微生态制剂在水产养殖中的应用

随着健康养殖发展的需求,微生态制剂在水产动物中的应用逐渐成为当今的研究热点。有益菌在提高人和动物营养和防病方面的作用已得到证实。关于高等动植物的生物防治理论也应用于水产养殖中,微生态制剂的应用作为抗生素的替代品逐渐成为水产养殖动物病害防治的一种生物控制模式。本文简要介绍了微生态制剂概念的形成和发展过程,分别在营养特性、免疫特性和改善养殖生态环境三个方面阐述了其在水产养殖中的应用。虽然,微生态制剂在水产中的应用取得了一定的成效,但是仍然处于发展的初级阶段,有待进一步的研究。文章还阐明了微生态制剂的生产工艺和施用原则,最后就微生态制剂的应用问题提出了作者自己的观点和展望。     

Interacting Symbionts and Immunity in the Amphibian Skin Mucosome Predict Disease Risk and Probiotic Effectiveness

Pathogenesis is strongly dependent on microbial context, but development of probiotic therapies has neglected the impact of ecological interactions. Dynamics among microbial communities, host immune responses, and environmental conditions may alter the effect of probiotics in human and veterinary medicine, agriculture and aquaculture, and the proposed treatment of emerging wildlife and zoonotic diseases such as those occurring on amphibians or vectored by mosquitoes. Here we use a holistic measure of amphibian mucosal defenses to test the effects of probiotic treatments and to assess disease risk under different ecological contexts. We developed a non-invasive assay for antifungal function of the skin mucosal ecosystem (mucosome function) integrating host immune factors and the microbial community as an alternative to pathogen exposure experiments. From approximately 8500 amphibians sampled across Europe, we compared field infection prevalence with mucosome function against the emerging fungal pathogen Batrachochytrium dendrobatidis. Four species were tested with laboratory exposure experiments, and a highly susceptible species, Alytes obstetricans, was treated with a variety of temperature and microbial conditions to test the effects of probiotic therapies and environmental conditions on mucosome function. We found that antifungal function of the amphibian skin mucosome predicts the prevalence of infection with the fungal pathogen in natural populations, and is linked to survival in laboratory exposure experiments. When altered by probiotic therapy, the mucosome increased antifungal capacity, while previous exposure to the pathogen was suppressive. In culture, antifungal properties of probiotics depended strongly on immunological and environmental context including temperature, competition, and pathogen presence. Functional changes in microbiota with shifts in temperature provide an alternative mechanistic explanation for patterns of disease susceptibility related to climate beyond direct impact on host or pathogen. This nonlethal management tool can be used to optimize and quickly assess the relative benefits of probiotic therapies under different climatic, microbial, or host conditions.     

Probiotics in aquaculture: importance and future perspectives

Aquaculture is one of the fastest developing growth sectors in the world and Asia presently contributes about 90% to the global production. However, disease outbreaks are constraint to aquaculture production thereby affects both economic development of the country and socio-economic status of the local people in many countries of Asia-Pacifi c region. Disease control in aquaculture industry has been achieved by following different methods using traditional ways, synthetic chemicals and antibiotics. However, the use of such expensive chemotherapeutants for controlling diseases has been widely criticized for their negative impacts like accumulation of residues, development of drug resistance, immunosuppressants and reduced consumer preference for aqua products treated with antibiotics and traditional methods are ineffective against controlling new diseases in large aquaculture systems. Therefore, alternative methods need to be developed to maintain a healthy microbial environment in the aquaculture systems there by to maintain the health of the cultured organisms. Use of probiotics is one of such method that is gaining importance in controlling potential pathogens. This review provides a summary of the criteria for the selection of the potential probiotics, their importance and future perspectives in aquaculture industry.     

The use of probiotics in aquaculture

This study aims to present comprehensive notes for the use of probiotics in aquaculture. Probiotics have been proven to be positive promoters of aquatic animal growth, survival and health. In aquaculture, intestines, gills, the skin mucus of aquatic animals, and habitats or even culture collections and commercial products, can be sources for acquiring appropriate probiotics, which have been identified as bacteria (Gram‐positive and Gram‐negative) and nonbacteria (bacteriophages, microalgae and yeasts). While a bacterium is a pathogen to one aquatic animal, it can bring benefits to another fish species; a screening process plays a significant role in making a probiotic species specific. The administration of probiotics varies from oral/water routine to feed additives, of which the latter is commonly used in aquaculture. Probiotic applications can be either mono or multiple strains, or even in combination with prebiotic, immunostimulants such as synbiotics and synbiotism, and in live or dead forms. Encapsulating probiotics with live feed is a suitable approach to convey probiotics to aquatic animals. Dosage and duration of time are significant factors in providing desired results. Several modes of actions of probiotics are presented, while some others are not fully understood. Suggestions for further studies on the effects of probiotics in aquaculture are proposed.     

Rhizosphere pseudomonads as probiotics improving plant health

Many root‐colonizing microbes are multifaceted in traits that improve plant health. Although isolates designated as biological control agents directly reduce pathogen growth, many exert additional beneficial features that parallel changes induced in animal and other hosts by health‐promoting microbes termed probiotics. Both animal and plant probiotics cause direct antagonism of pathogens and induce systemic immunity in the host to pathogens and other stresses. They also alter host development and improve host nutrition. The probiotic root‐colonizing pseudomonads are generalists in terms of plant hosts, soil habitats and the array of stress responses that are ameliorated in the plant. This article illustrates how the probiotic pseudomonads, nurtured by the carbon (C) and nitrogen (N) sources released by the plant in root exudates, form protective biofilms on the root surface and produce the metabolites or enzymes to boost plant health. The findings reveal the multifunctional nature of many of the microbial metabolites in the plant–probiotic interplay. The beneficial effects of probiotics on plant function can contribute to sustainable yield and quality in agricultural production.     

水产养殖饲用微生态制剂研究进展

微生态制剂作为新型饲料添加剂,能够有效调节水产动物营养保健和微生态平衡,减少抗生素使用,是理想的抗生素替代品,对保障高效种养殖、食品安全及环境可持续发展意义重大。我国饲用微生态制剂应用起步较晚且发展较慢,仍面临着难点和挑战。本文介绍了微生态制剂及饲用益生菌在鱼、虾及海参养殖中的应用,基于优良益生菌选育、培养条件优化及混合菌株发酵与制剂应用等生物技术研究现状,总结了近年来水产养殖饲用微生态制剂的研究进展,并对未来微生态制剂研究重点和发展前景进行了展望。     

Evaluation of the probiotics Bacillus subtilis and Lactobacillus plantarum bioencapsulated in Artemia nauplii against vibriosis in European sea bass larvae (Dicentrarchus labrax, L.)

Two potential probiotics Bacillus subtilis and Lactobacillus plantarum were evaluated for use in aquaculture as preventive measures against vibriosis. In vitro evaluation of the probiotics using co-culture assays with the pathogen Vibrio anguillarum and testing for the production of antibacterial substances showed the presence of antagonism and confirmed the production of antibacterial substances. Both potential probiotics were administered to the live fish feed Artemia franciscana nauplii, offering protection against a subsequent challenge of the nauplii with the fish pathogen V. anguillarum, with best survival rates of the nauplii and the most efficient protection offered by B. subtilis. Nauplii enriched with B. subtilis were further used to evaluate the protection of sea bass larvae against vibriosis. The untreated group of fish challenged with V. anguillarum presented low survival of 36.7 %, while the fish treated with nauplii enriched with the probiotic B. subtilis showed significantly increased survival rates of 86.7 % after challenge with the pathogen. The survival of healthy unchallenged fish treated with the probiotic was not significantly different from control unchallenged fish (90-94 %). Our results indicate that B. subtilis is a probiotic suitable to be used for the prevention of vibriosis in fish larvae and can be safely administered through their live feed Artemia nauplii.     

Modulation of the microbial ecology of the human colon by probiotics, prebiotics and synbiotics to enhance human health: an overview of enabling science and potential applications

The application of probiotics and prebiotics to the manipulation of the microbial ecology of the human colon has recently seen many scientific advances. The sequencing of probiotic genomes is providing a wealth of new information on the biology of these microorganisms. In addition, we are learning more about the interactions of probiotics with human cells and with pathogenic bacteria. An alternative means of modulating the colonic microbial community is by the use of prebiotic oligosaccharides. Increasing knowledge of the metabolism of prebiotics by probiotics is allowing us to consider specifically targeting such dietary intervention tools at specific population groups and specific disease states.     

益生菌的应用现状和发展前景

益生菌是一类严格选择的，如果给予足够的量，能够为宿主带来健康益处的活性微生物。常见的具有益生功能的微生物，包括传统益生菌乳酸菌(lactic acid bacteria)和酵母菌(Saccharomyces)等，以及下一代益生菌普拉梭菌(Faecalibacterium prausnitzii)、脆弱拟杆菌(Bacteroides fragilis)、嗜黏蛋白阿克曼菌(Akkermansia muciniphila)和普雷沃氏菌(Prevotella copri)等。益生菌与人体健康之间存在密切的关系，这些微生物可通过肠道刺激胃肠道反应或直接作用于口腔、阴道、皮肤等其他部位以调节宿主健康。因此，它们在食品、种植业、畜牧业以及医疗领域中得到广泛应用，成为改善宿主健康的有力工具。本文对乳酸菌等传统益生菌以及嗜黏蛋白阿克曼菌等下一代益生菌的功能的开发与应用进行了综述，总结了这几种益生菌在食品生产、疾病治疗以及农业生产等方面的应用潜力，展望了益生菌资源研究与应用的发展趋势，以期为研究新老益生菌功能的开发与应用提供参考。     

In vitro growth characteristics of five candidate aquaculture probiotics and two fish pathogens grown in fish intestinal mucus

The selection of probiotics for aquaculture is usually based on their antagonism towards pathogens. However, other criteria such as growth, attachment to intestinal mucus and production of beneficial compounds should also be considered. We suggest a protocol for the isolation and selection of potential probiotic bacteria based on their in vitro growth characteristics and propose a ranking index (RI) to screen potential aquaculture probionts. We suggest that the lag period and doubling time are the most important criteria for the comparison of growth curves, hence the RI is based on the doubling time (t(d)) and lag period (lambda) obtained from the growth profile of each bacterium. Bacteria were isolated from the gut of the common clownfish, Amphiprion percula, and screened for antagonistic activity towards seven aquatic pathogens. All five candidate probiotics showed antagonism to various aquatic pathogens. When grown in intestinal fish mucus no probiotic had a RI higher than the two tested pathogens (Aeromonas hydrophila and Vibrio alginolyticus). However, candidate probiont AP1 had a faster specific growth rate (micro) (0.05) than the pathogens (0.049 and 0.047 respectively), while AP5 grown in marine broth had a shorter lag period than the pathogens. Strategies to increase probiotic concentration include the inoculation of high concentrations and the preconditioning of these bacteria to reduce the lag period. It should be tested whether or not such strategies will allow the probiotic bacteria to dominate initially and thereby gain a competitive advantage. This could become an important aspect under in vivo conditions where both attachment and nutrient supply differ from that found in in vitro studies.     

Fermented functional foods based on probiotics and their biogenic metabolites

The claimed health benefits of fermented functional foods are expressed either directly through the interaction of ingested live microorganisms, bacteria or yeast with the host (probiotic effect) or indirectly as a result of ingestion of microbial metabolites produced during the fermentation process (biogenic effect). Although still far from fully understood, several probiotic mechanisms of action have been proposed, including competitive exclusion, competition for nutrients and/or stimulation of an immune response. The biogenic properties of fermented functional foods result from the microbial production of bioactive metabolites such as certain vitamins, bioactive peptides, organic acids or fatty acids during fermentation.     

Functional petit-suisse cheese: measure of the prebiotic effect

Prebiotics and probiotics are increasingly being used to produce potentially synbiotic foods, particularly through dairy products as vehicles. It is well known that both ingredients may offer benefits to improve the host health. This research aimed to evaluate the prebiotic potential of novel petit-suisse cheeses using an in vitro fermentation model. Five petit-suisse cheese formulations combining candidate prebiotics (inulin, oligofructose, honey) and probiotics (Lactobacillus acidophilus, Bifidobacterium lactis) were tested in vitro using sterile, stirred, batch culture fermentations with human faecal slurry. Measurement of prebiotic effect (MPE) values were generated comparing bacterial changes through determination of maximum growth rates of groups, rate of substrate assimilation and production of lactate and short chain fatty acids. Fastest fermentation and high lactic acid production, promoting increased growth rates of bifidobacteria and lactobacilli, were achieved with addition of prebiotics to a probiotic cheese (made using starter+probiotics). Addition of probiotic strains to control cheese (made using just a starter culture) also resulted in high lactic acid production. Highest MPE values were obtained with addition of prebiotics to a probiotic cheese, followed by addition of prebiotics and/or probiotics to a control cheese. Under the in vitro conditions used, cheese made with the combination of different prebiotics and probiotics resulted in the most promising functional petit-suisse cheese. The study allowed comparison of potentially functional petit-suisse cheeses and screening of preferred synbiotic potential for future market use.     

Effects of probiotics on growth,survival, and intestinal and liver morphometry of Gangetic mystus (Mystus cavasius)

The usage of probiotics proved advantageous in aquaculture due to its positive impact on fish growth, immune response and environment. This study was aimed to assess the effects of probiotics on growth, survival and histometry of intestine and liver in Gangetic mystus (Mystus cavasius) using two separate experiments for a period of 8 weeks (in aquaria) and 16 weeks (in earthen ponds). Three different probiotic treatments were incorporated i.e. commercial probiotic one; CP-1 (T1), commercial probiotic two; CP-2 (T2), Lab developed (Lab dev.) probiotic (T3) including a control. The results indicated that the probiotics usage especially Lab dev. probiotic (T3) significantly improved the growth parameters such as weight gain (g) and specific growth rate (SGR, %/day) as well as ensured better feed conversion efficiency. Zero mortality was observed in aquaria whereas probiotic application enhanced survivability in earthen ponds. Moreover, all probiotic treatment exhibited positive results for different histo-morphometric features of intestine and liver. Mucus secreting goblet cells and fattening of mucosal fold increased significantly with probiotic usage. The amount of regular shaped nucleus was maximum in T3 with least intra cellular distance between liver tissues in earthen ponds. The greatest value for hemoglobin with lowest glucose level was observed in T3 as well. Furthermore, probiotic ensured low concentration of ammonia during culture. Overall, it was anticipated that the application of probiotics in Gangetic mystus culture resulted positive effect on its growth, feed utilization, survivability, histo-morphometry, immunity and hematological parameters.     

Bacterial biota of shrimp intestine is significantly modified by the use of a probiotic mixture: a high throughput sequencing approach

The use of probiotics is a common practice of current shrimp aquaculture. Despite the immunophysiological responses that have been measured in shrimp exposed to probiotics, no information is currently available on the effect of this practice on the intestinal microbiota. The objective of this work was to evaluate the effect of a probiotic mixture on the intestinal microbiota of shrimp cultured under farm conditions. A culture-independent method based on high-throughput-sequencing (16S rRNA) was used to examine intestinal bacterial communities. A traditional system (without probiotics) was used as the reference. Targeted metagenomics analysis revealed that the probiotic mixture was based on bacteria in the phyla Proteobacteria and Firmicutes. A total of 23 species of bacteria were detected in the probiotic mixture; of these, 11 were detected in the intestine of shrimp reared in both systems, and 12 were novel for the system. Eight of the novel species were detected in shrimp cultured with the probiotic mixture; however, none of these novel species were related to marine or inclusively aquacultural environments, and only one (Bacillus subtilis) was recognized as probiotic for shrimp. The use of the probiotic mixture modified the bacterial profile of the shrimp intestine; however, most of the bacteria incorporated into the intestine were nonindigenous to the marine environment with no previous evidence of probiotic effects on any marine organism. The use of this probiotic mixture may represent a risk of causing environmental imbalances, particularly because farms using these types of probiotic mixtures discharge their effluents directly into the ocean without prior treatment.     

Effect of probiotics on bacterial population and health status of shrimp in culture pond ecosystem

The artificially manufactured probiotics having beneficial bacteria, Bacillus spp. was applied regularly in a modified extensive shrimp (Penaeus monodon) culture pond, located on the bank of Vellar estuary, Parangipettai. The populations of total heterotrophic bacteria (THB), beneficial bacteria (Bacillus spp.) and pathogenic bacteria (vibrios) were monitored in water and sediment of the pond. The results were compared with a control pond, situated in the same location having same water spread area, stocking density, species managed with same technologies and optimum environmental parameters in which no probiotic was applied. The populations of THB and Bacillus spp. in the experimental pond increased and the vibrios decreased after each application of probiotics. But the result of the control pond showed an increasing trend of the populations of THB, Bacillus spp. and vibrios towards days of culture. The control pond had lower levels of THB and Bacillus spp. and higher levels of vibrios than the probiotic applied (experimental) pond. Also the probiotics maintained optimum transparency and low organic load in the experimental pond as compared to control. In general, water and sediment had almost equal number of Bacillus spp. and vibrios, but sediment had higher THB load than water. The applications of probiotics lesser pathogenic vibrios and enhance beneficial bacilli in the culture leading to improved water quality, promoted growth and survival rates and increased the health status of the shrimp without stress and disease outbreaks. Thus the application of probiotics could lead to disease-free and profitable shrimp culture operations which will be helpful for shrimp farmers as most of them are now-a-days severely affected by microbial diseases.     

益生菌冷冻干燥高活性保护机制研究进展

摄取足量益生菌有助于维持肠道微生物群落的稳态,对维持人体肠道健康具有重要意义。然而,在工业化应用中,益生菌抗逆能力较弱且对储存条件要求高,导致益生菌产品对运输和活性维持条件要求较高,这些产业需求对高活力益生菌的制备工艺提出了挑战。干燥处理常应用于保持益生菌活性和稳定性,其中冷冻干燥技术应用最广泛,但冻干过程中益生菌会受到各类环境压力的刺激,引起细胞损伤甚至死亡。因此,可以显著提高益生菌存活率的冻干保护剂成为目前益生菌工业应用的研究热点。本文从益生菌常用及新发现的冻干保护剂种类及其作用机制进行了系统归纳,对菌株冻干后细胞存活率的影响因素进行全面综述,并对冻干保护剂研究方向进行了展望,旨在为高活力益生菌冻干菌粉的研制提供理论支持。     

Microbial treatment in chronic constipation

Chronic functional constipation is a kind of common intestinal disease that occurs in children, adults and elderly people. This disease not only causes great influence to physiological function, but also results in varying degrees of psychological barriers. At present, constipation treatments continue to rely on traditional methods such as purgative therapy and surgery. However, these approaches can disrupt intestinal function. Recent research between intestinal diseases and gut microbiota has gradually revealed a connection between constipation and intestinal flora disturbance, providing a theoretical basis for microbial treatment in chronic constipation. Microbial treatment mainly includes probiotic preparations such as probiotics, prebiotics, synbiotics and fecal microbiota transplantation (FMT). Due to its safety, convenience and curative effect, probiotic preparations have been widely accepted, especially gradually developed FMT with higher curative effects. Microbial treatment improves clinical symptoms, promotes the recovery of intestinal flora, and has no complications during the treatment process. Compared with traditional treatments, microbial treatment in chronic constipation has advantages, and is worthy of further promotion from clinical research to clinical application.     

Application of vaccines and dietary supplements in aquaculture: possibilities and challenges

The development of vaccines has proven essential for the development of a successful finfish aquaculture industry by preventing the occurrence of diseases like furunculosis and vibriosis in industrialised finfish farming. Further developments, like DNA vaccines, will aid in controlling even more diseases in the future. There are however many diseases where it is difficult to produce effective vaccines. Furthermore, many disease outbreaks may occur due to impaired animal welfare. Identifying factors associated with disease and optimizing health and welfare through biotechnological developments is likely to be an important research area in the future. The fact that dietary manipulation can affect fish gut microbiota thus improving disease resistance is well known from mammalian science, and is slowly gaining ground in finfish research. Both prebiotic and probiotic approaches have been used in fish, with particular focus on lactic acid bacteria. Positive effects include enhanced growth and feed efficiency, improved immunity and disease resistance. The synbiotic concept (using a combination of probiotics and prebiotics) is particularly promising and is gaining increased interest within the research community. Immunostimulants may also improve disease resistence via increase humoral and cellular immune responses. The most promising immunostimulants at present are β-glucans, alginate and Ergosan. Additionally, medical plant extracts and their products are receiving increased attention as immune modulators, but further studies are needed. There are also great expectations or the future usage of microalgae to control microbiota and optimize fish health.     

Probiotic Formulations: Application and Status as Pharmaceuticals—A Review

The use of probiotics is a new way to control and treat infections in this modern era. Application of beneficial bacteria to protect against detrimental bacteria in the gastrointestinal tract and thus reap a positive health benefit is the basis of probiotic therapy. Probiotics have a long global history of traditional use. They are normally consumed through fermented foods and are currently sold mostly as ingredients in foods or nutritional supplements. They are also supplied as pharma products. Recent research has highlighted the probiotic potential in the treatment or prevention of disease conditions, maintenance of health, improving immunity and in the reduction in the risk of future diseases. But their position in the pharmaceutical industry is still not very clear. Clinical practitioners use probiotic pharma products mostly as supplements. Their status as drugs is still unclear. This review is aimed to analyze probiotics as pharmaceuticals, their current status as dietary supplements and drugs, existing probiotic preparations and future research needs.