SUPLEMENTASI BAGASE DENGAN ENZIM SELULASE DAN PENGARUHNYA TERHADAP KECERNAAN BAHAN KERING, BAHAN ORGANIK DAN SERAT KASAR SECARA IN VITRO

ABSTRACTSupplementation of cellulase enzyme to agro-industrial residues can increase the nutritional value of the product. Advances in industrial biotechnology offer potential opportunities for economic utilization of agro-industrial residues such as palm pres fiber, rice straw, corn straw and bagase for animal feed. Bagase is a complex material, is the major by product of the sugar cane industry. This experiment examined the effect of applying a cellulase enzyme (Siqma & Co) on the digestibility of bagase in vitro. The enzyme was applied in liquid form at concentrations 1.0; 1.5 and 2.0 (g/100 g DM) to bagase. The bagase was incubated with enzyme for 48 h before in vitro digestion. The digestibility of dry matter, organic matter and fiber in vitro was detected. The results showed that digestibility of dry matter, organic matter and fiber were significantly different (P<0.01) across treatments. The increased of the cellulase enzyme supplemented to bagase can increased the nutritive values of the product and directly digestibility of dry matter, organic matter and fiber higher. Results from this study indicated that direct application of enzymes to bagase was capable to improving digestibility in-vitro. Key words : cellulase enzyme, bagase, digestibility, in vitro

A proposed methodology to standardize the determination of enzymic activities present in enzyme additives used in ruminant diets

There is increasing interest in using enzymes that degrade plant cell walls in ruminant diets to enhance production efficiency. Despite strong evidence from several studies suggesting a beneficial effect of enzyme supplementation on nutrient utilization and animal performance, overall the results have been somewhat inconsistent. One of the main problems faced by researchers is the lack of adequate biochemical characterization of the products used, which leads to a poor understanding of their mode of action. Of these biochemical characteristics, enzyme activities are the most important, but they are not always evaluated prior to use. Furthermore, as many arbitrary units of expression for these activities coexist, direct comparisons among studies are essentially impossible. In this paper, we propose a methodology that we feel accounts for the requirements of accuracy, simplicity and safety of use. In addition, a rationale for the standardization of the assays as a function of the conditions under which the enzymes are expected to act is presented. The standardization of these assays will benefit researchers, the feed industry, regulatory organizations, and ultimately the consumer, as it will result in the development of better, safer and more consistent enzyme additives for use in ruminant diets. Key words: Cellulase, enzyme additives, methodology, ruminants, xylanase

In vitro cellulolytic activity of the plant pathogen Clavibacter michiganensis subsp. sepedonicus

The activity of four Clavibacter michiganensis subsp. sepedonicus strains against various cellulose substrates was investigated. Sixty-seven Clavibacter michiganensis subsp. sepedonicus strains grew well on media amended with carboxymethylcellulose, 64 strains produced zones of hydrolysis. Endoglucanase activity was optimal at 37 °C and pH 6.0 against carboxymethylcellulose incorporated in plate assays. Zymogram and sodium dodecyl sulfate – polyacrylamide gel electrophoresis revealed the presence of a protein band corresponding to the cellulolytic activity in the molecular weight (MW) range of approximately 28 000. Protein bands in the same range were detected in five Clavibacter michiganensis subsp. sepedonicus strains. Studies on crude enzyme extracts of Clavibacter michiganensis subsp. sepedonicus strain N-1-1 revealed that p-nitrophenyl β-D-cellobioside (pNPC) was hydrolyzed, with optimal activity at 37 °C and pH 7.0.Key words: cellulase, endo-1,4-β-glucanase (EC 3.2.1.4), Corynebacterium sepedonicum, Solanum tuberosum.