The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform
Alison M Berry - One of the best experts on this subject based on the ideXlab platform.
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flavonoid like compounds from seeds of red alder alnus rubra influence host nodulation by frankia Actinomycetales
Physiologia Plantarum, 1997Co-Authors: Larry F Benoit, Alison M BerryAbstract:Nitrogen-fixing root nodules are formed by Frankia spp. (Actinomycetales) on dicotyledonous hosts such as alders (Alnus spp.). Flavonoid-containing preparations from seed washes of red alder (Alnus rubra Bong.), and individual compounds isolated from such preparations, influenced nodulation of A. rubra by Frankia. Nodulation was enhanced by one flavonoid-like compound, and apparently inhibited by two other such compounds. Four flavonoid-like compounds had no significant effect on nodulation. The seven individual compounds purified from the seed washes were characterized spectrally as possible flavanones and isoflavones. Both the enhancer and the inhibitors appeared to be possible flavanones.
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Flavonoid‐like compounds from seeds of red alder (Alnus rubra) influence host nodulation by Frankia (Actinomycetales)
Physiologia Plantarum, 1997Co-Authors: Larry F Benoit, Alison M BerryAbstract:Nitrogen-fixing root nodules are formed by Frankia spp. (Actinomycetales) on dicotyledonous hosts such as alders (Alnus spp.). Flavonoid-containing preparations from seed washes of red alder (Alnus rubra Bong.), and individual compounds isolated from such preparations, influenced nodulation of A. rubra by Frankia. Nodulation was enhanced by one flavonoid-like compound, and apparently inhibited by two other such compounds. Four flavonoid-like compounds had no significant effect on nodulation. The seven individual compounds purified from the seed washes were characterized spectrally as possible flavanones and isoflavones. Both the enhancer and the inhibitors appeared to be possible flavanones.
Larry F Benoit - One of the best experts on this subject based on the ideXlab platform.
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flavonoid like compounds from seeds of red alder alnus rubra influence host nodulation by frankia Actinomycetales
Physiologia Plantarum, 1997Co-Authors: Larry F Benoit, Alison M BerryAbstract:Nitrogen-fixing root nodules are formed by Frankia spp. (Actinomycetales) on dicotyledonous hosts such as alders (Alnus spp.). Flavonoid-containing preparations from seed washes of red alder (Alnus rubra Bong.), and individual compounds isolated from such preparations, influenced nodulation of A. rubra by Frankia. Nodulation was enhanced by one flavonoid-like compound, and apparently inhibited by two other such compounds. Four flavonoid-like compounds had no significant effect on nodulation. The seven individual compounds purified from the seed washes were characterized spectrally as possible flavanones and isoflavones. Both the enhancer and the inhibitors appeared to be possible flavanones.
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Flavonoid‐like compounds from seeds of red alder (Alnus rubra) influence host nodulation by Frankia (Actinomycetales)
Physiologia Plantarum, 1997Co-Authors: Larry F Benoit, Alison M BerryAbstract:Nitrogen-fixing root nodules are formed by Frankia spp. (Actinomycetales) on dicotyledonous hosts such as alders (Alnus spp.). Flavonoid-containing preparations from seed washes of red alder (Alnus rubra Bong.), and individual compounds isolated from such preparations, influenced nodulation of A. rubra by Frankia. Nodulation was enhanced by one flavonoid-like compound, and apparently inhibited by two other such compounds. Four flavonoid-like compounds had no significant effect on nodulation. The seven individual compounds purified from the seed washes were characterized spectrally as possible flavanones and isoflavones. Both the enhancer and the inhibitors appeared to be possible flavanones.
Wen-jun Li - One of the best experts on this subject based on the ideXlab platform.
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Update on the classification of higher ranks in the phylum Actinobacteria.
International Journal of Systematic and Evolutionary Microbiology, 2020Co-Authors: Nimaichand Salam, Jian-yu Jiao, Xiao-tong Zhang, Wen-jun LiAbstract:Genome analysis is one of the main criteria for description of new taxa. Availability of genome sequences for all the actinobacteria with a valid nomenclature will, however, require another decade’s works of sequencing. This paper describes the rearrangement of the higher taxonomic ranks of the members of the phylum ‘ Actinobacteria ’, using the phylogeny of 16S rRNA gene sequences and supported by the phylogeny of the available genome sequences. Based on the refined phylogeny of the 16S rRNA gene sequences, we could arrange all the members of the 425 genera of the phylum ‘ Actinobacteria ’ with validly published names currently in use into six classes, 46 orders and 79 families, including 16 new orders and 10 new families. The order Micrococcales Prevot 1940 (Approved Lists 1980) emend. Nouioui et al. 2018 is now split into 11 monophyletic orders: the emended order Micrococcales and ten proposed new orders Aquipuribacterales , Beutenbergiales , Bogoriellales , Brevibacteriales , Cellulomonadales , Demequinales , Dermabacterales , Dermatophilales , Microbacteriales and Ruaniales . Further, the class ‘ Actinobacteria ’ Stackebrandt et al. 1997 emend. Nouioui et al. 2018 was described without any nomenclature type, and therefore the name ‘ Actinobacteria ’ is deemed illegitimate. In accordance to Rule 8 of the International Code of Nomenclature of Prokaryotes, Parker et al. 2019, we proposed the name Actinomycetia which is formed by using the stem of the name Actinomycetales Buchanan 1917 (Approved Lists 1980) emend. Zhi et al. 2009, to replace the name ‘ Actinobacteria ’. The nomenclature type of the proposed new class Actinomycetia is the order Actinomycetales Buchanan 1917 (Approved Lists 1980) emend. Zhi et al. 2009.
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abundant and diverse endophytic actinobacteria associated with medicinal plant maytenus austroyunnanensis in xishuangbanna tropical rainforest revealed by culture dependent and culture independent methods
Environmental Microbiology Reports, 2012Co-Authors: Huahong Chen, Jihong Jiang, Lihua Xu, Guozhen Zhao, Wen-jun Li, Jie LiAbstract:Endophytes are now considered as an important component of biodiversity. However, the diversity of endophytic actinobacteria associated with tropical rainforest native medicinal plants is essentially unknown. In this study, the diversity of endophytic actinobacteria residing in root, stem and leaf tissues of medicinal plant Maytenus austroyunnanensis collected from tropical rainforest in Xishuangbanna, China was investigated with a combination of cultivation and culture-independent analysis on the basis of 16S rRNA gene sequencing. By using different selective isolation media and methods, a total of 312 actinobacteria were obtained, and they were affiliated with the order Actinomycetales (distributed into 21 genera). Based on a protocol for endophytes enrichment, three 16S rRNA gene clone libraries were constructed and 84 distinct operational taxonomic units were identified and they distributed among the orders Actinomycetales and Acidimicrobiales, including eight suborders and at least 38 genera with a number of rare actinobacteria genera. Phylogenetic analysis showed that 32% of the clones in the libraries had lower than 97% similarities with related type strains. Interestingly, six genera from the order Actinomycetales and uncultured clones from Acidimicrobiales have not, to our knowledge, been previously reported as endophytes. Our study confirms abundant endophytic actinobacterial consortium in tropical rainforest native plant and suggests that this special habitat represents an underexplored reservoir of diverse and novel actinobacteria of potential interest for bioactive compounds discovery.
Aharon Oren - One of the best experts on this subject based on the ideXlab platform.
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proposal to designate the order Actinomycetales buchanan 1917 162 approved lists 1980 as the nomenclatural type of the class actinobacteria request for an opinion
International Journal of Systematic and Evolutionary Microbiology, 2017Co-Authors: Aharon OrenAbstract:The name of the class Actinobacteria is illegitimate according to Rules 15, 22 and 27(3) because it was proposed without the designation of a nomenclatural type. I therefore propose to designate the order Actinomycetales Buchanan 1917, 162 (Approved Lists 1980) as its nomenclatural type, based on Rule 22 of the International Code of Nomenclature of Prokaryotes.
Noriyasu Shikura - One of the best experts on this subject based on the ideXlab platform.
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peptidoglycan cross linking in glycopeptide resistant Actinomycetales
Antimicrobial Agents and Chemotherapy, 2014Co-Authors: Jeanemmanuel Hugonnet, Nabila Haddache, Carole Veckerle, Lionel Dubost, Arul Marie, Noriyasu ShikuraAbstract:ABSTRACT Synthesis of peptidoglycan precursors ending in d-lactate (d-Lac) is thought to be responsible for glycopeptide resistance in members of the order Actinomycetales that produce these drugs and in related soil bacteria. More recently, the peptidoglycan of several members of the order Actinomycetales was shown to be cross-linked by l,d-transpeptidases that use tetrapeptide acyl donors devoid of the target of glycopeptides. To evaluate the contribution of these resistance mechanisms, we have determined the peptidoglycan structure of Streptomyces coelicolor A(3)2, which harbors a vanHAX gene cluster for the production of precursors ending in d-Lac, and Nonomuraea sp. strain ATCC 39727, which is devoid of vanHAX and produces the glycopeptide A40296. Vancomycin retained residual activity against S. coelicolor A(3)2 despite efficient incorporation of d-Lac into cytoplasmic precursors. This was due to a d,d-transpeptidase-catalyzed reaction that generated a stem pentapeptide recognized by glycopeptides by the exchange of d-Lac for d-Ala and Gly. The contribution of l,d-transpeptidases to resistance was limited by the supply of tetrapeptide acyl donors, which are essential for the formation of peptidoglycan cross-links by these enzymes. In the absence of a cytoplasmic metallo-d,d-carboxypeptidase, the tetrapeptide substrate was generated by hydrolysis of the C-terminal d-Lac residue of the stem pentadepsipeptide in the periplasm in competition with the exchange reaction catalyzed by d,d-transpeptidases. In Nonomuraea sp. strain ATCC 39727, the contribution of l,d-transpeptidases to glycopeptide resistance was limited by the incomplete conversion of pentapeptides into tetrapeptides despite the production of a cytoplasmic metallo-d,d-carboxypeptidase. Since the level of drug production exceeds the level of resistance, we propose that l,d-transpeptidases merely act as a tolerance mechanism in this bacterium.
