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BackgroundThe present study aims to apply an efficient eco-friendly and inexpensive process for green synthesis of silver nanoparticles (AgNPs) through the mediation of fungal proteins from Aspergillus fumigatus DSM819, characterization, and its application as antimicrobial finishing agent in textile fabrics against some infectious microorganisms.ResultsOptimum conditions for AgNP biosynthesis could be achieved by means of using 60% (v/v) of cell-free filtrate (CFF) and 1.5 mM of AgNO3 at pH 10.0 after 90 min. The obtained AgNPs were of spherical shape with 90% of distribution below than 84.4 nm. The biosynthesized AgNPs exerted an antimicrobial activity against the studied pathogenic microorganisms (E. coli, B. mycoides, and C. albicans). In addition, IC50 values against in vitro tumor cell lines were found to be 31.1, 45.4, 40.9, and 33.5 μg/ml for HCT116, A549, MCF7, and PC3, respectively. Even with a very low concentration (0.25%), the treated PET/C fabrics by AgNPs exerted an antimicrobial activity against E. coli, B. mycoides, and C. albicans to give inhibition zone diameter of 15, 15, and 16 mm, respectively.ConclusionsThe green biosynthesis approach applied in this study is a non-toxic alternative to the traditional chemical and physical methods, and would be appropriate for biological large-scale production and prospective treatments.Graphical abstract

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Endoglucanase (EG) from A. terreus DSM 826 grown on sugar cane bagasse as a carbon source was purified using acetone fractionation, then a Sepharose-4B chromatographic column, with purification of about 27-fold and 10.5% recovery. The optimum temperature and pH for activity of the purified EG were found to be 50 degrees C and pH 4.8, respectively. The purified enzyme can stand heating up to 50 degrees C for 1 h without apparent loss of activity. However, the enzyme, incubated at 80 degrees C for 5 min, showed about 56% loss of activity. Optimum EG activity was recorded with a citrate buffer system (pH 4.8; 0.05 M). Co2+ (2.5 x 10(-2) M) and Zn2+ (5 x 10(-2) M) were found to activate the purified EG of A. terreus DSM 826 by about 83 and 25%, respectively. On the other hand, Hg2+ inhibited the activity of the purified EG by about 50 and 71% at a concentration of 2.5 x 10(-2) and 5 x 10(-2) M, respectively. Carboxymethyl cellulose was found to be the best substrate for the purified EG, with V(max) values of 4.35 micrpmol min(-1) mg(-1) protein.

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Myceliophthora thermophila laccase was covalently immobilized on functionalized multiwalled carbon nanotubes (MWNT) arranged over a supporting membrane to obtain a permeable bio-barrier that could be applied in multibatch or continuous processes.

Laccase production by Penicillium martensii NRC 345 was optimized. Eight media with different components were screened. The enzyme formed by P. martensii NRC 345 was detected mainly exocellularly under shake culture condition. Laccase formation reaches its maximum value with specific activities of about 7.18 U/mg protein at the twenty-sixth day of incubation at pH 5.5 and 30°C. Galactose (5 g/l) and sodium nitrate (0.2 g/l) were found to be the best carbon and nitrogen sources for laccase formation, respectively. Replacement of galactose instead of glucose at the same concentration increased laccase production by about more than ten-fold. Among the various wastes used wheat bran induces the highest laccase production with specific activity of 39.52 U/mg protein. Tween-80 and CuSO 4 .5H 2 O, were also tested for laccase induction.