微生态制剂及其在饲料工业中的应用

微生态制剂是一种通过改善动物消化道内菌群平衡的含有微生物活菌及其代谢产物和促生长物质的制剂。主要综述了微生态制剂的分类、特点、作用机理、研究应用现状及发展方向。     

现代生物技术与饲用微生态制剂

近年来,使用抗生素的副作用越来越多地受到关注,世界上许多国家已出台相应政策来控制抗生素的使用。但是由于养殖行业的迅猛发展,养殖密度加大,养殖动物病害发病的风险提高,急需可替代抗生素的新型绿色饲料添加剂产品。微生态制剂作为一种新型绿色饲料添加剂,在养殖行业发挥了重要作用。随着饲用微生态制剂产品研发的深入,现代生物技术在提升微生态制剂的理论和应用研究方面发挥着重要作用。PCR、核酸分子杂交、基因工程以及组学等技术已应用于微生物菌种鉴定、基因改良、作用机理等研究中。本文对饲用微生态制剂的研发现状进行了阐述,并综述了现代生物技术在饲用微生态制剂研究中的应用。     

动物肠道菌群的研究进展

肠道微生物是由存在于肠道部位的细菌、古菌、真菌、原生动物以及病毒所组成的群体。人们通过对细菌16SrRNA序列进行测序与分析,对动物及其在特定条件下的肠道菌群进行了相关方面的研究并取得了很大的进展。此外,由微生态原理发展而成的益生菌、益生元和合生元等微生态制剂,可维持机体肠道微生物的平衡、提高肠道屏障功能、增强机体免疫力。因此越来越多的微生态制剂应用于畜牧业、水产业中。论文综述了小鼠、犬、猪这三种动物的肠道菌群及其应用的研究进展,旨在为进一步深入了解动物肠道菌群的结构、功能以及促进微生态制剂的应用提供参考。     

微生态制剂的作用机制及其在动物生产中的应用

近年来,微生态制剂的开发与应用受到社会各界的普遍关注。微生态制剂是一类优质饲料添加剂,具有安全性高、无致病性、毒副作用小和生物功能齐全的特点,包括益生菌、益生元和合生元三类物质,其在维持肠道菌群平衡、促进免疫系统发育及提高机体抗氧化性能等方面具有显著作用,可改善生产性能和健康状况,有利于动物生产优质产品。详细论述了微生态制剂的种类和益生菌、益生元和合生元的作用机制以及国内外关于微生态制剂在动物生产中的应用现状和对喀斯特地区健康养殖的应用潜力,从而为微生态制剂的研究方向及生产应用提供参考。     

一种复合微生态制剂对养殖水体中生物因子的影响

[目的]研究海水养殖池塘中投放以芽孢杆菌和假单胞菌为主的一种自主研发的微生态制剂对池塘养殖生物、微生物菌相、浮游生物的影响,以期为建立微生物生态调控技术体系提供参考.[方法]实验期间,每隔15d于试验池塘中泼洒微生态制剂一次,每月末取样测量水体和底泥中异养菌和弧菌密度、浮游生物种类和密度,实验结束时测量养殖生物的生长率和成活率.[结果]该微生态制剂能够显著提高南美白对虾和三疣梭子蟹的存活率和生长速度,试验组南美白对虾的存活率和体重增长率较对照组分别提高了11.3％和1 400％,试验组三疣梭子蟹的存活率和体重增长率较对照组分别提高了1.2％和37.5％;微生态制剂能够显著提高海水池塘的异养菌总数,从而抑制致病性弧菌的数量,试验组池水和底泥的异养菌平均密度在整个养殖期较对照组提高了58.5％和51.3％,而试验组水体中致病菌——弧菌的数量在整个养殖期较对照组降低了39.7％;微生态制剂使绿藻门和硅藻门的藻类密度明显增加,对蓝藻和甲藻的生长有抑制作用.[结论]该微生态制剂能够有效地改善养殖池塘中生物群落结构,提高某些养殖品种的生长速度.     

防霉防菌技术信息摘要

? EM制剂的神奇作用EM制剂( Effective Microorganisms,有效微生物菌群)产品是上世纪80年代从美国和日本等国发展起来的。那时美国并不叫EM制剂,而是叫芽孢杆菌制剂,因为该制剂主要是由三种芽孢杆菌(即枯草芽孢杆菌、地衣芽孢杆菌、蜡状芽孢杆菌)组合培养而成。其用途主要作为鱼类养殖清塘剂和农作物栽培促进剂。随着应用面的扩大和应用对象的不同要求,日本和美国等学者在此基础上又增加了乳酸杆菌、光合细菌、放线菌、酵母菌等微生物,便称之谓EM菌。后来又有学者增加了硝化细菌、霉菌等微生物。据报道,目前的菌种已发展到10个属的80多种菌种。我国从上世纪90年代引入该产品后,叫做微生态制剂,更有人叫它益生菌或菌肥。作者认为,更确切的名称,应该叫EM制剂,因为它是由一群有效微生物经增殖培养后组合起来的“集团菌”。     

复合微生态制剂对水产养殖水体净化作用的研究

目的：考察了复合微生态制剂对水产养殖水体的净化作用。方法：将实验室研制的复合微生态制剂MCB以不同的投放量加入各实验养殖池塘中,根据各池中溶氧、氨氮、亚硝酸盐、硫化物含量随时间的变化情况与空白对照池比较。结果：施放复合微生态制剂的各实验池均比未加复合微生态制剂的对照池溶氧含量明显增加,氨氮、亚硝酸盐、硫化物的含量明显降低;复合微生态制剂MCB的投放周期为10d左右,最佳投放量为9mg／L。结论：每10d左右,施放9mg／L的复合微生态制剂MCB,可对水产养殖水体起到较好的净化作用。     

动物微生态制剂研究应用进展

动物微生态制剂是在动物微生态理论指导下,采用已知有益的微生物所制成的生物制品或活菌制剂。综述了动物微生态制剂的产生起源、益生菌和微生态制剂的概念、微生态制剂所用菌株、作用机制、国内外应用现状及发展前景。     

微生态制剂的作用机制和临床应用

人体微生态系统对维持机体健康状态、预防和治疗疾病方面具有极其重要的作用。近的睐,临床上抗生素和免疫抑制剂的大量使用,造成微生态系统失衡从而引起疾病发生的病例越来越多。调节机体正常菌群平衡的微生态制剂开始受到广泛的关注和重视。1991年Fuller将微生态制剂定义为促进肠道菌群平衡的活的细菌性食品添加剂。目前常被用作微生态制剂的菌种有以下几种：双歧杆菌属、乳酸杆菌属、肠球菌亚种、类细菌亚种、杆菌亚种和链球菌亚种等。本文仅就微生态制剂的作用机制和临床应用方面的研究近况作一介绍。     

微生态制剂在肠内营养治疗的研究进展与应用

临床营养支持是以治疗或缓解疾病、增强治疗效果为目的,根据营养学原理采取的营养措施,主要可以分为肠外营养( Parenteral Nutrition,PN)和肠内营养(Enteral Nutrition,EN).今年来,随着医学研究与认识的加深,肠道的重要性越来越被人们所认识到.美国WILMORE曾提出肠道是外科应激反应的"中心脏器"学说[1].因此与肠外营养相比,肠内营养显得越发重要.人体肠道是一个巨大而复杂的微生态系统,其各种菌群之间的平衡对于人体的健康和疾病恢复有着重要的意义.微生态制剂( Microecologics)又称为微生态调节剂(Microecological).是根据微生态学基本原理,利用人体正常菌群成员或对其有促进作用的其他微生物等物质制成的生物制品.它具有调整微生态失调、恢复微生态平衡、促进宿主健康的作用.因此将微生态制剂应用于肠内营养有着明显的优势,同时也是目前临床营养支持的发展趋势.     

Microbial diversity and potential pathogens in ornamental fish aquarium water

Ornamental fishes are among the most popular and fastest growing categories of pets in the United States (U.S.). The global scope and scale of the ornamental fish trade and growing popularity of pet fish in the U.S. are strong indicators of the myriad economic and social benefits the pet industry provides. Relatively little is known about the microbial communities associated with these ornamental fishes or the aquarium water in which they are transported and housed. Using conventional molecular approaches and next generation high-throughput amplicon sequencing of 16S ribosomal RNA gene hypervariable regions, we characterized the bacterial community of aquarium water containing common goldfish (Carassius auratus) and Chinese algae eaters (Gyrinocheilus aymonieri) purchased from seven pet/aquarium shops in Rhode Island and identified the presence of potential pathogens. Our survey identified a total of 30 phyla, the most common being Proteobacteria (52%), Bacteroidetes (18%) and Planctomycetes (6%), with the top four phyla representing >80% of all sequences. Sequences from our water samples were most closely related to eleven bacterial species that have the potential to cause disease in fishes, humans and other species: Coxiella burnetii, Flavobacterium columnare, Legionella birminghamensis, L. pneumophila, Vibrio cholerae, V. mimicus. V. vulnificus, Aeromonas schubertii, A. veronii, A. hydrophila and Plesiomonas shigelloides. Our results, combined with evidence from the literature, suggest aquarium tank water harboring ornamental fish are an understudied source for novel microbial communities and pathogens that pose potential risks to the pet industry, fishes in trade, humans and other species.     

高矿浆浓度下黄铜矿浸出过程中微生物群落结构变化规律

目的：为阐明微生物群落演替及功能与浸出效率之间关系奠定基础,以及如何提高黄铜矿生物浸出效率和铜回收率提供理 论依据。方法：通过连续传代培养进行驯化,使得复合菌群的矿浆浓度耐受能力达到25 %（w/v）。采用该复合菌群在25 %矿浆浓 度下浸出黄铜矿,同时利用变性梯度凝胶电泳和克隆文库技术分析浸出过程中的微生物多样性。最后,采用实时荧光定量PCR 对 浸出过程中微生物群落结构进行定量解析。结果：28天内黄铜矿浸出率能够达到95.1 %,而驯化前的浸出率只有51.5%。该复合 菌群主要由Acidithiobacillus caldus, Sulfobacillus acidophilus,和Fereoplasma theroplasma thermophilum组成,其中Acidithbacillus caldus是浸出前期和后期的优势种群,而Sulfobacillus acidophilus在浸出中期均有竞争优势, Ferroplasma thermophilum在整个浸出过程中占 据整个群落的比例均较低。结论：本研究获得的复合菌群具有较强的浸出黄铜矿能力, Acidithiobacillus caldus和Sulfobacillus acidophilus在浸出过程中起着重要的作用,pH 值和铜浸出率与群落结构相关性较高。     

Microbial symbionts are shared between ants and their associated beetles

The transmission of microbial symbionts across animal species could strongly affect their biology and evolution, but our understanding of transmission patterns and dynamics is limited. Army ants (Formicidae: Dorylinae) and their hundreds of closely associated insect guest species (myrmecophiles) can provide unique insights into interspecific microbial symbiont sharing. Here, we compared the microbiota of workers and larvae of the army ant Eciton burchellii with those of 13 myrmecophile beetle species using 16S rRNA amplicon sequencing. We found that the previously characterized specialized bacterial symbionts of army ant workers were largely absent from ant larvae and myrmecophiles, whose microbial communities were usually dominated by Rickettsia, Wolbachia, Rickettsiella and/or Weissella. Strikingly, different species of myrmecophiles and ant larvae often shared identical 16S rRNA genotypes of these common bacteria. Protein-coding gene sequences confirmed the close relationship of Weissella strains colonizing army ant larvae, some workers and several myrmecophile species. Unexpectedly, these strains were also similar to strains infecting dissimilar animals inhabiting very different habitats: trout and whales. Together, our data show that closely interacting species can share much of their microbiota, and some versatile microbial species can inhabit and possibly transmit across a diverse range of hosts and environments.     

微生物消毒剂抗性机理

在物体表面和传播介质中,消毒剂能有效抑制或杀死微生物,广泛用于食品、卫生、健康、防疫等领域.在新型冠状病毒肺炎(COVID-19)疫情期间,全球消毒剂的使用量激增,对有效防控病毒传播和防止疫情扩散起到重要作用.但消毒剂的不正确使用会降低其有效性,甚至会诱导微生物产生抗性,从而增加传染性疾病的传播风险.微生物的消毒剂抗性...     

Microbial assimilation of new photosynthate is altered by plant species richness and nitrogen deposition

To determine how plant species richness impacts microbial assimilation of new photosynthate, and how this may be modified by atmospheric N deposition, we analyzed the microbial assimilation of recent photosynthate in a 6-year-long field experiment in which plant species richness, atmospheric N deposition, and atmospheric CO₂ concentration were manipulated in concert. The depleted δ¹³C of fumigation CO₂ enabled us to investigate the effect of plant species richness and atmospheric N deposition on the metabolism of soil microbial communities in the elevated CO₂ treatment. To accomplish this, we determined the δ¹³C of bacterial, actinobacterial, and fungal phospholipid fatty acids (PLFAs). In the elevated CO₂ conditions of this study, the δ¹³C of bacterial PLFAs (i15:0, i16:0, 16:1ω7c, 16:1ω9c, 10Me16:0, and 10Me18:0) and the fungal PLFA 18:1ω9c was significantly lower in species-rich plant communities than in species-poor plant communities, indicating that microbial incorporation of new C increased with plant species richness. Despite an increase in plant production, total PLFA decreased under N deposition. Moreover, N deposition also decreased fungal relative abundance in species-rich plant communities. In our study, plant species richness directly increased microbial incorporation of new photosynthate, providing a mechanistic link between greater plant detritus production in species-rich plant communities and larger and more active soil microbial community.     

Microbial community analysis in incompletely or destructively sampled systems

Analyses of microbial community dynamics are often constrained by the destructive, indirect, and incomplete nature of most sampling techniques. These methodological constraints compel assumptions that are rarely verified about the relationships among separate communities. We evaluated the consequences for community analysis of the common assumption that separate microbial communities are described by the same species abundance distribution. Sample data were generated from simulated communities in which the species abundance distributions were the same or were different. Samples from communities that had the same number of species or were described by the same species abundance distribution sometimes had significantly different numbers of species. Samples from simulated communities that had different species number-species abundance distribution combinations sometimes contained indistinguishable numbers of species. When sampling from independent communities described by unknown distributions (e.g., microbial communities on plant surfaces), the simulations showed that standardization of sample size (number of individuals or colony-forming units) does not guarantee samples of equal proportions of the total species in a community. Sample sizes that are logistically feasible for many microbial systems will provide only limited information for differentiating species numbers or species abundance distributions among separate communities over time. For ecologists studying destructively or incompletely sampled communities this seriously influences both the sample designs that are reasonable and the questions that can be addressed in such systems. Send offprint requests to: L. Kinkel.     

Microbial ecosystems in compost and granular activated carbon biofilters

Compost and granular activated carbon biofilters operated at a wastewater treatment plant simultaneously removed low concentrations of hydrogen sulfide and volatile organic compounds. Through the use of phospholipid fatty acid analyses, the effects of declining pH caused by sulfide oxidation were established for microbial growth, microorganism stress, and microbial community structure. Microorganisms on both media demonstrated increases in microbial densities, varying degrees of environmental stress, and domination by gram-negative bacteria. However, the declining pH had little effect on compound removal, which was greater than 99% for the hydrogen sulfide and greater than 70% for the oxygenated and aromatic hydrocarbons. The microbial communities adjusted to difficult environmental conditions through acclimation of the species present or by growth of low-pH-tolerant species. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 296-303, 1997.     

Molecular Microbial Diversity Survey of Sponge Reproductive Stages and Mechanistic Insights into Vertical Transmission of Microbial Symbionts

Many marine sponges, hereafter termed high-microbial-abundance (HMA) sponges, harbor large and complex microbial consortia, including bacteria and archaea, within their mesohyl matrices. To investigate vertical microbial transmission as a strategy to maintain these complex associations, an extensive phylogenetic analysis was carried out with the 16S rRNA gene sequences of reproductive (n = 136) and adult (n = 88) material from five different Caribbean species, as well as all published 16S rRNA gene sequences from sponge offspring (n = 116). The overall microbial diversity, including members of at least 13 bacterial phyla and one archaeal phylum, in sponge reproductive stages is high. In total, 28 vertical-transmission clusters, defined as clusters of phylotypes that are found both in adult sponges and their offspring, were identified. They are distributed among at least 10 bacterial phyla and one archaeal phylum, demonstrating that the complex adult microbial community is collectively transmitted through reproductive stages. Indications of host-species specificity and cospeciation were not observed. Mechanistic insights were provided using a combined electron microscopy and fluorescence in situ hybridization analysis, and an indirect mechanism of vertical transmission via nurse cells is proposed for the oviparous sponge Ectyoplasia ferox. Based on these phylogenetic and mechanistic results, we suggest the following symbiont transmission model: entire microbial consortia are vertically transmitted in sponges. While vertical transmission is clearly present, additional environmental transfer between adult individuals of the same and even different species might obscure possible signals of cospeciation. We propose that associations of HMA sponges with highly sponge-specific microbial communities are maintained by this combination of vertical and horizontal symbiont transmission.     

Deep Sequencing Reveals Highly Variable Gut Microbial Composition of Invasive Fish Mossambicus Tilapia (<Emphasis Type="Italic">Oreochromis mossambicus</Emphasis>) Collected from Two Different Habitats

Tilapia ( Oreochromis mossambicus ) is one of the most invasive fish found throughout the World and emerged as a major threat to the indigenous fishes in many countries. Investigating the gut microbial diversity of such fishes is one of the ways to understand its physiology. In the present study, we have explored the gut microbial community structure of tilapia using 16S rRNA gene sequencing on the Illumina Miseq platform. Our study showed significant differences in tilapia gut microbiota collected from different habitats (i.e. river and lakes) suggesting the influence of habitat on the gut microbial diversity of tilapia. This study gives a first insight into the mossambicus tilapia gut microbiota and provides a reference for future studies.     

综述与专论：微生物消毒剂抗性机理

在物体表面和传播介质中,消毒剂能有效抑制或杀死微生物,广泛用于食品、卫生、健康、防疫等领域。在新型冠状病毒肺炎(COVID-19)疫情期间,全球消毒剂的使用量激增,对有效防控病毒传播和防止疫情扩散起到重要作用。但消毒剂的不正确使用会降低其有效性,甚至会诱导微生物产生抗性,从而增加传染性疾病的传播风险。微生物的消毒剂抗性基因还会通过繁殖传代增殖或在不同种属间水平转移而加剧其污染和传播风险,严重威胁到公共卫生安全。目前,抗生素抗性基因(ARG)的广泛出现引起了全球对公共卫生的关注,但对消毒剂的抗性认识非常有限。本文综述了近年来微生物对消毒剂抗性的研究,着重就微生物通过形成生物膜、降低细胞膜通透性、过量表达外排泵、产生消除或减弱消毒剂的特异性酶、改变作用靶点等方式产生抗性的机理进行综述。另外针对微生物消毒剂抗性的获得和传播,对染色体和质粒介导的抗性基因、环境中微生物消毒剂抗性与抗生素抗性的关联进行了论述。消毒剂抗性基因能通过质粒、噬菌体等可移动遗传元件,以转化、转导或接合的方式转移传播,对科学消毒提出新要求。