After discarding marine microorganisms from conchocelis of Porphyra yezoensis and Porphyra haitanensis, their axenic cultures were obtained through treatment with antibiotics. Antibiotic disc tests were carried out to...After discarding marine microorganisms from conchocelis of Porphyra yezoensis and Porphyra haitanensis, 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.展开更多
Introduction Diatoms,a diverse group of photosynthetic unicellular algae,have gained significant global attention due to their ecological importance and multifaceted applications in scientific research.Their ecologica...Introduction Diatoms,a diverse group of photosynthetic unicellular algae,have gained significant global attention due to their ecological importance and multifaceted applications in scientific research.Their ecological roles are critical,encompassing nutrient cycling,carbon sequestration,and primary productivity,which establish them as essential components of aquatic food webs.The remarkable species richness of diatoms underscores their evolutionary success and highlights their integral roles in both freshwater and marine ecosystems.In addition to their environmental significance,diatoms possess a rich biochemical profile comprising valuable compounds with immense potential for biotechnological applications.These applications span diverse fields,including biofuel production,pharmaceuticals,and wastewater remediation.Despite the vast diversity and biochemical richness of diatoms,laboratory cultivation and maintenance remain challenging.To address these challenges,two primary methodologies have been developed:xenic and axenic culture techniques.Xenic culture involves maintaining diatoms alongside associated microorganisms,thereby replicating natural conditions and preserving ecological interactions.In contrast,axenic culture techniques focus on isolating pure diatom strains by employing meticulous sterilization processes,enabling precise experimental manipulation and fundamental research.Understanding the significance of xenic and axenic cultivation methodologies is essential for unlocking the full potential of diatoms across diverse scientific domains.This review elaborates on the methodologies,scope,and applications of xenic and axenic culture techniques for diatoms.By examining the intricacies of these cultivation approaches,it seeks to provide insights into optimizing diatom culture practices,advancing research initiatives,and harnessing the biotechnological potential of these extraordinary microorganisms.展开更多
Axenic microalgal strains are highly valued in diverse microalgal studies and applications. Antibiotics, alone or in combination, are often used to avoid bacterial contamination during microalgal isolation and culture...Axenic microalgal strains are highly valued in diverse microalgal studies and applications. Antibiotics, alone or in combination, are often used to avoid bacterial contamination during microalgal isolation and culture. In our preliminary trials, we found that many microalgae ceased growing in antibiotics at extremely high concentrations but could resume growth quickly when returned to an antibiotics-free liquid medium and formed colonies when spread on a solid medium. We developed a simple and highly efficient method of obtaining axenic microalgal cultures based on this observation. First, microalgal strains of different species or strains were treated with a mixture of ampicillin, gentamycin sulfate, kanamycin, neomycin and streptomycin （each at a concentration of 600 mg/L） for 3 days; they were then transferred to antibiotics-free medium for 5 days; and finally they were spread on solid f/2 media to allow algal colonies to form. With this method, five strains ofNannochloropsis sp. （Eustigmatophyceae）, two strains of Cylindrotheca sp. （Bacillariophyceae）, two strains of Tetraselmis sp. （Chlorodendrophyceae） and one strain ofAmphikrikos sp. （Trebouxiophyceae） were purified successfully. The method shows promise for batch- purifying microalgal cultures.展开更多
法国Axens公司开发的多产丙烯渣油流化催化裂化（RFCC）“PetroRiser”新技术工业应用。这项新技术是FCC联盟中的一部分（FCC联盟由Axens、TheShawGroup、Total S A、IFP四家公司联合组建），采用该新技术的工业化许可项目定于2008年7...法国Axens公司开发的多产丙烯渣油流化催化裂化（RFCC）“PetroRiser”新技术工业应用。这项新技术是FCC联盟中的一部分（FCC联盟由Axens、TheShawGroup、Total S A、IFP四家公司联合组建），采用该新技术的工业化许可项目定于2008年7月公布。展开更多
文摘After discarding marine microorganisms from conchocelis of Porphyra yezoensis and Porphyra haitanensis, 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.
文摘Introduction Diatoms,a diverse group of photosynthetic unicellular algae,have gained significant global attention due to their ecological importance and multifaceted applications in scientific research.Their ecological roles are critical,encompassing nutrient cycling,carbon sequestration,and primary productivity,which establish them as essential components of aquatic food webs.The remarkable species richness of diatoms underscores their evolutionary success and highlights their integral roles in both freshwater and marine ecosystems.In addition to their environmental significance,diatoms possess a rich biochemical profile comprising valuable compounds with immense potential for biotechnological applications.These applications span diverse fields,including biofuel production,pharmaceuticals,and wastewater remediation.Despite the vast diversity and biochemical richness of diatoms,laboratory cultivation and maintenance remain challenging.To address these challenges,two primary methodologies have been developed:xenic and axenic culture techniques.Xenic culture involves maintaining diatoms alongside associated microorganisms,thereby replicating natural conditions and preserving ecological interactions.In contrast,axenic culture techniques focus on isolating pure diatom strains by employing meticulous sterilization processes,enabling precise experimental manipulation and fundamental research.Understanding the significance of xenic and axenic cultivation methodologies is essential for unlocking the full potential of diatoms across diverse scientific domains.This review elaborates on the methodologies,scope,and applications of xenic and axenic culture techniques for diatoms.By examining the intricacies of these cultivation approaches,it seeks to provide insights into optimizing diatom culture practices,advancing research initiatives,and harnessing the biotechnological potential of these extraordinary microorganisms.
基金Supported by the National Basic Research Program of China(973 Program)(No.2011CB200901)the National Technical Supporting Project Foundation(No.2011BAD14B01)the National High Technology Research and Development Program of China(863 Program)(No.2013AA065801)
文摘Axenic microalgal strains are highly valued in diverse microalgal studies and applications. Antibiotics, alone or in combination, are often used to avoid bacterial contamination during microalgal isolation and culture. In our preliminary trials, we found that many microalgae ceased growing in antibiotics at extremely high concentrations but could resume growth quickly when returned to an antibiotics-free liquid medium and formed colonies when spread on a solid medium. We developed a simple and highly efficient method of obtaining axenic microalgal cultures based on this observation. First, microalgal strains of different species or strains were treated with a mixture of ampicillin, gentamycin sulfate, kanamycin, neomycin and streptomycin （each at a concentration of 600 mg/L） for 3 days; they were then transferred to antibiotics-free medium for 5 days; and finally they were spread on solid f/2 media to allow algal colonies to form. With this method, five strains ofNannochloropsis sp. （Eustigmatophyceae）, two strains of Cylindrotheca sp. （Bacillariophyceae）, two strains of Tetraselmis sp. （Chlorodendrophyceae） and one strain ofAmphikrikos sp. （Trebouxiophyceae） were purified successfully. The method shows promise for batch- purifying microalgal cultures.
