Enhanced production of cellulases by various fungal cultures in solid state fermentation of cassava waste

Cellulases are a group of hydrolytic enzymes capable of degrading cellulose to the smaller glucose units. These enzymes are produced by fungi and bacteria. The solid waste of sago industry using cassava tubers was fermented by Aspergillus niger, Aspergillus terreus and Rhizopus stolonifer in solid state fermentation. The cassava waste contained dry wt of 13.4% cellulose and 2.9% protein by dry weight. The highest cellulase activity was observed on the 10th day in R. stolonifer mediated fermentation. R. stolonifer was more efficient in bioconverting cassava waste into fungal protein (9%) compared to A. niger and A. terreus

Screening of winery and olive mill wastes for lignocellulolytic enzyme production from Aspergillus species by solid-state fermentation

Wastes from olive oil and wine industries (as exhausted grape marc, vineshoot trimmings, two-phase olive mill waste, vinasses, and olive mill wastewater) were evaluated for lignocellulolytic enzyme production (as endocellulases, endoxylanases, and feruloyl esterases) by solid-state fermentation (SSF) with Aspergillus niger, Aspergillus ibericus, and Aspergillus uvarum. To study the effect of different solid medium composition and time in enzyme production, a PlackettBurman experimental design was used. Variables that had a higher positive effect in lignocellulolytic enzyme production were urea, time, and exhausted grape marc. The maximum values of enzymatic activity per unit of substrate dry mass were found with A. niger for feruloyl esterase. Enzymatic extracts from SSF with A. niger achieved maximum feruloyl esterase activity (89.53 U/g) and endoxylanase activity (3.06 U/g) and with A. uvarum for endocellulase activity (6.77 U/g). The enzyme cocktails obtained in the SSF extracts may have applications in biorefinery industries.Jose Manuel Salgado is grateful for the postdoctoral fellowship (EX-2010-0402) of the Education Ministry of Spanish Government. Luis Abrunhosa was supported by the grant SFRH/BPD/43922/2008 from Fundacao para a Ciencia e Tecnologia-FCT, Portugal

Surface Modification of Coir Fibers for Extended Hydrophobicity and Antimicrobial Property for Possible Geotextile Application

Experimental investigations are conducted to study the effectiveness of protective coating with cashew nut shell liquid (CNSL) on coir. CNSL solution has been applied on suitably pretreated coir yarns and coating concentrations are optimized to reduce moisture absorption and microbial growth. Two common cellulose and lignin degrading fungi (Aspergillus niger and Rhizopus stolonifer) have been taken as test organisms. Qualitative and quantitative analyses are carried out to measure fungal growth on untreated and treated fibers. The study shows that treated fibers inhibit the development of fugal growth on fiber surface by 95%. The reduced moisture absorption and improved hydrophobicity of the treated yarns are also reported. Increase in tensile strength up to 17% is noticed. The better properties achieved are explained on the basis of selection of the coating methodology and also the interfacial features of the coatings with the coir fiber. The results indicate the possibility of future application of such treated fibers in geotextiles having better performance compared to the untreated counterparts