scholarly journals Effect of the Mycorrhizosphere on the Genotypic and Metabolic Diversity of the Bacterial Communities Involved in Mineral Weathering in a Forest Soil

2007 ◽  
Vol 73 (9) ◽  
pp. 3019-3027 ◽  
Author(s):  
S. Uroz ◽  
C. Calvaruso ◽  
M. P. Turpault ◽  
J. C. Pierrat ◽  
C. Mustin ◽  
...  

ABSTRACT To date, several bacterial species have been described as mineral-weathering agents which improve plant nutrition and growth. However, the possible relationships between mineral-weathering potential, taxonomic identity, and metabolic ability have not been investigated thus far. In this study, we characterized a collection of 61 bacterial strains isolated from Scleroderma citrinum mycorrhizae, the mycorrhizosphere, and the adjacent bulk soil in an oak forest. The ability of bacteria to weather biotite was assessed with a new microplate bioassay that measures the pH and the quantity of iron released from this mineral. We showed that weathering bacteria occurred more frequently in the vicinity of S. citrinum than in the bulk soil. Moreover, the weathering efficacy of the mycorrhizosphere bacterial isolates was significantly greater than that of the bulk soil isolates. All the bacterial isolates were identified by partial 16S rRNA gene sequence analysis as members of the genera Burkholderia, Collimonas, Pseudomonas, and Sphingomonas, and their carbon metabolism was characterized by the BIOLOG method. The most efficient isolates belonged to the genera Burkholderia and Collimonas. Multivariate analysis resulted in identification of three metabolic groups, one of which contained mainly bacterial isolates associated with S. citrinum and exhibiting high mineral-weathering potential. Therefore, our results support the hypothesis that by its carbon metabolism this fungus selects in the bulk soil reservoir a bacterial community with high weathering potential, and they also address the question of functional complementation between mycorrhizal fungi and bacteria in the ectomycorrhizal complex for the promotion of tree nutrition.

2010 ◽  
Vol 76 (14) ◽  
pp. 4780-4787 ◽  
Author(s):  
Christophe Calvaruso ◽  
Marie-Pierre Turpault ◽  
Elisabeth Leclerc ◽  
Jacques Ranger ◽  
Jean Garbaye ◽  
...  

ABSTRACT In acidic forest soils, availability of inorganic nutrients is a tree-growth-limiting factor. A hypothesis to explain sustainable forest development proposes that tree roots select soil microbes involved in central biogeochemical processes, such as mineral weathering, that may contribute to nutrient mobilization and tree nutrition. Here we showed, by combining soil analyses with cultivation-dependent analyses of the culturable bacterial communities associated with the widespread mycorrhizal fungus Scleroderma citrinum, a significant enrichment of bacterial isolates with efficient mineral weathering potentials around the oak and beech mycorrhizal roots compared to bulk soil. Such a difference did not exist in the rhizosphere of Norway spruce. The mineral weathering ability of the bacterial isolates was assessed using a microplaque assay that measures the pH and the amount of iron released from biotite. Using this microplate assay, we demonstrated that the bacterial isolates harboring the most efficient mineral weathering potential belonged to the Burkholderia genus. Notably, previous work revealed that oak and beech harbored very similar pHs in the 5- to 10-cm horizon in both rhizosphere and bulk soil environments. In the spruce rhizosphere, in contrast, the pH was significantly lower than that in bulk soil. Because the production of protons is one of the main mechanisms responsible for mineral weathering, our results suggest that certain tree species have developed indirect strategies for mineral weathering in nutrient-poor soils, which lie in the selection of bacterial communities with efficient mineral weathering potentials.


2018 ◽  
Vol 41 (3) ◽  
pp. 255-264 ◽  
Author(s):  
J. Abraham Pérez-Pérez ◽  
David Espinosa-Victoria ◽  
Hilda V. Silva-Rojas ◽  
Lucía López-Reyes

Bacteria are an unavoidable component of the natural earthworm diet; thus, bacterial diversity in the earthworm gut is directly linked to decomposition of organic matter and development of the surrounding plants. The aim of this research was to isolate and to identify biochemically and molecularly the culturable bacterial microbiota of the digestive tract of Eisenia foetida. Earthworms were sourced from Instituto de Reconversión Productiva y Bioenergética (IRBIO) and Colegio de Postgraduados (COLPOS), México. Bacterial isolation was carried out on plates of Brain Heart Infusion (BHI) culture medium. Fifty six and 44 bacterial isolates were obtained from IRBIO and COLPOS, respectively. The population was composed of 44 Gram-negative and 56 Gram-positive isolates. Over 50 % of the bacterial isolates were rod-shaped cells. The 16S rRNA gene was sequenced and nine genera were identified in worms from IRBIO (Bacillus, Paenibacillus, Solibacillus, Staphylococcus, Arthrobacter, Pantoea, Stenotrophomonas, Acinetobacter and Aeromonas) and six in worms from COLPOS (Bacillus, Paenibacillus, Stenotrophomonas, Staphylococcus, Acinetobacter and Aeromonas). Bacillus was the predominant genus, with eight and six species in the oligochaetes from IRBIO and COLPOS, respectively. The most represented bacteria in the worms from both sites were Bacillus sp. and B. subtilis. The predominance of Bacillus was probably due to spore formation, a reproductive strategy that ensures survival and dispersion in the soil and oligochaetes digestive tract. The gut of E. foetida not only harbored bacterial species of agronomic importance but also species potentially pathogenic for humans (Staphylococcus warneri, Pantoea agglomerans and Stentrophomonas sp.). The larger bacterial diversity in worms from IRBIO could be due to their feeding on cattle manure, which is a rich source of bacteria.


2007 ◽  
Vol 57 (3) ◽  
pp. 548-551 ◽  
Author(s):  
Hang-Yeon Weon ◽  
Byung-Yong Kim ◽  
Min-Kyeong Kim ◽  
Seung-Hee Yoo ◽  
Soon-Wo Kwon ◽  
...  

Two bacterial strains, designated GH34-4T and GH41-7T, were isolated from greenhouse soil cultivated with cucumber. The bacteria were strictly aerobic, Gram-negative, rod-shaped and oxidase- and catalase-positive. 16S rRNA gene sequence analysis indicated that these strains belong to the genus Lysobacter within the Gammaproteobacteria. Strain GH34-4T showed highest sequence similarity to Lysobacter yangpyeongensis GH19-3T (97.5 %) and Lysobacter koreensis Dae16T (96.4 %), and strain GH41-7T showed highest sequence similarity to Lysobacter antibioticus DSM 2044T (97.5 %), Lysobacter enzymogenes DSM 2043T (97.5 %) and Lysobacter gummosus ATCC 29489T (97.4 %). Levels of DNA–DNA relatedness indicated that strains GH34-4T and GH41-7T represented species clearly different from L. yangpyeongensis, L. antibioticus, L. enzymogenes and L. gummosus. The major cellular fatty acids of strains GH34-4T and GH41-7T were iso-C16 : 0, iso-C15 : 0 and iso-C17 : 1 ω9c, and the major isoprenoid quinone was Q-8. The DNA G+C contents of GH34-4T and GH41-7T were 62.5 and 66.6 mol%, respectively. On the basis of the polyphasic taxonomic data presented, it is evident that each of these strains represents a novel species of the genus Lysobacter, for which the names Lysobacter niabensis sp. nov. (type strain GH34-4T=KACC 11587T=DSM 18244T) and Lysobacter niastensis sp. nov. (type strain GH41-7T=KACC 11588T=DSM 18481T) are proposed.


Plant Disease ◽  
2021 ◽  
Author(s):  
Stefanie De Armas ◽  
Guillermo Alesio Galván ◽  
María Inés Lapaz ◽  
Pablo González-Barrios ◽  
Esteban Vicente ◽  
...  

Onion is among the most consumed vegetables in Uruguay, grown in the Northwestern and Southern regions of the country. The onion supply presents interannual variations associated with significant postharvest losses, mainly caused by bacterial rots. Besides bulb rotting, onion leaf lesions as well as infections on seed-stalks during seed production may be devastating for some varieties under conducive conditions. This research aimed to identify the causal agents of bulb rots and leaf blight of onion crops in Uruguay. Symptomatic bulbs, seeds-stalks and leaves were collected from commercial fields from 2015 to 2020. Bacterial colonies were isolated and identified at genera level using physiological tests and 16S rRNA gene sequence analysis. A collection of 59 Pantoea spp. isolates was obtained (11 from bulbs and 48 from leaves and seeds-stalks). Multilocus sequence analysis (MLSA) using four housekeeping genes (rpoB, gyrB, leuS and fusA) allowed the assignment of the isolates to five Pantoea species: P. ananatis, P. agglomerans, P. allii, P. eucalypti and P. vagans. The last two species were not previously reported as onion pathogens elsewhere. The ability to cause disease symptoms was tested by leaf inoculation and red onion scale assays. Pantoea ananatis isolates showed the highest aggressiveness in both assays. Specific isolates from P. allii (MAI 6022), P. eucalypti (MAI 6036), P. vagans (MAI 6050), and Pantoea sp. (MAI 6049) ranked the second in aggressiveness on onion leaves, while only three isolates belonging to P. eucalypti (MAI 6036 and MAI 6058) and P. agglomerans (MAI 6045) exhibited the same scale clearing phenotype as P. ananatis. Leaf inoculation assays were also performed on a set of eight onion cultivars and breeding lines. Overall, P. ananatis MAI 6032 showed the highest aggressiveness in all tested cultivars, followed by P. eucalypti MAI 6036. The presence of new reported bacterial species leads to complex disease management and highlights the need for further studies on virulence factors and the epidemiology of these pathogens.


2011 ◽  
Vol 61 (7) ◽  
pp. 1612-1616 ◽  
Author(s):  
Lingyun Qu ◽  
Qiliang Lai ◽  
Fengling Zhu ◽  
Xuguang Hong ◽  
Jinxing Zhang ◽  
...  

Two novel Gram-negative, oxidase- and catalase-positive, rod-shaped bacterial strains, designated YCSA28T and YCSA39, were isolated from sediment of Daqiao saltern, Jimo, Qingdao, on the east coast of China. The two strains grew optimally at 28–30 °C, at pH 7.5 and in the presence of 7–8 % (w/v) NaCl. They were assigned to the genus Halomonas, class Gammaproteobacteria, based on 16S rRNA gene sequence analysis. The major cellular fatty acids of the two strains were C18 : 1ω7c (42.9 %), C16 : 0 (23.1 %) and C16 : 1ω7c/ω6c (18.0 %), and Q-9 was the major ubiquinone. The G+C content of the DNA of strains YCSA28T and YCSA39 was 63.7 and 63.9 mol%, respectively. The predominant respiratory lipoquinone, cellular fatty acid profiles and DNA G+C content of strains YCSA28T and YCSA39 were consistent with those of recognized species of the genus Halomonas. Levels of DNA–DNA relatedness between strains YCSA28T and YCSA39, between YCSA28T and Halomonas ventosae Al12T, and between YCSA39 and H. ventosae Al12T were 95, 45 and 50 %, respectively. Together, these data indicated that strains YCSA28T and YCSA39 represent a single novel species of the genus Halomonas, for which the name Halomonas daqiaonensis sp. nov. is proposed. The type strain is YCSA28T ( = CGMCC 1.9150T  = NCCB 100305T  = MCCC 1B00920T).


2016 ◽  
Vol 29 (2) ◽  
pp. 84-88
Author(s):  
A Hakim ◽  
S Hoque ◽  
SM Ullah

Ten effluent samples from two different sites located at Hazaribagh tannery belt and Dhaka EPZ, Savar were collected. This study aimed to compare the bacterial composition isolated from tannery and textile effluents and to investigate the occurrence of metal toxicity tolerant and dye degrading bacteria and to select the potential strains for the use in bioremediation. The average bacterial count of HT and DETDE varied in between 3.35×106 and 5.45×106 cfu/mL and 4.8×106 and 7.75×106cfu/mL, respectively. A total of 12 bacterial isolates were characterized as strains of Bacillus, Staphylococcus, and Pseudomonas. A few, however, were re-cultured on other recommended media for verification of diagnostic characteristics. Maximum numbers of bacterial species were isolated from textile effluent. The results showed that a Gram-positive bacillus with a yellow pigment was considered as a major group of the population. Among them three isolates were identified based on alignments of partial sequence of 16S rRNA gene. These are also being used in different wastewater and metal treatment plants all over the world.Bangladesh J Microbiol, Volume 29, Number 2, Dec 2012, pp 84-88


2005 ◽  
Vol 55 (4) ◽  
pp. 1675-1680 ◽  
Author(s):  
Marcel Nordhoff ◽  
David Taras ◽  
Moritz Macha ◽  
Karsten Tedin ◽  
Hans-Jürgen Busse ◽  
...  

Limit-dilution procedures were used to isolate seven, helically coiled bacterial strains from faeces of swine that constituted two unidentified taxa. Comparative 16S rRNA gene sequence analysis showed highest similarity values with species of the genus Treponema indicating that the isolates are members of this genus. Strain 7CPL208T, as well as five further isolates, and 14V28T displayed the highest 16S rRNA gene sequence similarities with Treponema pectinovorum ATCC 33768T (92·3 %) and Treponema parvum OMZ 833T (89·9 %), respectively. Polar lipid profiles distinguished 7CPL208T and 14V28T from each other as well as from related species. Based on their phenotypic and genotypic distinctiveness, strains 7CPL208T and 14V28T are suggested to represent two novel species of the genus Treponema, for which the names Treponema berlinense sp. nov. and Treponema porcinum sp. nov. are proposed. The type strain for Treponema berlinense is 7CPL208T (=ATCC BAA-909T=CIP 108244T=JCM 12341T) and for Treponema porcinum 14V28T (=ATCC BAA-908T=CIP 108245T=JCM 12342T).


2006 ◽  
Vol 56 (9) ◽  
pp. 2113-2117 ◽  
Author(s):  
Akiko Kageyama ◽  
Yoko Takahashi ◽  
Satoshi Ōmura

Three novel bacterial strains were isolated from a soil sample collected in Japan by culture on a GPM agar plate supplemented with superoxide dismutase and catalase. The strains were Gram-positive, catalase-positive, non-motile bacteria with l-ornithine as a diagnostic diamino acid of the peptidoglycan. The acyl type of the peptidoglycan was N-glycolyl. The major menaquinones were MK-12, 13 and 14. Mycolic acids were not detected. G+C contents of the DNA were in the range 69–71 mol%. Comparative 16S rRNA gene sequence analysis revealed that the isolates belonged to the genus Microbacterium and were closely related to Microbacterium terregens, Microbacterium aurum, Microbacterium koreense, Microbacterium schleiferi and Microbacterium lacticum. However, M. aurum, M. koreense and M. lacticum clearly differed from the isolated strains based on the presence of l-lysine as the cell-wall diamino acid and various other chemotaxonomic characteristics. Levels of DNA–DNA relatedness showed that the isolated strains represented three separate genomic species. Based on both phenotypic and genotypic data, the following novel species of the genus Microbacterium are proposed: Microbacterium deminutum sp. nov. (type strain KV-483T=NRRL B-24453T=NBRC 101278T), Microbacterium pumilum sp. nov. (type strain KV-488T=NRRL B-24452T=NBRC 101279T) and Microbacterium aoyamense sp. nov. (type strain KV-492T=NRRL B-24451T=NBRC 101280T).


2010 ◽  
Vol 60 (9) ◽  
pp. 2076-2081 ◽  
Author(s):  
Chanwit Suriyachadkun ◽  
Suwanee Chunhametha ◽  
Chitti Thawai ◽  
Tomohiko Tamura ◽  
Wanchern Potacharoen ◽  
...  

Two novel bacterial strains were isolated from tropical rain forest soil from Thailand. Strains A-T 0875T and A-T 1383T stained Gram-positive and were filamentous bacteria that developed cylindrical sporangia containing four oval- to rod-shaped spores at the ends of short sporangiophores on branched aerial mycelium. The cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids; whole-cell hydrolysates contained rhamnose, madurose, glucose, galactose and 3-O-methylmannose as whole-cell sugars. The predominant menaquinone was MK-9(H4). Mycolic acids were not detected. The diagnostic phospholipid was phosphatidylethanolamine. The predominant cellular fatty acids were iso-C16 : 0 and 10-methyl-C17 : 0. For both strains, the G+C content of the genomic DNA was 71 mol%. Phenotypic and chemotaxonomic analyses showed that the characteristics of the two isolates were typical of members of the genus Planotetraspora. Furthermore, 16S rRNA gene sequence analysis also indicated that the strains belonged to the genus Planotetraspora but as representatives of two novel species. Following an evaluation of our phenotypic, chemotaxonomic and genotypic studies, two novel species are proposed, Planotetraspora kaengkrachanensis sp. nov. (type strain A-T 0875T=BCC 24832T=NBRC 104272T) and Planotetraspora phitsanulokensis sp. nov. (type strain A-T 1383T=BCC 26045T=NBRC 104273T).


2006 ◽  
Vol 56 (7) ◽  
pp. 1645-1649 ◽  
Author(s):  
Byung-Yong Kim ◽  
Hang-Yeon Weon ◽  
Sylvie Cousin ◽  
Seung-Hee Yoo ◽  
Soon-Wo Kwon ◽  
...  

Two yellow-pigmented, Gram-negative, rod-shaped bacterial strains, GH1-10T and GH29-5T, were isolated from greenhouse soils in Korea. 16S rRNA gene sequence analysis indicated that these strains were related to members of the genus Flavobacterium. Strain GH1-10T was most closely related to Flavobacterium psychrolimnae and Flavobacterium denitrificans, with sequence similarities of 95.9 and 95.2 %, respectively. Strain GH29-5T was most closely related to ‘Flavobacterium saliodium’, F. denitrificans and Flavobacterium frigoris, with sequence similarities of 94.3, 92.5 and 92.5 %, respectively. The major cellular fatty acids of GH1-10T were iso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c) and iso-C17 : 0 3-OH, and those of GH29-5T were iso-C15 : 0, iso-C17 : 0 3-OH, iso-C15 : 1 G and iso-C15 : 0 3-OH. Both strains contained menaquinone with six isoprene units (MK-6) as the sole quinone. The DNA G+C contents of GH1-10T and GH29-5T were 35 and 39 mol%, respectively. Based on the phylogenetic and phenotypic data presented, it is concluded that the two bacteria represent two separate novel species of the genus Flavobacterium. The names proposed to accommodate these organisms are Flavobacterium daejeonense sp. nov., with type strain GH1-10T (=KACC 11422T=DSM 17708T), and Flavobacterium suncheonense sp. nov., with type strain GH29-5T (=KACC 11423T=DSM 17707T).


Sign in / Sign up

Export Citation Format

Share Document