山白树茎尖培养和快速繁殖

植物名称:山白树(Sinowilsonia henry)。材料类别:研究材料于1984年6月采自陕西太白山蒿坪寺附近。取一年生枝条经约5％肥皂水洗涤,自来水冲洗后,70％乙醇浸泡30秒,无菌水冲洗,0.1％HgCl_2溶液灭菌 9分钟,再用无菌水冲     

家养金鱼

养水篇 人类离不开空气,鱼儿同样也离不开水,养鱼先养水,已经成为养鱼者的共识。在所有的养鱼用水中,自来水是最方便易取了。此外,自来水经过净化除菌,水质清洁,杂质少,细菌与有害物质少。不过,自来水中氯离子含量较高,使用之前必须经过去氯处理。     

家养金鱼

养水篇人类离不开空气,鱼儿同样也离不开水,养鱼先养水,已经成为养鱼者的共识。在所有的养鱼用水中,自来水是最方便易取了。此外,自来水经过净化除菌,水质清洁,杂质少,细菌与有害物质少。不过,自来水中氯离子含量较高,使用之前必须经过去氯处理。自来水去氯主要采用晾晒法、化学法和活性炭过滤法等3种方法。晾晒法是将自来水在阳光下曝晒48小时左右,或在阴天     

植物生长调节剂在彩色马蹄莲组培与快繁中的生理效应

马蹄莲(Zantedeschia aethiopica Spreng)红色和黄色品种的幼嫩叶片在自来水下冲洗2 h,0.1%HgCl2 2%乙醇溶液浸泡5～7 min,无菌水冲洗4～5遍,剪成0.5 cm的方块,接种在MS KT5 mg·L-1(单位下同) 6-BA 1.0 3%白糖 0.4%琼脂的培养基上.     

透百合离体快速繁殖

1 植物名称透百合(Lilium elegans),品种为Connecticut King(康皇)及Milano(米兰)。 2 植物材料茎尖、带腋芽的茎段。 3 培养条件将外植体用自来水冲洗10min后,投入70％酒精内消毒30 s,再用加入数滴吐温-80的0.1％升汞溶液浸泡10～12min,无菌水冲洗3～4次,在无菌条件下将茎尖或茎段切成约1 cm长。芽分化培养基(1)MS+BA 1～3 mg/L(单位下同)+NAA 0.1     

快速繁殖龙牙楤木

龙牙楤木 (Aralia elata)，五加科楤木属植物，主要分布于我国东北三省的山林间，其新鲜的嫩芽 (见封面 )是一种具有独特香味、美味可口和营养丰富的山野菜。为了满足市场需要和积极保护野生植物资源，我们利用组培方法对龙牙木进行快速繁殖获得成功。现将其方法简述如下： 　　利用从野外采集回的嫩芽作为外植体，经自来水冲洗干净后，在无菌条件下用 75％酒精消毒 30秒钟，无菌水冲洗 3次，再浸泡于 0. 1％升汞溶液 8分钟，无菌水冲洗 5次。用解剖刀将 嫩芽切成 2毫米长的小块，接种到愈伤组织诱导培养基 (MS＋ 2， 4－ D1. 0mg/L＋ 6…     

更正

铁线蕨(Adiantumraddianum)成熟孢子孢子萌芽和原叶体发育培养基:(1)1/2MS+6-BA0.3mg·L-1(单位下同);(2)1/2MS+6-BA2+NAA0.2。孢子体形成和增殖培养基:(3)3/4MS+6-BA0.5+NAA0.2。生根培养基:(4)1/2M S+IBA1+C0.1。上述培养基均加3%白砂糖、0.5%卡拉胶,pH5.8。培养温度为(25±2)℃,光照时间8￣10h·d-1,光照度约3000lx。取带成熟孢子的铁线蕨叶片,用自来水加少量洗衣粉冲洗干净。然后在超净台上,先用70%酒精浸泡10s,无菌水冲洗3次,再用2%次氯酸钠浸泡15m i n,无菌水冲洗5次。消毒后,刮取孢子或将整片带孢子的叶片直接放入培养基(…     

培养基灭菌方式对细菌分离效率的影响

自然界蕴含大量未/难培养微生物,分离这些微生物对理论研究和资源开发具有重要意义。本研究使用高压灭菌和过滤除菌方式制备培养基,采用稀释涂布方法,从红树林灰泥样品中分离获得123株细菌,通过16S rRNA基因序列分析对其进行鉴定,进而探究培养基灭菌方式对细菌分离效果的影响。结果表明：过滤除菌培养基生长的单菌落数目（339±82）个显著多于高压灭菌培养基生长的单菌落数目（179±65）个;两种培养基分离细菌的群落结构在门、科和属分类水平上总体相似,但优势类群的数目和少数类群存在差异;过滤除菌培养基分离细菌的Shannon Wiener’s指数、均匀度、新种率、基因多样性均高于高压灭菌培养基,而其与近缘模式菌株相似度的平均值和中位数则低于高压灭菌培养基。因此,过滤除菌培养基分离获得细菌的多样性、均匀性和新颖性均高于高压灭菌培养基。本研究首次探究培养基灭菌方式对细菌分离效果的影响,具有更高分离效率的过滤除菌培养基为未/难培养微生物菌株资源获取提供了借鉴。     

吸光度法快速确定菌悬液浓度及其适用范围

采用麦氏比浊法,将大肠埃希菌的菌悬液浓度调整到约8×108cfu/g,再将其稀释成多个梯度,在600nm的波长下用紫外分光光度计测定吸光度值,同时将各个梯度的菌悬液分别做菌落总数试验,得到不同吸光度值对应的菌落总数,并制作标准曲线,通过测量菌悬液的吸光度值确定菌悬液浓度及其适用范围。试验证明,用此法确定菌悬液浓度时,其菌落总数宜在105~108cfu/g之间,不适用于在105cfu/g以下的菌悬液,所得结果比麦氏比浊法准确。     

鞘蕊花的组织培养

植物名称鞘蕊花(Coleus forskohlii)。材料类别:顶芽、侧芽。培养条件:取鞘蕊花幼嫩的顶芽和侧芽,经自来水冲洗后去叶,用0.1％的升汞灭菌5min,再用无菌水冲洗数次后切成0.5～1.0cm长的带芽茎段,接入诱导培养基上。基本培养基为MS并附加不同浓度的BA,NAA和GA_3(单位mg/L);培养     

Isolation and identification of ochratoxin A-producing Aspergillus section Nigri strains from California raisins

Aims: To determine incidence and levels of ochratoxin A (OTA) in California raisins and to isolate and characterize OTA‐producing fungi from California raisin vineyard populations. Methods and Results: Forty raisin clusters sampled from four California vineyards in the San Joaquin Valley were analysed for OTA content using immunoaffinity and HPLC methods. OTA was detected in 93% of the samples, at levels from 0·06 to 11·4 ng g^?1. From these raisin samples, a total of 400 strains of Aspergillus were isolated and analysed for OTA production. Twelve isolates (3%), from five raisin samples, produced OTA. These isolates were identified as Aspergillus carbonarius, based on morphological characteristics and multilocus sequence analysis. Levels of OTA produced by these isolates on raisin agar ranged from 0·9 to 15 μg g^?1. Conclusions: OTA is a common contaminant of raisin vineyards, but average levels are much lower than EU regulatory limits for dried fruit. The primary species responsible for OTA contamination in California raisins is A. carbonarius. Significance and Impact of the Study: This study illustrates that low‐level OTA contamination of raisins occurs in California and that ecological studies of A. carbonarius within the Aspergillus section Nigri population on raisins are warranted to monitor ochratoxigenic potential of the crop.     

A note on the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples

V ojak , P.W.L., E dwards , C. & J ones , M.V. 1985. A note on the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples. Journal at Applied Bacteriology 59, 375–379.
Media for the enumeration of manganese-oxidizing bacteria in estuarine water and sediment samples were compared. A peptone/yeast extract medium containing manganese sulphate and 30% (v/v) sea salts solution gave the highest percentage of manganese-oxidizers and high total viable counts. A survey of estuarine (River Tamar) and marine (English Channel) sites indicated that manganese-oxidizing bacteria comprise a significant but variable proportion (11–85%) of the total bacterial count.     

Effects of amendments on biodegradation of crude petroleum by sediment bacteria from Bonny River Estuary

The biodegradation of Bonny light crude petroleum by bacteria in batch culture was enhanced by the addition to culture media, of 0.2 mg of urea and soya bean lecithin per 100 ml of crude oil, sediment and water mixture. Biodegradation was found to be purely an aerobic process. There was a direct relationship between hydrocarbon content and proportion (%) of total heterotrophic count that was capable of growing on crude petroleum as sole carbon and energy source.     

Association of Elm Yellows Subgroup 16SrV‐B Phytoplasma with a Disease of Hovenia dulcis

Japanese raisin (Hovenia dulcis) trees with typical phytoplasma‐like symptoms were observed for the first time in South Korea. The disease, named Japanese raisin witches’ broom, is progressively destructive. The cause of the graft‐transmissible disease was confirmed by electron microscopy and molecular studies. The 16S rDNA sequence analysis showed that the phytoplasma was closely related to the elm yellows (EY) group, ribosomal subgroup 16SrV‐B. The 16S‐23S rDNA intergenic spacer region, fragment of rp operon and secY gene sequences had 96–99% similarity with members of EY phytoplasma. Based on the sequence analyses and phylogenetic studies, it was confirmed that the phytoplasma infecting Japanese raisin trees in Korea belongs to the EY group.     

冬季太湖表层底泥产毒蓝藻群落结构和种群丰度

应用荧光定量PCR对冬季太湖不同湖区底泥表面有毒微囊藻和总微囊藻种群丰度进行调查,同时基于PCR-DGGE技术对底泥中有毒微囊藻群落结构进行分析。结果表明:微囊藻在太湖底泥表面分布广泛,所有采样点都检测到有毒微囊藻存在,且不同湖区有毒微囊藻和总微囊藻种群丰度存在显著差异,有毒微囊藻和微囊藻基因型丰度范围分别为1.23×10⁴-3.75×10⁶拷贝数/g干重和2.56×10⁴-1.07×10⁷ 拷贝数/g干重,有毒微囊藻与微囊种群丰度的比例为4.8％-35.2％;DGGE指纹图谱显示,冬季太湖不同湖区表层底泥中有毒微囊藻群落结构相似性较高,相似性系数为70.2％-96.0％。虽然不同湖区基因型组成存在差异,但所有样品中占优势的基因型是一致的。同时发现,优势基因型所占的比例与样品的香农多样性指数呈负相关。序列分析表明,mcyA序列长度为291bp,序列相似性超过97％。综合定量PCR结果和底泥中叶绿素a和藻蓝素浓度的测定结果,可以得出2010年冬季太湖蓝藻越冬主要集中在梅梁湾、竺山湾、贡湖湾和湖心。通过建立荧光定量PCR分析方法,为研究湖泊底泥中蓝藻种群丰度动态变化奠定了基础。     

Microbial communities in the saturated groundwater environment II: Diversity of bacterial communities in a Pleistocene sand aquifer and their in vitro activities

Bacterial cell numbers obtained from 103 water and sediment samples from a Pleistocene sandy aquifer in the Lower Rhine region (Bocholt, FRG) were determinated on P-agar and by direct count. Below 5 m under the surface, colony-forming unit (cfu) numbers in water samples were less than 100/ml, and in many cases less than 50/ml. In sediment samples, they were 10- to 100-fold higher (10²–10⁴ cfu/g dry wt), but changing markedly between different depths. Direct cell counts yielded numbers two to three orders of magnitude higher.About 2,700 strains of bacteria from 60 samples were isolated randomly and characterized by morphological and physiological properties. Of all the isolates, 71.6% were gram-negative, and 52.2% were gram-negative straight rods. Water communities, with one exception, had low proportions of gram-positive bacteria (<11%), whereas in all but one of the sediment communities percentages of gram-positive isolates were three- to sevenfold higher (35–43%). Water and sediment communities, as well as communities from different sampling sites and communities from different depths of the same sampling site, differed in their qualitative and quantitative morphotype composition and physiological capabilities.The in vitro activities of strains within a single community were quite different, indicating that each community is composed of many diverse bacteria, several having extremely different capabilities. Thus, each community has its own specific activity pattern. Gram-positive bacteria showed on an average lower total activities than did gram-negative bacteria. Grampositive bacteria as well as gram-negative bacteria from sediment had higher values of in vitro activities than the corresponding groups isolated from water. Many water and sediment bacteria preferred the same substrates which were utilized at high rates. However, there were differences in the degradation of the various other substrates present, and each community showed preferences for particular substrates, which they degraded best.The results of cell morphology and physiology studies indicated that all eight characterized communities were very different from one another and very diversely structured.     

Temporal Variations in Heterotrophic Mesophilic Bacteria from a Marine Shallow Hydrothermal Vent off the Island of Vulcano (Eolian Islands, Italy)

Abstract The fluctuations of the total microbial abundance, the culturable heterotrophic bacterial population, and the composition of heterotrophic bacteria were investigated in relation to environmental parameters in a shallow, marine hydrothermal vent off the Island of Vulcano (Eolian Islands, Italy). Standing stock dynamics were studied by measuring the total population of picoplankton by direct count and the population of viable heterotrophic bacteria in water and sediment samples collected monthly. The environmental factors most strongly linked to the total microbial abundance and heterotrophic bacterial populations were pH and H₂S content in water and C/N ratio in sediment samples. The pattern of variation of microbial populations associated with water was different from those associated with sediment. Assessment of the qualitative composition of aerobic heterotrophic bacterial communities was based on 30 morphological and biochemical characteristics for each strain. Numerical analysis was used for an initial survey of the similarity among the isolates. The data were successively used to determine the structure and the metabolic potential of water and sediment bacteria. Metabolic properties varied between water- and sediment-isolated bacteria. Bacteria from water were structurally more diverse, and active in the use of carbohydrates, than those from sediment. Moreover, most of the sediment bacteria were able to grow at a high temperature (60 and 70°C). The fluctuations of bacterial characteristics in relation to environmental parameters present an evident temporal variation in water, but not in the sediment habitat. Received: 13 January 1997; Accepted: 7 August 1997     

城市河道底泥污染生物修复技术研究

城市河道受污染底泥对水体产生大的二次污染,为有效的控制底泥污染物的释放和开发有效的水体治理技术方法,本研究利用人工模拟河道在连续流条件下,对河道污染底泥的生物修复及其对水体生物修复的影响进行了试验研究。研究结果表明:采用曝气增氧和投加底泥生物修复制剂联合处理的方式能达到好的底泥生物修复效果,能有效的提高底泥的生物降解活性(G值),削减底泥氮磷污染物的释放量,底泥G值与底泥氮、磷污染物释放量呈显著负相关性:单独采用曝气增氧和投加土著微生物制剂联合实施的生物修复方法对河道污染水体均具有良好的修复效果,但底泥的生物修复将对河道水体生物修复的效果产生大的影响。底泥生物修复后,对水体进行生物修复的处理效果更加显著,在相同实验条件下,对水体COD、氨氮的最大去除率由65.0%和16.30%提高到72.0%和41.0%,水体生物修复的周期由13 d缩短为6 d。     

Ecology of Vibrio parahaemolyticus in Chesapeake Bay

A study of the ecology of Vibrio parahaemolyticus and related vibrios in the Rhode River area of Chesapeake Bay was carried out over the period December 1970 through August 1971. The incidence of V. parahaemolyticus and related vibrios was found to be correlated with water temperature. The vibrios could not be detected in the water column during the winter months, although they were present in sediment. From late spring to early summer, when water temperatures were 14 +/- 1 C, vibrios over-wintering in sediment were released from the bottom communities and attached to zooplankton, proliferating as the temperature rose. The number of vibrios in and on plankton was reflected in the water column bacterial population densities at water temperatures of ca. 19 C. Thus, temperature of the water column in the range of 14 to 19 C was found to be critical in the annual cycle of the vibrios. Interaction between sediment, water, and zooplankton was found to be essential in the natural estuarine ecosystem. Bacterial counts of zooplankton were found to be temperature dependent. The bacterial population associated with zooplankton was found to be predominantly on external surfaces and was specific, differing from that of the sediment. Vibrio spp. and related organisms comprised the total bacterial population associated with zooplankton in summer months. The ecological role of Vibrio spp., including V. parahaemolyticus, was found to be significant, with respect to their property of chitin digestion and in relation to the population dynamics of zooplankton in Chesapeake Bay.     

Evidence of a dormant but infective state of the fish pathogen Pasteurella piscicida in seawater and sediment.

The stability of Pasteurella piscicida strains in seawater and sediment microcosms at different temperatures (6 and 20 degrees C) was investigated during a 1-month period. Three strains of P. piscicida showed similar survival kinetics. By a standard plate count method they survived in water and sediment for only 6 to 12 days, depending on the strain and type of microcosm. During this starvation period, the metabolic activity of the cells was reduced by more than 80%. Culturable cells of each P. piscicida strain persisted better in sediment than in water, as well as at 20 degrees C compared to 6 degrees C. However, in all the microcosms, the acridine orange direct counts remained at about 10(5) cells per ml during the experimental period, which demonstrated that P. piscicida possesses a capacity to enter a viable but not culturable state. Moreover, dormant cells were always resuscitated by the addition of fresh medium to the microcosms, since we recovered numbers of culturable cells similar to the acridine orange direct counts. These resuscitated cells exhibited the same respiration rate as that seen prior to the start of the experiments. Although the biochemical, physiological, and serological characteristics; lipopolysaccharides; membrane proteins; and plasmid content of P. piscicida strains were unaffected during the starvation conditions, the dormant cells were smaller (dwarf cells) and had increased surface hydrophobicity. The starved cells maintained their infectivity and pathogenic potential for fish, with 50% lethal doses similar to those of the original strains.