Quantitative characteristics of microorganisms in permafrost at different depths and their relation to soil physicochemical properties     

Wei Zhang  XiaoPei Dong  GuangXiu Liu  GaoSen Zhang  XiuKun Wu  XiSheng Tai  HaoZhi Long  BaoGui Zhang 《寒旱区科学》2012,4(2):0127-0131

Microorganisms in permafrost can live in cold environments due to coadapted physicochemical processes in this environment. In this paper, the relation between microbial number and soil physicochemical properties at the headwaters area of the Urumqi River is analyzed by using fluorescence microscopy counting and oligo-culture techniques. In total, 20 samples from a 200-cm permafrost core were used as study materials. The study reveals that the number of culturable bacteria has a significantly positive correlation with soil water content, total carbon and total nitrogen concentrations, and a significantly negative correlation with soil pH value. In addition, the ratio of culturable bacteria to total cell number decreases with depths. The results demonstrate that the number of culturable bacteria in permafrost is closely correlated with soil physicochemical properties and depositional age.  相似文献   

四种不同饵料对真蛸(Octopus vulgaris)生长与肠道微生物影响的研究     

骆启豪  王卫军  倪乐海  景福涛  许贺  李赞  李彬  杨建敏 《海洋与湖沼》2021,52(3):729-737

本研究分析了不同饵料对真蛸(Octopus vulgaris)生长与肠道微生物的影响。实验采用4种饵料:蓝点马鲛(鱼组)、天津厚蟹(蟹组)、四角蛤蜊(贝组)和日本枪乌贼(鱿鱼组)分别投喂真蛸,分析了各实验组真蛸的日均摄食量、特定生长率、饵料转化率、经济效益比,以及饵料对肠道微生物菌群结构和多样性的影响。实验结果表明:在生长性能指标方面,贝组的日均摄食量最高,而饵料转化率低于鱼组与蟹组;鱼组与蟹组的日均摄食量差异不大,但蟹组真蛸的特定生长率和饵料转化率高于其他三组且经济效益最佳;鱿鱼组的日均摄食量、特定生长率、饵料转化率和经济效益比均低于其他三组。在真蛸肠道微生物群落的丰富度与多样性方面,鱼组均高于其他各组,而鱿鱼组的丰富度最低;在门水平上,软壁菌门、螺旋体门、变形菌门等10个门为真蛸的优势菌群;在属水平上,摄食率最大的贝组真蛸肠道菌群中的支原体、乳球菌等11种菌为优势菌群,特定生长率最大的蟹组中真蛸肠道菌群中的弧菌、小纺锤状菌等5种菌为优势菌群。综合不同饵料对真蛸生长性能指标和肠道菌群的影响,认为蟹类是真蛸理想的饵料。  相似文献   

Fluid inclusions as a tool to constrain the preservation conditions of sub-seafloor cryptoendoliths     

M. Ivarsson  C. Broman  S. Lindblom  N.G. Holm 《Planetary and Space Science》2009,57(4):477-490

The combination of fluid inclusion analyses and microfossil analyses is an excellent method to study the preservation process of deep sub-seafloor microorganisms. By studying fluid inclusions in the same mineral phases as microfossils, it is possible to reconstruct the conditions that prevailed when the microorganisms where entombed and to put them in a geological and environmental context.This study has been performed on carbonate and gypsum veins in drilled basalt samples from three seamounts belonging to the Emperor Seamounts in the Pacific Ocean: Detroit, Nintoku and Koko Seamounts. The study show that variations in salt composition (MgCl₂, NaCl, KCl and CaCl₂) and salinity (2.1 and 10.5 eq. wt% NaCl) of the hydrothermal fluids do not have an influence on the occurrence of microfossils throughout the samples. The microorganisms were trapped and entombed at minimum temperatures of ∼130 °C which implies that the microorganisms could have existed at temperatures of ∼130 °C for shorter periods of time. The microorganisms were entrapped at shallow-marine to submarine conditions and the entrapment of the microorganisms occurred relatively late compared to the volcanic activity.  相似文献   

Bioremediation of sulphate rich mine effluents using grass cuttings and rumen fluid microorganisms   总被引：1，自引：0，他引：1  

Harma A. Greben  Jacobin Baloyi  Julia Sigama  Stephanus N. Venter 《Journal of Geochemical Exploration》2009,100(2-3):163-168

Acid Mine Drainage (AMD) needs to be treated before it can be re-used or discharged in receiving water bodies due to the low pH, high salinity and high sulphate concentrations of the water. Several treatment methods are currently applied including chemical treatment (e.g. neutralisation of the low pH waters), physical treatment (e.g. reverse osmosis) and biological treatment to reduce the high sulphate concentration. When treating AMD biologically, sulphate reducing bacteria (SRB) reduce sulphate to sulphide, provided that a suitable and cost effective carbon and energy source is present. In the present study mine water was remediated biologically, using the degradation products of grass-cellulose, as carbon and energy sources for the sulphate reducing bacteria. A laboratory scale one stage anaerobic bioreactor (20 L volume) containing grass cuttings and biomass consisting of rumen fluid microorganisms and immobilized SRB, was initially fed with synthetic sulphate rich water and later with diluted AMD. The results indicated an average of 86% sulphate removal efficiency when feeding synthetic sulphate rich feed water to the reactor. When feeding diluted AMD, the highest sulphate removal efficiency was 78%. The sulphate removal was dependant on Chemical Oxygen Demand (COD) concentrations in the reactor. Increased COD concentrations were obtained when fresh grass was added to the reactor on a regular basis. Metal removal, especially iron, was observed due to the metal sulphide precipitates formed during biological sulphate removal.  相似文献   

乳酸菌及其代谢产物对刺参幼体肠道菌群和非特异性免疫的影响     

宫魁  王宝杰  刘梅  蒋克勇  邱楚雯  骆作勇  范瑞用  王雷 《海洋科学》2013,37(7):7-12

以初始体质量为(2.74±0.17)g 的刺参(Apostichopus japonicus)为研究对象, 在室内养殖池进行60 d饲喂实验, 研究饲料中添加乳酸菌制剂和乳酸菌代谢产物对刺参肠道菌群、部分免疫指标及生长的影响。在基础饲料中分别添加乳酸菌制剂和乳酸菌代谢产物各2 mL/m³(按饲养水体折算), 配制2 种实验饲料。实验结果显示: 与对照组比, 饲料中添加乳酸菌与乳酸菌代谢产物均显著降低了刺参肠道弧菌数及大肠杆菌数(P＜0.05); 饲料中添加乳酸菌及其代谢产物能使刺参肠道酸性磷酸酶和碱性磷酸酶活力显著升高, 溶菌酶活性有所提升, 其中乳酸菌制剂实验组与代谢产物实验组免疫酶活力差异不显著;两实验组刺参的特定生长率显著高于对照组(P＜0.05)。上述结果表明, 乳酸菌制剂与乳酸菌代谢产物对刺参的肠道菌群平衡、免疫力及生长均具有良好的促进作用, 且两者之间差异不显著。  相似文献   

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

李晓晖  俞勇  李会荣  张琳  蒋欣音  任大明 《极地研究(英文版)》2008,19(1):77-84

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.  相似文献   

复方中草药对吉富罗非鱼生长及肠道菌群的影响   总被引：1，自引：0，他引：1  

汤菊芬  吴灶和  简纪常  鲁义善  王蓓 《广东海洋大学学报》2009,29(6):46-49

将A、B、C三种复方中草药分别按质量分数1.5%的比例添加到罗非鱼商品饲料中,喂养初始体重约16.58±0.48g的吉富罗非罗28d,通过测定罗非鱼的增重率、饲料系数、肠道菌群等指标,研究三种复方中草药制剂对罗非鱼生长性能及肠道菌群的影响。结果显示:三种复方中草药制剂对罗非鱼的增重率、成活率、饲料系数等生长性能指标虽无显著影响(P>0.05),但与对照组相比,添加1.5%的复方中草药制剂C可使吉富罗非鱼的增重率提高10.82%,饲料系数降低4.71%,蛋白质效率提高15.68%;三种复方中草药制剂均可显著促进罗非鱼肠道细菌、双歧杆菌、乳酸杆菌的生长(P<0.05),C方中草药制剂还可显著抑制大肠杆菌生长(P<0.05)。结果表明,C方中草药制剂可显著促进罗非鱼肠道中乳酸杆菌等有益菌群的增殖,抑制大肠杆菌生长,从而有效促进罗非鱼生长。  相似文献   

高压下深海碳循环的过程及其对生命活动的影响     

刘亮霆  肖湘 《中国地质调查》2021,8(4):66-78

目前约25%化石燃料来源的CO₂被海洋吸收,缓解了人类活动对气候变化的影响。海洋通过多个概念的碳泵将大气中的CO₂输送到深海。深海高压和低温的特点有利于CO₂溶解,目前已经储存了相当于大气含量50倍的无机碳,另外,深海沉积物中还储存有大量甲烷水合物。认识深海中的碳循环过程,对于保护海洋固碳能力、开发固碳潜力有重要意义。总结了国内外在海洋碳库、碳输送研究方面的进展,重点讨论了深海C元素转化循环的过程以及高压对生命活动的影响。微生物驱动了深海碳循环,大部分浮游植物所包含的有机碳在沉降过程中被微生物矿化成CO₂以及转化为难降解的有机碳,使深海成为巨大的、长周转时间的有机碳库; 高压能提高古菌甲烷厌氧氧化的活性,提升屏蔽海底甲烷释放的能力,同时,高压下氧化甲烷的过程中不仅产生碳酸氢盐,还产生可支持异养生物的乙酸,因此,全球甲烷厌氧氧化的通量可能被低估; 高压下细胞代谢额外产生的氨,可作为氨氧化古菌固定无机碳的潜在能量来源。总之,研究现在以及未来的人类活动对深海碳循环过程的影响以及环境效应,评估应用深海作为地球工程技术平台封存CO₂的可能性,都迫切需要加深对碳循环在内的深海元素循环的认识。  相似文献   

国外海洋抗肿瘤活性物质的研究与开发   总被引：15，自引：0，他引：15  

李盛英  郑忠辉 《海洋通报》2003,22(2):76-82

海洋生物是抗肿瘤活性物质的重要来源。近十几年来，已从不同的海洋生物中分离鉴定了许多结构新颖的抗肿瘤活性物质，显示出诱人的研究开发前景。本文综述了目前国外从海洋动物、海洋植物和海洋微生物抗肿瘤活性物质的研究开发进展。  相似文献   

斑节对虾节水型养殖期间虾池硫化物含量的变化特征   总被引：4，自引：0，他引：4  

甘居利  林钦  李卓佳  黄洪辉  杨美兰  蔡文贵  王增焕  吕晓瑜  贾晓平 《台湾海峡》2005,24(1):83-89

在斑节对虾节水型养殖期间,观测了虾池底质和海水中硫化物含量的变化.结果表明,投放有益微生物的试验池与未投放有益微生物的对照池相比,底质硫化物含量波动较小,增高的速度较慢、增幅较小.在养殖后期试验池底质硫化物含量只增高了 68%,而对照池的增高了 252%.养殖过程中海水硫化物浓度呈阶段式和波浪式增高,在试验池中其浓度多数时间比对照池中的低.有益微生物能在一定程度上抑制水体和底质中硫化物的积累,但对老化虾池效果较差.由于节水型养殖模式利用有益微生物分解养殖过程中产生的有机物,采用单细胞藻类吸收利用营养盐,使养殖环境质量得到改善.  相似文献