Abstract:The objective of this study was to investigate the relationship between gene expression of nutrient (amino acid, peptide, sodium and proton) transporters in the small intestine and embryonic growth in domestic pigeons (Columba livia). One hundred and twenty-five fertilized eggs were randomly assigned into five groups and were incubated under optimal conditions (temperature of 38.1 °C and relative humidity of 55%). Twenty embryos/birds from each group were sacrificed by cervical dislocation on embryonic day (E) 9, 11, 13, 15 and day of hatch (DOH). The eggs, embryos (without yolk sac), and organs (head, brain, heart, liver, lungs, kidney, gizzard, small intestine, legs, and thorax) were dissected, cleaned, and weighed. Small intestine samples were collected for RNA isolation. The mRNA abundance of intestinal nutrient transporters was evaluated by real-time reverse transcription-polymerase chain reaction (RT-PCR). We classified these ten organs into four types according to the changes in relative weight during embryonic development. In addition, the gene expression of nutrient transporters was differentially regulated by embryonic day. AT, EAAT3, LAT4, PepT1, NHE2, NHE3, and y + LAT2 showed positive correlations with intestinal weight (0.80

The objective of this study was to optimize the submerged cultured conditions of carbonic anhydrase (CA) production from the strain of Bacillus mucilaginosus K02 by mono-factor tests with blank control and orthogonal design methodology. When the bacteria was cultured under the condition of monofactor tests with blank control and orthogonal designs, and conventional mono-factor test and orthogonal designs, respectively, the CA productions increased from 5.32 µU/L under the basic medium to 34.53 and 26.12 µU/L. The kinetic analysis of 5 L-fermentor showed that the specific production rate of CA in the optimized medium was almost equaled to the one obtained in the basic and optimized medium with conventional methods. The result demonstrated that CA synthesis was positively correlated with cell growth, and the mono-factor tests with blank control applied in the optimizing composition of the media could achieve better results in contrast to the conventional method.