Overexpression of an Acidic Endo-β-1,3-1,4-glucanase in Transgenic Maize Seed for Direct Utilization in Animal Feed

Abstract

BackgroundIncorporation of exogenous glucanase into animal feed is common practice to remove glucan, one of the anti-nutritional factors, for efficient nutrition absorption. The acidic endo-β-1,3-1,4-glucanase (Bgl7A) from Bispora sp. MEY-1 has excellent properties and represents a potential enzyme supplement to animal feed.Methodology/Principal FindingsHere we successfully developed a transgenic maize producing a high level of Bgl7AM (codon modified Bgl7A) by constructing a recombinant vector driven by the embryo-specific promoter ZM-leg1A. Southern and Western blot analysis indicated the stable integration and specific expression of the transgene in maize seeds over four generations. The β-glucanase activity of the transgenic maize seeds reached up to 779,800 U/kg, about 236-fold higher than that of non-transgenic maize. The β-glucanase derived from the transgenic maize seeds had an optimal pH of 4.0 and was stable at pH 1.0–8.0, which is in agreement with the normal environment of digestive tract.Conclusion/SignificanceOur study offers a transgenic maize line that could be directly used in animal feed without any glucanase production, purification and supplementation, consequently simplifying the feed enzyme processing procedure.

Fungal β‐1,3‐1,4‐glucanases: production, proprieties and biotechnological applications

“…MEY‐1 was selected to be have an excellent properties and a potential supplement for poultry feed. Zhang et al . successfully developed transgenic maize producing a high β ‐glucanase activity (Bgl7A) in the seeds.…”

“…MEY-1 was selected to be have an excellent properties and a potential supplement for poultry feed. Zhang et al 66 successfully developed transgenic maize producing a high -glucanase activity (Bgl7A) in the seeds. Feeding trials have shown that the effectiveness of glucanase as a feed additive was maximized at approximately 30 000 units per kg of diets.…”

Production of a Highly Protease-Resistant Fungal α-Galactosidase in Transgenic Maize Seeds for Simplified Feed Processing

“…Feed pelleting was carried out as descripted previously [ 17 , 20 ]. α-Galactosidase activities and dry matter contents (DM) were measured before and after the pelleting process.…”

“…Maize as the main ingredient of animal feed (nearly 50%) is an ideal natural bioreactor in which a β-glucanase gene from Bispora sp. MEY-1 has been successfully expressed with the activity of 779,800 U/kg seeds [ 20 ]. The development of transgenic maize will not only reduce the loss of resources and simplify the production process, but also provide an environmentally friendly approach to produce feed enzymes.…”

Nutritionally Enhanced Food Crops; Progress and Perspectives

“…Not only can food crops be biofortified by genetic engineering, they can also be designed to contain bioreactive compounds which have improved health benefits or reduce the risk of chronic diseases, such as cancer and heart disease [ 89 , 90 ]. The following section provides two examples of these “designer crops”.…”