo University - Faculty of Agriculture - Department of Microbiology

The objectives of this thesis were to isolate, screen and select the most active indigenous bacterial and fungal isolates from the retted water and soil of the flax straw (Linum usitatissimum) and to evaluate their efficacy to introduce promising enzymes for ecofriendly bioprocessing applications of flax fibers. The use of these enzymes can help to accelerate the flax retting and reduce the use of harsh chemical in fiber bleaching with improving of fiber quality. One of the objectives was to assess the bioremediation of azo dyes residues generated from flax coloring industry. The determination of fibers quality after treatments was evaluated. In this study, Bacillus humi, Chryseobacterium culicis and Micrococcus luteus isolates which showed specific pectinase activity 37.17, 33.53 and 28.00 U/mg respectively were used for enhancing the retting process. The combinations of these isolates were tested in the lab scale cylindrical experimental bioreactor and each of the combinations was compared with the classical retting process of the industrial units. The combined treatment using isolates: Chryseobacterium culicis, Micrococcus luteus and Bacillus humi resulted in the reduction of the retting duration by 30%. The fungal isolates of Aspergillus pulverulentus and Fusarium umdm were significantly different in biomass accumulation, enzyme activity (pectinase and laccase), total protein and enzyme specific activity. The fungal specific activities were measured throughout 15 days of incubation. Fungal pectinase activity was optimized using different incubation temperatures and pH. Results showed the best incubation temperature was at 40oC and the best pH was 5. Pectinase activity in flax tissue was determined after application by immersion, soaking and spraying. The immersion of flax straw in pectinase enzyme solution after ultrasonication pretreatment was the best in enzyme activity in the tissues

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