• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.181-185
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• 2007

This study was conducted to evaluate the effects of dietary delta-aminolevulinic acid (ALA) on egg production and egg quality in laying hens. A total of 114 (30-wk age) ISA brown commercial hens were used in current trial for 28 days. Dietary treatments included 1) CON (basal diet), 2) 0.05 (basal diet + ALA 0.05%), 3) 0.1 (basal diet + ALA 0.1%) and 4) 0.2 (basal diet + ALA 0.2%). There were four dietary treatments with four replication per treatment and twelve laying hens per replication. During the overall period, egg production was quadratically affected (P=0.01) by ALA supplementation compared with control treatment. Egg weight increased (linear effect, P=0.01; quadratic effect, P=0.01) as the level of delta-aminolevulinic acid supplementation increased in the diets. Yolk color was increased quadratically (P=0.03). The difference of hemoglobin concentration was increased (quadratic effect, P=0.01) as the level of delta-aminolevulinic acid supplementation increased in the diets. In conclusion, the results of the experiment suggest that dietary delta-aminolevulinic acid could affect egg weight, yolk color and hemoglobin concentration in laying hens.

• 산업보건소식
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• no.38
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• pp.8-12
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• 1987

• New & Renewable Energy
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• v.19 no.4
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• pp.11-19
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• 2023

Levulinic acid (LA) derived from cellulosic biomass, serves a crucial intermediate that can be used in various chemical conversions. This study focused on optimizing the production of LA using two types of pretreated rice husk (de-ashed and delignificated cellulosic biomass) in a batch reaction system through catalytic conversion with sulfuric acid. To determine the optimal conditions, the conversions of glucose and α-cellulose were examined to compare the effects of pretreatment on the rice husk. The experimental parameters covered a broad spectrum, including temperatures ranging from 140℃ to 200℃, a reaction time was up to 600 minutes, and a substrate to catalyst (acid solution) ratio of 100 g/L. The highest LA yield was 44.8%, achieved from de-ashed rice husk with 3.0 wt.% of sulfuric acid at 180℃ and with a reaction time of 180 minutes. In the case of the delignificated rice husk, a LA yield of 43.6% was obtained with 3.0 wt.% of sulfuric acid at 200℃ and with reaction time of 30 minutes.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.341-348
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• 2016

This study aimed to develop a microbial process for producing aminolevulinic acid (ALA) using crude glycerol. In the culture of ALA-producing cells (Escherichia coli/pH-hemA) in a medium containing crude glycerol, the cell density and production were 1.8-fold and 1.2-fold lower than those obtained from pure glycerol, respectively. However, the cell growth and production were improved by supplementing the medium with trehalose (30 or 100 g/l). Engineered cells (E. coli/pH-hemA/pS-otsBA) were constructed to express otsBA and their culture performance was compared with that of control cells (E. coli/pH-hemA/ pSTV28). The effects of isopropyl β-D-1-thiogalactopyranoside (IPTG) concentration and the time of induction were examined to improve the cell growth and ALA production in engineered cells cultured using crude glycerol. When 0.6 mM of IPTG was added at the beginning of the exponential growth phase, the ALA produced by cells was 2,121 mg/l, which was comparable to that from pure glycerol. The results demonstrate that otsBA expression endowed cells with the capacity to tolerate the toxicity of crude glycerol for direct use.