SCREENING AND MOLECULAR CHARACTERIZATION OF BACILLUS SP PR01 FOR THE PRODUCTION OF PROTEASE ENZYME
The current study was attempted to isolate and characterize the protease producing Bacillus sp. Among the 3 strains isolated from soil sample collected f rom kuppam region, Chennai, India. One strain (PR01) exhibited potent proteolytic activity. Based on the morphological, biochemical and molecular characterization, the isolate (PR01) was identified as Bacillus sp. The strain was designated as Bacillus sp P R01. The maximum growth of Bacillus sp PR01was observed at pH 7. The optimum temperature for the growth of Bacillus sp PR01 was found to be 27 ° C an d incubation time for 2 days. The maximum growth was noted when yeast extract was used as a nitrogen source a nd dextrose was used as the carbon source. The production of enzyme Bacillus sp PR01 was carried out in production medium. The t otal protein concentration was determined and the specific activity was also performed by casein hydrolysis assay.
CLASSICAL IDENTIFICATION, 16S RDNA SEQUENCING, AND MOLECULAR CHARACTERIZATION OF BACILLUS SPECIES FROM CONVENIENCE FOODS
Identification of microorganisms is central to the study of microbiology at all levels of research. The methods employed are also important. It is however very pertinent that scientists the world over continuously improve on the method of microbial identification for greater efficiency. A study was conducted to isolate and identify Bacillus species from some ready-to-eat (RTE)/convenience food samples. The Bacillus species isolated were identified by using the classical method. The same isolates were further identified via use of the 16S rDNA sequencing method. The classical method identified all bacilli isolates as members of a precise species in the genus Bacillus, but with discrepancies observed in 3 out of 9 identified cases (33.3%) when comparison was made with PCR/sequencing method. PCR/sequencing method provided results which were in accordance with both classical and genotypical identification in more than 70% of cases. This study emphasized the presumptive nature of classical methods in identifying Bacillus species/strains, without additional sensitive and molecular methods. Identities from the PCR method hold greatest sway and are regarded as most reliable as it involves the analysis of genetic sequences of this group of microorganisms.
Characterization of chryseobacterium aquaticum strain PUPC1 producing a novel antifungal protease from rice rhizosphere soil.
Strain PUPC1 produces an antifungal protease as well as plant growth promoting enzymes such as 1- aminocyclopropane-1-carboxylate (ACC) deaminase and phosphatase. Morphological, cultural, and physiological characteristics as well as 16S rRNA gene-sequence-based phylogenetic analysis confirmed the taxonomic affiliation of PUPC1 as Chryseobacterium aquaticum. The optimum growth of PUPC1 was observed at pH 6.0 and 30 degrees , and maximum protease production was observed in medium B amended with 1% tryptone, 0.5% sucrose, and 0.005% MnCl2. The protease was purified by ammonium sulfate precipitation, Sephadex G-75 gel filtration chromatography, and electroelution from preparative SDS-PAGE. The protease had a molecular mass of 18.5 kDa. The optimum pH and temperature stability of the protease were pH 5.0- 10.0 and temperature 40-70 degrees . Chryseobacterium aquaticum PUPC1 and its protease showed a broad-spectrum antifungal activity against phytopathogenic fungi. Strain PUPC1 also exhibited plant growth promoting traits. The objective of the present investigation was to isolate a strain for agricultural application for plant growth promotion and biocontrol of fungal diseases.