Encapsulation of in vitro-derived explants of olive (Olea europaea L. cv. Moraiolo): II. Effects of storage on capsule and derived shoots performance

The experiments described in this paper were designed to examine the effect of storage at different temperatures for various periods on regrowth and proliferation ability of encapsulated olive microcuttings (capsules). The proliferation and rooting ability of the shoots derived from the capsules were compared with those maintained in normal proliferation by 45 days period of subculturing. A simple method of encapsulated microcuttings storage in plastic cuvettes was used. Interesting feature was the ability of the capsules to retain their viability and regrowth after storage at room temperature as well as at 4 °C for 15 and 30 days and both axillary buds on the nodes of almost all capsules sprouted successfully. Improvement in proliferation and rooting abilities were found in subsequent culturing of the shoots developed from the capsules. The study indicates bright prospects of commercial application of alginate nutrient capsule technology in various situations like supply of certified plant material from both official or private organizations to the plant nurseries and/or exchange of germplasm at international level without refrigerated containers just in plastic cuvettes.     

Identification of sialyl oligosaccharides including an oligosaccharide nucleotide in colostrum of an addax (Addax nasomaculatus) (Subfamily Antelopinae)

Mammalian milk/colostrum usually contains milk oligosaccharides along with the predominant lactose. Although milk oligosaccharides of a variety of Bovidae species including cow, sheep and goat have been characterized, those of the addax, an Antelopinae species of the Bovidae, have not as yet been clarified. In this study, several sialyl oligosaccharides were purified from a sample of addax colostrum and characterized as follows: Neu5Ac(α2‐8)Neu5Ac(α2‐3)Gal(β1‐4)Glc, Neu5Gc(α2‐8)Neu5Gc(α2‐3)Gal(β1‐4)Glc, Neu5Ac(α2‐3)Gal(β1‐4)Glc, Neu5Ac(α2‐6)Gal(β1‐4)GlcNAc, Neu5Gc(α2‐3)Gal(β1‐4)Glc, Neu5Gc(α2‐6)Gal(β1‐4)Glc, Neu5Gc(α2‐6)Gal(β1‐4)GlcNAc. In addition, an oligosaccharide nucleotide Neu5Gc(α2‐6)Gal(β1‐4)GlcNAcα1‐UDP was characterized. Molecular species of a variety of sialyl oligosaccharides found in milk and colostrum of these Bovidae were compared.     

涂膜苹果在贮藏期间钙信使组分的变化

海藻酸钠涂膜金冠苹果后,可减少腐烂,保持果实品质。涂膜抑制了果实成熟衰老过程中可溶性Ｃａ２＋的增加和Ｃａ２＋－ＡＴＰａｓｅ活性下降,推迟ＣａＭ峰值的出现,表明钙信使系统与苹果果实的衰老有关。     

化学合成寡糖诱导烟草抗黑胫病的初步研究

 抑菌测定和盆栽试验表明:化学合成的Lewis^x和Lewis^a寡糖对烟草黑胫病病原菌菌丝生长无明显影响;Lewis^x五糖和七糖处理烟草,可使烟草植株产生对黑胫病菌(Phytophthora nicotianae)的抗性,在处理浓度0~10μg/m L内,随着浓度增高诱导效果增强,当浓度达10 μg/m L时,诱导防病效果达90%以上。Lewisx七糖处理,可导致烟草叶片过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸裂解酶(PAL)等防卫酶活性不同程度地提高,PPO、POD及PAL分别在处理后第4d、第6d和第8d达到最大值,比对照分别增加了70.7%、150.0%和142.8%。     

培养条件对低聚木糖增殖青春双歧杆菌的影响

以低聚木糖为底物碳源，在严格厌氧培养条件下研究了pH值、还原剂和低聚木糖浓度等因素对该糖增殖青春双歧杆菌的影响。研究表明，在初始pH5.5-8.0的范围内低聚木糖均可增殖青春双歧杆菌，但pH8.0的微碱性培养效果更好。添加L－半胱氨酸和硫代乙醇酸钠还原剂可迅速降低培养液的初始氧化还原电位，有利于双歧杆菌的快速增殖，还原剂的初始浓度以0.5-1.0g/L为宜。人体持续摄入低聚木糖可保证其对双歧杆菌的增殖作用。在2.5-10g/L内，增加低聚木糖的初始浓度可提高双歧杆菌的菌体浓度和增殖速率，当糖浓为5.0g/L时青春双歧杆菌对该糖的利用效果最好。培养至18h，菌体浓度达1.03g/L，糖的转化率达42.2%。     

Prospective Alternatives of Antibiotics in Animal Diet

Antibiotics have been uded in animal feeding for long history.In recent years,much attention has been received for their negative effects on animal and human being as well.Technology has been focused on alternatives of antibotics,such as probiotics,oligosaccharides,acidifiers,Chinese herds,chemical drugs,and other environmental measures.Their mechanism,effects,relatd factors and their prospect in the future were discussed in this paper.     

Cloning and Characterization of a Novel Alginate Lyase from Paenibacillus sp. LJ-23

As a low molecular weight alginate, alginate oligosaccharides (AOS) exhibit improved water solubility, better bioavailability, and comprehensive health benefits. In addition, their biocompatibility, biodegradability, non-toxicity, non-immunogenicity, and gelling capability make them an excellent biomaterial with a dual curative effect when applied in a drug delivery system. In this paper, a novel alginate lyase, Algpt, was cloned and characterized from a marine bacterium, Paenibacillus sp. LJ-23. The purified enzyme was composed of 387 amino acid residues, and had a molecular weight of 42.8 kDa. The optimal pH of Algpt was 7.0 and the optimal temperature was 45 °C. The analysis of the conserved domain and the prediction of the three-dimensional structure indicated that Algpt was a novel alginate lyase. The dominant degradation products of Algpt on alginate were AOS dimer to octamer, depending on the incubation time, which demonstrated that Algpt degraded alginate in an endolytic manner. In addition, Algpt was a salt-independent and thermo-tolerant alginate lyase. Its high stability and wide adaptability endow Algpt with great application potential for the efficient preparation of AOS with different sizes and AOS-based products.     

影响香蕉人工种子再生因素研究

以香蕉巴西蕉品种吸芽为诱导材料,获得的诱导小芽作为香蕉人工种子的包埋的胚芽;研究不同浓度的海藻酸钠对香蕉人工种皮包埋材料的影响、不同的CaCI2溶液浸泡时间对种皮的影响及不同基质对人工种子再生的影响。结果表明：选择大小一致及活力旺盛的小芽为胚芽,制备的香蕉人工种子发芽率一致、发芽率高;海藻酸钠浓度为2.0%时,最合适作为香蕉人工种子的包埋材料;MS NAA1.0作为包埋营养液时,香蕉人工种子发芽率及生根率最高,达到99%以上;最适合香蕉人工种子的萌发基质是MS固体培养基。     

The Ameliorative Effect of COST on Diet-Induced Lipid Metabolism Disorders by Regulating Intestinal Microbiota

Background: Chitosan oligosaccharides, with an average molecular weight ≤ 1000 Da (COST), is a natural marine product that has the potential to improve intestinal microflora and resist lipid metabolism disorders. Methods: First, by establishing a mice model of lipid metabolism disorder induced by a high fat and high sugar diet, it is proven that COST can reduce lipid metabolism disorder, which may play a role in regulating intestinal microorganisms. Then, the key role of COST in the treatment of intestinal microorganisms is further confirmed through the method of COST-treated feces and fecal bacteria transplantation. Conclusions: intestinal microbiota plays a key role in COST inhibition of lipid metabolism disorder induced by a high fat and high sugar diet. In particular, COST may play a central regulatory role in microbiota, including Bacteroides, Akkermansia, and Desulfovibrio. Taken together, our work suggests that COST may improve the composition of gut microbes, increase the abundance of beneficial bacteria, improve lipid metabolism disorders, and inhibit the development of metabolic disorders.     

Structures,Properties and Applications of Alginates

Alginate is a hydrocolloid from algae, specifically brown algae, which is a group that includes many of the seaweeds, like kelps and an extracellular polymer of some bacteria. Sodium alginate is one of the best-known members of the hydrogel group. The hydrogel is a water-swollen and cross-linked polymeric network produced by the simple reaction of one or more monomers. It has a linear (unbranched) structure based on d-mannuronic and l-guluronic acids. The placement of these monomers depending on the source of its production is alternating, sequential and random. The same arrangement of monomers can affect the physical and chemical properties of this polysaccharide. This polyuronide has a wide range of applications in various industries including the food industry, medicine, tissue engineering, wastewater treatment, the pharmaceutical industry and fuel. It is generally recognized as safe when used in accordance with good manufacturing or feeding practice. This review discusses its application in addition to its structural, physical, and chemical properties.