4.1.1 Biotechnology and Biofertilizer
In addition to the phenotypic studies by physiological and biochemical characterization, the DNA based molecular characterization (one of the biotechnological tool)
study provides more appropriate insight for the phylogenetic classification of organisms into numerous taxonomic levels. However, the traditional methods of classification (morphological and biochemical) grouped all isolates in a few categories like
either Gram-negative or Gram-positive in the case of bacteria. The sequences of
rRNA, especially 16S rRNA gene have much prominence with reference to the
evolutionary studies of bacteria. In addition to having the extremely conserved
region, 16S rRNA gene also includes a mutable part which is a useful tool to
categorize different genera. The conserved part of this gene is important for designing the primers for PCR of several taxa at various levels of taxonomy starting from
one strain to complete phyla (Vetrovsky and Baldrian 2013). From 16S rRNA genebased molecular characterization study, Pseudomonas and Acinetobacter species
were identified to dominate bacterial genera among the population of phosphate
solubilizing bacteria in rhizospheric soil of different plants (Munir 2018). In that
study, an up-scaling in root number was found upon inoculation with identified
phosphate solubilizing bacteria in the existence as well as in the nonexistence of
pesticides.
In another study, from the samples collected from root, leaves, and stems of
10 rice cultivars, 12 species were identified as plant growth-promoting bacteria
(PGPB) using nif (nitrogen-fixing) gene-specific primer(Sang et al. 2014). These
diazotrophic bacteria were characterized using molecular markers and effectively
applied to stimulate plant development and inducing fungal resistance in several
plants within a short period of time. In another study 9 g – positive bacterial strains
were characterized by 16S rRNA gene sequencing and phylogenic analysis among
legumes’rhizospheric soil led to the identification of plant growth-promoting bacteria (PGPR) (Hayat et al. 2013). In this study, the application of the identified strain
RH-5 as biofertilizer was reported to upsurge crops grains and biomass (beans; 50%,
wheat; 40–45%) above control. In similar research by 16S rRNA gene sequencing
and phylogenic analysis zinc-tolerant bacteria with PGP(plant growth-promoting)
properties; Acinetobacterhaemolyticus, Enterobacter cloacae, Serratiamarcescens
and Citrobacterfreundii have been identified. When these isolates are applied as a
biofertilizer showed Phosphorus (P)solubilization activity and phytoremediation for
reclamation of soil at high ZnSO 4 concentrations (Neha et al. 2013). In another
observation isolate CNE215 from nodules and CRE1 from roots identified by
molecular diversity of polymerase chain reaction (PCR) amplified 16S rRNA evaluated under field conditions and showed up to 22.5% increasing in grain yield of
chickpea when they applied as biofertilizer over uninoculated control (Sain et al.
2013).
Endophytic bacteria Pseudomonas and Rahnella isolates proposed as potential
microbial biofertilizers for sustainable banana production via the application of
DNA based molecular characterization (Ngamau et al. 2012). Using the aid of
20 The Potential of Biotechnology on Soil Quality by Minimizing Agrochemical. . .
411
In addition to the phenotypic studies by physiological and biochemical characterization, the DNA based molecular characterization (one of the biotechnological tool)
study provides more appropriate insight for the phylogenetic classification of organisms into numerous taxonomic levels. However, the traditional methods of classification (morphological and biochemical) grouped all isolates in a few categories like
either Gram-negative or Gram-positive in the case of bacteria. The sequences of
rRNA, especially 16S rRNA gene have much prominence with reference to the
evolutionary studies of bacteria. In addition to having the extremely conserved
region, 16S rRNA gene also includes a mutable part which is a useful tool to
categorize different genera. The conserved part of this gene is important for designing the primers for PCR of several taxa at various levels of taxonomy starting from
one strain to complete phyla (Vetrovsky and Baldrian 2013). From 16S rRNA genebased molecular characterization study, Pseudomonas and Acinetobacter species
were identified to dominate bacterial genera among the population of phosphate
solubilizing bacteria in rhizospheric soil of different plants (Munir 2018). In that
study, an up-scaling in root number was found upon inoculation with identified
phosphate solubilizing bacteria in the existence as well as in the nonexistence of
pesticides.
In another study, from the samples collected from root, leaves, and stems of
10 rice cultivars, 12 species were identified as plant growth-promoting bacteria
(PGPB) using nif (nitrogen-fixing) gene-specific primer(Sang et al. 2014). These
diazotrophic bacteria were characterized using molecular markers and effectively
applied to stimulate plant development and inducing fungal resistance in several
plants within a short period of time. In another study 9 g – positive bacterial strains
were characterized by 16S rRNA gene sequencing and phylogenic analysis among
legumes’rhizospheric soil led to the identification of plant growth-promoting bacteria (PGPR) (Hayat et al. 2013). In this study, the application of the identified strain
RH-5 as biofertilizer was reported to upsurge crops grains and biomass (beans; 50%,
wheat; 40–45%) above control. In similar research by 16S rRNA gene sequencing
and phylogenic analysis zinc-tolerant bacteria with PGP(plant growth-promoting)
properties; Acinetobacterhaemolyticus, Enterobacter cloacae, Serratiamarcescens
and Citrobacterfreundii have been identified. When these isolates are applied as a
biofertilizer showed Phosphorus (P)solubilization activity and phytoremediation for
reclamation of soil at high ZnSO 4 concentrations (Neha et al. 2013). In another
observation isolate CNE215 from nodules and CRE1 from roots identified by
molecular diversity of polymerase chain reaction (PCR) amplified 16S rRNA evaluated under field conditions and showed up to 22.5% increasing in grain yield of
chickpea when they applied as biofertilizer over uninoculated control (Sain et al.
2013).
Endophytic bacteria Pseudomonas and Rahnella isolates proposed as potential
microbial biofertilizers for sustainable banana production via the application of
DNA based molecular characterization (Ngamau et al. 2012). Using the aid of
20 The Potential of Biotechnology on Soil Quality by Minimizing Agrochemical. . .
411