• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.84-92
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• 1999

The rumen microbial ecosystem is coming to be recognized as a rich alternative source of genes for industrially useful enzymes. Recent advances in biotechnology are enabling development of novel strategies for effective delivery and enhancement of these gene products. One particularly promising avenue for industrial application of rumen enzymes is as feed supplements for nonruminant and ruminant animal diets. Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. Cellulases, xylanases, ${\beta}$-glucanases, pectinases, and phytases have been shown to increase the efficiency of feedstuff utilization (e.g., degradation of cellulose, xylan and ${\beta}$-glucan) and to decrease pollutants (e.g., phytic acid). These enzymes enhance the availability of feed components to the animal and eliminate some of their naturally occurring antinutritional effects. In the past, the cost and inconvenience of enzyme production and delivery has hampered widespread application of this promising technology. Over the last decade, however, advances in recombinant DNA technology have significantly improved microbial production systems. Novel strategies for delivery and enhancement of genes and gene products from the rumen include expression of seed proteins, oleosin proteins in canola and transgenic animals secreting digestive enzymes from the pancreas. Thus, the biotechnological framework is in place to achieve substantial improvements in animal production through enzyme supplementation. On the other hand, the rumen ecosystem provides ongoing enrichment and natural selection of microbes adapted to specific conditions, and represents a virtually untapped resource of novel products such as enzymes, detoxificants and antibiotics.

• Fisheries and Aquatic Sciences
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• 제7권2호
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• pp.51-57
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• 2004

Total phosphorus contents in rice bran and soybean meal were determined to be 5.81 and $2.77\%$, respectively, and $97.2\%$ of phosphorus in rice bran and $66.4\%$ in soybean meal were presented as phytate phosphorus. Optimum pH condition for hydrolysis of phytate in rice bran and soybean was determined to be in the pH range of 3.7 and 5.3. The highest activity of phytase for hydrolysis of phytate in both samples was determined to be at $55^{\circ}C$ for rice bran and $55-60^{\circ}C$ for soybean. Hydrolysis of phytate in soybean meal at pH 5.0 increased with the co-reaction or consecutive reaction with protease; however, in rice bran hydrolysis decreased with co-reaction with protease. Phytate degradation of soybean meal in the presence of pepsin at pH 2.5 showed higher than that of rice bran. Phytate degradation of rice bran in the presence of trypsin or pancreatin at pH 7.0 increased the activity around 2-times compared with the activity in the absence of trypsin or pancreatin. The results of this study suggest that hydrolysis of phytate in rice bran or soybean meal with phytase and protease may provide an alternative process for the preparation of aquacultural feed with a low level of organic phosphorus.

• BMB Reports
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• 제37권3호
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• pp.282-291
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• 2004

Phytases catalyze the release of phosphate from phytic acid. Phytase-producing microorganisms were selected by culturing the soil extracts on agar plates containing phytic acid. Two hundred colonies that exhibited potential phytase activity were selected for further study. The colony showing the highest phytase activity was identified as Aspergillus niger and designated strain 113. The phytase gene from A. niger 113 (phyI1) was isolated, cloned, and characterized. The nucleotide and deduced amino acid sequence identity between phyI1 and phyA from NRRL3135 were 90% and 98%, respectively. The identity between phyI1 and phyA from SK-57 was 89% and 96%. A synthetic phytase gene, phyI1s, was synthesized by successive PCR and transformed into the yeast expression vector carrying a signal peptide that was designed and synthesized using P. pastoris biased codon. For the phytase expression and secretion, the construct was integrated into the genome of P. pastoris by homologous recombination. Over-expressing strains were selected and fermented. It was discovered that ~4.2 g phytase could be purified from one liter of culture fluid. The activity of the resulting phytase was 9.5 U/mg. Due to the heavy glycosylation, the expressed phytase varied in size (120, 95, 85, and 64 kDa), but could be deglycosylated to a homogeneous 64 kDa species. An enzymatic kinetics analysis showed that the phytase had two pH optima (pH 2.0 and pH 5.0) and an optimum temperature of $60^{\circ}C$.

• 한국미생물·생명공학회지
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• 제34권1호
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• pp.28-34
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• 2006

현재 probiotics로 상업화되어 있는 B. coagulans IDCC 1201(상업용 명칭 : Lactobacillus sporogenes)이 acid phytase 및 $Co^{2+}$를 cofactor로 갖는 metalloenzyme 특성을 가진 phytase를 생산하고, cofactor로 사용되는 $Co^{2+}$ ion이 B. coagulans IDCC 1201 유래 phytase의 열 안정성에 기여하였다. 또한 B. coagulans IDCC 1201의 phytase 유전자 서열을 분석한 결과 B. subtilis 168 유래의 enzyme 서열과 높은 상동성을 나타내었다. 본 연구결과를 토대로 B. coagulans IDCC 1201 장내 균총의 정상화를 가져와, 질병 예방과 면역력 향상을 구현함과 동시에 가축이 곡물에 함유된 phytic acid의 섭취로 인한 항영양인자, 환경오염등의 문제점을 해결할 수 있는 사료 첨가제로써의 산업적 효용가치가 풍부할 것으로 전망된다.

• Animal Bioscience
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• 제36권5호
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• pp.740-752
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• 2023

Objective: Dietary phytase increases bioavailability of phytate-bound phosphorus (P) in pig nutrition affecting dietary calcium (Ca) to P ratio, intestinal uptake, and systemic utilization of both minerals, which may contribute to improper bone mineralization. We used phytase to assess long-term effects of two dietary available P (aP) levels using a one-phase feeding system on gene expression related to Ca and P homeostasis along the intestinal tract and in the kidney, short-chain fatty acids in stomach, cecum, and colon, serum, and bone parameters in growing gilts and barrows. Methods: Growing pigs (37.9±6.2 kg) had either free access to a diet without (Con; 75 gilts and 69 barrows) or with phytase (650 phytase units; n = 72/diet) for 56 days. Samples of blood, duodenal, jejunal, ileal, cecal, and colonic mucosa and digesta, kidney, and metacarpal bones were collected from 24 pigs (6 gilts and 6 barrows per diet). Results: Phytase decreased daily feed intake and average daily gain, whereas aP intake increased with phytase versus Con diet (p<0.05). Gilts had higher colonic expression of TRPV5, CDH1, CLDN4, ZO1, and OCLN and renal expression of TRPV5 and SLC34A3 compared to barrows (p<0.05). Phytase increased duodenal expression of TRPV5, TRPV6, CALB1, PMCA1b, CDH1, CLDN4, ZO1, and OCLN compared to Con diet (p<0.05). Furthermore, phytase increased expression of SCL34A2 in cecum and of FGF23 and CLDN4 in colon compared to Con diet (p<0.05). Alongside, phytase decreased gastric propionate, cecal valerate, and colonic caproate versus Con diet (p<0.05). Phytase reduced cortical wall thickness and index of metacarpal bones (p<0.05). Conclusion: Gene expression results suggested an intestinal adaptation to increased dietary aP amount by increasing duodenal trans- and paracellular Ca absorption to balance the systemically available Ca and P levels, whereas no adaption of relevant gene expression in kidney occurred. Greater average daily gain in barrows related to higher feed intake.