Khan NT*, Namrajameel, Khan MJ
Department of Biotechnology, Faculty of Life Sciences and Informatics, Balochistan University of Information Technology Engineering and Management Sciences, Quetta, Pakistan
Nida Tabassum Khan Department of Biotechnology Faculty of Life Sciences and Informatics Balochistan University of Information Technology Engineering and Management Sciences (BUITEMS) Quetta, Pakistan Tel: 03368164903 E-mail: email@example.com
Article Type: Review article
Manuscript ID: IJBS-1-111
Publisher: Boffin Access Limited.
Journal Type: Open Access
Copyright: : © 2018 Khan NT, et al.
Creative Commons Attribution 4.0
Khan NT, Namrajameel, Khan MJ. Microbial Biofertilizers. Int J Biopharm Sci. 2018 Oct;1(3):111
Biofertilizers are constituents of microbial cells that colonizes rhizosphere of the plants to improve nutrient uptake by increasing the rate of mineralization of insoluble nutrients in the soil through numerous natural process such as nitrogen fixation, phosphorous fixation etc.
Arbuscular Mycorrhiza; Bacillus subtilis; Bacilluscirculans; Azolla; Azospirillum
Biofertilizer is a biotic constituent of specific microbial cells, which when applied, stimulates plant growth by accelerating the rate of nutrient release through nitrogen fixation, phosphorus cycle, etc. . In vitro cultures of specific microbes are selected for the preparation of biofertilizers to fulfill the specific nutrient requirements of different plants . Biofertilizer is categorized into different given below.
a. Nitrogen fixing
b. Phosphorous solubilizing
c. Phosphorous mobilizes
d. Biofertilizers for Micronutrients
e. Plant Growth Promoting Rhizobacteria
Rhizobium: Rhizobium is a nitrogen fixing bacteria that colonize the root nodules of legume plants and is an effective biofertilizers . They are referred as cross inoculation group for being specific to form root nodules in legume plants and has seven genera [15,16]. For all legume plants it is applied as seed inoculant .
Azotobacter: Another nitrogen fixing bacteria inoculant that produces ample slime which aids in soil aeration. e. g. A. Chroococcum .
Azospirillum: Nitrogen fixing bacteria that colonize the non-leguminous graminaceous plants rhizosphere and intercellular spaces of root cortex e. g. Azospirillum lipoferum, A. Brasilense, A. Amazonense . Besides these have the ability to reduce nitrate, denitrify, etc. . Azospirillum is inoculated through seed, seedling root dip and soil application methods .
Cyanobacteria: Free-living/symbiotic cyanobacteria is used as a biofertilizers for rice .
Azolla: Azolla is a free-floating water fern that fixes atmospheric nitrogen in association with cyanobacteria . it is used as biofertilizer for wetland rice .
Phosphate solubilizing microorganism: Microorganisms such as Pseudomonasstriata, Bacilluspolymyxa, Penicillium, Aspergillus, etc. secretes organic acids that cause dissolution of bound phosphates in soil .
Arbuscular Mycorrhiza: Intracellular obligate fungal endosymbionts that possesses vesicles for storage of nutrients and arbuscles for directing phosphorus, zinc and sulfur into the root system .
Silicate solubilizing bacteria: Some microbes are capable of dissolution silicates by secretion of organic acids like citric, oxalic acid, etc. . e. g. Bacillus sp. .
Plant Growth Promoting Rhizobacteria: Such inoculants are either bioprotectants (suppresses plant disease), biofertilizers (improves nutrient acquisition) or biostimulants (phytohormone production) . e. g. Pseudomonas and Bacillus species .
Though this technology is cost effective, environmental friendly, but still there are numerous limitations that restrict its implementation .Technical limitations
This biofertilizers proves to be an effective way of supplementing the plants with soluble essential nutrients for the sake of good growth and commercial benefit.