凡隆气单胞菌(Aeromonas veronii)拮抗菌4-1-3的筛选鉴定及其活性物质初探

凡隆气单胞菌是泥鳅养殖中容易发生而且致死率较高的病原菌之一.为筛选凡隆气单胞菌拮抗菌、研发防治此病害的生物制剂,采集泥鳅养殖池底泥样品,通过滤纸抑菌圈法筛选凡隆气单胞菌拮抗细菌,结合形态观察、生理生化实验和16S rRNA基因序列分析进行菌株鉴定.采用硫酸铵沉淀和离子交换层析方法分离纯化抑菌物质,电泳检测其分子量.结果显示,从样品中分离到17株细菌,其中筛选出的拮抗菌4-1-3,能够高效抑制凡隆气单胞菌,抑菌圈直径达到15.2 mm.经菌株鉴定后命名为Pseudomonas fluorescens 4-1-3.该菌产生的抑菌物质为胞外蛋白,分子量约为100 kDa,推测该物质是荧光假单胞菌产生拮抗物质的一种新类型,有望进一步研制成防治水产病害的生物制剂.     

凡隆气单胞菌(Aeromonas veronii)拮抗菌4-1-3的筛选鉴定及其活性物质初探

凡隆气单胞菌是泥鳅养殖中容易发生而且致死率较高的病原菌之一。为筛选凡隆气单胞菌拮抗菌、研发防治此病害的生物制剂,采集泥鳅养殖池底泥样品,通过滤纸抑菌圈法筛选凡隆气单胞菌拮抗细菌,结合形态观察、生理生化实验和16S rRNA基因序列分析进行菌株鉴定。采用硫酸铵沉淀和离子交换层析方法分离纯化抑菌物质,电泳检测其分子量。结果显示,从样品中分离到17株细菌,其中筛选出的拮抗菌4-1-3,能够高效抑制凡隆气单胞菌,抑菌圈直径达到15.2 mm。经菌株鉴定后命名为Pseudomonas fluorescens 4-1-3。该菌产生的抑菌物质为胞外蛋白,分子量约为100 kDa,推测该物质是荧光假单胞菌产生拮抗物质的一种新类型,有望进一步研制成防治水产病害的生物制剂。     

草鱼病原菌AvX005的分离鉴定及其拮抗菌筛选研究

2016年4—7月,湖南望城乔口渔场爆发了较大范围的草鱼疾病,自爆发病的草鱼病变组织中进行细菌分离与培养,分离得到一株优势菌,回复感染试验测定,该菌株具有较强的致病性。经菌落形态观察、冷场扫描电镜观察、生理生化试验及16SrDNA基因序列同源性分析,鉴定为维氏气单胞菌,编号为AvX005(GenBank登录号:KU64116.1),在此基础上以维氏气单胞菌AvX005为指示菌,通过点种法和纸片扩散法筛选拮抗菌,拮抗试验发现新筛选的解淀粉芽孢杆菌对维氏气单胞菌AvX005有较好的拮抗效果,采用酸沉淀、C18反相柱色谱分离到抑菌活性物,LC-MS/MS鉴定分子量为1045.29。根据抑菌活性物的理化性质,初步确定解淀粉芽孢杆菌产生的抑菌活性物可能为脂肽类化合物。该研究不仅可为快捷、准确检测由维氏气单胞菌引起的鱼类疾病提供参考及填补国内维氏气单胞菌拮抗菌在分类地位、生物学特性等方面的不足,而且也为我国草鱼维氏气单胞菌病的生物防治提供科学资料。     

嗜水气单胞菌拮抗菌甲基营养型芽孢杆菌WM-1发酵条件优化

为优化嗜水气单胞菌拮抗菌——甲基营养型芽孢杆菌WM-1的发酵条件,获得抑菌物质产生的最佳培养基配方和培养条件,本实验以嗜水气单胞菌为指示菌,以发酵上清液的抑菌活性为检测指标,采用单因素和正交实验设计,对菌株WM-1的发酵条件进行优化。结果显示,菌株WM-1最适发酵培养基为可溶性淀粉1.0%、牛肉膏1.5%、硫酸镁0.07%、磷酸氢二钾0.05%;最佳发酵条件为初始pH 7.5、培养温度30°C、装液量20%、摇床转速210 r/min、培养时间48 h。在最适培养基和最佳发酵条件下,菌株WM-1发酵液抑菌圈直径达(22.5±0.50)mm,抑菌活性比优化前提高了40.6%。本研究为嗜水气单胞菌的防治提供了新的材料、为甲基营养型芽孢杆菌应用于嗜水气单胞菌的生物防控提供了理论基础。     

2株水产病原气单胞菌拮抗菌的筛选鉴定及生物学特性

气单胞菌是水产养殖鱼类的重要病原菌,暂无针对多种气单胞菌感染防治的有效措施。红树林沉积物中芽孢杆菌丰富,是活性微生物的重要储库。笔者自深圳东涌红树林沉积物中筛选获得2株对6种鱼类病原性气单胞菌均具有较强拮抗活性的菌株AH10和AQ1,基于形态学、生理生化特性和分子生物学分析结果,将2株拮抗菌鉴定为解淀粉芽孢杆菌和贝莱斯芽孢杆菌。生物学特性测试结果表明,2株菌的生长特性相似,最适生长温度为32℃、pH 5～7、盐度0～20。药敏试验结果显示,2株菌除对四环素耐药、对链霉素中度敏感外,对绝大多数抗生素均高度敏感。拮抗试验结果显示,2株菌除对嗜水气单胞菌、舒氏气单胞菌等6种气单胞菌具有拮抗作用外,亦均对爱德华氏菌、类志贺邻单胞菌等水产病原菌具有拮抗作用。其中,解淀粉芽孢杆菌AH10和贝莱斯芽孢杆菌AQ1分别对类志贺邻单胞菌和杀鲑气单胞菌的拮抗作用最强。生物安全试验表明,2株菌对斑马鱼和鲢均无致病性,生物安全性良好。本研究结果可为水产养殖中气单胞菌病的生物防治提供新的微生物资源,具有较好的应用前景和进一步研究价值。     

短小芽孢杆菌X93及胞外产物抑菌活性的研究

从健康养殖大黄鱼肠道中筛选出对病原弧菌有拮抗作用的潜在益生菌株X93,利用细菌快速鉴定系统和16S rDNA方法进行细菌种类鉴定;通过点种法对其抗菌谱进行测定;采用平板扩散法,研究了培养时间、温度、盐度、蛋白酶K和Fe3+等因素对其胞外产物抑菌活性的影响。结果显示:该菌株为短小芽孢杆菌(GenBank accession No.HM137033);对20株病原指示菌中的13株均产生不同程度的抑制作用,抗菌谱较广;菌株培养48 h后的胞外产物抑菌作用最强;在pH为7时,抑菌活性最大;达到最大抑菌活性的温度和盐度分别为28 ℃、5;蛋白酶K和不同浓度的FeCl3均会降低其抑菌活性。该菌对病原弧菌、迟缓爱德华菌和嗜水气单胞菌等水产上常见主要致病菌有良好的拮抗效果,且具有抑菌作用的胞外产物对温度、盐度和Fe3+有一定的适应范围,适宜作为益生菌株,有望在实际养殖环境中得到应用。     

泥鳅鳃出血病病原菌及其拮抗菌的分离鉴定

泥鳅鳃出血病是泥鳅养殖过程中的易发疾病,自病灶部位分离到优势病原菌JY5,随后自发病泥鳅养殖池底泥分离到可抑制病原菌JY5生长的拮抗菌CJT23。通过对菌株JY5和CJT23进行菌落形态观察、生理生化鉴定和16S rDNA序列分析,初步判定病原菌JY5为维氏气单胞菌,拮抗菌CJT23为边缘假单胞菌。对边缘假单胞菌CJT23进行药敏试验,结果表明,该菌对环丙沙星、诺氟沙星、庆大霉素、链霉素、恩诺沙星、复方新诺明6种药物表现出敏感及中敏,提示在使用边缘假单胞菌CJT23防治泥鳅鳃出血病时应避免使用上述6种敏感及中敏抗生素;拮抗谱试验结果表明,边缘假单胞菌CJT23对病原菌维氏气单胞菌JY5、副溶血弧菌、鳗弧菌、创伤弧菌、嗜水气单胞菌、温和气单胞菌和哈维氏弧菌表现出不同程度的抑菌性,其抑菌圈直径分别为(21.00±0.41)、(17.97±0.21)、(15.93±0.26)、(12.73±0.26)、(12.63±0.17)、(12.57±0.12) mm和(11.47±0.17) mm,而对豚鼠气单胞菌无抑菌效果。本试验结果可为泥鳅鳃出血病的生物防治提供基本材料依据,并为泥鳅的可持续性养...     

嗜水气单胞菌拮抗菌的筛选

用平板划线法或点种法对212株分离自养殖水体和水产动物胃肠道的细菌进行筛选,得到1株对嗜水气单胞菌(Aerom onas hydrophila)有拮抗作用的细菌MLS-7。经过生理生化的初步鉴定,该菌为粪肠球菌(Entero-coccus faecalis)。MLS-7上清液抑菌试验和共培养试验表明其对嗜水气单胞菌有较强的抑菌作用。进一步对MLS-7抑菌谱进行测定,确认其对鱼源的病原菌有一定的抑菌作用。     

中华鳖常见细菌病的病原鉴定及药物体外拮抗比较

对中华鳖疖疮穿孔病、腐皮病、出血性肠道坏死症、细菌性肝水肿病与白点病等5种常见鳖病的16株病原菌进行鉴定与抑菌效果测定,其中温和气单胞菌6株,类志贺邻单胞菌1株,嗜水气单胞菌6株,豚鼠气单胞菌3株。各分离株对中华鳖与实验小鼠均具强毒力。对16株病菌的体外拮抗结果统计表明,不同鳖病致病菌的药物拮抗作用存在明显差异,而病症一致采集地各异的中华鳖病菌其体外药物敏感性亦有所不同,以丁胺卡那、氟嗪酸、环丙沙星、新霉素、庆大霉素、红霉素、卡那霉素、呋喃妥因等抗生素的抑菌效用最为显著,中高敏频次≥10。     

刺参养殖池塘中一株植物乳杆菌的分离及其生物学特性

2017年5月,从山东东营刺参(Apostichopus japonicus)养殖池塘底泥中分离获得49株乳酸菌。以刺参“腐皮综合征”的2株致病菌[灿烂弧菌(Vibrio splendidus)和假交替单胞菌(Pseudoalteromonas nigrifaciens)]为指示菌进行拮抗作用实验,获得1株具有显著抑菌活性的乳酸菌CLY-5,对该菌株进行了生理生化实验、16S rDNA序列分析、生长特性及其对刺参的安全性研究。结果显示,菌株CLY-5对灿烂弧菌和假交替单胞菌具有较好的抑制作用,且菌株的胞内产物与胞外产物均具有抑菌效果,抑菌圈分别为20 、23 mm和27 、38 mm,胞外产物的拮抗作用优于胞内产物。利用该菌对刺参进行高浓度浸浴测试其安全性,浓度为1×109、1×108和1×107 CFU/ml,实验期间刺参状态良好,无死亡现象。16S rDNA序列分析表明,CLY-5与植物乳杆菌(Lactobacillus plantarum NR117813.1)的相似性为100%,初步鉴定该菌株为植物乳杆菌。菌株CLY-5在30℃~44℃、pH 6~8范围内生长较快,20 h进入对数生长期,28~32 h达到生长高峰。筛选的植物乳杆菌具有良好的抑菌能力,且其生长特性适应刺参池塘的养殖环境,为刺参疾病的生态防控及乳酸菌资源的开发提供应用数据参考。     

Anguilla huangi Teng, Lin, and Tzeng, 2009, is a junior synonym of Anguilla luzonensis Watanabe, Aoyama, and Tsukamoto, 2009

Anguilla luzonensis and A. huangi were each described in 2009 using eels obtained from northern Luzon Island. We examined the taxonomic status of these two groups of eels using morphological and molecular genetic characters. There were no significant differences in two vertebrae counts between eels of A. luzonensis and A. huangi. Mitochondrial 16S ribosomal RNA and cytochrome b genes sequences were obtained and compared among 28 specimens of A. luzonensis, the holotypes of A. luzonensis and A. huangi, and one specimen of the other 15 anguillid species. The specimens of A. luzonensis exhibited almost identical sequences, including the holotype, with only a few site differences, and the genetic difference between the holotypes of A. luzonensis and A. huangi was within the range of differences of specimens of A. luzonensis. The other anguillid species were genetically very different from A. luzonensis and A. huangi, although A. interioris is a closely related species. It is clear that A. luzonensis and A. huangi are the same species, and according to the principle of priority in zoological nomenclature, A. luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 is the valid species name, and A. huangi Teng, Lin, and Tzeng, 2009 is a junior synonym of A. luzonensis.     

Atlantic Fisheries Technological Conference,Moncton, NB,August 21, 1995

No abstract available for this article.     

Age,growth, maturity and the overfishing of the iconic sciaenid,Argyrosomus japonicus,in south-eastern,Australia

Mulloway (Argyrosomus japonicus) occur in estuarine and coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan, where they are important in fisheries. This study identified that mulloway in south-eastern Australia had similar growth rates, but matured at smaller lengths and younger ages, to those in South Africa and Western Australia. Growth of both sexes was similar to about 5 years, after which females grew faster and attained a greater maximum length than males. Female mulloway matured at 4–5 years of age with a L₅₀ of 68 cm, whereas males matured at 2–3 years of age with a L₅₀ of 51 cm. The commercial fishery in New South Wales was characterised by declining catches and a reduction in the proportion of mulloway of mature lengths in landings. During 2002–2005 commercial landings were dominated (83%) by fish within 15 cm of the current minimum legal total length of 45 cm and aged 2 and 3 years (>80%), even though mulloway can attain lengths of 200 cm and live >30 years. Estimates of the rates of instantaneous total mortality ranged between 0.34 and 0.45, whilst the rate of instantaneous natural mortality (M) was estimated to be approximately 0.12. Yield-per-recruit analyses indicated that mulloway in New South Wales are being growth overfished and substantial increases in yield could be achieved by increasing the length at first harvest. Values of the spawning potential ratio were below 0.2 under a range of mortality estimates, suggesting that mulloway are at risk of recruitment overfishing. These results suggest that the spawning stock of mulloway in south-eastern Australia has been depleted and that remedial management action is required to protect this iconic species.     

Effects of Mosquitofish,Gambusia affinis,on Channel Catfish,Ictalurus puncatatus,Production Ponds

Mosquitofish, Gambusia sp., have been spread throughout the world to biologically control mosquitoes. However, the fish has gained a reputation as an invasive species and has been implicated in displacing native aquatic species. Gambusia affinis are native to the southeastern United States and commonly occur in commercial channel catfish, Ictalurus punctatus, production ponds. We investigated effects of mosquitofish presence on zooplankton populations, water quality, disease occurrence, and fish production in experimental ponds. There were no differences between ponds with or without mosquitofish in numbers of calanoid copepods, cyclopoid copepods, total copepods, Bosmina sp., Ceriodaphnia sp., Moina sp., Daphnia sp., or total cladocerans. There were also no differences in copepod and cladoceran sizes. Copepod nauplii were more numerous during the summer months in ponds with mosquitofish. There were no differences in water quality variables (soluble reactive phosphorus, nitrate, nitrite, ammonia, total nitrogen, total phosphorus, pH) or phytoplankton density between ponds stocked with and without mosquitofish. Catfish production and disease occurrence were also similar between ponds with and without mosquitofish. Although mosquitofish may cause problems when stocked outside their native range, there does not appear to be any adverse effects of mosquitofish presence in catfish production ponds.     

Surface disinfection of Pacific threadfin, Polydactylus sexfilis, and amberjack, Seriola rivoliana, eggs

The effects of exposing the eggs of Pacific threadfin and amberjack eggs (AEs) to different concentrations of hydrogen peroxide for 5 min on hatch rate and survival were assessed in a series of experiments using a petri dish model rearing system. Despite significant inter‐batch variation in hatch rate, it was shown that eggs of both species could be safely exposed to up to 11 340 mg L⁻¹ H₂O₂ for 5 min. Exposure to 34 230 mg L⁻¹ H₂O₂ for 5 min was shown to be lethal to AEs at a late stage of development. In two further experiments, it was demonstrated that Pacific threadfin eggs were resistant to all tested concentrations of a range of polyvinylpyrrolidone iodine (PVP‐I) concentrations and contact times (up to 1000 mg L⁻¹ PVP‐I for 10 min). The level of bacteria adhering to the eggs of both species was highly variable. Where eggs were heavily colonized (>10⁴ cfu egg⁻¹), hydrogen peroxide concentrations of at least 11 340 mg L⁻¹, or PVP‐I concentrations higher than 500 mg L⁻¹ for 10 min, were required for effective sterilization. In less colonized batches, rinsing in sterile seawater or exposure to lower (550 mg L⁻¹) concentrations of H₂O₂ was sufficient to result in high apparent levels of surface sterility (<1 cfu egg⁻¹).     

Compositional differences,antioxidant activity,angiotensin-converting enzyme inhibition,and sensory characteristics of kamaboko fermented in wheat,rice, brown rice,and soybean koji

Fisheries Science - Fermentation of kamaboko in koji with wheat (KW), rice (KR), brown rice (KB), or soybean (KS) was performed by simulation of tofuyo processing. Moisture and protein content...     

Sperm Motilities in Waigieu Seaperch,Psammoperca waigiensis: Effects of Various Dilutions,pH, Temperature,Osmolality, and Cations

The objectives of this study were to evaluate the effects of varying dilutions, pH, temperature, osmolality, and cations on sperm motility parameters in waigieu seaperch, Psammoperca waigiensis. The maximum velocity of average in path (VAP), percentage of motile cells (MOT), and duration of sperm motility (DSM) were observed when semen was diluted in artificial seawater (ASW) at a ratio of 1:100 (144.9 ± 0.6 µm/sec, 95.6 ± 0.4%, and 230.3 ± 2.3 sec, respectively), at 30 C (142.0 ± 0.6 µm/sec, 93.6 ± 0.4%, and 238.3 ± 0.9 sec, respectively), and pH 8 (144.8 ± 0.6 µm/sec, 93.3 ± 0.4%, and 234.0 ± 1.5 sec, respectively). Maximum VAP, MOT, and DSM were obtained in each solution containing 0.6 M NaCl (143.8 ± 1.0 µm/sec, 91.3 ± 2.0%, and 230.6 ± 4.2 sec, respectively), 0.6 M KCl (135.1 ± 3.1 µm/sec, 91.1 ± 3.1%, and 230.3 ± 3.7sec, respectively), 0.2M CaCl₂ (105.3 ± 4.7μm/sec, 47.9 ± 2.7%, and 120.7 ± 1.3 sec, respectively), 0.2 M MgCl₂ (107.3 ± 3.0 m/s, 42.1 ± 3.3%, and 120.3 ± 4.8 sec, respectively), and osmolality of 400 mOsm/kg (145.1 ± 2.5 µm/sec, 93.0 ± 2.1%, and 346.5 ± 4.4s, respectively). We used these mediums as artificial insemination media for fertilizing matured eggs. The results showed that the fertilization and hatching rates in 0.6 M NaCl (75.3 ± 0.6% and 57.0 ± 2.4%, respectively), ASW (70.8 ± 1.2% and 51.2 ± 1.8%, respectively), or 400 mOsm/kg (72.9 ± 1.8% and 55.3 ± 1.6%, respectively) were higher than that in seawater (63.9 ± 1.2% and 39.2 ± 3.9%, respectively). In conclusion, using 0.6 M NaCl, ASW, or 400 mOsm/kg as an artificial insemination medium is effective for fertilizing of waigieu seaperch.     

Operating parameters affecting biofloc technology: carbon source,carbon/nitrogen ratio,feeding regime,stocking density,salinity, aeration,and microbial community manipulation

Aquaculture International - The world population continues to increase day by day. Therefore, aquaculture needs to grow in order to response the need for protein foods and to cope with the problem...