Comparative Study On Enzyme Activity Related With Glucose Metabolism In Rumen Bacteria And Protozoa Of Sheep Fed With Different Concentrate To Forage Ratio

This paper study the change of enzyme activity related with glucose metabolism inrumen bacteria and protozoa of sheep fed with different concentrate to forage ratio, Toprovide test data for in-depth understanding of rumen protozoa in therumen microbes in therole of glucose metabolism. Six healthy Chinese merino sheep (Xinjiang Type),1-years oldand were fitted with the rumen canula, with the average body weight of32±1.36kg wereselected and divided into3periods according to self-control experimental design, forage toconcentrate ratios were15:85,30:70,50:50per period.The showed that the determination of enzyme activity, in the rumen bacteria cell extracts:glucose kinase activity in forage to concentrate ratio of30:70was significantly higher than15:85(P<0.01); In the rumen protozoa cell extracts: the specific activity of Glucokinase weredecreased with the increase of concentrate to forage ratio, Phosphofructokinase activitysignificantly higher than30:70and50:50when the concentrate to forage ratio was15:85(P<0.01), Pyruvate kinase activity significantly higher than15:85when the concentrateto forage ratio was was30:70(P<0.01). When the same concentrate to forage ratio, theactivity of glucokinase, phosph-ofructokinase and pyruvate kinase of rumen protozoa cellextracts were significantly higher than rumen bacteria extracts (P<0.01). Each1mL bacteriain rumen fluid: Glucokinase, phosphofructokinase and pyruvate kinase activity was rised withthe increasing of concentrate to forage ratio; each1mL protozoa in rumen fluid: Glucokinaseand pyruvate kinase activity on the concentrate to forage ratio of30:70and50:50weresignificantly higher than15:85(P<0.01), Phosphofructokinase activity was rised with theconcentrate to forage ratio when the same concentrate to forage ratio, the activity ofglucokinase, phosphofructokinase and pyruvate kinase in per mL rumen protozoa were higherthan bacteria. In rumen bacteria and protozoa, Phosphoglucomutase and UDP-glucose pyrophosphorylase activity was rised with the concentrate to forage ratio increases, and theenzyme activity of protozoa was greater than bacteria.The showed that determination of Kmvalue, there were smaller Kmvalue of bacteria: Kmvalue glucokinase(the substrates wae glucose) in bacterial Km=1.30×10-4M and Km=1.66×10-4M in protozoa; Kmvalue of phosphofructokinase(the substrates wae fructose-6-phosphate) inbacterial Km=1.36×10-4M and Km=7.12×10-4M in protozoa; Kmvalue of UDP-glucosepyrophosphorylase (the substrates wae UDP-glucose) in bacteria Km=2.35×10-5M andKm=4.68×10-5M in protozoa. There were smaller Kmvalue of Protozoa: Kmvalue of Pyruvatekinase (the substrates wae phosphoenolpyruvate) in bacteria Km=2.83×10-2M andKm=1.65×10-2M in protozoa; Kmvalue of Phosphoglucomutase (the substrates waeglucose-1-phosphate) in bacteria Km=2.58×10-4M and Km=2.02×10-4M in protozoa.The research results show, the concentrate to forage ratio of50:50can significantlyimprove the glucose content in sheep rumen bacteria, protozoa, and can improve glucokinase,phosphofructokinase, pyruvate kinase, Phosphoglucomutase and UDP-glucosepyrophosphorylase activity of rumen bacteria and protozoa. Although, in the same ofconcentrate to forage ratio, glucose content of rumen bacteria were significantly higher thanprotozoa’s, But the enzyme activity5kinds of rumen protozoa’s glucose metabolism weresignificantly higher than that of bacteria. Therefore, rumen protozoa have vigoroused glucosemetabolism, plays an important role in glucose metabolism of rumen microorganisms.