The strategy of bioconversion of potato waste with rumen fluid from slaughterhouse is a new idea to reduce their environmental pollution. This study aimed to evaluate the potential of using rumen fluid microorganisms along with urea for bioconversion of potato waste (PW) through determining the nutritive value of the remaining product by chemical composition analysis and gas production test. Furthermore, the concentrations of ammonia and volatile fatty acids (VFAs), pH, and enzymatic activities in the fermentation medium were determined. A mixture of 400 mL of rumen fluid and 200 g of PW along with different levels of urea nitrogen (UN) including 0 (0UN), 1.5 (1.5UN), 3 (3UN), or 4.5 (4.5UN) g were incubated for 24 h at 39 °C in anaerobic fermentation chambers. Dry matter disappearances of PW after 24-h incubation with rumen fluid were 68.79, 78.03, 73.76, and 70.86% for 0UN, 1.5UN, 3UN, and 4.5 UN, respectively and adding 1.5 g UN to fermentation mixture resulted in higher DM disappearance compared to other treatments (P < 0.05). The protein content of the remained PW after processing (the solid phase of the fermentation mixture) was higher for N supplemented groups (P < 0.05) than the control one (0UN) and the highest amount was found for 3UN (30.23% crude protein). The crude protein content of the remained PW (the solid phase of the fermentation mixture) after 24-h incubation with rumen fluid and 3 g UN increased about threefold compared to the initial PW. When PW processed in 3UN mixture, it resulted in higher microbial protein synthesis compared to other treatments (P < 0.001). Higher total VFA concentration in the rumen fluid (the liquid phase of the fermentation mixture) was recorded by supplementing the fermentation mixture with 3 g UN so, more that threefold increase was observed compared to the 0UN mixture (P < 0.001). Higher hydrolytic enzyme activities were measured in the rumen fluid after incubating PW compared to the initial rumen fluid. The highest carbohydrate degrading activities were observed for 1.5UN and the highest protease and urease activities were measured for 4.5UN group. It can be concluded that the bioconversion of PW with rumen fluid makes an opportunity to produce a new protein feedstuff for livestock animals. The potential of PW, as the substrate for rumen microorganisms, was improved by urea addition and increased its protein content. In addition, the remained fermentation medium after incubation can be considered as a source of some enzymes and VFAs. Therefore, the bioconversion of PW with rumen fluid and supplementation with urea can be used as a tool to remove two agriculture wastes and produce a new protein feedstuff for livestock animals.
Effects of nitrogen supplementation on bioconversion of potato waste by rumen fluid from slaughterhouses to produce eco-friendly products
ZEIDAN MOHAMED SALEM A;
2022-01-01
Abstract
The strategy of bioconversion of potato waste with rumen fluid from slaughterhouse is a new idea to reduce their environmental pollution. This study aimed to evaluate the potential of using rumen fluid microorganisms along with urea for bioconversion of potato waste (PW) through determining the nutritive value of the remaining product by chemical composition analysis and gas production test. Furthermore, the concentrations of ammonia and volatile fatty acids (VFAs), pH, and enzymatic activities in the fermentation medium were determined. A mixture of 400 mL of rumen fluid and 200 g of PW along with different levels of urea nitrogen (UN) including 0 (0UN), 1.5 (1.5UN), 3 (3UN), or 4.5 (4.5UN) g were incubated for 24 h at 39 °C in anaerobic fermentation chambers. Dry matter disappearances of PW after 24-h incubation with rumen fluid were 68.79, 78.03, 73.76, and 70.86% for 0UN, 1.5UN, 3UN, and 4.5 UN, respectively and adding 1.5 g UN to fermentation mixture resulted in higher DM disappearance compared to other treatments (P < 0.05). The protein content of the remained PW after processing (the solid phase of the fermentation mixture) was higher for N supplemented groups (P < 0.05) than the control one (0UN) and the highest amount was found for 3UN (30.23% crude protein). The crude protein content of the remained PW (the solid phase of the fermentation mixture) after 24-h incubation with rumen fluid and 3 g UN increased about threefold compared to the initial PW. When PW processed in 3UN mixture, it resulted in higher microbial protein synthesis compared to other treatments (P < 0.001). Higher total VFA concentration in the rumen fluid (the liquid phase of the fermentation mixture) was recorded by supplementing the fermentation mixture with 3 g UN so, more that threefold increase was observed compared to the 0UN mixture (P < 0.001). Higher hydrolytic enzyme activities were measured in the rumen fluid after incubating PW compared to the initial rumen fluid. The highest carbohydrate degrading activities were observed for 1.5UN and the highest protease and urease activities were measured for 4.5UN group. It can be concluded that the bioconversion of PW with rumen fluid makes an opportunity to produce a new protein feedstuff for livestock animals. The potential of PW, as the substrate for rumen microorganisms, was improved by urea addition and increased its protein content. In addition, the remained fermentation medium after incubation can be considered as a source of some enzymes and VFAs. Therefore, the bioconversion of PW with rumen fluid and supplementation with urea can be used as a tool to remove two agriculture wastes and produce a new protein feedstuff for livestock animals.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
