This study was designed to produce yeast (Schwanniomyces occidentalis) phytase in rice with a view to future applications in the animal feed industry. To achieve high-level production, chimeric genes with the secretory signal sequence of the rice chitinase-3 gene were constructed using either the original full-length or N-truncated yeast phytase gene, or a modified gene whose codon usage was changed to be more similar to that of rice, and then introduced into rice (Oryza sativa L.). When the original phytase genes were used, the phytase activity in the leaves of transgenic rice was of the same level as in wild-type plants, whose mean value was 0.039 U/g fresh weight (g-FW) (1 U of activity was defined as 1 micromol P released per min at 37 degrees C). In contrast, the enzyme activity was increased markedly when codon-modified phytase genes were introduced: up to 4.6 U/g-FW of leaves for full-length codon-modified phytase, and 10.6 U/g-FW for truncated codon-modified phytase. A decrease in the optimum temperature and thermal stability was observed in the truncated heterologous enzyme, suggesting that the N-terminal region plays an important role in enzymatic properties. In contrast, the optimum temperature and pH of full-length heterologous phytase were indistinguishable from those of the benchmark yeast phytase, although the heterologous enzyme was less glycosylated. Full-length heterologous phytase in leaf extract showed extreme stability. These results indicate that codon modification, combined with the use of a secretory signal sequence, can be used to produce substantial amounts of yeast phytase, and possibly any phytases from various organisms, in an active and stable form.

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1467-7652.2004.00098.xDOI Listing

Publication Analysis

Top Keywords

phytase
13
signal sequence
12
yeast phytase
12
codon-modified phytase
12
high-level production
8
yeast schwanniomyces
8
schwanniomyces occidentalis
8
occidentalis phytase
8
transgenic rice
8
codon modification
8

Similar Publications

Filamentous fungi are a cornerstone in the biotechnological production of enzymes, proteins, and organic acids. However, challenges in understanding and controlling the relationship between morphology and productivity can limit their application. This study addresses these challenges using Thermothelomyces thermophilus, a promising thermophilic fungus known for the production of thermostable enzymes.

View Article and Find Full Text PDF

The use of exogenous phytase and vitamin D metabolites such as 25-hydroxycholecalciferol (25-OH-D) for poultry is well consolidated, but the potential for additive effects when supplementing both requires further investigation. This study investigated possible interactions between supplementation of 25-OH-D and high doses of phytase for broilers fed Ca- and P-deficient diets. A total of 1 200 one-d-old male broiler chicks were randomly allocated from one of four dietary treatments in a 2 × 2 factorial arrangement: 600 or 2 000 phytase units (FYT)/kg and with or without the inclusion of 25-OH-D at 69 µg/kg, with 12 replicates of 25 broilers each.

View Article and Find Full Text PDF

PE7-Mediated Alleviation of Phosphate Starvation and Growth Promotion of Netted Melon ( L. var. Naud.).

Microorganisms

November 2024

Environmentally-Friendly Agricultural Research Center, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.

Members of species are able to enhance the level of available phosphorus (P) for plant absorption through mechanisms of P solubilization and mineralization. In our study, PE7 showed P-solubilizing activity in simple phosphate broth (SPB) medium, and acetic acid, iso-butyric acid, and iso-valeric acid were major organic acids responsible for the increase in soluble P and decrease in pH of SPB medium. In addition, strain PE7 released phytase on phytase-screening agar (PSA) medium, and analysis of semi-quantitative reverse transcription and polymerase chain reaction (sqRT-PCR) revealed that the gene expression was the highest at 1 day after incubation.

View Article and Find Full Text PDF

To begin formulating broiler diets on a digestible calcium (Ca) basis, robust Ca digestibility values for ingredients and factors affecting this digestibility are needed. This study had three main objectives: (1) determine the standardized ileal digestibility (SID) of Ca and phosphorus (P) for seven plant-based feed ingredients in broilers, (2) assess the impact of phytate source on SID Ca from limestone (LS), and (3) evaluate the effect of phytase on SID Ca and P for the different ingredients. Two experiments were conducted to satisfy these objectives.

View Article and Find Full Text PDF

In tropical and subtropical climate regions, heat stress is one of the main causes of production losses in laying quails, aggravated by the antinutritional effects of the phytate in diet ingredients, which negatively affect the bioavailability of minerals, especially calcium and phosphorus. This situation results in a reduction in production and the quality of eggs from commercial laying quails. Several nutritional strategies are utilized to reduce the adverse effects of high temperatures and antinutritional factors such as phytate.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!