Topic
Agrococcus
About: Agrococcus is a research topic. Over the lifetime, 27 publications have been published within this topic receiving 741 citations.
Papers
1 Jan 1996
TL;DR: In this article, a new aerobic, gram-positive, nonsporulating rod-shaped organism is described, which is called Leucobacter komagatae gen. nov., sp.
Abstract: A new aerobic, gram-positive, nonsporulating rod-shaped organism is described. Strain IF0 15245T (T = type strain) has the following characteristics: the menaquinone contains a side chain with 11 isoprenyl units; the guanine-plus-cytosine content of the DNA is 66.2 mol%; 2,4-diaminobutyric acid, glutamic acid, alanine, glycine, and y-aminobutyric acid are present in the cell wall at a molar ratio of ca. 1:1:2:1:1; and glucose and galactose are also present in the cell wall. A comparison of partial 16s rRNA sequences revealed that IF0 1524ST represents a distinct line of descent within the gram-positive bacteria with high guanine-plus-cytosine contents. The taxonomic characteristics of this organism are different from those of previously described aerobic, gram-positive, nonsporulating, rod-shaped bacteria. The name Leucobacter komagatae gen. nov., sp. nov., is proposed for this organism. The type strain is strain IF0 15245. The following three genera of gram-positive, aerobic, irregular rods with 2,4-diaminobutyric acid (DAB) in their cell walls have been described previously: the genera Clavibacter (3), Rathayibacter (32), and Agromyces (33). Recently, the new genusAgrococcus (7), whose members also contain DAB in their peptidoglycans, has been proposed. These genera are differentiated by their menaquinone types, the compositions of their cell wall sugars, their DNA G+C contents, their pigmentation, and selected physiological features (1,3,4). The menaquinone found in the genus Clavibacter is MK-9, the menaquinone found 10 in the genus Rathayibacter is MK-10, the menaquinone found in the genus Agromyces is MK-12, and the menaquinones found in the genus Agrococcus are MK-11 and MK12. Strain IF0 15245T (T = type strain), which was a contaminant in an ampoule labeled “Pseudomonas riboflavina” (18), is a gram-positive, nonmotile, rod-shaped organism. This strain has DAB in its cell wall, and its predominant menaquinone is MK-11. The presence of MK-11 reliably distinguishes strain IF0 15245T from the members of the genera Agrococcus, Agromyces, Clavibacter, and Rathayibacter that have been described, but the taxonomic position of strain IF0 15245T has remained uncertain. To clarify the taxonomic position of this organism and its intergeneric relationships with the previously described gram-positive, high-G + C-content bacteria, we determined a partial 16s rRNA sequence of IF0 15245T and compared it with sequences of 20 representative actinobacteria and related organisms (1 1). In this paper, we describe the taxonomic features of strain IF0 15245T, and on the basis of morphological, physiological, and chemotaxonomic characteristics and 16s rRNA sequence analysis data we propose that this organism should be classified in the new genus Leucobacter, as Leucobacter komagatae gen. nov., sp. nov.
98 citations
TL;DR: This study proved mangrove plants harbored a high diversity of cultivable endophytic actinobacteria, which can be a promising source for discovery of novel species and bioactive compounds.
Abstract: Endophytic actinobacteria are one of the important pharmaceutical resources and well known for producing different types of bioactive substances. Nevertheless, detection of the novelty, diversity, and bioactivity on endophytic actinobacteria isolated from mangrove plants are scarce. In this study, five different mangrove plants, Avicennia marina, Aegiceras corniculatum, Kandelia obovota, Bruguiera gymnorrhiza, and Thespesia populnea, were collected from Beilun Estuary National Nature Reserve in Guangxi Zhuang Autonomous Region, China. A total of 101 endophytic actinobacteria strains were recovered by culture-based approaches. They distributed in 7 orders, 15 families, and 28 genera including Streptomyces, Curtobacterium, Mycobacterium, Micrococcus, Brevibacterium, Kocuria, Nocardioides, Kineococcus, Kytococcus, Marmoricola, Microbacterium, Micromonospora, Actinoplanes, Agrococcus, Amnibacterium, Brachybacterium, Citricoccus, Dermacoccus, Glutamicibacter, Gordonia, Isoptericola, Janibacter, Leucobacter, Nocardia, Nocardiopsis, Pseudokineococcus, Sanguibacter, and Verrucosispora. Among them, seven strains were potentially new species of genera Nocardioides, Streptomyces, Amnibacterium, Marmoricola, and Mycobacterium. Above all, strain 8BXZ-J1 has already been characterized as a new species of the genus Marmoricola. A total of 63 out of 101 strains were chosen to screen antibacterial activities by paper-disk diffusion method and inhibitors of ribosome and DNA biosynthesis by means of a double fluorescent protein reporter. A total of 31 strains exhibited positive results in at least one antibacterial assay. Notably, strain 8BXZ-J1 and three other potential novel species, 7BMP-1, 5BQP-J3, and 1BXZ-J1, all showed antibacterial bioactivity. In addition, 21 strains showed inhibitory activities against at least one "ESKAPE" resistant pathogens. We also found that Streptomyces strains 2BBP-J2 and 1BBP-1 produce bioactive compound with inhibitory activity on protein biosynthesis as result of translation stalling. Meanwhile, Streptomyces strain 3BQP-1 produces bioactive compound inducing SOS-response due to DNA damage. In conclusion, this study proved mangrove plants harbored a high diversity of cultivable endophytic actinobacteria, which can be a promising source for discovery of novel species and bioactive compounds.
96 citations
TL;DR: The results showed the potential of Dodonaea viscosa endophytic bacteria as PGPBs, which in future can be further explored for their host range/molecular mechanisms.
Abstract: Dodonaea viscosa, a wild and perennial shrub that can tolerate harsh environmental conditions, was used for the isolation of its endophytic bacteria and their potential was explored for the promotion of Canola growth. The bacteria identified through 16S rRNA gene sequencing, belonged to ten different genera namely Inquilinus, Xanthomonas, Pseudomonas, Rhizobium, Brevundimonas, Microbacterium, Bacillus, Streptomyces, Agrococcus and Stenotrophomonas. All the strains produced small amount of IAA (indole acetic acid) in the absence of tryptophan and comparatively more in the presence of tryptophan. All the bacterial strains were positive for ammonia production, cellulase and pectinase activity, but few of them showed phosphate solubilization, siderophore and hydrogen cyanide production. Only three strains showed ACC (1-aminocyclopropane-1-carboxylate) deaminase activity when tested using in-vitro enzyme assay. Members of genera Bacillus, Pseudomonas and Streptomyces showed positive chitinase, protease and antifungal activity against two phytopathogenic fungi Aspergillus niger and Fusarium oxysoprum, while members of Xanthomonas, Pseudomonas and Bacillus showed significant root elongation of Canola which could be related with their positive plant-growth-promoting (PGP) traits. Among the three plant growth promoting Bacillus strains, B. idriensis is never reported before for its PGP activities. These results showed the potential of Dodonaea viscosa endophytic bacteria as PGPBs, which in future can be further explored for their host range/molecular mechanisms.
87 citations
TL;DR: It appears that some of the Gram-negative bacteria identified should now be regarded as potentially useful in some cheese technologies, and the assessment of their positive versus negative role should be objectively examined.
Abstract: The surface microflora (902 isolates) of Livarot cheeses from three dairies was investigated during ripening. Yeasts were mainly identified by Fourier transform infrared spectroscopy. Geotrichum candidum was the dominating yeast among 10 species. Bacteria were identified using Biotype 100 strips, dereplicated by repetitive extragenic palindromic PCR (rep-PCR); 156 representative strains were identified by either BOX-PCR or (GTG)5-PCR, and when appropriate by 16S rDNA sequencing and SDS-PAGE analysis. Gram-positive bacteria accounted for 65% of the isolates and were mainly as- signed to the genera Arthrobacter, Brevibacterium, Corynebacterium, and Staphylococcus. New taxa related to the genera Agrococcus and Leucobacter were found. Yeast and Gram-positive bacteria strains deliberately added as smearing agents were sometimes undetected during ripening. Thirty-two percent of the isolates were Gram-negative bacteria, which showed a high level of diversity and mainly included members of the genera Alcaligenes, Hafnia, Proteus, Pseudomonas, and Psy- chrobacter. Whatever the milk used (pasteurized or unpasteurized), similar levels of biodiversity were observed in the three dairies, all of which had efficient cleaning procedures and good manufacturing practices. It appears that some of the Gram- negative bacteria identified should now be regarded as potentially useful in some cheese technologies. The assessment of their positive versus negative role should be objectively examined.
85 citations
TL;DR: Focusing on the diversity of coral-associated Actinobacteria may help to understand how corals thrive under harsh environmental conditions and may lead to the discovery of novel antimicrobial metabolites with potential biotechnological applications.
Abstract: Marine Actinobacteria, particularly coral-associated Actinobacteria, have attracted attention recently. In this study, the abundance and diversity of Actinobacteria associated with three types of coral thriving in a thermally stressed coral reef system north of the Arabian Gulf were investigated. Coscinaraea columna, Platygyra daedalea and Porites harrisoni have been found to harbor equivalent numbers of culturable Actinobacteria in their tissues but not in their mucus. However, different culturable actinobacterial communities have been found to be associated with different coral hosts. Differences in the abundance and diversity of Actinobacteria were detected between the mucus and tissue of the same coral host. In addition, temporal and spatial variations in the abundance and diversity of the cultivable actinobacterial communities were detected. In total, 19 different actinobacterial genera, namely Micrococcus, Brachybacterium, Brevibacterium, Streptomyces, Micromonospora, Renibacterium, Nocardia, Microbacterium, Dietzia, Cellulomonas, Ornithinimicrobium, Rhodococcus, Agrococcus, Kineococcus, Dermacoccus, Devriesea, Kocuria, Marmoricola, and Arthrobacter, were isolated from the coral tissue and mucus samples. Furthermore, 82 isolates related to Micromonospora, Brachybacterium, Nocardia, Micrococcus, Arthrobacter, Rhodococcus, and Streptomyces showed antimicrobial activities against representative Gram-positive and/or Gram-negative bacteria. Even though Brevibacterium and Kocuria were the most dominant actinobacterial isolates, they failed to show any antimicrobial activity, whereas less dominant genera, such as Streptomyces, did show antimicrobial activity. Focusing on the diversity of coral-associated Actinobacteria may help to understand how corals thrive under harsh environmental conditions and may lead to the discovery of novel antimicrobial metabolites with potential biotechnological applications.
84 citations
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| Year | Papers |
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| 2020 | 1 |
| 2018 | 4 |
| 2017 | 1 |
| 2016 | 3 |
| 2015 | 4 |
| 2014 | 3 |