Crocus sativus is the only plant species which produces apocarotenoids like crocin, picrocrocin and safranal in significant amounts. These compounds impart organoleptic properties to saffron (dried stigmas of Crocus flower) making it world’s costliest spice. Crocus apocarotenoids have tremendous medicinal properties as well. Effect of endophytes on Crocus apocarotenoid production and the molecular mechanism involved has not been reported so far. Here we studied the effect of an oleaginous fungal endophyte, Mortierella alpina CS10E4 on Crocus growth, apocarotenoid metabolism and tolerance to corm rot disease. The results demonstrated that there was a significant improvement in many morphological and physiological traits in endophyte treated Crocus plants including total biomass and size of corms, stigma biomass, number of apical sprouting buds, and number of adventitious roots. The endophyte also shifted metabolic flux towards enhanced production of apocarotenoids by modulating the expression of key pathway genes. Further, M. alpina CS10E4 enhanced tolerance to corm rot disease by releasing arachidonic acid which acts as conserved defense signal and induces jasmonic acid production in endophyte treated Crocus corms. This is first report on effect of a fungal endophyte on Crocus apocarotenoid metabolism and stress tolerance.
The nutritional challenge faced by the monogastric animals due to the chelation effects of phytic acid, fuel the research on bioprospecting of probiotics for phytase production. Pediococcus acidilactici SMVDUDB2 isolated from Kalarei, exhibited extracellular phytase activity of 5.583 U/mL after statistical optimization of fermentation conditions viz. peptone (1.27%); temperature (37 °C); pH (6.26) and maltose (1.43%). The phytase enzyme possessed optimum pH and temperature of 5.5 and 37 °C, respectively and was thermostable at 60 °C. The enzyme was purified 6.42 fold with a specific activity of 245.12 U/mg with hydrophobic interaction chromatography. The purified enzyme had K m and V max values of 0.385 mM and 4.965 μmol/min respectively, with sodium phytate as substrate. The strain depicted more than 80% survival rate at low pH (pH 2.0, 3.0), high bile salt concentration (0.3 and 0.5%), after gastrointestinal transit, highest hydrophobicity affinity with ethyl acetate (33.33 ± 0%), autoaggregation (77.68 ± 0.68%) as well as coaggregation (73.57 ± 0.47%) with Staphylococcus aureus (MTCC 3160). The strain exhibited antimicrobial activity against Bacillus subtilis (MTCC 121), Mycobacterium smegmatis (MTCC 994), Staphylococcus aureus (MTCC 3160), Proteus vulgaris (MTCC 426), Escherichia coli (MTCC 1652) and Lactobacillus rhamnosus (MTCC 1408). The amount of exopolysaccharide produced by the strain was 2 g/L. This strain having the capability of phytate degradation and possessing probiotic traits could find application in food and feed sectors.
In the present study, out of 264 phosphate (P) solubilizing Bacillus strains isolated from apple rhizosphere, only
twelve isolates were found to be efficient (showed most of the plant growth
promoting activity) which were further characterized at molecular level using 16S
rDNA partial gene sequencing. Out of 12 isolates, MZPSB 207 was found to be most
efficient P-solubilizing (864.71 μg/ml) isolate which also showed indole acetic acid
production (51.83 μg/ml), siderophore production, ammonia production, antagonistic
property (against Rhizoctonia solani and
Fusarium oxysporum), hydrolytic enzymes
productions (protease, chitinase and cellulase), 1-aminocyclopropane-1-carboxylate
(ACC) deaminase production (7.7 μm αKB
mg-1 h-1). The in-vitro seed germination assay showed that Bacillus (twelve isolates) inoculated seeds showed more
seed germination and seedling vigor rate as compared to uninoculated control
treatment.For the genetic diversity studies of efficient 12 strains, the polyphasic
approach using 16S-rDNA, Repetitive element sequence (rep) based PCR (ERIC-PCR and
BOX-PCR) were used. Based on 16S rDNA partial gene sequencing the isolated Bacillus genus was divide into four groups. First group
(five isolates), second group (two isolates), third group (three isolates) and
fourth group (two isolates) which showed close genetic relatedness to the B. subtilis, B.
pumulis, B. megaterium and B. amyloliquefaciens, respectively. The rep PCR
fingerprinting showed variability between and within the species. The large
variability was showed by ERIC-PCR whereas some variability was showed by BOX-PCR.
The results clearly showed that 16S rRNA gene sequencing is unable to discriminate
the isolates at strain level. But rep-PCR fingerprinting is excellent tool to
characterize and discriminate the strains at the genomic level.
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