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Research Paper | Agriculture | India | Volume 12 Issue 5, May 2023

Thermotolerant Bacillus as Plant Growth Promoting Rhizobacteria

R. Uma Sankareswari

Abstract: Bacteria that colonize plant roots and promote plant growth are referred to as plant growth - promoting rhizobacteria (PGPR). PGPR are highly diverse and in this article, we focus on rhizobacteria as biocontrol agents. The present study was conducted to characterize the native plant growth promoting (PGP) bacteria from compost sample and rice rhizosphere sample in Agricultural College and Research Institute, Madurai, Tamil Nadu for the isolation of Bacillus using Tryptic Soy Agar media, Nutrient agar media and Pikovaskaya media. Taken Nine isolates from compost sample using TSA Media and four isolates from rice rhizosphere sample using Nutrient Agar media and two isolates using Pikovaskaya media. The bacterial isolates were purified, screened in vitro for PGP characteristics and evaluated for their beneficial effects on the early growth of plants. Microscopic observation showed that most of the ten isolates bear rod shaped and Gram positive bacteria. Among the fifteen bacterial isolates, five isolates not able to adapt after 72 hrs of incubation and the population was drastically reduced at 70 - 75 degree Celsius at pH 4 - 5 and 8 - 10. Hence the isolates were adapted to grow at temperature ranges under three different carbon sources such as acetate, lactate and succinate from 40 to 65 degree Celsius at varied pH 6 - 7. All the seven isolates had significant result for IAA production in which four isolates ComB2, RRBN2, RRBPK2 and ComB10 showed higher phosphate concentration and phosphorus solubilization efficiency (350, 150.3, 145.3 and 142.0%).

Keywords: Bacillus, PGPR,, Compost sample, Rhizosphere soil

Edition: Volume 12 Issue 5, May 2023,

Pages: 2351 - 2355