Characteristic of a GH10 Xylanase From The Anaerobic Rumen Fungus Anaeromyces Robustus and Application in Bread Making

The rumen of ruminants contains a variety of fungi capable of producing xylanases to break down plant cell walls. In this study, a new GH10 xylanase gene ArXyn10c20 from anaerobic rumen microorganism Anaeromyces robustus was successfully expressed in Pichia Pastoris GS115, with a protein molecular weight of approximately 42 kDa and showed the similarity by 64.08% with the β-Xylanase form Neocallimastix Californiae. The optimal pH and temperature for ArXyn10c20 was 5.5 at 40℃. ArXyn10c20 was stable in the pH range 5.0 – 9.0 for 1h which the residual enzyme activity was all above 75%. The activity of recombinant xylanase was significantly enhanced by 1 mM Cu 2+ . The products of ArXyn10c20 hydrolysis of beechwood xylan were xylobiose, xylotriose and xylotetraose by TLC analysis. In food applications, ArXyn10c20 can significantly improve the quality of dough and bread. With the addition of 7.5 mg ArXyn10c20, the hardness, gumminess and chewiness of the bread decreased by 42.24%, 45.33% and 55.36% respectively and the reducing sugar increased by 18.67%. The new discovered xylanase ArXyn10c20 has great potential in food industry.

Produk Metabolisme Rumen pada Sapi Perah Laktasi

(Rumen metabolism product on lactating dairy cattle) ABSTRACT. The rumen microorganism, as yeast, have an important role in rumen fermentation processes and the rumen metabolism product. A research had been done to study the use of yeast, Saccharomyces cereviseae in Lactating dairy cattle ration. The research had been conducted by experimental method, in a Latin Square Design. The animal were subjected as column and periods function as row. The treatment to be tested were four levels of yeast addition, namely : 0, 5, 10 and 15 g/cattle/day. The variables measured were rumen metabolism product : Total Volatile Fatty Acids (T-VFA), Acetate (C2), Propionate (C3), Butyrate (C4), Formiate, Valerate, Nitrogen Ammonia and C2/C3. Based on the all variables measured, it was indicated that the addition of yeast Saccharomyces cereviseae up to 15 g/cattle/day have not changed the rumen metabolism product on lactating dairy cattle; although it was a normally production of total VFA (96,86 ± 9,94 mM/L and C2/C3 (3,08 ± 0,14), but it was very high production of N-NH3 (12,85 ± 2,72 mM/L). To increase the efficiency of metabolism processes, it is need the addition of fermentable carbohydrate in ration.

Penggunaan Ampas Bir dalam Ransum untuk Meningkatkan Kualitas Daging Domba

The utilization of brewery waste in ration to improved the quality of lamb meatABSTRACT. An experiment has been conducted to study the utilization of brewery waste in ration to improved the meat quality of lamb. High quality of lamb meat can be reached by manipulation of rumen fermentation. Tannins in brewery waste can decrease the activity of rumen microorganism and inhibite the rumen biohydrogenation processes. The experiment was conducted with an experimental method by in vivo technique, using 16 heads of local lamb, 4-5 months old, with body weight range of 5-10 kg. The trial was conducted for 150 days, using Completely Randomized Block Design with 4 replicates. The treatment tested were 4 levels of Brewery Waste : R1 = 12%; R2 = 24%; R3 = 36% and R4 = 48%. The variables measured were : physical and chemical quality of meat. The result indicated, that the treatment tested significantly affect the meat quality physically, except to the percentage of edible distal meat and proximal bone weight.Based on the all variables measured, the research conclusion : (1) the utilization of brewery waste up to 48% dry matter ration, could be used, without any physiology and metabolism disturbance; (2) the highest increasing of unsaturated fatty acid was stearic acid (C18:0) as much as 54. 60%, was reach by R3 (36% brewery waste); the linoleic acid increased as much as 43.91% reach by R4 (48% brewery waste); the oleic acid increased as much as 37.48% by R2 ( 24% brewery waste). From the result can be suggested that the need of tannin brewery waste as biohydrogenation inhibitor would be more effective and efficient whenever brewery waste usage has been increased up to 60% dry matter ration.

Usnic acid, a secondary metabolite of lichens and its effect on in vitro digestibility in reindeer

Usnic acid, a common secondary metabolite in prefered lichens by reindeer and caribou, has been tested for its effect on In Vitro Dry Matter Digestibility (IVDMD) using inocula from four reindeer. When Cladonia alpestris (stellaris (OpicJ) was used as substrate and reindeer rumen liqour as media of incubation together with usnic acid, digestibility was considerably enhanced. This was also true for a lower prefered lichen Stereocaulon paschale (L.), but the effect was less pronounced. The results suggest that reindeer host some rumen microorganism able to metabolize lichen secondary metabolities.