Effects Of Dietary Protein Levels On The Nutritional Utilization And Nitrogen Metabolism Of Male Adults Of Blattella Germanica

The long-term adaptation of the Blattella germanica to low nitrogen environment led to its evolution of nitrogen storage mechanism,which is conducive to its survival.As the high-protein food was becoming increasingly abundant,the protein in kitchen waste increased,and the nitrogen level inside the B.germanica was also on the rise.Therefore,the special nitrogen utilization mechanism of the B.germanica does not match with the high protein environment,which may have a certain effect on the B.germanica.This study investigated the effects of four kinds of diet with different protein content(5%?25%?45% and 65%)on the nutritional utilization and nitrogenium metabolism of male adults of B.germanica by using nutritional ecology,physiological biochemistry,cytology and molecular biology methods.The researches are as follows:(1)Effects of different dietary protein levels on the nutritional utilization and physiology of male adults of B.germanica.(2)Effects of different dietary protein levels on the nitrogen utilization and of male adults of B.germanica.(3)Effects of different dietary protein levels on the fat body structure of male adults of B.germanica.(4)Effects of different dietary protein levels on the metabolic pathways of uric acid inside male adults of B.germanica.Research results are as follows:(1)With the increase of protein content in the diet,the mortality rate and standard metabolic rate of male adults of B.germanica were rising.The relative growth rate,food utilization rate and food conversion rate of male adults of B.germanica fed with 45% protein content were the highest.(2)With the increase of protein content,the body nitrogen,fecel nitrogen,nitrogen consumption rate,nitrogen excretion rate,nitrogen generating rate,nitrogen assimilation rate,the activity of xanthine oxidase and the contents of uric acid in B.germanicad went up.However,the group fed with 65% protein content had the lowest nitrogen utilization rate.Besides,the group fed with 45% protein content maintained the highest glutamic oxaloacetic transaminase(GOT)activities,and the glutamic pyruvic transaminase(GPT)activities of B.germanica fed with 25% and 45% protein content diet were also significantly higher than that of B.germanica fed with 5% and 65% protein content diet.(3)The urates,bacterial cells and autophagosomes in fat body of the 65% protein group were remarkably higher than those in the 25% protein group,and the vegetative cells in the 65% protein group were significantly shriveled.(4)The 65% protein group had the lowest mRNA expression levels of uric acid oxidase gene and the highest mRNA expression levels of allantoinase,allantoase,urease and glutamine synthase genes.This study shows that the change of protein in the diet would alter the nutrition utilization of B.germanica.Even in 65% protein group,the B.germanica would adapted to the high protein nitrogen environment by changing its metabolic rate and the fat body cell structure.Nevertheless,the high protein environment would exert negative influences,such as the weakening of antioxidant ability of B.germanica,and the abnormity of uric acid decomposition pathway.Our study provides theoretical basis for revealing the adaptive mechanism of periplaneta germanica under protein changes,and enriches the nitrogen utilization mechanism of insects with special nitrogen utilization mechanism.Under the prevalence of protein diet,it provides a scientific theoretical basis for predicting the occurrence of B.germanica population,and provides a theoretical basis for the development of new bait.