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1.
用对虾饲料培养基从健康凡纳滨对虾肠道分离出500株黏附细菌,以产淀粉酶、脂肪酶和蛋白酶能力为指标,筛选出产该3种消化酶的细菌90株,占总菌株的18%.对其中生长较快的69株进行16S rDNA 基因测序,确定其分类地位.结果显示,69株菌分别属于不动杆菌属(Acinetobacter)、芽孢杆菌属(Bacillus)、葡萄球菌属(Staphylococcus)、假交替单胞菌属(Pseudoalteromonas)、气单胞菌属(Aeromonas)、嗜盐单胞菌属(Halomonas)、利斯顿氏菌属(Listonella)、莫拉氏菌属(Moraxella)等,其中数量最多是芽胞杆菌属,占鉴定细菌总数的53.62%,数量最少是气单胞菌属和嗜盐单胞菌属,均占鉴定细菌总数的2.90%.表明对虾肠道黏附菌群中具有较多能分泌多种消化酶的细菌,可进一步开发为促进对虾消化功能的益生菌  相似文献   

2.
从高山榕(Ficus altissima Bl.)叶斑病的病叶上分离到一株真菌,经接种鉴定为高山榕叶斑病的病原物。通过形态学观察,发现该病原物为链格孢属(Alternaria sp.)。利用直接菌落PCR测定了此病原物的核糖体DNA的转录间区、内聚半乳糖醛酸酶基因以及基因组中OPA1-3区域的DNA。结合序列分析和形态学观察结果,该菌鉴定为A.gaisen。  相似文献   

3.
【目的】探讨四种酵母对镰孢菌生长和T-2毒素消减的控制效应,为红鱼干防霉脱毒的应用提供理论依据。【方法】将三株鱼干源酵母分离株季也蒙毕赤酵母Ym0104、奥默柯达酵母Yk0104(Yk)和阿氏丝孢酵母Yt0104(Yt)以及一株酿酒酵母BY4741的发酵液,与三株产T-2毒素(T-2)镰孢菌(鱼干源F11、F21菌株,标准菌株DL1445-5)、不同浓度T-2在红鱼干(DRF)培养基上共培养,通过测定镰孢菌生长半径以及T-2残留量来评价四种酵母发酵液对镰孢菌生长抑制作用以及T-2的消减效果。【结果】四种酵母菌对三株镰孢菌的生长均有抑制作用,其中Ykt的抑制作用最强;对T-2均有一定的消减作用,其中Yk的消减效果最好。【结论】Yk对红鱼干中镰孢菌和T-2毒素有良好的消减效应。  相似文献   

4.
从南海海域的鱼类、贝类、海藻以及海泥样品中分离出199株海洋真菌,分属于青霉属、曲霉属和酵母属等9个属,其中以青霉属和曲霉属真菌居多,分别占28.6%和26.8%。以大肠杆菌和金黄色葡萄球菌作为指示菌,筛选出抑菌活性菌株7株,其中2株既抗大肠杆菌又抗金黄色葡萄球菌,4株抗金黄色葡萄球菌,1株抗大肠杆菌。  相似文献   

5.
从桉树枯叶中分离到的4株微生物菌株,对好食脉孢霉(Neurospora sitophila)具有拮抗作用。其中ED013、ED018和ED015抑菌圈之间差异不显著,与对照无菌水和多菌灵有极显著性的差异。ED014抑菌圈比前3个菌株效果差,但也与照无菌水和多菌灵有极显著性的差异。根据形态特点及生理生化测定结果鉴定4株菌株属于芽孢杆菌(Bacillusspp.)。  相似文献   

6.
从桉树枯叶中分离到的4株微生物菌株,对好食脉孢霉(Neurospora sitophila)具有拮抗作用。其中ED013、ED018和ED015抑菌圈之间差异不显著,与对照无菌水和多菌灵有极显著性的差异。ED014抑菌圈比前3个菌株效果差。但也与照无菌水和多菌灵有极显著性的差异。根据形态特点及生理生化测定结果鉴定4株菌株属于芽孢杆菌(Bacillus spp.)。  相似文献   

7.
西津水库网箱养殖区浮游植物特征及水质营养状态   总被引:2,自引:0,他引:2  
于2006年10月至2008年7月对西津水库米埠坑网箱养殖区浮游植物进行两个年度共8次调查。第1年发现浮游植物6门53属,冬季出现种属最多,达到43属,春、夏季最少,为35属,浮游植物年平均数量为35.18×104 L-1,平均生物量为1.07 mg·L-1。第2年度采集到浮游植物6门47属,以春季出现种属最多,达到40属,夏季最少,为29属,第2年浮游植物年平均数量低于第1年,为19.77×104 L-1,生物量高于第1年,达到1.22 mg·L-1。综合营养指数评价结果显示,米埠坑网箱养殖区处于中营养水平,有向富营养化过渡的趋势。  相似文献   

8.
广东省罗非鱼主养区无乳链球菌的分离、鉴定与致病性   总被引:3,自引:0,他引:3  
从广东省5个罗非鱼主养区患暴发性的罗非鱼中分离到15株菌,挑选其中的5株(不同地域、不同组织分离的菌株)进行人工感染试验,表现出自然发病的症状,确定此5株分离菌为导致罗非鱼暴发病的主要病原。通过形态学观察和生理生化实验,并结合16SrRNA基因序列分析,5株分离菌株均为无乳链球菌(Streptococcus agalactiae)。5株分离菌在形态学和生理生化实验结果上保持一致,16SrRNA基因序列同源性达98.6%~99.8%,但在致病性和对药物的敏感性上却呈现一定的差异。另外10株分离菌株通过生理生化实验鉴定也为无乳链球菌。研究表明,广东省罗非鱼流行性暴发病的病原菌主要为无乳链球菌。  相似文献   

9.
黄喉拟水龟体表溃疡病原菌SG_(24)的分类鉴定   总被引:1,自引:0,他引:1  
从患溃疡的黄喉拟水龟病灶中分离到一株病原菌SG24。对菌株SG24进行了常规生理生化测定和ATBExpression半自动细菌鉴定仪鉴定,并测定16S rRNA序列,分析其与相关细菌相应序列的同源性,构建了系统进化树。普通细菌学方法结果显示菌株SG24为黏质沙雷氏菌(Serratia marcescens)。以沙雷氏菌属的16S rRNA基因序列设计一对引物进行PCR扩增,获得了菌株SG24大小约950 bp的16S rRNA部分基因片段,测序结果显示菌株SG24与黏质沙雷氏菌同类,与已登录的黏质沙雷氏菌(S.marcescensDQ207558)的16S rRNA同源性大于99%。综合以上分类鉴定结果,确定菌株SG24属于沙雷氏菌属的黏质沙雷氏菌。药物敏感试验结果表明:菌株SG24对链霉素、庆大霉素、壮观霉素、强力霉素、卡那霉素、阿米卡星、诺氟沙星、氧氟沙星和复方新诺明敏感。  相似文献   

10.
拮抗香蕉枯萎病菌海洋细菌的筛选和鉴定   总被引:3,自引:0,他引:3  
从93份中国南部海域近海海泥样品中分离出1800多株海洋细菌,以对峙培养法,测定海洋细菌对香蕉枯萎菌的拮抗作用,再以琼脂划线培养法(agar streak)测定菌株的抑菌活性,结果表明:约55.6%的菌株对香蕉枯萎菌有一定的拮抗作用,其中58株菌株抑制香蕉枯萎菌生长所形成的抑菌带宽度大于10.0mm,抑菌作用较好,复筛后其中13个菌株形成的抑菌带宽在15.0mm以上。经反复转接和对峙培养,筛选出拮抗效果好、抑菌活性稳定的菌株TC-1,初步鉴定为芽孢杆菌属的细菌,TC-1对14种病原微生物都有较好的抑菌效果。  相似文献   

11.
Until recently,little was known about the fungi found in shark gills and their biomedicinal potential. In this article,we described the isolation,bioactivity,diversity,and secondary metabolites of bioactive fungi from the gill of a shark(Carcharodon carcharias). A total of 115 isolates were obtained and grown in 12 culture media. Fifty-eight of these isolates demonstrated significant activity in four antimicrobial,pesticidal,and cytotoxic bioassay models. Four randomly selected bioactive isolates inhibited human cancer cell proliferation during re-screening. These active isolates were segregated into 6 genera using the internal transcribed spacer-large subunit(ITS-LSU) rDNA-sequence BLAST comparison. Four genera,Penicillium,Aspergillus,Mucor,and Chaetomium were the dominant taxa. A phylogenic tree illustrated their intergenera and intragenera genetic diversity. HPLC-DAD-HRMS analysis and subsequent database searching revealed that nine representative strains produced diverse bioactive compound profiles. These results detail the broad range of bioactive fungi found in a shark's gills,revealing their biopharmaceutical potential. To the best of our knowledge,this is the first study characterizing shark gill fungi and their bioactivity.  相似文献   

12.
Until recently, little was known about the fungi found in shark gills and their biomedicinal potential. In this article, we described the isolation, bioactivity, diversity, and secondary metabolites of bioactive fungi from the gill of a shark (Carcharodon carcharias). A total of 115 isolates were obtained and grown in 12 culture media. Fifty-eight of these isolates demonstrated significant activity in four antimicrobial, pesticidal, and cytotoxic bioassay models. Four randomly selected bioactive isolates inhibited human cancer cell proliferation during re-screening. These active isolates were segregated into 6 genera using the internal transcribed spacer-large subunit (ITS-LSU) rDNA-sequence BLAST comparison. Four genera, Penicillium, Aspergillus, Mucor, and Chaetomium were the dominant taxa. A phylogenic tree illustrated their intergenera and intragenera genetic diversity. HPLC-DAD-HRMS analysis and subsequent database searching revealed that nine representative strains produced diverse bioactive compound profiles. These results detail the broad range of bioactive fungi found in a shark’s gills, revealing their biopharmaceutical potential. To the best of our knowledge, this is the first study characterizing shark gill fungi and their bioactivity.  相似文献   

13.
In order to estimate the biodegradation of three polycyclic aromatic hydrocarbons (PAHs) compounds, bacterial strains were isolated from marine sediments in three heavily contaminated sites (Yuandang Lake, Dongdu Port and Aquacultural zones in Maluan Bay) in Xiamen Western Sea. The results show three bacterial strains, which used pyrene as the sole carbon source, were identified as strains of Aureobacterium sp.,Arthrobacter sp., Rhodococcus sp. The PAH-degrading bacteria isolated had a strong ability to degrade phenanhrene, fluoranthene and pyrene at different degradation rates. The highest degradation rate was observed when three PAH compounds were mixed with an individual strain in the medium. The three PAHs were degraded after one week with a degradation rate of 89.94 % for phenanthrene and 93.4 % for both of fluoranthene and pyrene.In addition, after 25 days of incubation, the degradation rate was 99.98 % for phenanthrene and 99.97 % for both of fluoranthene and pyrene. Optical density was measured to estimate bacterial growth during the degradation of PAHs. Highest levels of bacterial growth were observed with a three PAH mixture in the culture, suggesting that the concentration of PAHs influenced bacterial growth and the highest levels of degradation for most series were detected after one week of incubation.  相似文献   

14.
Anaerobic, aerobic, and facultative bacteria are all present in corrosive environments. However,as previous studies to address corrosion in the marine environment have largely focused on anaerobic bacteria, limited attention has been paid to the composition and function of aerobic and facultative bacteria in this process. For analysis in this study, ten samples were collected from rust layers on steel plates that had been immersed in seawater for dif ferent periods(i.e., six months and eight years) at Sanya and Xiamen,China. The cultivable aerobic bacterial community structure as well as the number of sulfate-reducing bacteria(SRB) were analyzed in both cases, while the proportion of facultative SRB among the isolated aerobic bacteria in each sample was also evaluated using a novel approach. Bacterial abundance results show that the proportions are related to sea location and immersion time; abundances of culturable aerobic bacteria(CAB) and SRB from Sanya were greater in most corrosion samples than those from Xiamen,and abundances of both bacterial groups were greater in samples immersed for six months than for eight years. A total of 213 isolates were obtained from all samples in terms of CAB community composition,and a phylogenetic analysis revealed that the taxa comprised four phyla and 31 genera. Bacterial species composition is related to marine location; the results show that Firmicutes and Proteobacteria were the dominant phyla, accounting for 98.13% of the total, while Bacillus and Vibrio were the dominant genera,accounting for 53.06% of the total. An additional six facultative SRB strains were also screened from the isolates obtained and were found to encompass the genus Vibrio(four strains), Staphylococcus(one strain),and Photobacterium(one strain). It is noteworthy that mentions of Photobacterium species have so far been absent from the literature, both in terms of its membership of the SRB group and its relationship to corrosion.  相似文献   

15.
The phylogenetic diversity of cuhurable psychrophilic bacteria associated with sea ice from the high latitude regions of Canadian Basin and Chukchi Sea, Arctic, was investigated. A total of 34 psychropilic strains were isolated using three methods of ( Ⅰ ) dilution plating ( at 4 ℃ ), ( Ⅱ ) bath culturing ( at - 1 ℃ ) and dilution plating, and ( Ⅲ) cold shock ( -20 ℃ for 24 h), bath culturing and dilution plating under aerobic conditions. Sea-ice samples were exposed to -20 ℃ for 24 h that might reduce the number of common microorganisms and encourage outgrowth of psyehrophilic strains. This process might be able to be introduced to isolation psychrophilic bacteria from other environmental samples in future study. 16S rDNA nearly full-length sequence analysis revealed that psychrophilic strains felled in two phylo- genetic divisions, γ-proteobacteria (in the genera ColweUia,Marinobaeter、Shewanella,Glaciecola,Marinomortas and Pseudoalteromortas ) and Cytophaga-Flexibacter-Baeteroides ( Flavobacterlum and Psyehroflexus). Fifteen of bacterial isolates quite likely represented novel species (16S rDNA sequence similarity below 98% ). One of strains (BSi20002) from Canadian Basin showed 100% sequence similarity to that of Marinobacter sp. ANT8277 isolated from the Antarctic Weddell sea ice, suggesting bacteria may have a bipolar distribution at the species level.  相似文献   

16.
The present study aimed at assessing the antifouling activity of bacteria associated with marine sponges. A total of eight bacterial strains were isolated from the surface of sponge Sigmadocia sp., of them, SS02, SS05 and SS06 showed inhibitory activity against biofilm-forming bacteria. The extracts of these 3 strains considerably affected the extracellular polymeric substance producing ability and adhesion of biofilm-forming bacterial strains. In addition to disc diffusion assay, microalgal settlement assay was carried out with the extracts mixed with polyurethane wood polish and coated onto stainless steel coupons. The extract of strain SS05 showed strong microalgal settlement inhibitory activity. Strain SS05 was identified as Bacillus cereus based on its 16S rRNA gene. Metabolites of the bacterial strains associated with marine invertebrates promise to be developed into environment-friendly antifouling agents.  相似文献   

17.
The Andaman and Nicobar Islands are one of the Union Territories of India, located in the eastern part of the Bay of Bengal. In 2010 summer, the increment in sea surface water temperature (up to 34℃) resulted in the bleaching of about 74% to 77% of corals in the South Andaman. During this event, coral species such as Acropora cerealis, A. humilis, Montipora sp., Favia pallida, Diploastrea sp., Goniopora sp. Fungia concinna, Gardineroseries sp., Porites sp., Favites abdita and Lobophyllia robusta were severely affected. This study is to assess the recovery status of the reef ecosystem by estimating the percentage of Live Coral cover, Bleached coral cover, Dead coral with algae, Rubble, Sandy flat, Algal assemblage and other associated organisms. The sedimentation rate (mg cm-2 d-1) and coral coverage (%) were assessed during this study period. The average sedimentation rate was ranged between 0.27 and 0.89 mg cm-2 d-1 . The observed post bleaching recovery of coral cover was 21.1% at Port Blair Bay and 13.29% at Havelock Island. The mortality rate of coral cover due to this bleaching was estimated as 2.05% at Port Blair Bay and 9.82% at Havelock Island. Once the sea water temperature resumed back to the normal condition, most of the corals were found recovered.  相似文献   

18.
The bacterial flora in the digestive tube of Bullacta exarata Philippi and its rearing shoal were investigated. A to-tal of 157 strains of heterotrophic bacteria, isolated from crop, stomach intestine and other parts of the digestive tube,mainly belong to the genera Photobacterium, Bacillus, Pseudomonas Vibrio and some genera of the family Enterobacteri-aceae. There are significantly more varieties of bacteria in crop than in stomach and intestine. A total of 173 strains of bacte-ria were isolated from the rearing shoal, belonging to 13 genera. The 5 predominant genera, such as Bacillus and Photobac-terium, are the same as those in the digestive tube, but greatly differ in percentages. The number of heterotrophic bacteriaand Vibrio in rearing shoal change in line with the alteration of the temperature, and are significantly affected by the use ofpesticides.  相似文献   

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