Fishery Wastes as a Yet Undiscovered Treasure from the Sea: Biomolecules Sources,Extraction Methods and Valorization

The search for new biological sources of commercial value is a major goal for the sustainable management of natural resources. The huge amount of fishery by-catch or processing by-products continuously produced needs to be managed to avoid environmental problems and keep resource sustainability. Fishery by-products can represent an interesting source of high added value bioactive compounds, such as proteins, carbohydrates, collagen, polyunsaturated fatty acids, chitin, polyphenolic constituents, carotenoids, vitamins, alkaloids, tocopherols, tocotrienols, toxins; nevertheless, their biotechnological potential is still largely underutilized. Depending on their structural and functional characteristics, marine-derived biomolecules can find several applications in food industry, agriculture, biotechnological (chemical, industrial or environmental) fields. Fish internal organs are a rich and underexplored source of bioactive compounds; the fish gut microbiota biosynthesizes essential or short-chain fatty acids, vitamins, minerals or enzymes and is also a source of probiotic candidates, in turn producing bioactive compounds with antibiotic and biosurfactant/bioemulsifier activities. Chemical, enzymatic and/or microbial processing of fishery by-catch or processing by-products allows the production of different valuable bioactive compounds; to date, however, the lack of cost-effective extraction strategies so far has prevented their exploitation on a large scale. Standardization and optimization of extraction procedures are urgently required, as processing conditions can affect the qualitative and quantitative properties of these biomolecules. Valorization routes for such raw materials can provide a great additional value for companies involved in the field of bioprospecting. The present review aims at collecting current knowledge on fishery by-catch or by-products, exploring the valorization of their active biomolecules, in application of the circular economy paradigm applied to the fishery field. It will address specific issues from a biorefinery perspective: (i) fish tissues and organs as potential sources of metabolites, antibiotics and probiotics; (ii) screening for bioactive compounds; (iii) extraction processes and innovative technologies for purification and chemical characterization; (iv) energy production technologies for the exhausted biomass. We provide a general perspective on the techno-economic feasibility and the environmental footprint of the production process, as well as on the definition of legal constraints for the new products production and commercial use.     

益生菌在反刍动物生产中应用的研究进展

益生菌可以作为一种绿色添加剂应用于反刍动物饲料中,逐渐替代抗生素、激素、农用化学物质。大量研究表明,其一有益微生物菌剂可以调节动物体肠道内正常的微生物关系,并提高动物体的代谢水平和其对营养物质的利用率;其二有益微生物菌剂能够增强机体的免疫功能,进而提高机体的免疫和抗病能力;其三有益微生物菌剂可以起到减少污染和净化环境的作用。研究主要针对有益微生物的主要功能和其作用机理,以及近年来其在反刍动物营养和饲料中的应用研究进展进行综述。     

水稻—毛豆—草莓高效复合种植模式

为了确保草莓的高产、优质、高效种植,同时缓解近年来因生产规模急剧扩增导致的连作重茬问题,高邮市农委开展了水稻—毛豆—草莓高效复合种植模式的研究。采取水旱轮作方式防控连作障碍;利用毛豆根系的固氮功能以地养地,使水稻、草莓2季种植自然顺利地衔接起来;三者轮作还有效均衡地利用了土壤养分,减轻了土传病害的发生,对水生与旱生杂草均有明显抑制作用;使土地利用率得以提高,水稻、草莓的产量和品质明显提升,更增加了土壤有机质,实现了粮经菜安全生产供应。     

益生菌微胶囊化对仔猪生长性能及免疫功能的影响

目前,利用微胶囊包埋保护益生菌已成为研究热点。本试验采用挤压法,选择不同种类的壁材进行复配,通过对益生菌的微胶囊化,来保护其免受外界不利环境影响。结果表明:制备益生菌微胶囊的最佳工艺为海藻酸钠3%,明胶0.2%,氯化钙2%,搅拌速度800 r/min。将益生菌微胶囊添加到日粮中可以提高仔猪生产性能和免疫力,并且添加量为0.3%时效果最好。     

一起莲藕施用劣质复合肥经济纠纷农业司法鉴定案例分析

通过书面证据审查、现场勘验和实验室测定等方法,认定涉诉莲藕经济损失是多种原因所致,其中原告施肥技术不当为主要原因,施用劣质复合肥为次要因素。鉴定组估算了涉诉劣质复合肥对莲藕经济损失的影响效应。法院经质证审查采信了鉴定意见,为法院公正审理案件提供了法定证据和科学的司法证明。     

实践型·复合型食品学科研究生的培养模式探讨

为培养迎合食品学科发展与食品行业所需的实践型、复合型研究生,就现阶段食品专业研究生培养在课程体系、教学模式、考核评定体系、实验室管理、联合培养等方面面临的问题进行了探讨,并提出相应的解决方案,旨在为我国食品专业研究生培养提供相应的依据。     

Effect of drying on the viability of the probiotic bacterium Lactobacillus plantarum Lab9 (CPQBA 144‐09 DRM 03) impregnated in the feed for tilapia (Oreochromis sp.)

Drying experiments were conducted at different temperatures and air flux velocities to determine the proper drying conditions for reducing moisture in commercial fish feed impregnated with probiotic lactic acid bacteria and to assess the effect on bacteria viability over time. At temperatures of 45°C, the drying time was shorter, without the air flux velocity under study having a relevant influence. The drying conditions influenced the viability of the bacteria in the feed; the least loss of viability was obtained with a velocity of 0.8 m s^?1 and a temperature of 45°C during 15 min. Using these drying conditions, 5 kg of feed was dried and stored for a month at temperature of 26°C and relative humidity of 75%. The viability of the bacteria and the moisture of the feed were measured every 3 days during the storage period. Loss of viability followed first order kinetics, with a constant k of 0.112 days^?1. Thus, the viability of the bacteria in the feed is less than 10⁶ CFU g^?1 after 43 days.     

益生菌在家禽饲料中应用的研究进展

益生菌主要通过提高饲料营养的消化利用、提高动物免疫调节能力为宿主动物胃肠道(GIT)健康提供益生作用。益生菌通过提高肠绒毛高度、改善黏膜结构来帮助营养成分的消化吸收、增强上皮细胞紧密连接的调节功能、防御病原菌、维持细胞稳态。益生菌对于热应激引起的环境挑战,也有很好的调节功能。     

微生态制剂在提高畜禽免疫力中的作用机制

作为一种替代抗生素的新型绿色添加剂,微生态制剂在畜禽养殖中主要用于维持畜禽健康、促进动物生长、提高饲料利用率。文章从调控动物胃肠道内微生物菌群、刺激动物免疫器官发育、分泌代谢产物激活动物自身免疫反应、改善养殖场环境进而改善动物健康状况等方面对现有的微生态制剂免疫机制进行综述。     

絮凝剂复配处理经格栅沉淀后猪场污水的研究

为了寻找絮凝剂对猪场污水絮凝效果的最佳复配方案,以经格栅沉淀后的猪场污水为对象,分别比较阳离子聚丙烯酰胺(C-PAM)、阴离子聚丙烯酰胺(A-PAM)、氯化铝、氯化铁、聚合硫酸铁(PFS)等5种絮凝剂的絮凝效果。选用其中效果较好的聚合硫酸铁与阳离子聚丙烯酰胺进行复配,通过复合絮凝试验得到最佳配比,PFS投加量1.6 g/L、C-PAM投加量0.6 mg/L,并按先PFS后C-PAM的顺序投加,对猪场污水悬浮物(SS)和浊度去除率分别为96.8%和99.2%。