Impact of Different Rates of Nitrogen Supplementation on Soil PhysicochemicalProperties and Microbial Diversity in Goji Berry

Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signifi-cantly enhance fruit yield and Goji berry industrial development in Ningxia,China.This study aimed to analyze the functions of differential nitrogen application rates including low(N1),medium(N2),and high(N3)levels in soil microbial community structure(bacterial and fungal)at 2 diverse soil depths(0-20,20-40 cm)through high-throughput sequencing technology by targeting 16S RNA gene and ITS1&ITS2 regions.All the observed physicochemical parameters exhibited significant improvement(p<0.05)with increased levels of nitrogen and the highest values for most parameters were observed at N2.However,pH decreased(p<0.05)gradually.The alpha and beta diversity analyses for bacterial and fungal communities’metagenome displayed more similarities than differences among all groups.The top bacterial and fungal phyla and genera suggested no obvious(p>0.05)differences among three group treatments(N1,N2,and N3).Furthermore,the functional enrichment analysis demonstrated significant(p<0.05)enrichment of quorum sensing,cysteine and methionine metabolism,and transcriptional machinery for bacterial communities,while various saprotrophic functional roles for fungal communities.Conclusively,moderately reducing the use of N-supplemented fertilizers is conducive to increasing soil nitrogen utilization rate,which can contribute to sustainable agriculture practices through improved soil quality,and microbial community structure and functions.

Effects of Non-protein Nitrogen Supplement on Growth Performance of Graze Cattle

[Objective] The experiment was conducted to investigate the growth performance of graze cattle fed on non-protein nitrogen （NPN） supplement. [ Method] The experiment was conducted in late spring and early summer before grazing. Thirty Chinese SimmentaI-Taihang taxa bulls at the age of 9-10 months weighing 150-170 kg were divided into the control group, experimental group 1 and experimental group 2, 10 in each group, Each cattle in the experimental group 1 fed on the basal diet supplemented 1.0 kg cornmeal every day. Each cattle in the experimental group 2 fed on the basal diet supplemented 1.0 kg cornmeal and 0.25 kg NPN supplement every day. Those in the control group were fed on the basal di- et. The experiment was performed for 100 d. [Result] The average daily gain of the experimental group I was 217 g larger than that of the control group, while the average daily gain of the experimental group 2 was 429 g larger than that of the control group. The differences in the average daily gain were significant between the three groups. [ Conclusion ] The growth performance of cattle grazed in northern slopes was obviously improved by supplementing a small amount of concentrate in feed. The improvement was more remarkable if a small amount of NPN supplement was also added in feed.

Optimizing a nitrogen-supplemented, condensed corn soluble medium for growth of the Polyhydroxyalkanoate producer Pseudomonas putida KT217

Pseudomonas putida KT217 produces medium-chain-length polyhydroxyalkanoate(mcl-PHA)that is of commercial interest as a biodegradable plastic.To reduce PHA production costs,a less expensive medium to grow P.putida KT217 to a high cell dry weight(CDW)was developed.P.putida KT217 was grown in aerated shake flasks on a condensed corn solubles(CCS)based medium that provided several organic acids and carbohydrates that were utilized for growth.The medium was prepared by adding various amounts of fresh CCS(100-600 g/L,or 34.9-209.4 g/L dry basis)to water and then centrifuging and filtering.The CCS permeate media contained dry matter levels of 28.8-164.9 g/L.The CCS permeate medium containing 108.4 g/L solids produced approximately 6 g CDW/L,at a growth rate of 1.03 per hour,and maximum cell population of 4×109 CFU/mL.Because CCS is low in nitrogen,ammonium hydroxide was added at a level of 1.73 g/L,and this significantly increased the CDW(>20 g/L)produced in an aerated bioreactor.Therefore,a nitrogen supplemented CCS medium could provide a cheap source of nutrients for production of P.putida KT217 and PHA.