BACKGROUND: Peptones are one of the most expensive components of microbial culture media. The present study was performed to produce microbial peptone from sheep wool using a new chemical process. RESULTS: Wool peptone (WP) was found to have high protein (67.8 g per 100 g) and ash (29.2 g per 100 g) contents. Glutamic acid was the most abundant amino acid in WP with a content of 8175 mg per 100 g). Wool peptone (WP) also had a high content (5042 mg per 100 g) of cystine, a sulphur-containing amino acid. Optimal concentration of WP was determined as 5 g L −1 for the fungi and 6 g L −1 for the bacteria. Staphylococcus aureus showed very poor growth performance in WP medium. Growth performances of Saccharomyces cerevisiae, Bacillus subtilis and Penicillium chrysogenum were at moderate levels in WP medium. The best growth performance for Aspergillus niger was observed in WP medium with a biomass production of 8.17 g L −1 . Second best growth performance for Escherichia coli was achieved with WP among the tested peptones. a good growth substrate, especially for A. niger and E. coli. This is the first investigation on use of wool as peptone source or substrate for microorganisms. CONCLUSION: Wool peptone (WP) was shown to be REFERENCES1 AL-Bahri MBAG, AL-Naimi SA and Ahammed SH, The optimum conditions for production of soya peptone by acidic hydrolysis of soya proteins.

PinX1 encoded by a remarkable tumor suppressor gene and located in human chromosome 8p23 is known as telomerase inhibitor. In recent years, this protein has been of interest as clinically tumor suppressor. Pichia pastoris expression system is preferred to produce heterologous proteins and is suitable for industrial and research purposes. In the present study, human PinX1 gene (hPinX1) was cloned in E. coli One Shot TOP10 cells and overexpressed in P. pastoris strain X-33 intracellularly, using a strong AOX (alcohol oxidase) promoter. The recombinant cells were grown in shaking flask. Induction time, methanol concentration and initial pH were optimized for obtaining high levels of hPinX1 protein production. Recombinant protein production was confirmed by Western blot analysis and the relative expression levels of rhPinX1 were quantified. According to Western blot analysis, molecular mass of produced hPinX1 was determined as 47.5 kDa. At the end of optimization studies, the best fermentation conditions were determined as induction time 48 h, methanol concentration 3% and initial culture pH 5.0. This process would be an applicable way for obtaining recombinant hPinX1 using P. pastoris expression system. This is the first report on recombinant production of hPinX1 in P. pastoris.