Carbohydrate active enzymes are affected by diet transition from milk to solid food in infant gut microbiota

ABSTRACT Infants experience a dramatic change in their food in the first year after birth when they shift from breast milk to solid food. This results in a large change in presence of indigestible polysaccharides, a primary energy resource of gut microbes. How the gut microbiota adapts to this dietary shift has not been well examined. Here, by using metagenomics data, we studied carbohydrate-active enzymes (CAZymes) of gut microbiota, which are essential enzymes catalyzing the breakdown of polysaccharides, during this dietary shift. We developed a new approach to categorize CAZyme families by food intake and found CAZyme families associated with milk or solid food. We also found CAZymes with most abundance in 12 months infants that are not associated with solid food or milk but may be related to modulating carbohydrates in the mucus. Additionally, the abundance of gut CAZymes were found to be affected by many other factors, including delivery modes and life style in adults. Taken together, our findings provide novel insights into the dynamic change of gut CAZymes in early human life and provide potential markers for food interference or gut microbiota restoration.

EFISIENSI PEMANFAATANENERGICAHAYAMATAHARIOLEHFITOPLANKTON DALAMPROSES FOTOSINTESISDIWADUKMALAHAYU

Cahaya matahari merupakan sumber energi utama yang menentukan produktivitas suatu ekosistem akuatik. Ketersediaan cahaya akan menentukan kecepatan fotosintesis yang akan menentukan kecepatan pertumbuhan produsen primer. Tujuan penelitian ini adalah untuk mengetahui efisiensi pemanfaatan cahaya matahari oleh fitoplankton di Waduk Malahayu. Penelitian ini dilakukan di Waduk Malahayu, Kabupaten Brebes, Jawa Barat, pada bulan Oktober 2010. Pengamatan produktivitas primer kotor, kelimpahan fitoplankton, intensitas cahaya, dan klorofil-a dilakukan pada dua stasiun yaitu stasiun keramba jaring apung dan dam pada kedalaman 0,5; 2; dan 4 m dengan metode survei berstrata. Pengukuran produktivitas primer kotor dilakukan dengan metode botol gelap dan terang. Hasil penelitian menunjukkan nilai produktivitas primer kotor diWadukMalahayu berkisar 45,6-121,9 mgC/jamdan konsentrasi klorofil-a berkisar 3,7-11,8mg/m3. Kelimpahan individu fitoplankton diWaduk Malahayu berkisar 100,6-112,67 ind./l dengan genera yang dominan adalah Oscillatoria (Cyanophyceae) dan Peridinium (Dinophyceae). Efisiensi penggunaan cahaya matahari oleh fitoplankton di Waduk Malahayu berkisar 0,5-2,7%. Efisiensi cahaya matahari menurun dengan bertambahnya kedalaman air. Sunlight is primary energy resource that determine the productivity of aquatic ecosystem. Its availability will determines the photosynthetic rate and primary producer growth rate. Study in order to know thr effeciency of sunlight uptake by phytoplankton inMalahayu Reservoir, Brebes Regency, Central Java in October 2010. Sampling were for gross primary productivity, phytoplankton abudance, light intensity, and chlorophyll-a carried at two stations, keramba jaring apung and dam and at three water depth, surface, 2 and 4 m with stratified sampling method. Measurement of gross primary productivity was conducted with dark and ight botle method. Gross primary productivity ranged from 45.6-121.9 mgC/hr with chlorophyll-a concentration between 3.7-11.8 mg/m3. Phytoplankton abundance ranged from 10.06-112.67 ind./l with Oscilatoria and Peridinium as dominant genera. Efficiency of sunlight uptake by phytoplankton ranged from 0.5-2.7% and its value decreased along with an increasing water depth.

Uncertainty Analysis of Primary Resource Savings at Cogeneration

Uncertainty Analysis of Primary Resource Savings at Cogeneration The article provides the uncertainty analysis for electricity and heat energy production measurements at a cogeneration plant. It is analysed how the uncertainty in the input data affects the uncertainty in the data on primary resource savings. In the work, the standard uncertainties have been estimated for both data sets. The uncertainty budget is defined for determination of the primary energy resource savings.