人們在嘗試過多種處理霉菌毒素方法之后,現(xiàn)在越來越傾向于采用飼料中添加霉菌毒素處理劑的方式來解決霉菌毒素問題,但目前霉菌毒素吸附劑種類繁多,其主要成分和處理機制也各有不同,各有利弊。
1 、活性炭和一些高聚合物
活性炭是一種具有比表面積高的多孔不溶性物質(zhì);聚乙烯聚吡咯烷酮 (PVPP)是一種具有良好的吸附性不溶性高分子多孔兩性聚合物,因此兩者成為一些處理劑的成分。體外試驗表明活性炭和PVPP等對毒素有較好的吸附作用,但在體內(nèi)的效果得不到驗證,而且其作用機理是物理吸附,對飼料中的某些營養(yǎng)成分有較強吸附作用,因此聚乙烯聚吡咯烷酮和活性炭逐漸淡出人們的視野。
2、 鋁硅酸鹽類
大多數(shù)霉菌毒素處理劑的主要成分都是非金屬無機礦物,如沸石、凹凸棒土、膨潤土、蒙脫石、硅藻土、海泡石等等不同類型的硅鋁酸鹽,這是因為其具有良好的電負性和多孔性特性。這種特性使得一些品質(zhì)好的鋁硅酸鹽類對黃曲霉毒素B1有較好的吸附能力,但經(jīng)江蘇奧邁試驗對其它幾種霉菌毒素吸附效果比較微弱。這些硅鋁酸鹽對極性毒素的吸附力很大程度上取決于其陽離子交換量的多少、比表面積尤其是內(nèi)比表面積,江蘇奧邁科技收集不同來源的天然硅鋁酸鹽樣品并進行檢測分析,發(fā)現(xiàn)絕大多數(shù)天然的礦物樣品的CEC很難超過60 mmol/100g,同時發(fā)現(xiàn)大多數(shù)天然的礦物樣品的重金屬含量都超過GB/T 22144-2008 天然礦物質(zhì)飼料通則的要求,增加了飼料安全風險。
3 、聚糖類物質(zhì)
聚糖類物質(zhì)因于其巨大的表面積和眾多的化學鍵而成為很多霉菌毒素處理劑的主要成分,江蘇奧邁科技通過電子顯微鏡掃描聚糖類物質(zhì)也證實了這一觀點。然而聚糖類物質(zhì)的負面效應是:化學鍵易受復雜消化道環(huán)境的影響,使得其真正體內(nèi)吸附效果難于評價。Zaghini等(2005)在含有2.5mmol/LAFB1的蛋雞日糧中添加0.11%的甘露聚糖,結果表明甘露聚糖能夠吸附AFB1,可降低胃腸道對AFB1的吸附和其在組織中的水平,但也有研究表明一些細胞壁多糖水解物的生產(chǎn)成本高,而且實際使用效果并不穩(wěn)定(Danicke, et al, 2004)。
4、 酶解和生物轉(zhuǎn)化方式的處理劑
有人提出用酶解和生物轉(zhuǎn)化方式來解決飼料霉菌毒素問題,這是一個有意義和開發(fā)前景的方法,但這涉及到酶工程、基因工程等研究手段,因此大部分工作仍停留在研究階段。有研究發(fā)現(xiàn)乳酸菌、雙歧桿菌、白腐真菌、假密環(huán)菌及黑曲霉等菌株具有解毒作用,但又有研究發(fā)現(xiàn)某些通常認為是安全的微生物可能在特定條件下產(chǎn)生有毒代謝物,一些毒素被降解后其產(chǎn)物仍有毒性或毒性更大。另外,一些研究也證明了霉菌毒素是可以通過生物酶降解作用得以去除的,陳儀本提出應用生物學方法降解毒素的技術關鍵在于:篩選出能產(chǎn)高活性解毒酶的菌株、在原料中創(chuàng)造一個有利于酶促反應的含水微環(huán)境,但這個微環(huán)境難以促成。因此,霉菌毒素酶解和生物降解方法需要具備很多前提條件,包括酶解條件、產(chǎn)物、未知危害等。
就目前而言,對天然硅鋁酸鹽分子結構進行針對性處理是改善其吸附選擇性和吸附能力、同時廣泛研究和篩選霉菌毒素親和物質(zhì)、或者抵抗霉菌毒素給機體帶來的損傷、氧化等作用的物質(zhì),或者促動動物代謝循環(huán)和解毒的活性物質(zhì)等等都是相對有效的措施。江蘇奧邁深入研究天然硅鋁酸鹽的理化特性,篩選具有良好吸附特性的礦物進行特殊的改性處理,同時配合特定的生物活性物質(zhì)使得產(chǎn)品在吸附力、親水疏水性、吸附選擇性、協(xié)助動物機體解毒上都有針對性優(yōu)化,是解決飼料霉菌毒素污染風險的一個良好對策。
The English version
People after tried many kinds of processing method of mycotoxin, now more and more inclined to adopt the way of feed mycotoxins treatment agent is added to solve the problem of mycotoxin, but at present there are many different kinds of mycotoxins adsorbent, its main composition and processing mechanism is different also, each have advantages and disadvantages.
1, activated carbon, and some high polymer
Activated carbon is a kind of high specific surface area of porous insoluble substance; Polyethylene polyethylene pyrrolidone (PVPP) is a kind of good adsorption between insoluble polymer porous polymer, so the two become some treating agent composition. Test in vitro showed that activated carbon and PVPP on toxin has good adsorption effect, but in the body can not get the effect of verification, and its mechanism of action is physical adsorption, to feed some nutrients, has the strong adsorption of polyethylene pyrrolidone and the activated carbon gradually faded.
2, aluminum silicate
Most of the main components of the mold toxin treatment agent are non-metallic inorganic minerals, such as zeolite, attapulgite, bentonite, montmorillonite, sepiolite, diatomite, and so on the different types of silicon aluminium acid salt, this is because it has good electronegativity and porous properties. This makes some good quality aluminum silicate has better adsorption ability to the aflatoxin B1, but jiangsu and marsal experiments on several other mycotoxin adsorption effect are faint. These silicon aluminate on polarity toxin adsorption strength largely depends on the cation exchange capacity, specific surface area, especially in the specific surface area, jiangsu the Wallace collection of science and technology from different sources of natural silicon aluminate sample testing and analysis, found that most of the natural mineral samples CEC is very difficult to more than 60 tendency for 100 g, also found that most of the natural mineral samples of heavy metal content is more than the GB/T 22144-2008 the requirements of the general principles of the natural mineral feed, increasing the feed safety risk.
3, chitosan
Chitosan material due to its large surface area and many chemical bonds and become a lot of the main components of the mold toxin treatment agent, Mr Michael in jiangsu science and technology through electronic microscope scanning glycan substances also confirmed this view. However chitosan material in the negative effect is: chemical complex vulnerable to the influence of the digestive tract environment, make it real in vivo adsorption effect is difficult to evaluate. Zaghini (2005) in laying hens diet containing 2.5 tendency/LAFB1 add 0.11% of mannan, can adsorption results show that the mannan.zymosan AFB1, can reduce the adsorption of gastrointestinal tract of AFB1 and its levels in the organization, but also have some research suggests that the cell wall polysaccharide hydrolysate of production cost is high, and the actual use effect is not stable (Danicke et al, 2004).
4, enzymatic hydrolysis and biological transformation way of treatment
Some enzyme solution and bioconversion method to solve the problem of feed mycotoxins, this is a meaningful and development prospect of method, but it involves the research methods such as enzyme engineering, gene engineering, so most of the work is still in research stage. Studies have found that lactobacillus, bifidobacterium, white-rot fungi, false ring bacteria and aspergillus Niger strain with detoxification, but studies have found that some are usually considered safe microbes may cause toxic metabolites under certain conditions, some toxin degradation after the product is toxic or more toxic. In addition, some research has also proved that the mold toxin can be by enzyme degradation to remove yi-ben Chen put forward the application of biological method is the key of the technology of degradation of toxins: screening strains can produce highly active detoxification enzyme, in the raw materials to create a conducive to enzymatic reaction of water environment, but I can't contribute to the environment. Mycotoxin, therefore, enzymatic hydrolysis and biological degradation method requires a lot of prerequisites, including enzymatic hydrolysis conditions, product, unknown hazards, etc.
For now, the natural sialic acid salt substructure targeted treatment is to improve its adsorption selectivity and adsorption capacity, as well as broad research and screening of mycotoxin affinity material, or resistance mycotoxin bring damage to the body, such as oxidation of the material, or any animal metabolism circulation and detoxification of active substances, and so on are relatively effective measures. Jiangsu took the further study of the natural physical and chemical properties of silicon aluminium acid salt, mineral filter has good adsorption properties for special modification, at the same time together with the specific bioactive substances made products in adsorption, hydrophilic, hydrophobic, adsorption selectivity, assist in animal body detoxification targeted optimization, is a good solution to feed mycotoxins pollution risk countermeasures.
|