Biochemical Characterization of Fast- and Slow-Growing Rhizobia That Nodulate Soybeans

“…When ketolactose test was performed, most of the isolates were found to be negative for the production of 3-ketolactose from lactose (Table 3). However, four fast-growing isolates (3c, 5a, 14b, 18e) and one slow-growing isolate (12c) were found positive (showed growth on the medium) which are in contradiction to earlier work carried out by Sadowsky et al (1983). At present, the rhizobia are being authenticated using PCR-based molecular techniques; therefore the results obtained through biochemical methods should be revalidated for further work.…”

Section: Resultsmentioning

confidence: 59%

Biochemical characterization and metabolic diversity of soybean rhizobia isolated from Malwa region of Central India

Sharma¹,

Srivastava²,

Sharma³

2010

PLANT SOIL ENVIRON

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Soybean cultivation in many zones of India shows occurrence of native rhizobia besides other exotically adapted strains. In the current study, 22 rhizobial isolates (recovered from 12 different soybean growing sites) and 8 reference strains were selected for biochemical and metabolic characterization. Of 22 isolates, 18 were recovered as fast growing isolates while the rest were slow growing based on bromothymol blue (BTB) test. Unlike earlier belief that rhizobia have no ability to grow on glucose peptone agar medium, in this study, some isolates and some reference strains grew well on this medium. Similarly, when all the isolates were subjected to ketolactose test, some of the isolates were found to show growth on the medium. In contrast, based on C-utilization pattern (15 carbohydrates) a remarkable metabolic diversity was observed among the rhizobial isolates recovered in the study. The clustering and matching analysis showed that most of isolates were matching with slow growing reference strains, a few were with fast growing reference strains and some were found to be unique and hence not matching with any of reference strains. Such analysis suggests the occurrence of metabolically distinct types of rhizobia besides commonly known types (B. japonicum, B. elkanii and S. fredii) of soybean rhizobia and further validation is suggested through 16SrRNA gene sequencing technique.

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“…Isolate AUAVR-49 was the lowest in mean generation time. Production of organic acid, large colony size, and short mean generation time is the characteristics of fast growing rhizobial isolates (Sadowsky et al, 1983). Characteristic of the isolates such as colony diameter, mean generation time, colony texture, and growth properties on YEMA+BTB proved that all the isolates were fast-grower.…”

Section: Resultsmentioning

confidence: 98%

Characterization of Phosphate Solubilizing Faba Bean (<i>Vicia faba</i> L.) Nodulating Rhizobia Isolated from Acidic Soils of Wollega, Ethiopia

Kenasa¹,

Jida²,

Assefa³

2014

Sci. Technol. Arts Res. J.

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Article InformationSome species of rhizobial bacteria nodulating faba bean are characterized by phosphate solubilization. In order to study their in vitro and symbiotic characteristics, twelve rhizobial isolates nodulating faba bean were collected from acidic soil of Wollega, Ethiopia. Solubilization index of the isolates ranges from 1.25 to 2.10. Mean Generation Time of the isolates were less than 2.34; and growth of isolates on Yeast Extract Mannitol agar with bromothymoleblue media were accompanied by change of color from blue to yellow. AUAVR-51 and AUAVR-52 were the highest in TCP-Solubilizion Index. The two isolates were also recognized as stress tolerant when tested in vitro for extreme temperature, osmotic, acidic pH, intrinsic antibiotics, and acidic-aluminum as compared to the other isolates. However, there was no unique metabolic diversity and specialization of AUAVR-51 and AUAVR-52 isolates with respect to carbon and nitrogen source utilization. On the other hand, isolates AUAVR-51 and AUAVR-52 were characterized by effective and highly effective symbiosis on sterile potted sand growth, respectively. In general, phosphate solubilizing rhizobia nodulating faba bean from acidic soil are fast grower; and their solubilization potential varies. However, the contribution of these isolates as double fertilizer should be tested in the real acidic soil characterized by immobilized phosphorous.

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Biochemical Characterization of Fast- and Slow-Growing Rhizobia That Nodulate Soybeans

Cited by 91 publications

References 13 publications

Genotypic Characterization of Indigenous Rhizobium Strain from Cultivated Cowpea (Vigna unguiculata L.) in Bangladesh

Genotypic Characterization of Indigenous Rhizobium Strain from Cultivated Cowpea (Vigna unguiculata L.) in Bangladesh

Biochemical characterization and metabolic diversity of soybean rhizobia isolated from Malwa region of Central India

Characterization of Phosphate Solubilizing Faba Bean (<i>Vicia faba</i> L.) Nodulating Rhizobia Isolated from Acidic Soils of Wollega, Ethiopia

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