生产多不饱和脂肪酸海洋微生物的培养

多不饱和脂肪酸（ＰＵＦＡ），尤其是二十碳五烯酸（ＥＰＡ）和二十二碳六烯酸（ＤＨＡ），在生物体内有着重要的生理调节功能和保健作用。但人体不能合成或仅能合成微量的ＥＰＡ和ＤＨＡ，故只能依赖从食物中摄入。随着对ＥＰＡ、ＤＨＡ等多不饱和脂肪酸的需求量越来越大，单靠目前的海洋鱼油生产已远远不能满足需要。利用海洋微生物尤其是藻类、真菌和细菌生产多不饱和脂肪酸，大有前途。当前除了从海洋生物群中继续筛选ＥＰＡ和ＤＨＡ含量高的、易于提纯的海洋真菌、细菌和微藻外，还对已有的高产ＰＵＦＡ海洋微生物的培养条件进行优化研…     

不同种属的微生物对养殖水体中有机物质的生物降解

随着社会经济和科学技术的不断发展 ,我国的水产养殖业取得了很大的成就 ,并成为我国农业经济中的一个支柱产业。进入 2 1世纪后 ,由于中国加入 WTO的日益临近 ,我国的水产养殖业面临前所未有的机遇和严峻的挑战。这一切促使我国的水产养殖业步入高品质的名特水产养殖。目前在我国的名特水产养殖中采用高密度养殖的模式 ,养殖水体自身有机污染十分严重。同时受外源性污染的影响 ,养殖水体的环境质量日益下降。水体有机污染不仅可造成水体缺 O2 ,直接危害养殖生物 ,同时也是养殖品种暴发性疾病频繁发生的主要诱因。因此养殖水体的水质控制…     

西峡红柱石微生物除铁探索

本文介绍西峡红柱石，经过常规选矿之后，利用微生物除铁的成果。此项探索为红柱石精选除铁提供了新的途径。     

Screening and molecular classification of low-temperature protease from Antarctic microorganism and its characterization

107 strains producing protease were screened from 260 strains of Antarctic psychrophilic bacteria, among which proteolytic activity of five strains was more than 45 U ml^-1. The 16S rRNA gcne sequences homology and phylogcnetic analysis of five Antarctic psychrophillc bacteria showed that NJ276, NJS-9, NJ16-70,NJ345 belonged tO the described genus Pseudoalteromonas and NJ341 belonged to the genus Colwellia. The growth and the protease characteristic of four Antarctic psychrophilic bacteria had been studied, and the result showed that the 6ptimal temperature for growth and protease-produeing of four strains was about 10℃. Their growth and protease-produeing were still high during incubatlng 2-5 days. The maximum proteolytic activity occurred at pH 9 for four Antarctic psychrophilic bacteria. The optimal temperature of protease action of both strains NJ276 and NJ5-9 was about 50℃, however, the optimal temperature of protease aetlon of both strains NJ341 and NJ345 was about 40 ℃, and their proteolytic activity under 0℃ exhibited nearly 30% of the maximum activity, but their thermal stabilities were weaker. These results indicated that proteases from NJ341 and NJ345 were low-temperature proteases.     

Siderophores from Marine Microorganisms and Their Applications

1　Introduction　Ironisanessentialelementwhichisdifficulttoob tainduetoitslowsolubilityunderthephysiologicalconditions ,anditisalsothemostimportanttransitionmetalionfornearlyalllivingsystems.Manypatho genicbacteriausuallyobtainironfromtheiron bind ingprot…     

Simulation of coupled pelagic-benthic ecosystem of the Yellow Sea Cold Water Mass

A one-dimensional coupled pelagic-benthic box model for the Yellow Sea Cold Water Mass （YSCWM） is developed. The model is divided into three boxes vertically according to the depths of thermocline and euphotic layer. It simulates well the oligotrophic shelf ecosystem of the YSCWM considering effects of nutrients deposition and microbial loop. Main features of vertical structure of various variables in ecosystem of the YSCWM were captured and seasonal variability of the ecosystem was well reconstructed. Calculation shows that the contribution of microbial loop to the zooplankton can reach up to 60%. Besides, input of inorganic nutrients from atmospheric deposition is an important mechanism of production in upper layer of the YSCWM when stratified.     

The Philippine National Collection of Microorganisms （PNCM）： Repository of Microbial Diversity of the Country

The prime function of the Philippine National Collection of Microorganisms (PNCM), being the national repository of microbial strains, is to collect and preserve strains for their continued viability and availability for future use. To date, a total of 2144 strains of bacteria (1357), yeasts (250), filamentous fungi (377), algae (14), and strains still to be identified (146) are maintained at the PNCM. These are preserved and maintained using various methods which include modified liquid drying (lyophilization), ultra-low temperature (-70℃) storage in 10% glycerol, storage in sterile soil, distilled water and overlaying with mineral oil. Periodic viability testing is done to assess the stability of these preserved cultures under storage. Aside from preservation and maintenance of cultures, the PNCM is also involved in several research activities. One of these is the isolation, characterization and identification of some Vibrio isolates from the Philippines. Details on this particular study is presented in this report.     

Effects of DNA extraction and universal primers on 16S rRNA gene-based DGGE analysis of a bacterial community from fish farming water

Among many reports investigating microbial diversity from environmental samples with denaturing gradient gel electrophoresis (DGGE), limited attention has been given to the effects of universal primers and DNA extraction on the outcome of DGGE analysis. In this study, these effects were tested with 16S rRNA gene-based DGGE on a bacterial community from farming water samples. The results indicate that the number of discernable bands in the DGGE fingerprint differed with the primer pairs used; the bands produced by 63f/518r, 341f/926r and 933f/1387r primer pairs were obviously fewer than those by 968f/1401r. Also, we found that each DNA extraction method resulted in different community profiles, reflected by the number and intensity of bands in the DGGE fingerprint. Furthermore, the main bands (theoretically representing dominant bacteria) differed with the extraction methods applied. It is therefore believed that the effects of universal primers and DNA extraction should be given more attention and carefully chosen before performing an investigation into a new environment with DGGE.     

南极发现微生物群落这一冰下生态系统或许可以回答有关“雪球地球”时代生命问题

美国科学家4月16日说，他们发现南极泰勒冰川下的一个湖泊中存在古老的微生物系统，该系统在没有光合作用及外部营养源的情况下已经延续了上百万年。研究人员报告说，由于泰勒冰川有一个大断面，该冰川下方一个湖泊的水一滴一滴地从断面的冰隙中流淌出来，把附近的岩石和冰面染成了橙色。科研人员通过分析这些流出的水发现，     

Studies on culture condition and extracellular hydrolase of psychrophilic bacteria from Arctic sea ice

Arctic sea ice in the polar region provides a cold habitat for microbial community. Arctic sea ice microorganisms are revealed to be of considerable importance in basic research and potential in biotechnological application. This paper investigated the culture condition and extraceIlular hydrolase of 14 strains of different Arctic sea ice bacteria. The results showed that optimal growth temperature of strains is 15 ℃ or 20 ℃. The optimal pH is about 8.0. They hardly grow at acid condition. 3 % NaCl is necessary for better growth. These strains have different abilities in producing amylase, protease, eellulase and lipase. Pseudoalteronomas sp. Bsi429 and Pseudoalteronomas sp. Bsi539 produced both cellulose, protease and lipase. These results provide a basis for further developing and exploiting the cold adapted marine enzyme resources.     

Study on Algae Removal by Immobilized Biosystem on Sponge

In this study, sponges were used to immobilize domesticated sludge microbes in a limited space, forming an immobilized biosystem capable of algae and microcystins removal. The removal effects on algae, microcystins and UV260 of this biosystem and the mechanism of algae removal were studied. The results showed that active sludge from sewage treatment plants was able to remove algae from a eutrophic lake＇s water after 7 d of domestication. The removal efficiency for algae, organic matter and microcystins increased when the domesticated sludge was immobilized on sponges. When the hydraulic retention time （HRT） was 5h, the removal rates of algae, microcystins and UV260 were 90%, 94.17% and 84%, respectively. The immobilized biosystem consisted mostly of bacteria, the Ciliata and Sarcodina protozoans and the Rotifer metazoans. Algal decomposition by zoogloea bacteria and preyingby microcreatures were the two main modes of algal removal, which occurred in two steps： first, absorption by the zoogloea; second, decomposition by the zoogloea bacteria and the predacity of the microcreatures.     

Axenic culture of free-living conchocelis of<Emphasis Type="Italic">Porphyra yezoensis</Emphasis> and<Emphasis Type="Italic">Porphyra haitanensis</Emphasis>

After discarding marine microorganisms from conchocelis of Porphyra yezoensis and Porphyra ha/tanens/s, their axenic cultures were obtained through treatment with antibiotics. Antibiotic disc tests were carried out to determine the effectiveness of each antibiotic in eliminating contaminating microorganisms. Five of 12 antibiotics tested were selected and used to produce the axenic cultures in this study, which showed that 200 μg/mL streptomycin, 250 μg/mL penicillin, 252 μg/mL kanamycin, 30 μg/mL neomycin, 200 μg/mL chloramphenicol were effective concentrations for eliminating microorganisms from conchocelis when antibiotics were added singly step by step; whereas simultaneous combination of 150 μg/mL streptomycin, 250 (or 350) μg/mL penicillin, 150 (or 250) μg/mL kanamycin, 70 μg/mL neomycin and 200 μg/mL chloramphenicol was also effective for producing the axenic cultures. However,it seemed that the treatments with antibiotics applied individually were more feasible than those with all antibiotics added at the same time. This may be due to the combined inhibiting effect of antibiotics on the growth and development of conchocelis.     

Recent researches of bioactive metabolites in marine organisms-associated microorganisms

1　Introduction　Sincetheearly 196 0s ,oceanhasbeenconsideredasanewanduntouchedsourceofpotentiallyusefulcom pounds .Theresultsfromtheresearchesontheorgan ismssuchassponges,softcorals ,algae ,ascidians ,bryozoansandmollusks ,havedemonstratedthatma rineorga…     

Land use effects on soil organic carbon,microbial biomass and microbial activity in Changbai Mountains of Northeast China

Land use changes are known to alter soil organic carbon （SOC） and microbial properties, however, information about how conversion of natural forest to agricultural land use as well as plantations affects SOC and microbial properties in the Changbai Moun- tains of Northeast China is meager. Soil carbon content, microbial biomass carbon （MBC）, basal respiration and soil carbon mineraliza- tion were studied in five selected types of land use： natural old-growth broad-leaved Korean pine mixed forest （NF）; spruce plantation （SP） established following clear-cutting of NF; cropland （CL）; ginseng farmland （GF） previously under NF; and a five-year Mongolian oak young forest （YF） reforested on an abandoned GF, in the Changbai Mountains of Northeast China in 2011. Results showed that SOC content was significantly lower in SP, CL, GF, and YF than in NF. MBC ranged from 304.4 mg/kg in CL to 1350.3 mg/kg in NF, which was significantly higher in the soil of NF than any soil of the other four land use types. The SOC and MBC contents were higher in SP soil than in CL, GF, and YF soils, yielding a significant difference between SP and CL. The value of basal respiration was also higher in NF than in SP, CL, GF, and YF. Simultaneously, higher values of the metabolic quotient were detected in CL, GF, and YF soils, indicat- ing low substrate utilization of the soil microbial community compared with that in NF and SP soil. The values of cumulative mineral- ized carbon and potentially mineralized carbon （Co） in NF were significantly higher than those in CL and GF, while no significant dif- ference was observed between NF and SP. In addition, YF had higher values of Co and C mineralization rate compared with GF. The results indicate that conversion from NF into agricultural land （CL and GF） uses and plantation may lead to a reduction in soil nutrients （SOC and MBC） and substrate utilization efficiency of the microbial community. By contrast, soils below SP were more conducive to the preservation of soil organic matter, which was reflected in the comparison of microbial indicators among CL, GF, and YF land uses. This study can provide data for evaluating soils nutrients under different land use types, and serve as references for the rational land use of natural forest in the study area.     

有益微生物对水质因子的调控效应

随着我国水产养殖业的发展 ,集约化、半集约化的养虾模式随之迅猛发展 ,养殖规模不断扩大。在养殖过程中 ,因残存饵料腐烂 ,生物代谢 ,以及生物残体沉积 ,致使养殖水体理化环境和生态环境恶化 ,从而影响生物的生长、发育和行为活动。为改善养殖环境 ,促进水产养殖业健康可持续性地发展 ,近年来微生物技术在水产养殖业中得到了广泛应用[1,2 ] ,1) 。利用芽孢杆菌和光合细菌等有益微生物能调节和稳定养殖水体中的水质因子 ,分解、转化养殖水体的有机物的特性 ,达到改良、净化和营造养殖生态环境的效果 ,在生产上取得了明显的成效。为此 ,从 1 …     

湛江市腌制金线鱼的微生物及理化指标检测

按照相关国家标准,分析湛江市腌制金线鱼(Nemipterus virgatus)中的微生物和理化指标.结果表明:腌制金线鱼的微生物安全指标中有3组样品菌落总数略超标,其他指标符合西班牙等国家腌渍鱼制品微生物标准;耐盐菌数为菌落总数20倍以上,优势耐盐菌全为革兰阴性杆菌,6株优势嗜盐菌中有2株为革兰阳性球菌;理化指标中挥发性盐基氮含量均低于300 mg/kg,符合水产品质量要求;甲醛及亚硝酸盐含量均低于5 mg/kg,相对较低.可见,湛江市腌制金线鱼安全质量状况较好     

Environmental Characterization of Periphyton Community

The present paper deals with the behavior of the Attached Microbial Community （AMC） for water self-purification at different riverbeds in a typical local river. The study quantitatively investigated the problem starting with in-situ sampling. It was found that more biomass of AMC was at riffles with wider distribution than in pools. High current velocity （HCV） plays a negative role at the initial stage of attachment on the riverbed, but HCV aids the community proliferation after stable attachment. External disturbances such as rainfalls and discharges from dams or reservoirs would detach the periphyton depending on the intensity of turbulence in water. However, it was discovered that the flock of periphyton could be restored very quickly because it was not completely removed. Thus, in order to enhance self-purification by periphyton, a suitable configuration of the riverbed must be constructed, and occasional appropriate repair along the channels would improve the decontamination of the river.